iiiiiiliii

I

liiiiiii

ill

PREFACE
INTRODUCTION

By R. C. L. PERKINS.

^FAUNA HAWAIIENSIS

OR THE

ZOOLOGY OF THE SANDWICH (HAWAHAN) ISLES

Being Results of the Explorations instituted by the Joint Committee

appointed by

THE ROYAL SOCIETY OF LONDON FOR PROMOTING NATURAL KNOWLEDGE
AND THE BRITISH ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE

And carried on with the assistance of those Bodies and of the Trustees of
THE BERNICE PAUAHI BISHOP MUSEUM AT HONOLULU.

EDITED BY

DAVID SHARP, M.B., M.A., F.R.S.
11*

SECRETARY OF THE COMMITTEE.

VOLUME 1. PART VI.

PREFACE
By the EDITOR.

INTRODUCTORY ESSAY ON THE FAUNA
By R. C. L. PERKINS.

Pages i — ccxxviii and i6 Plates.

CAMBRIDGE
AT THE UNIVERSITY PRESS

1913

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IX

CONTENTS OF THE THREE VOLUMES, SYSTEMATICALLY

ARRANGED.

As the vicmoirs have necessarily been published in an irregular manner, the following

table laill be found useful.

Vertebrata. Vol. I, viz.: — Reptilia pp. 365-368, Aves pp. 36S-465, Mammalia p. 465

Hymenoptera Aculeata. Vol. I, pp. 1-122 and Introduction in Vol. I, pp. Ixxiii-cii

Hymenoptera Parasitica. Vol. I, pp. 277-364 and Introduction pp. cii-cxi

Hymenoptera, Supplement Vol. II, pp. 600-686

Coleoptera (part i, viz.: — Phytophaga, Rhynchophora, Proterhinidae, Heteromera and Cioidae)
Vol. II, pp. 91-270: (part ii, viz.: — Caraboidea) Vol. Ill, pp. 175-292: (part iii, viz.: — Cleridae
to Hydrophilidae) Vol. Ill, pp. 367-579: (part iv, viz.: — Anobiidae and Supplement to Ceram-
b\-cidae, Curculionidae and Proterhinidae) Vol. Ill, pp. 581-666: Review of Coleoptera,
Introduction pp. c.xii-cxliv

Strepsiptera. Vol. ill, p. 667

Lepidoptera. (Macrolepidoptera) Vol. I, pp. 123-275 and Supplement Vol. Ill, pp. 345-366.
(Microlepidoptera) Vol. I, pp. 469-759. Review cf Lepidoptera in Vol. I, Introduction
pp. cxliv-clxx

Neuroptera. Vol. II, pp. 31 -89, Supplement Vol. tl, pp. 691-696, and Introduction in Vol. I,
pp. clxx-clxxx

Diptera. Vol. Ill, pp. 1-92 (incl. Supplement), and (second supplement) Vol. II, pp. 697-700:
Review in Introduction Vol. I, pp. clxx.x-clxxxix

Hemiptera. Vol. Ill, pp. 95-174, and Vol. II, pp. 531-599: Review in Introduction Vol. I,
pp. clx.xxix-ccx

Thysanoptera. Vol. Ill, pp. 669-701 and Review in Introduction Vol. I, p. ccxi

Psocoptera or Psocidae : (included in Neuroptera, q.v.)

Embioptera or Embiidae : (included in Neuroptera, q.v.)

Isoptera or Termitidae : (included in Neuroptera, q.v.)

Mallophaga. Vol. iii, pp. 305-321

Odonata (included in Neuroptera, q.v.)

Orthoptera. Vol. 11, pp. 1-30, Supplement Vol. li, pp. 687-690, and Review in Introduction
pp. ccxi-ccxx

Thysanura. Vol. Ill, pp. 293-297 and Introduction p. ccxx

Collembola. V^ol. Ill, pp. 299-303, and Review in Introduction p. ccx.x;

Myriopoda. Vol. Ill, pp. 323-338 and Introduction p. ccxxi

Arachnida. Vol. Ii, pp. 443-519, Supplement Vol. in, pp. 339-344, Review in Introduction
pp. ccxxi-cc.xxiii : Acarina Vol. Ill, pp. 702-704

Crustacea. Isopoda Vol. 11, pp. 521-526. Amphipoda pp. 527-530

MoUusca. Vol. il, pp. 271-41 1 and Review in Introduction pp. ccxxiii-ccxxviii

Vermes, Oligochaeta. Vol. II, pp. 413-426 and Introduction p. cc.xxviii

Vermes, Entozoa. Vol. Ii, pp. 427-441 and Introduction p. ccx.xviii

F. H. I. b

CONTENTS OF THE THREE VOLUMES ARRANGED
ACCORDING TO THE AUTHORS' NAMES.

ASHMEAD, W. H. Hymenoptera Parasitica Vol. I, pp. 277-364

Bagnall, R. S. Thysanoptera Vol. Ill, pp. 669-701
BeddaRD, F. E. Earthworms Vol. II, pp. 413-426

Chapman, B. L. vide Kellogg and Chapman

DOLLFUS, Adrien. Crustacea, Isopoda Vol. Ii, pp. 521-526

FOREL, Aug. Heterogyna or Formicidae Vol. i, pp. 1 16-122

GODWiN-AuSTEN, Col. H. H. Anatomy of Mollusca (intercalations) Vol. II, pp. 277 etc
Grimshaw, p. H. Diptera Vol. iii, pp. 1-92

Kellogg, V. L. and Chapman, B. L. Mallophaga Vol. iii, pp. 305-321
Kirkaldy, G. W. Hemiptera Vol. 11, pp. 531-599 and Vol. HI, pp. 95-174

Meyrick, E. Macrolepidoptera Vol. I, pp. 123-275, and Supplement Vol. Ill, pp. 345-366

Pearce, N. D. F. Acarina Vol. HI, pp. 702-704

Perkins, R. C. L. Essay on the Land-fauna Vol. I, pp. xv-ccxxviii

Vertebrata Vol. i, pp. 365-466

■ Hymenoptera Aculeata Vol. I, pp. 1-115, Supplement Vol. II, pp. 600-612, Review

in Introduction, pp. Ixxiii-cxi

Coleoptera [parts of] Vol. II, pp. 117-270, Vol. HI, pp. 581-644, and pp. 650-666,

also Review in Introduction pp. cxii-cxliv

Strepsiptera Vol. Ill, p. 667

Diptera (Pipunculidae and Idioniyia) Vol. II, pp. 697-700, Review of Diptera in

Introduction pp. clxxx-clxxxix

Orthoptera Vol. II, pp. 1-30, Supplement thereto pp. 687-690, Review in Introduction

pp. ccxi-ccxx

ScOTT, Hugh. Coleoptera [parts of] Vol. Ill, pp. 415-422, 431-434, 455-474, 502-505,

508-538 and p. 644
Sharp, D. Coleoptera [parts of] Vol. 11, pp. 91-116, Vol. Hi, pp. 175-292, 367-579 and

pp. 645-650
Shipley, A. E. Entozoa Vol. 11, pp. 427-441

Silvestri, F. Thysanura Vol. Ill, pp. 293-297 and Myriopoda pp. 323-338 t.c.
Simon, Eugene. Arachnida Vol. 11, pp. 443-519 and Supplement Vol. hi, pp. 339-344
Speiser, p. Diptera Pupipara Vol. HI, pp. 86-92

Stebbing, Rev. T. R. R. Crustacea Amphipoda Vol. II, pp. 527-530
Syke.s, E. R. Mollusca Vol. i, pp. 271-41 1

Walsingham, The Lord. Microlepidoptera Vol. i, pp. 469-759

XI

PREFACE

THE importance of the fauna of the Hawaiian islands has long been recognised,
but as no adequate exploration of their zoology had been attempted, the British
Association for the advancement of science appointed a Committee in the year 1890
"to report on the present state of our knowledge of the Sandwich Islands, and to take
steps to investigate ascertained deficiencies in the fauna, with power to co-operate with
the Committee appointed for the purpose by the Royal Society, and to avail themselves
of such assistance as may be offered by the Hawaiian Government or the Trustees of
the Museum at Honolulu." The Committee of the Royal Society just alluded to was
appointed almost simultaneously, and the two Committees have continued to work
together till the present time.

The joint Committee has received the most valuable support and assistance from
the Trustees of the Bernice P. Bishop Museum at Honolulu. Indeed one of the most
important duties in writing this Preface is to make this acknowledgment, and to return
thanks for this support.

At an early meeting of the Committee it was decided to limit its investigation to
the Land-fauna. Two reasons influenced this decision, viz. (i) that this was as much
as the Committee could hope to accomplish, and (2) that while the Land-fauna was
known to be undergoing great impoverishment, it was believed that the Marine-fauna
was comparatively exempt from analogous changes.

The Committee decided to undertake an exploration of the Islands, and was so
fortunate as to secure for the purpose the services of Mr R. C. L. Perkins, then a young
graduate of the University of Oxford. Dr Perkins continued his exploration for some
years. As he has given an account thereof in the Introduction that follows this prefa-
tory notice it is unnecessary to give particulars here, beyond saying that he underwent
great dangers and fatigues, in his arduous and solitary task, with the most determined
perseverance, the most unflinching courage ; camping out in the mountains, without a
companion, for periods as long as he was able to carry food and equipment.

As the result of his work the Committee found itself in possession of an enormous
number of specimens, and in pursuance of its work decided on investigating this
material and reporting thereon.

It is not possible to state exactly the number of specimens that have resulted from
Dr Perkins' labours, but it cannot be far short of 100,000, and not improbably exceeds

62

xii FAUNA HAWAIIENSIS

that number. The Insects of the Archipelago were previous to this investigation
supposed to be scanty in the number of species, and it was believed that individuals of
each species were as a rule also very few. Both these conclusions have now been
shown to be incorrect. Dr Perkins estimates the number of known species of this
Class of animals to be upwards of 3,300 ; and he considers this number to be probably
not much more than one half of the total Hawaiian Insect-fauna.

The other Classes of Arthropoda are represented by a considerable number of
species. Mollusca is specially rich, nearly 500 species or forms having been recorded.
Aves has about 50 peculiar species. The other Classes of animals have been by no
means satisfactorily investigated, so that no general zoological Census of the islands
can yet be given. But it may be said that at the present time if an exhaustive list of
the land and marine fauna could be compiled it might amount to 10,000 species, the
great majority of them being peculiar to these precincts. And even this number is
liable to be greatly increased if the classes of microscopic animals were included ; the
Protozoa being, so far as is known to the writer, still untouched. These points are
mentioned because it would be a matter for profound regret were it supposed that the
work of this Committee — long as it may have lasted — has completed our knowledge of
Hawaiian zoology. The Islands having now passed into the control of a State super-
abundant in wealth and power we may hope that some real effort may be made, by
means of local Associations or expeditions from the United States, to supplement our
imperfect knowledge. At present there is so far as we know, only one Natural History
Association in the Archipelago — the Hawaiian Entomological Society, established in
1905.

Though the task of the Committee may be considered as still incomplete, various
reasons render its dissolution advisable. The Committee has lost during; its existence
two Chairmen, and Dr Perkins who has done most of its work is not able to continue
to make for it the great exertions he did make for so many years.

He has however drawn up for us a review of the subject of Hawaiian Zoology.
This, in the form of an introduction, will follow this prefatory note. The fauna of
the Archipelago has undergone great changes owing to human interference with the
natural conditions. It has always been a difficult task to estimate what part of the
Fauna is due to recent natural immigration, what to human introduction. The intimate
acquaintance of Dr Perkins with the fauna for so many years gives a special value to
his review, which, we have no doubt, will be of great assistance to future investigators.

It will be seen from his Introduction that he considers the whole of the fauna is
due to ancient and recent immigration, and is now augmented by human introductions.
And the peculiarities of the fauna apparently fully justify this conclusion. On this
subject we may refer to Wallace's chapter on dispersal and migration (Geographical

PREFACE

xiu

distribution of animals, Chap, ii) which correctly foreshadows the way in which this
fauna has been formed. The peculiar conditions of life in Hawaiia are to some extent
illustrated by the maps and landscapes that accompany Dr Perkins' Essay.

The Committees when first constituted consisted of Dr VV. T. Blanford, Colonel
Godwin-Austen, Mr O. Salvin, Dr P. L. Sclater, Mr E. A. Smith, with Sir W. H.
Flower and Professor Alfred Newton as Chairmen, Dr S. J. Hickson as Treasurer and
D. Sharp as Secretary. Subsequently Dr F. D. Godman and C. V. Riley joined it.
Sir W. H. Flower and Professor Newton, the early Chairmen having deceased, their
duties were taken up by the present Chairman Dr F. D, Godman. Professor Hickson
the Treasurer, and D. Sharp the Secretary, have filled these offices throughout the
2 2 years of the existence of the Committee.

The Honourable C. R. Bishop, the founder of the Bernice P. Bishop Museum, has
afforded by the instrumentality of the Trustees of that institution the most valuable
assistance to the Committee; and as an acknowledgment thereof the Fauna Hawaiiensis
has been dedicated to him.

It appears from the Accounts of the Treasurer that the Committee has derived its
funds from seven sources, viz.: — (i) the Trustees of the Bernice P. Bishop Museum;
(2) the Council of the Royal Society; (3) the Government Grant Committee of the
Royal Society; (4) the British Association for the advancement of science; (5) the
British Museum (Natural History); (6) Sale of the Fauna Hawaiiensis; (7) Bank
Interest. The Treasurer reports that the total from these various sources amounts at
present to ^47 1 7. 6^-. 3^.

The first set of the specimens resulting from the work of the Committee has been
placed in the British Museum (Natural History), which Institution possesses the types
of all the new species described in Fauna Hawaiiensis (except possibly a very few
described though the property of others). The second set of specimens has, as a rule,
been given to the Naturalists who worked out the collections, and whose names will be
found in the Table of Contents in Vol. I of the Fauna Hawaiiensis. The third set has
been sent to the Bernice P. Bishop Museum, Honolulu. A considerable number of
specimens has been given to Dr Perkins for his assistance in Honolulu, where he has
been for some years a resident. In addition to these extensive parts of the collections,
others have been given to the great Museums at Edinburgh, Dublin, Manchester,
Cambridge, Christiania, Stockholm, Copenhagen, Paris, Berlin, Dresden, the Netherlands,
Florence, Turin, and Boston U.S. The few specimens still remaining are promised to
the Museum of Harvard University.

D. SHARP

(Hon. Secretary of the Committee and
Editor of the Fauna Hawaiiensis).

ERRATA

The following corrections should be made in the text :

Vol. I, p. 31, line 3, for 'first' read second.

Vol. II, p. 13, line 16, for ' interno ' read externo.

,, p. 607, at bottom of page delete N. conifer, which is an Odynertis.

„ PI. V, figs. 7 and 7 n, in description of Plate, for ' A. koelense ' read A. amaurodytum.
Vol. Ill, p. 591, second line from bottom, for ' Anobiids ' read Xyletohius.

,, p. 616, line 7, twice, and lines 11, 12, 16 and 18, for 'I' read II.
Introduction, p. Ixiii, 6 lines from bottom, for 'isolation' read specific endemicity.

XV

INTRODUCTION

BEING A REVIEW OF THE LAND-FAUNA OF HAWAIIA
By R. C. L. PERKINS

Arrangement. — Prefatory, p. xv ; general features of the islands, p. xvi ; general aspect of the
fauna and flora, p. xxiv ; time devoted to collecting, and methods, p. xxxii ; some previous
misconceptions, p. xxxviii ; number of species of insects and causes of their extinction, p. xli ;
introduced, immigrant, endemic, p. xlii ; distribution by natural agencies, p. xlvi ; flight-
lessness, p. xlviii ; origin of the fauna, p. Hi ; species formation, p. Ixi ; summary of the
general part of the introduction, p. Ixx. Special review of some of the divisions of the
fauna', viz.: Hymenoptera, p. Ixxiii, Coleoptera, p. cxii, Lepidoptera, p. cxliv, Neuroptera,
p. clxx, Embiidae, p. clxxiv, Termitidae, p. clxxiv, Psocidae, p. clxxv, Odonata, p. clxxv,
Diptera, p. clxxx, Hemiptera, p. clxxxix, Orthoptera, p. ccxi, Thysanura and Collembola,
p. ccxx, Myriapoda, p. ccxxi, Arachnida, p. ccxxi, Mollusca, p. ccxxiii. Vermes, p. ccxxviii.

This portion of the 'Fauna Hawaiiensis ' may be termed an Introduction to
the study of the land-fauna of the Hawaiian islands, and its chief use may be as
a guide to further and more special research. It is rather in the form of a series
of disconnected essays than a continuous account, this being due to the fact that it
has been mostly written at wide intervals of time and in small portions, when the
pressure of other work, which could not be neglected, was relaxed. Some repetition
will consequently be found, and it has been necessary finally to cut short some
questions, which it was intended should be fully discussed, and also to pass by many
altogether. The rather full resume of the Fauna that is given will enable any one
to find further illustrations of many of the points that are discussed and furnish hints
for further investigation. During the twenty years that I have been working on
this Fauna I have received much help in various ways from many people, all of
whom I cannot mention individually. To Dr D. Sharp and the late Prof. Alfred
Newton I have been particularly indebted for advice and encouragement and to the
former also for much help in working out various groups, which otherwise I certainly
could not have attempted. Of those, who have their home in the islands, I owe
much to the kindness of Messrs Francis Gay and Aubrey Robinson on Kauai, to
Mrs Greenwell and her sons on Hawaii, and also to the late Mr R. Meyer of Molokai

' For a similar review of Aves refer to Vol. i, pp. 368-465.

xvi FAUNA HAWAIIENSIS

and the late Mr Valdemar Knudsen of Kauai, both of whom took much interest in
scientific work. To numerous others, many alas! now dead, I am also indebted.
Mr G. C. Munro, himself an ornithologist, gave me much assistance on many occasions
and once or twice spent a day collecting with me. My friend Mr Albert Koebele,
the only entomologist in the islands, during most of the period of my active collecting,
accompanied me on several collecting trips and gave me many valuable specimens.
Unfortunately for the most part he was absent on economic work in other countries.
To the Hon. C. R. Bishop, the founder of the Bernice P. Bishop Museum in Honolulu,
to the Trustees of the same, and to Dr W. T. Brigham, the Director, under whose
guidance it has become a model institution, I am also indebted for help in various
ways. Of recent years my colleagues in economic entomology have furnished me
with specimens and information, and I have particularly made use of the observations
of Mr O. H. Swezey, who has so successfully studied the life-histories of many of
the larger and smaller Lepidoptera. The untimely death of my two assistants
Messrs G. W. Kirkaldy and F. VV. Terry, who were particularly interested in the
Hemiptera and Diptera of the islands is much to be deplored. To Mr W. M. Giffard
I am indebted for the gift of numerous specimens and the chance to examine many
others, by which I have been enabled to gain additional knowledge on the variability
of many species. From Bro. Matthias Newell I have received much help on many
occasions, including the gift of valuable specimens. Mr Scott B. Wilson, who himself
studied the Hawaiian Avifauna on various occasions, gave me much useful informa-
tion, when I first left England for Honolulu, and other assistance.

General features of the islands.

The material collected by myself and others and described or enumerated in
this work has been gathered almost entirely from the six largest and most lofty of
the eight chief islands of the Hawaiian archipelago. The other two islands Niihau
and Kahoolawe, each with an altitude considerably exceeding looo ft. above sea-level,
have long since been denuded of their forest, having served as pastures for sheep and
cattle. If any native fauna now exists on these, it must consist of very few species,
and is not likely to be of any great importance. Kahoolawe, as seen from the island
of Lanai, is often for days together, owing to the destruction of its vegetation, enveloped
in clouds of red dust and may now be said to be blowing out to sea. It is no longer
of any value even as a pasturage. Niihau, the most north-westerly of the main group,
still supports large numbers of sheep. From Niihau to Hawaii, in a direction north-
west to south-east, the main islands extend over a little more than five degrees of
longitude.

North-west of Niihau is a chain of small islands, reefs, and shoals, continuing
the archipelago west through i8 more degrees of longitude, the whole Hawaiian group

■ INTRODUCTION . xvii

covering some 1800 miles. These small islands have been to some considerable extent
explored in search of birds, but very little is known of their other inhabitants.

Laysan, a low island, is remarkable for its Drepanid birds and various Noctuid
moths, both clearly allied to species inhabiting the main islands of the group, while
Midway also has produced a few insects allied to those on the larger islands. Both
these islands, however, have yielded species with no allies on the main group,
e.g. Laysan the small bird Taiare faniiliaris and Midway a species of true Chrysopa
in Neuroptera and a Noctuid moth of the genus Prodenia. Laysan has for a number
of years been worked for its guano deposits, and, more recently, a cable station has
been made on Midway, so it is probable that both these islands are now, or soon
will be, overrun with imported insects.

Niihoa or Bird island rising to an elevation of about 900 ft. is the most lofty
of the smaller islands, and was visited by an excursion party some 25 years ago.
Its geology was studied by Dr S. E. Bishop, but its zoology was neglected. No
doubt it contained some much more interesting animals than the countless sea-birds
that were noticed. The vegetation being dry was carelessly set on fire, and probably
the most interesting part of the fauna was destroyed. It is known that there then
existed a thick-billed Passerine bird, probably allied to Telespiza of Laysan.

Oahu, Plate V. Of the forest-bearing islands the one whose fauna has been
most studied is Oahu. Here more than half a century ago Deppe and Townsend
made an extensive collection of the native birds, at a time when these were evidently
abundant, more numerous, as they state, than on the more northern island of Kauai.
In more recent times the relative abundance of birds on these two islands has entirely
changed, no doubt owing to the chief port and settlement of the group having become
established at Honolulu on Oahu, and the greater and earlier interference with its
natural conditions, that were brought about thereby. Blackburn's well-known re-
searches on the insect fauna were mainly carried out on Oahu during the six years
of his residence at Honolulu. Similarly the great variety of its land molluscs and
the beauty of many of these have induced many residents in Honolulu to become
collectors, either temporarily or continuously.

The area of Oahu is 598 square miles and for its size there is reason to suppose
that it is or has been one of the richest of the group in its fauna. It is rather more
than 70 miles from Kauai, at their nearest points, and 25 from Molokai. Like Maui
and Molokai it is formed of a fusion of two islands. Of quadrangular shape the
west side is occupied by the Waianae range, of much greater age than the longer
Eastern or Koolau range, and, doubtless, existing as a distinct island long before
the latter emerged from beneath the sea. The highest peak of the Waianae range
is Kaala (4030 ft.). There are several large and deep valleys each containing a
stream of water on its western side, and on the eastern side it is also much eroded
into deep gulches and valleys. On this side its lower slopes are overlaid by the

F. H. I. c

XVIll

FAUNA HAWAIIENSIS

later lavas from the younger Koolau range, so that between the two ranges is an
elevated plateau rising to nearly looo ft. above the sea. This plateau was once
densely forested, but is now practically denuded, having served as pasturage for
cattle, while more recently it has been partly put under cultivation for the production
of pine-apples. The extent of forest on the Waianae range is now small, the intro-
duced goats and cattle having been largely responsible for its destruction.

The Koolau range is much more heavily forested, though it has been greatly
denuded during the last half century. The backbone of these mountains is much
serrated, and the highest point Konahuanui, rather more than 3000 ft., lies a few
miles behind the town of Honolulu, while there are several other peaks between
2500 ft. and 3000 ft. On the windward side for a long extent the erosion has been
very great, forming perpendicular or very steep cliffs ; on the leeward side the slopes
are much more gradual, but are channeled by many valleys and gulches, which, in
the more southern part especially, are often separated from one another by very narrow
and sharp ridges at least towards their heads.

More recent than the Koolau range proper ace some other craters, e.g. the
Tantalus series, lying close behind Honolulu, and forming a favourite collecting
ground, owing to their nearness to the city and easiness of access, while younger
still are various isolated craters situated on or near the coast, e.g. Punchbowl, Diamond
and Koko heads and others. Diamond head near Honolulu is interesting from the
fact that it contains in a subfossil state great numbers of the shells of land molluscs,
including several species of the Achatinellid genus Aniastra and Leptachatiria as well
as Succinea, Pupa, Eudodonta and others. Achatinella itself does not appear to be
found with these. A species of Succinea is still living there, but molluscs such as
Leptachatina, Eudodonta and Aniastra could no longer exist under the present dry
and barren conditions. Formerly vegetation and moisture must have been very
different to support these creatures.

Oahu, though the area of its forests is much diminished, is certainly rich in the
number of species of the plants that compose this. The most extensive forest is
found in the north-western area of the Koolau range. Parts of this area, however,
appeared to me to afford much less variety in their botanical productions than the
southern and more northern ends of the range. I have reason to suppose that the
part of the range nearest to Honolulu (and containing, as has been said, the highest
peak) has the richest fauna.

Kauai, Plate V, the most northern of the forest-clad islands, is separated from
Oahu by a channel of rather more than 70 miles, where narrowest, a much greater
distance than divides any other island from its nearest neighbour. It is of 'slighdy
less area than Oahu, and its outline is more nearly circular. The culminating peak
is near the centre of the island, and is above 5000 ft. high. From this summit,
Mt. Waialeale, and the adjoining plateau, valleys and gulches radiate to the coast.

INTRODUCTION xix

As usual, erosion is very great on the windward as compared with the western side
of the mountain. There are a number of constantly flowing streams of considerable
size, some almost worthy of the name of river. As on Oahu and in fact on all the
islands, the forests have been much denuded, but the central portion of the island is
well-wooded. In some parts the vegetation is very varied, but in others at no great
distance it is very uniform, and it is quite clear that causes quite apart from age may
determine the variety or otherwise of the plants on different islands or on different
parts of an island. The elevated plateau of the interior is for a large part of a boggy
nature, and forms the main watershed of the island.

Niihau, the small island west of Kauai and now forestless (as has been already
mentioned), was not visited by me. Shells of land molluscs of the genus Carelia
have been found in a subfossil state there, indicating no doubt a once heavy forest and
considerable moisture. It does not appear that the destruction of the forest has been
recent, or that any considerable vegetation of larger growth existed at the time of
Cook's arrival at the islands.

Molokai, Plate VI. East of the south coast of Oahu, and separated from it by
a channel of about 25 miles, is the narrow island of Molokai, with an area of 261 square
miles. Like Oahu and Maui it is formed of two distinct components, the western
mountain or Mauna Loa, with an elevation of nearly 1400 ft., and the larger and
more important eastern division with its highest peaks, Olokui 4600 ft. and Kamakou
4958 ft. Mauna Loa has for years been used as a sheep-pasture and is now almost
denuded of native trees. No doubt before the advent of the white man it was fairly
well forested, and the empty shells of dead Achatinellids of the genus Amasira have
been found there, sure evidence of a condition of moisture that has passed away with
its forest.

The eastern mountains have also been much denuded of their woods on the
leeward slopes and for a large part not much dense forest remains except near the
backbone of the mountain, where leeward and windward sides meet. On one large
area fairly well covered with forest in 1893, but showing some signs of further
deterioration in 1896, I reckoned that between the latter year and 1902 two-thirds
or more of all the trees had died. This destruction was due to cattle and an introduced
Japanese deer. The latter, indeed, became so plentiful that skilled hunters were
brought from California to slaughter as many as possible. Both cattle and deer finally
entered the wettest and densest parts of the forest, so that in 1902 the appearance of
these was totally different from that which they presented six years previously. The
Molokai woods have a fairly varied growth of trees and bushes in some localities, but
there is an entire absence of Koa forest, and as the Koa [Acacia kod) is one of the
most productive trees for the entomologist, a deficiency of species of insects is natural
on this account. Evidently there was once a considerable growth of the allied Acacia
koaia or of this and A. koa on the lower slopes, below 2000 ft., but these were at the

c 2

XX FAUNA HAWAIIENSIS

time of my earliest visit mostly dead, and what remained alive were scattered trees,
outside the limits of true forest, and quite unproductive.

On the north side of the island there has been much erosion, forming the deep
valleys of Waikolu, Pelekunu and Wailau.

Lanai, Plate VII, is the smallest of the forest-bearing islands, and its highest
point is 3400 ft. above the sea. The forest occupies only a small area of the whole
island, in the neighbourhood of its highest ridge, above the Palawai valley. Catde,
sheep and wild goats have been responsible for this deforestation. It is quite obvious
on examination that parts of the higher mountains of Lanai, though now much drier,
were once of the boggy nature of the wettest parts of Molokai and other of the islands.
A few of the insects peculiar to such boggy uplands still maintain their existence in
spite of the drying up of the forest, but, doubtless, many have disappeared. I found
a large variety of mostly small-sized trees in the remaining wooded parts of the island,
but, as on Molokai, Koa forest is wanting. One feature in 1896 was the compara-
tive abundance of the half-dozen species of native land-birds in this small patch of
forest, their number being out of all proportion greater than that of the species on
Oahu with its comparatively large forest area. The large Maunalei gulch on the
north side contains the one permanent stream of water ; in 1894 the forest on its sides
had already been destroyed by wild goats, so that it was difficult and dangerous to
descend into the upper parts of the valley from above, since, in climbing down, the
bare rocks and earth were easily dislodged both by the climber and by the numerous
flocks of startled goats.

Maui, Plate VI, a large island with an area of 728 square miles, lies east of
Lanai and Molokai and is separated from these islands, at the nearest points, by channels
of only about 8 to 10 miles in width. When standing in the mountains of Molokai
above Kamalo and looking at West Maui it is quite easy, under favourable conditions
of light, to distinguish several of the trees, which are chief components of the forest
of the latter, the different colours of their foliage being obvious to the naked eye.

Maui consists of two geologically distinct islands united into one, the connection
being a sandy isthmus. The west division is much older than the larger eastern
mountain, but the connection between them does not rise to any considerable height
above the sea (about 150 ft.) as compared with the intermediate plateau of the Oahuan
ranges. Probably it has never borne more than a scrubby vegetation, and this fact is
of importance in considering the means of distribution of species from Haleakala to
West Maui and vice versa.

The highest altitude of West Maui is nearly 5800 ft., Eke with its boggy summit
being about 1 200 ft. lower. These high altitudes are usually wrapped in mists and
rain ; the ground, mosses and other vegetation are always saturated with moisture, so
that, unless under exceptional circumstances, collecting in a general way is almost
impossible. The streams issuing from these watersheds have eroded great numbers

IN TROD UC TION xxi

of gulches and larger valleys, the lao, Waihee, Olowalu and others being conspicuous.
The vegetation of the west and east side of West Maui is very different.

East Maui is formed of the great mountain Haleakala, the highest point being
rather more than 10,000 ft. above the sea, and on the edge of the summit caldera.
Owing to its altitude. East Maui differs essentially from any of the islands already
mentioned in the fact that here for the first time we are dealing- with a mountain, in
which there is an extensive area above the limits of forest growth, while the summit is
nearly devoid of vegetation. The bottom of the great caldera is about 7000 ft. above
the sea and its sides are in some parts precipices of 2000 — 3000 ft. high. It contains
numerous cinder craters, which are themselves five to nine hundred feet in height.
The northern slope of the mountain is seamed with gulches, the forest-belt on that
side intercepting the heavy rain-fall, while the western slope is dry and comparatively
little eroded. This northern forest-belt differs much in the variety of its plants in
different parts of its extension from west to east. In some parts during recent years
many trees have died from a disease of obscure origin, so that fears have arisen as to
the permanency of the watersheds, the water supply being of the greatest value for
purposes of irrigation. On the drier western side the trees have been much destroyed
by cattle, but on the windward side the growth of forest is extensive and in parts forms
a very dense belt. Owing to its elevation, the summit of Haleakala is sometimes
capped with snow in the course of the winter months.

Hawaii, Plate VIII, is by far the largest of the islands, its area being 4015 square
miles, or much more than that of all the others together. Its northern extremity is
30 miles distant from Maui. It is of subtriangular outline and has been formed from
five volcanic centres. Mauna Loa (13,650 ft.) and Kilauea (4040 ft.) are still active
volcanoes, occupying with their slopes the south portion of the island, Kilauea lying
east of the large mountain ; Hualalai (8269 ft.), near the middle of the west side of
the island, was last in eruption in 1801. Mauna Kea (13,825 ft.) is the most lofty
of Hawaiian mountains, and is regularly snow-capped during the winter months. In
the Hilo district its slopes bear a wide and dense forest-belt, though this has been
lessened on the lower side by the cultivation of sugar-cane and other causes. North
of this, in the Hamakua district, the belt of forest is much thinner, and some years
since was considerably ravaged by fire. However, although much has been destroyed
by cattle or cultivation, it may be said that all the districts, into which Hawaii is
divided, still have extensive forest areas. In the variety of their vegetation these
forests differ much according to locality, nor is an older part of the island always
everywhere more rich than a younger one. Thus some parts of the older Mauna Kea
are comparatively uniform in their vegetation, some parts of Mauna Loa well varied ;
but it is possible that the richest localities of Kea are richer than those of Loa, and
the poorest of Loa poorer than the same of Kea.

In the northern corner of the island lie the Kohala mountains, much the oldest

xxii FAUNA HAWAIIENSIS

portion of the island, and which no doubt existed as a separate island long prior to
the emergence of the other volcanic centres. These mountains rise to an elevation of
five and a half thousand feet, and on the windward side are covered from the coast-line
to the boggy summit with a dense and very humid forest. On this side are the large,
deep valleys of Waipio and Waimanu, due to erosion.

There is no real break between the forests that clothe the different mountains of
Hawaii, but all are or have been in some parts continuous, so as to allow of a ready
passage for their denizens from one mountain to another. Doubtless, owing to the
destruction wrought by man and his imported domestic animals during recent years,
there are now large areas treeless or nearly so, where before continuous forest existed
and made the connection still wider. Between the Kohala mountains and Mauna Kea
are the uplands of Waimea, which have long been used as a pasturage for cattle to the
detriment of their native vegetation. Between the three great mountains Loa, Kea
and Hualalai is a vast arid tract reaching an elevation of over 6000 ft, of excessive
roughness, being traversed by many lava flows from Mauna Loa.

The maps of the islands, which we have been permitted to reproduce by the
kindness of Mr Willis T. Pope, Superintendent of Public Instruction in the islands,
give a good general idea of the rough and broken character of the ground over which
most of the collector's work is done.

A map showing the relative positions of the Islands was issued with Part i, Vol. I
of this work.

As a group the Hawaiian islands are amongst the most isolated portions of land
surface. The main islands are placed a little within the tropic of Cancer or in the
same latitude as a middle strip of Mexico. They are much nearer to the North
American continent than any other, the coast of California being distant about 2100
miles, the portion of Mexico, above mentioned, being considerably more distant still.
On the west Hong Kong is in the same latitude. Almost south of the group, the
Samoan and Fijian groups, the only islands of considerable size, are 30 to 40 degrees
distant. Between these and the Hawaiian group lie a number of small islands, but the
nearest of these, Palmyra (5° 49' 04" N.), is very remote and separated by an enormous
depth of ocean. The extreme outlying islands (Midway, Ocean, etc.) to the N.W. of
the archipelago are equally separated from other lands.

The general features of the Fauna are somewhat similar to those of Madeira and
the Canary islands and to New Zealand, but in details they are very different from
any of these. Tahiti and the Samoan group are not sufficiently well known to make
any comparison of much value.

Owing to the mountainous character of the islands there is great diversity of
climate in different localities. The prevalence of the trade-winds through a great
part of the year causes much heavier precipitation on the windward side of the islands,
while on the lee side, though the mountains may have copious rains daily, the coastal

INTRODUCTION xxiii

region gets little or none of these. The region of heaviest precipitation, whether on
windward or leeward side, is generally from 1 200 to 5000 ft. above sea level, or corre-
sponds with the region of dense forest.

The temperature at the United States Weather Bureau Station in Honolulu for
the years 1905 — 1909 is recorded as follows :

1905 1906 1907 1908 J 909
Highest shade temp. (Fahr.) 84° 85° 86° 85° 84°

Lowest temp. 57° 57° 62° 61° 56°

On the lowlands a temperature of 90 or even more is occasionally but very
rarely noted, and one as low as 52° rarely occurs.

The decrease of temperature with elevation is reckoned as i°F. for each 320 ft.
of ascent in the mountains.

At the U.S. Weather Bureau Station the annual rainfall in Honolulu for the five
years above quoted was i6'99, 2577, 30*13, I9"i7 and 20"8i inches, while in some
coastal localities the rainfall would be considerably less. A few miles behind the
town the rainfall is much heavier; thus on Mount Tantalus, in 1905, at an elevation
of 1300 ft. it amounted to 99'68 inches, while on the ridges behind Tantalus it would
have been much heavier still — probably twice as heavy — since they precipitate much
of the rain before it reaches the Tantalus group. In a wet district, such as windward
Hawaii, the rainfall for the same five years at Hakalau in the Hamakua district at an
elevation of 200 ft. was i67"59, i22'8o, i82"6o, I47"i9 and 152-54 inches, and a few
miles above, at 1200 ft. elevation, it was much heavier still, 26o"67 (1907), 2o6'33 (1908)
and 23375 (1909).

In 1907 (a year selected at random) at Waiakea (50 ft.) in the Hilo district of
Hawaii it was rainy on 333 days ; at Waianae, a very dry district of Oahu, on
60 days of the same year.

As by far the greater part of the Fauna has its home in the wet-belt or forest-belt
it will be easily understood that any particular collecting trip can be, and often is, very
seriously interfered with by climatic conditions. On the high mountains of the Kona
side of Hawaii, there is (where it has not been destroyed) a very dense forest-belt with
heavy rainfall and a much drier but well-forested region above this. Something like
this is also found on the windward side, but there is this great difference, that, on the
latter, the region below the forest enjoys a large rainfall, while on the Kona side the
lower slopes and coastal region are for the greater part of the year extremely dry and
parched up.

In the winter the highest mountains of Hawaii and less frequently Haleakala on
Maui are snow-capped, the snow sometimes extending down into the forest-belt. Frost
is rarely observed below 4000ft. even in the winter months. In Feb. 1902, in some
more or less open forest land on Molokai at 3000 ft. the ground was white with
hoar-frost on several consecutive days, and all the tender pink-coloured terminal leaves

xxiv FAUNA HAVVAIIENSIS

of Myrsine were blackened and killed by the cold. In the denser forest at a higher
elevation no such effect was visible, and no signs of frost were seen there on these
days. When one is camping in the rain-belt and in search of creatures, for successfully
collecting which a fair amount of fine weather is essential, it is very tantalizing to see
the lowlands blazing in the sunshine, while the forest-belt day after day is wrapped in
fog and rain.

General aspect of the Flora and Fauna.

The fauna of the islands is necessarily so intimately connected with the peculiarities
of the flora, while the peculiarities of the latter are in like manner sometimes evidently
connected with the remarkable characters of the fauna, that some consideration of the
vegetation of the islands is necessary. Every student of the natural history of the
islands is much indebted to the late Dr W. F. Hillebrand, whose "Flora of the Hawaiian
Islands" has proved a most valuable work. In some introductory remarks, which he did
not live to complete, he cites 860 species of Phanerogams and Vascular Cryptogams as
natural immigrants or as peculiar to the islands, after deducting those introduced by
man since and before the discovery of the islands by foreigners. Of the 860 species
653 are endemic (or 75"9 per cent.) and 250 of the species belong to 40 endemic genera.
Of Phanerogamous plants 81 "4 per cent, are endemic, of Dicotyledinous 85'6. Since
Hillebrand's work, as is natural, additional species have been discovered from time to
time and some changes have been made in the number of the genera that are endemic,
but until the completion of the study of the flora by botanists of to-day the above
figures may be accepted. From my own observations I have reckoned that the
endemic plants, given as 653 by Hillebrand, are probably not more than two-thirds
of those that exist. This reckoning is made from the considerable number of species,
not included in Hillebrand, that I have casually observed, when investigating the fauna,
and on the consideration that the systematic botanist would generally speaking adopt
Hillebrand's views as to specific characters. It is clear that the additions to the list
of endemic plants will be mainly in an increase of species allied to those already known,
rather than in the discovery of striking new forms. In other words the general
features of the flora are adequately known.

Owing to the mountainous character of the islands, with great differences in
rainfall and temperature at different altitudes, the flora varies very greatly at different
heights on the mountains.

Littoral plants are very poorly represented, mostly by natural immigrants of wide
distribution elsewhere. Many of these have fruits or seeds that float for long periods,
and have no doubt reached the islands on ocean currents. A few only are endemic,
e.g. the parasitic dodder i^Heliotropiuni anonialuvi) and species of the Composite genus
Lipochaela. The littoral insect fauna (excluding foreign forms) is likewise poor, and

INTRODUCTION xxv

most of the species that are attached to the coasts also range inland over the plains or
ascend the dry and bare lower slopes of the mountains. They are xerophilous rather
than strictly littoral, and some of them even reappear in the dry open country above
the forest-line and rain-belt, even at elevations above 7000 ft. Some, however, if not
absolutely confined to the region of littoral plants, yet never wander far inland. These
include a number of endemic bees and wasps, which visit the flowers of such plants as
Vitcx trifolia, Scaevola kocnigii, Tribuhts, Waltheria etc., the wasps finding their prey
amongst these and other sublittoral vegetation, such as species of Sida, Lipochaeta and
foreign weeds. The Otiorhynchine beetle Rhyncogomis vestitus is attached to Vitex,
the endemic moth, Pyrausta iitorea, to Scaevola, while the caterpillars of a few Noctuid
moths and some Hemiptera (both Heteropterous and Homopterous) feed on grasses
and low flowering plants that grow in the sand. On the whole the littoral fauna
appears to be at any rate less poor than its flora.

On the leeward side of the islands, owing to the comparatively small amount of
rainfall and (usually) the absence of any heavy rains during the greater part of the
year, the vegetation of the coastal region and lower mountain slopes is for the most
part dried up, and only after heavy rains does the verdure reappear. At the present
time, however, numbers of xerophilous plants, introduced by man, do much to lessen
the arid appearance of the lowlands. Chief of these is the algaroba or mesquite
{Prosopis), the most valuable tree ever imported into the islands. In some of the
driest coastal districts it now forms quite a forest-belt, affording food and shelter to
cattle and other animals, and an abundance of excellent firewood. An Opuntia of
very early introduction, a mimosa [Acacia farnesiana) and Lantana camara are very
conspicuous and to the stranger might have the appearance of being really native.

Most of this region and the mountain slopes that lie below the forest, where they
are not under irrigation or cultivated, have for years been grazed over by cattle. This
region is also overrun by foreign weeds, imported by man, and little is left of the native
vegetation. Where there is a covering of grasses, these are generally foreign. How-
ever, in the most arid districts of the islands, where foreign weeds have failed to
establish themselves to any great extent, or at least do not thrive, and on some of the
rough lava flows, avoided by the cattle, a considerable number of native shrubs and
trees may still be found. In a few places on these dry mountain slopes there yet
remain a few choice endemic plants, now mostly extremely rare, such as the red-flowered
cotton tree [Gossypium drynarioides) and the shrubby \\o\^X. (Viola helioscopia). Though
so greatly denuded, here and there, either singly or in clumps, we meet with various
endemic or immigrant species of interest, e.g. Maba, Sanfahtm, Nothocestruni, Gardenia,
Nototrichitim, Dodonaea and Erythrina. Pandanus odoratissimits grows scattered or
in thickets in many places, and groves of bread-fruit trees occur rarely, as evidence of
former cultivation.

A number of plants of aboriginal introduction belong to this region, but all of

F. H. I. d

XXVI

FAUNA HAWAIIENSIS

them more or less frequently extend upwards till they form part of the regular forest.
The Hau tree i^Paritium iiliaceum) thnve?, equally near the sea-coast and above loooft.
elevation in the mountains, where it sometimes forms impenetrable thickets. Akiiritis
triloba, the candle-nut tree, and Eugenia malaccensis, the so-called 'native apple,' are
most partial to the valleys, the former in some localities extending upwards to an
elevation of 3000 ft. or more, the latter attaining only about half that height in the
mountains. Both, but the former more especially, may form an important element in
the true forest-belt, so as to have the appearance of indigenous plants. Their foreign
nature, apart from other considerations, is evidenced by the absence of any special
fauna in connection with them. Neither of them are unsuited as pabulum for indigenous
insects, since some of the polyphagous species feed upon them and especially on the
Aleurites, but they have no special fauna. With these the 'Ki' or ' Ti ' {Cordyline)
is often very conspicuous. Apart from these aboriginal introductions, as one ascends
the lower slopes or valleys and there is an increase in the rainfall, the introduced guava
may occupy the whole soil to the exclusion of all other trees or shrubs. Where the
moisture is sufficient, the foreign grass, Paspaliiin conjugahim, commonly known as
' Hilo grass,' from the fact that it first appeared in that district of Hawaii, covers the
whole ground ; or in drier localities other equally indifferent grasses are in occupation.

There is no doubt that what one now sees on the dry lower slopes of the leeward
side of the islands is but a remnant of a once more or less open forest land, which has
had a very special fauna of its own. In addition to the trees already mentioned some
of the more common components of the present continuous forest-belt extended down
into this region, Acacia koa and Metrosiderus for instance. Only in special localities
can one now get a glimpse of this fauna, for excepting a few wide ranging or hardy
species, or such as are specially protected, all the native insects of this region have
been destroyed either by imported predaceous insects or by the destruction of the forest
itself and the changes of conditions that have ensued. In a few spots there yet remain
in Lepidoptera species of Scotoryfhra, Talis, Thyrcopa, Hodegia etc. ; in Coleoptera
PlagitJimysus and special species of Rhyncogotms, Proterhinus and Labrocertis, together
with some Hemipterous insects, Jassids and Fulgorids, quite peculiar to it. The loss
of all but a remnant of this, no doubt, once rich and extensive fauna is much to be
regretted, for it may be suspected that here some of the finest native species once
occurred. Passerine birds regularly descended into the clumps of trees of this open
country, as in fact we have ourselves noticed in special localities in past years. From
these, in Cook's time, they passed still downwards, since we are told that several
species were found frequenting the coconut palms on the beach. Achatinelline shells
as well as other land Mollusca were no doubt numerous, in the upper part at least,
of this region.

It is certain that in prehistoric, but comparatively recent times, the climate
and vestiture of the lowlands of some of the dry districts of the islands must have

INTRODUCTION xxvii

been very different from the present condition. Thus at the base of the cone of
Diamond Head on the coast a few miles S.E. of Honolulu are found extensive deposits
of many species of land Mollusca {Amastra, Leptacliatina, Endodonta, Succinea etc.),
the species differing little, if at all, from those now living in the forest-clad parts of
the Oahuan mountains. Similar deposits are found on the leeward side of the Waianae
range at no great elevation above the sea and in various other localities. Such places
are amongst the most arid to be found on the island at the present time. While
Succinea can be found living near the coast in the driest localities, most of the other
genera can thrive only where there is a liberal supply of dampness, and where the
vegetation is dense enough to retain this. It is very important to remember that such
different conditions have existed in past time, when one considers the possibility of the
survival and establishment of any chance immigrants that may have reached the shores.
Where the immigrant would now find a barren and arid region on its arrival, very
different conditions may have existed in other times.

Above the lower dry mountain slopes, at elevations varying usually from 1200 —
3000 ft., one reaches the belt of continuous forest. Where undisturbed by man or
beast, this is often so dense as to be impenetrable without cutting a pathway, or at
least breaking through by force. Luxuriant growths of leie {Freycinetia) in many
localities and in others wiry-stemmed ferns [Gleichenid) make progress difficult. The
width of this forest-belt varies very gready according to the locality and according to
the destruction that has been the work of man. In some places no such forest-belt
exists, in others it has been reduced to an open timbered country, covered with foreign
grasses. This is the last stage preceding destruction, when the remaining trees produce
their seed in vain, for the thick growth of grass prevents any young trees springing up
to replace the old. We have known a forest so den.se that it could be traversed only
along a narrow made path, generally knee-deep in mud, to be reduced to open wood-
land by the ravages of cattle within a period of about fifteen years.

On Oahu (and elsewhere) the lower part of this forest consists or in past time has
consisted to a large extent of the fine and valuable Acacia, A. koa, which altogether
fails or becomes sparing in the highest forests of this island. On some of the islands
(Molokai and Lanai) there is now no Acacia forest, though evidences of its former
existence still remain. On the lofty mountains of the other islands the Koa may
extend throughout the whole forest-belt, but it is wanting over extensive areas from
natural causes. The Ohia, Metrosiderus, is the commonest of all forest trees extending
both above and below the region of dense forest, and is the main constituent of the
forests throughout the whole group of islands. It is extraordinarily variable, and can
adapt itself to the most varied conditions of climate and station, to an extent indeed
of which the Koa seems quite incapable. From one of the largest of forest trees it
may become, on boggy mountain tops, a trailing shrub, or a small erect plant with
simple stem no thicker than a pencil and bearing a single large terminal flower. Its

d 2

xxviii FAUNA HAWAIIENSIS

variations under more normal conditions are very great, and it is presumably the parent
of the other species of its genus that are considered distinct and endemic. Both the
Koa and Ohia are of great importance to the fauna, since hosts of creatures are
dependent on them. The former probably supports the larger number of peculiar
forms, of which, no doubt, many have been exterminated by its extensive destruction.
Throughout this forest-belt ferns, both epiphytic and terrestrial, are most numerous and
varied, often covering the whole surface of the ground beneath the trees or clothing
the trunks of the latter. Here the tree-ferns acquire their greatest size and beauty.
The fauna connected with ferns is quite rich, not only tree-ferns but the lesser species
also yielding their own peculiar insects. In the Rhyncophorous beetles a number of
species of Proterhiniis are restricted each to a particular species of fern, and tree-ferns
support Heteramplms and Dryophthoriis. Small crickets of the genus Pai'atrigonidiuin
affect each their own special ferns, as do some Hemiptera (Heteropterous and Homo-
pterous) and larvae of various Macro- and Micro- Lepidoptera feed only on these.
Tree-ferns are a favourite resort of numerous Carabid beetles, and the dead fronds are
the home of Machilis and many other creatures. It seems probable that in the islands
the fauna attached to ferns is proportionately much more extensive than one usually
finds to be the case elsewhere. For this reason some of the endemic birds are constantly
to be found seeking for food on the stems and amongst the fronds, and some of the
land Molluscs are also very partial to them.

It is not necessary to give a list of the trees and shrubs that form this compact
forest-belt, for herein are found species of nearly all the important genera of plants,
while many are altogether confined to it. Its components are very different in different
localities, the difference depending in many cases on the nature of the soil or of the
rainfall. In drier localities one will sometimes find a less dense and more varied forest
than in a closely adjoining and wetter district, or a wetter part of the belt may be more
varied in its vegetation than that at a higher elevation and with a lesser rainfall. Apart
from the Ohia and Koa already mentioned the following are very important trees or
shrubs to the student of the fauna : the arborescent Lobeliaceae, the Rutaceous Pelea
and Zanthoxyluin ; Cheirodendron and other Araliaceae ; the Rubiaceae generally ;
Pipturiis and other Urticaceae ; Myrsme (Myrsinaceae), Broussaisia (Saxifragaceae),
Elaeocarpus (Tiliaceae), Perrotetia (Celastraceae), the Leguminous Sopliora chrysophylla
and an endemic Rubus. However, most trees and shrubs of this belt are more or less
productive, and one may add to the above Eugenia sandwzcensis, the numerous species
of Pittosporum, Santalum, Myoporuin, Nothocestrum, Charpentiera, Pisonia and the
arborescent or woody Compositae.

On the highest mountains towards the upper limits of the forest there is often
a very uniform flora, rich nevertheless in species of birds and insects. Acacia koa,
Sophora chrysophylla, and Myoporiun sandivichense sometimes form its chief com-
ponents. Lower down Metrosiderus interspersed with lesser trees such as Myrsine,

INTRODUCTION xxix

Goiildia, Straussia, Pelea and arborescent lobelias may be dominant. Naturally two
such localities though adjoining one another have a vastly different fauna. Of the
lesser plants found within the forest-belt, violets with woody stems, a giant Gtmnera,
the pink-flowered begonia (Hillebrandia), the liliaceous Asielia, and some of the
endemic Labiates are the most likely to attract the attention of the non-botanist. On
the summits of the lesser mountains (those not attaining 8000 ft.) there is sometimes
developed a bog-flora, characterized by species peculiar to itself. Bog moss, endemic
sedges, grasses, violets, Dfvsera and creeping and woolly forms of plants elsewhere
erect and glabrous are characteristic. Such bogs are more or less evident on all the
forest-clad islands, excepting Lanai, and even there one can see signs that such a
condition formerly existed.

On the highest mountains of Maui and Hawaii the forest fails long before their
summits, often snow-clad, are reached. Above its upper limit dwarf trees and bushes
are found with ferns and grasses to which a drier climate is congenial. Sophora,
Santaluvi, Myoporiivi, arborescent or shrubby Composites are common constituents,
while the Epacridaceous Cyathodes and Vaccinium reticulatum cover much ground.
Some of the endemic species of Geranium attract the eye by their silver foliage, while
the silver-sword Argyroxiphium, a handsome and peculiar Composite, is found as high
as 12,000 ft. A somewhat similar vegetation is found in some localities within the
limits of the forest-belt, where extensive open lava fields occur and there is a lack of
permanent moisture.

On the windward side the forest-belt on some of the islands has suffered less
destruction than on the lee side and, if quite undisturbed, it still extends downwards to
the cliffs that fringe the shore. Where the coast is not bounded by cliffs the lower
slopes are usually denuded, but owing to the rainfall are green throughout the year and
well covered with vegetation. The native fauna, however, as on the dry side of the
islands has been mostly destroyed by change of conditions and the predominance of
imported predaceous insects. The fauna of the windward side is, I think, contrary to
what one might expect from the condition of the vegetation, poorer than that of the
dry side, although the forest-belt (as on the slopes of Mauna Kea above Hilo) here
reaches its greatest development. Wherever I have investigated, this is certainly the
case so far as Coleoptera are concerned. However in the rain-soaked woods of the
windward forests Lepidoptera are particularly abundant, as also are some Diptera, and
the beautiful condition in which one finds the most delicate and minute moths, during
the frequent torrential downpours is frequently a matter for wonderment. In such
places more hardy insects, such as Pyrantels tammeamea and P. atalanta, Deilephila
ivilsoni and others, pay little attention to the heavy showers and may be seen active
under such conditions during the day time, while moths in general are equally so after
dark.

It is not necessary to give any special list of the fauna of the true forest-belt.

XXX FAUNA HAWAIIENSIS

Herein probably nineteen-twentieths of the endemic species now existing have their
home. Here will be found all the genera and species of Passerine birds and nearly all
of the land Mollusca, especially the Achatinellidae. Very rarely do these latter pass
above the 4000 ft. line above sea-level and then only in the case of a few species of one
or two genera or subgenera. Other creatures appear similarly to keep within certain
bounds as to elevation, the crickets of the genus Paratrigonidmin and Banza [Brachy-
metopa) rarely passing the line just mentioned in spite of the continuity of the forest
upwards. Unless the woods have been opened up by man or cattle, wasps fail to
establish themselves in the wettest and densest of these. In some localities xerophilous
insects and plants pass through dense and wet forests by means of the recent bare and
open lava flows, which cannot retain moisture.

Above the forest-line on the highest mountains in the open country there is an
insect fauna of species peculiar to the region, but it is very meagre as compared with
that of the forest immediately below. This could scarcely be otherwise considering
the limited character of the flora and the fact that so many of the insects are strictly
attached to arboreal plants. Nevertheless, it is now a much more productive country
than most of the open region below the forest, for the reason that its fauna has not
been destroyed by introduced predators. In particular its species of Carabid beetles
remain abundant up to an elevation of nearly 10,000 ft.

Wherever the soil and other conditions are suitable a great deal of the lowlands
and lower mountain slopes are given up to the cultivation of sugar cane, which on the
dry side of the islands is grown under irrigation, but in wet districts usually finds
sufficient moisture in the rainfall. For the sugar plantations of dry districts water is
procured either from the mountain streams directly, or by tunneling in the mountains,
or by pumping from artesian wells on the lowlands or at low elevations. Where cane
is not grown either for lack of water or other reasons, the land is often overrun with
cattle both above and below the forest and in many cases the forest itself is invaded.
Fortunately now that it is realized how cattle inevitably destroy all Hawaiian forests
and cause the drying up of the watersheds, on which the entire prosperity of the islands
depends, large areas of woodland have been reserved and all cattle excluded. Though
this exclusion has not been carried out nearly as rigidly as one might wish yet there is
reason to believe that what has been done and may still be done in this matter will
preserve a great part of the endemic fauna and flora for future generations. Only the
small islands of Kahoolawe and Niihau are beyond redemption so far as native vege-
tation is concerned.

Leaving out of consideration all foreign plants, whether imported by man or
naturally immigrant, the lack of conspicuous flowering plants is a most striking feature
not only of the forest but of the open country. Were it not for the natural immigrant,
Metrosiderus polytnorpha, the chief constituent of the forests, the latter would be
sombre indeed. This tree with its abundant red flowers, when, as is often the case, it

IN TROD UC TION xxxi

comes into blossom over large areas at the same time, presents a really bright appear-
ance, and this effect is heightened by the large numbers of the common scarlet and
crimson Drepanid birds that resort to the flowers for the sake of their abundant nectar.
It is true that there are some other flowers, such as Gardenia, that are conspicuous and
fragrant, or showy like the native species of Hibiscus and the begonia, Hillebrandia,
but these are too local or infrequent to change the general impression. In open places
the yellow flowers of some of the gregarious Compositae attract the eye, but in other
countries would hardly be noticed as being more than a rather superior weed. Frey-
cinetia in flower or fruit has for a short season a bright appearance, though in many
districts nearly every one is devoured or befouled by foreign rats. Perhaps after
Metrosiderus, the Mamani [Sophora chrysophylld) which grows gregariously and also
attracts the red birds, makes the best show. Of the arborescent lobelias the flowers,
though often large and numerous, are rather strange than beautiful; in many species
they are hidden beneath or amongst the foliage and often they appear to decay almost
before they are fully mature. On the other hand the ferns with a large variety of
species, often of considerable beauty, are the more attractive from the absence of con-
spicuous flowering plants. Nowhere in the islands will one find any display of the
latter comparable with that which is so usual in the meadows or open woodlands of
countries outside the tropics.

Having spoken of the general inconspicuousness of the flowers and the bright
colours of some of the commonest birds, we may notice the general aspect of the
fauna. The greater number of species of the native birds have green, yellow or oliva-
ceous plumage and are not conspicuous, though some of them are of strange or even
grotesque form. Here belong the Drepanididae, but five genera (at least in some of
their species) have red plumage either in both sexes or at least in the male. The
Meliphagine Acrulocerais have mainly black or dark plumage, as do several of the
Drepanididae, but none are entirely black, since red, white or yellow forms part of
the colour pattern. The thrushes {Phadornis) are of sombre colours, but the males
of the fly-catchers {Offl.yz^»?/w) are often prettily variegate.

The absence of gaily coloured native butterflies or diurnal moths prevents the
insects from making any conspicuous showing. It is doubtful whether to ordinary
observers there is, excepting the fine Pyravieis tammeamea, a single insect that would
be considered beautiful. At least that species only can be said to represent brightly
coloured insects in the way that Vestiaria, Himatione and others do the birds. The
vast majority of the insects are utterly inconspicuous and unnoticed unless specially
sought for. In most places, whether in forest land or in the open, one will observe the
endemic bees or wasps, insects of small or medium size, mostly appearing black in life,
and the species very uniform in general appearance. Their great abundance in many
places, the dark, blue-shining wings of many of them and their activity by day attract
our attention. In many woodlands and by the side of mountain streams some of the

xxxii FAUNA HAWAIIENSIS

larger red-bodied dragon flies of the family Agrionidae may even be called conspicuous,
while others like A. nigrohamatum have a remarkable appearance as they fly towards
one, owing to the bright yellow colour of the face and the striking turquoise-blue of the
eyes. Apart, from these it is quite possible for the casual observer to walk through
miles of forest and see not a single even moderately conspicuous insect. At the most,
moths of insignificant size and appearance are frequently disturbed from tree-trunks or
undergrowth, as he walks along. These remarks, it should be understood, will apply to
localities, where there is in reality a rich endemic insect fauna, and serve to show its
hidden nature.

The arboreal species of Achatinellidae, though not large, are many of them of very
bright colours and even beautiful, but in the woods they are far from conspicuous. It
is easy to imagine that any one not specially searching for these, or for other creatures
in the same habitat, might pass them by daily without being aware of their existence.
Even in the wettest weather they do not move around by day with the freedom of
many land Molluscs of other countries. The terrestrial species are of sombre colour
and well concealed, as also are many of the species which habitually frequent the trunks
and branches of trees rather than the foliage.

The endemic spiders are mainly inconspicuous and many of the forms that frequent
the trunks and branches of trees match their environment so well as to be nearly in-
visible. Others remain hidden beneath bark or between leaves spun together. Web-
making species are often numerous in shallow caves or hollows in the sides of mountain
ravines, or in the cavities of old tree-trunks, or they spin their webs near to the ground.
Being so favourite a food of the Passerine birds, the arboreal forms especially, were
they not well concealed by day, would have had little chance of survival. The great
decrease in the number of native birds may well lead to an increase in the number of
spiders, even if it has not already done so. Certainly, in 1892, individuals of the
species living exposed on the limbs of trees on Hawaii, where birds were very numerous,
were most uncommon.

Account of time spent in collecting and methods employed.

Before beginning a more special account of the Hawaiian Fauna it seems advisable
to refer to the time that has been spent on the various islands of the group in collecting
material. I arrived in Honolulu early in 1892 and during the spring months collected
chiefly in the Waianae range of Oahu, partly on the eastern and partly on the west
side of these mountains, but more successfully on the latter. Except for an odd day or
two I did not attempt the Koolau range, which was the scene of most of Mr Blackburn's
entomological field-work. Throughout the summer I was stationed on the west side of
Hawaii, working chiefly on Mauna Loa, then a paradise for native birds, and to some
extent on Hualalai. Collecting was done at all elevations from the dry coast, through

IN TROD UCTION """'' "^ | ^ xxxiii

the wet-belt, where heavy rain fell almost every day, to the higher and drier forest of
4000 ft. and upwards, and to the summit of Hualalai. The winter months of 1892 —
1893 were spent almost entirely on the western slopes of the Northern end of the
Koolau range of Oahu, where the forest-belt was more extensive than elsewhere. This
part of the range appears to me to be decidedly inferior for general collecting as com-
pared with the Honolulu end, at any rate during so wet a winter as was this one, but
here, if anywhere, there seemed to me to be a chance of meeting with certain birds, of
which it was specially desired that specimens should be obtained. However, neither
the 'Oo,' Acmlocei'ais apicalis, nor the species of Heniignathus and Heterorhyncluis
peculiar to the island and obtained by early collectors in the first half of last century,
were to be found, either by myself or other ornithologists, and it may be that they had
already become extinct there. This, with perhaps one or two exceptions, was as unsuc-
cessful a collecting e.xperience, as I ever met with.

In May 1893 ^ crossed over to Molokai and, the west half of the island being
practically forestless, camped on the southern slope of the forest-bearing end, near the
middle of the island. All animal life seemed abundant after my experience on Oahu.
Common species of birds were plentiful, though not in the extraordinary numbers
observed on Hawaii, and of course all the Mollusca and most of the insects were new to
me. This was a very wet summer in the mountains, and for the first six weeks there
was hardly a day without long and heavy rains in the woods a few miles behind my
camp, and when it was not actually raining, these were mostly enveloped in thick fog",
through which objects were visible only for a short distance. In spite of this, collecting
was good. After a time I pitched a tent in the midst of the highest boggy forest near
the back ridge of the mountains. From my different camps I was able to get to Kalae
on the west, where I also made a short stay, to the valley of Waikolu, and down into
the deep valley of Pelekunu, where I stayed for a time in the then native village on the
windward coast. It was not till the autumn that I was able to leave Molokai, owing
to the large amount of time spent in securing the rarer birds. And here I should
state, that not only on Molokai, but elsewhere the scarce birds are without doubt
difficult to get even in moderate series. I should consider that, both on Molokai and
other islands, at least half of my whole collecting time was taken up in acquiring
those that I obtained. For some of these birds it was necessary to be continually
on the watch, and even then, and in the best localities, it was quite possible to spend
weeks without seeing, or even hearing, a single individual. For this reason, until I
had secured my specimens, I never dared to go about unhampered with gun and other
necessaries for bird-collecting, even though I was specially in search of insects.

When it is considered how small and well-hidden are most of the latter, it will be
easily understood that the many days spent specially in search of rare birds, for which
both sight and hearing need to be kept constantly strained, did not result in a great
accumulation of entomological specimens.

F. H. I. e

xxxiv FAUNA HAWAIIENSIS

After my experience of the previous winter I concluded that it would be better to
spend this season on the small and comparatively dry island of Lanai, the forest area
being very small. Nearly all my extensive series of Lanai birds, shells and insects were
obtained during these months. In March 1894 I proceeded to Maui, working with not
too much success in the broken West Maui mountains, where I have invariably had
bad luck from weather or other causes, and with satisfactory results on Haleakala. As
I was returning to England for the winter I was unable to make a stay of more than
two months, after which I went to Kauai and collected over the high plateau of the
middle of the island and also to some extent on the lower and drier parts of the moun-
tains. During this summer I revisited Lanai for a short period of camping and finally
proceeded to windward Hawaii for a brief stay. At the end of the summer I left for
England and for four months was engaged in working on the specimens, so far collected,
and described the bees and wasps that had been obtained, this latter work being revised
subsequently and published much later.

In the spring of 1895 on my return to the islands I first made a lengthy stay on
Kauai, visiting various parts of the islands and afterwards went to Hawaii, collecting in
the Hilo, Puna and Kau districts. In the winter months several camping expeditions
were made on Mauna Kea, birds being the chief object. On two of these expeditions
there was not a single day without heavy rain and the collecting was very trying. On
account of the density of the forest, I had a gang of natives with me, in order to cut
trails through the forest. They all suffered much from the wet and cold, it being
impossible to dry clothes for sleeping in, and one of them met with a bad accident. On
my last attempt, however, I had exceptional weather for two weeks and secured the
bird I chiefly wanted, and some rather nice insects. In February 1896 I spent some
time in a tent on the Waianae mountains, at a higher elevation than had been possible
in 1892, and afterwards revisited Kauai (more than once), Molokai, Lanai, Hawaii and
Maui. One of the Kauai expeditions, when I camped on the wet side of the island, was
very poor in results, but other localities yielded well. In January 1897 some time was
spent in collecting on the west side of the West Maui mountains, but this collecting was
done under many difficulties. Leaving Maui, I camped out for some weeks on Kauai.
Shortly afterwards I left for England by way of Arizona and Mexico. After working
on the collections and completing the descriptions of Hymenoptera already referred to,
as well as the Neuroptera, Orthoptera and some families of Coleoptera, I returned to
the islands early in igoo. In this and the following year my work was almost entirely
confined to Oahu. I rarely carried a gun, and paid little attention to anything but
insects and mostly limited my observations to certain groups of these. Very little
indiscriminate collecting was attempted. Beetles such as are easily obtained by indis-
criminate beating of trees or by sweeping these, were almost all collected by special
search, as I wished to obtain a more certain knowledge of their habits and particulariy
of the restriction of species to one food-plant, the variation of individuals found in

INTRODUCTION xxxv

company and that of different colonies. Practically all the specimens obtained were
mounted, when freshly killed, and to a large extent examined at the time. Observa-
tions were made in widely separated localities and in both mountain ranges. During
this period I had facilities for working at the specimens in the office of my friend
Mr A. Koebele, the Government entomologist of the islands, who accompanied me on a
number of my trips. Although, as has been said, my latter work was of a more special
nature, yet more new species than might have been expected were obtained. The time
spent by me in general collecting (i.e. excluding my last mentioned visit to the islands)
did not differ much in the case of the four islands Kauai, Maui, Molokai and Oahu,
averaging about eight months to each. On Lanai the small size of the island and its
few species of birds only necessitated about four months work, but the great island of
Hawaii consumed about twenty months, largely on account of its richness in species of
birds, as compared with any other of the group.

All my collections were specially packed and shipped in Honolulu, and although
practically all the Lepidoptera and many of the other insects were pinned, and must
have received much rough handling in their several changes from steamer to train
and vice versa, I think hardly a specimen was damaged or even shifted. A single lot
unwisely sent by mail, for a special reason, was considerably damaged.

In 1902 and 1903, having ceased to collect for the Committee and become engaged
in local economic entomology, I was able to visit several of the islands and collected a
great deal of material, some of it still being unworked or undescribed, while some of the
species are included in the systematic portion of this work. In 1902 I made an exten-
sive investigation, by breeding them, of many of the parasitic Hymenoptera and in
1903 I paid a good deal of attention to the native leaf-hoppers (Hornoptera). My
account of the birds was published at the end of 1903 (Vol. i, p. 365). After this date
except for occasional single days or for short periods I have done little field-work, and
when working have nearly always had some special object in view, rather than to collect
indiscriminately. Though greatly occupied with economic entomological w.ork I com-
pleted the Anobiidae (published in 1910), a group of beetles on which I had been
occupied, as occasion offered, for about ten years, and wrote supplementary papers on
other Coleoptera and several of the other Orders. As to the groups of insects, which
have been worked out for the Committee by well-known specialists, in most of these I
have had occasion to determine large numbers of species, or even considerable collec-
tions, the material having been collected both by myself and others. I have thought it
advisable to refer at this length to such work as I have personally done in connection
with the Hawaiian fauna, both in the field and study, because on this are based the
conclusions that I have arrived at in this Introduction. From observations of a less
wide nature or limited to a single group I might have arrived at other conclusions.

It has already been said how much time was taken up in the search for some of the
rarer birds and in the acquisition of a good series of specimens of these. As to the

e 2

xxxvi FAUNA HAWAIIENSIS

insects far more time was given to a special search for Coleoptera than any other Order.
After the beetles the Microlepidoptera probably occupied the most time. Many of
these were collected in very wet and sometimes windy localities and as they could not
be carried alive in so rough a country without damaging themselves, I found it neces-
sary to kill and pin them, as soon as they were caught. Liquid ammonia was always
used in killing, except for stray specimens picked up, when I was specially in search of
other insects or of birds. It was often necessary to carry an umbrella in order to obtain
shelter from the wind and rain, when pinning the specimens in the field. On compara-
tively few days the Hymenoptera claimed my whole attention, these being (at least
the Aculeata) conspicuous and easily collected, and this also applies to the Odonata.
The Neuroptera, Orthoptera, and Hemiptera, as represented in our fauna, are naturally
met with in collecting beetles and now and then I spent a day strictly in catching the
larger Lepidoptera. To the Mollusca on Molokai and Lanai I paid a good deal of
special attention and very special attention to certain species.

As to the modes of collecting the most successful are exactly those which would be
employed by a successful collector in any other country, the difference between the
islands and most countries being that many situations, which might be expected to
produce a good harvest, will be found comparatively barren. Very few species of
Coleoptera will be swept from low herbage, even in the finest localities. Sweeping,
when employed, should be rather done amongst the branches of trees and shrubs. This
is very natural, seeing that nearly all the beetles are attached to, or bred in wood, dead
or alive, but chiefly in dead or diseased trees. A good many of the species sun them-
selves on the foliage of living trees and shrubs, but rarely descend to low plants.
Comparatively speaking, very rarely is any beetle seen upon the wing. These remarks
of course apply solely to the endemic fauna. Light is very attractive to Lepidoptera,
both large and small, and especially in wet localities, no doubt for the reason that in
these, dark cloudy nights are most frequent. Clear cold nights are almost useless, and
worse still if there is a strong wind. Even the smallest moths will sometimes come
freely during very heavy rain, and a black windless night with torrential downpours,
which cease at intervals, are the very best, during those intervals. Even the butterflies,
Pyrameis tammeamea and P. atalanta sometimes are not infrequent visitors under such
conditions. Flowers are attractive to many moths both by day and night, especially
the Ohia {Metrosiderus) from which at night some kinds may be shaken to the ground,
either unable or unwilling to fly. The usual bait of sugar, tried at various times, in
good localities for Agrotis, failed to attract anything except the little Hypenodes, so
similar to the European one, which, as is well known, is itself very freely attracted.
Fern-fronds in a certain stage of decay are very attractive to Agrotis, and when feeding
on these they make no attempt to fly, but fall to the ground, when disturbed. Aculeate
Hymenoptera and Odonata do not need looking for, but it needs a practised eye to
distinguish the very similar species of the former, so as to be able to pick out the

INTRODUCTION xxxvii

rarities without a wholesale slaughter. Flowers, except a few fleshy kinds that easily
decay, are not attractive to beetles, excepting some species of Nitidulidae and the
Elaterid genus Eopentlies. The minute and obscure Diptera, the endemic species
largely consisting of small Dolichopodidae, which shrink and distort on drying, and
of infinite numbers of Drosophilidae, many of these also becoming distorted, have been
little collected.

It is quite certain that only a fraction of the fauna has yet been collected, and that
the groups are very unequally known. The small group of native dragon flies may not
be greatly added to and the aculeate Hymenoptera are fairly collected, both of these
being as one might almost say obtrusively present as a whole, as compared with other
insects, of which but few species are both numerous and conspicuous at the same time.
On the other hand three hundred species of DrosopJiila would be a moderate estimate
of those existing. It is possible that half the number of existing species of insects have
been collected, but this is by no means certain.

During the last ten years, since the annexation of the islands, it has gradually
become much more easy to get about than was the case during the chief period of my
collecting, and many mountain localities have been opened up, which before were
impossible for the collector or at least very difficult of access. At the same time the
existing forest is being much more strictly preserved from destruction.

I did much of my collecting from a small tent, which, usually, I had packed for me
on horse or mule over the lower slopes to the lower edge of the forest and from that
point packed it myself with the necessary supplies and collecting apparatus into the
heart of the forest. Skinning birds and pinning insects while either sitting on the
ground or lying down was at first troublesome, but after a time seemed natural enough.
In some very wet forests, where I had to spend much time for the birds, I was obliged
to carry a limited supply of oil and a small oil-stove on account of the difficulty or
impossibility of making a fire on my arrival at night after a long day's collecting, during
the continuous and heavy rains. But such cases were exceptional, and otherwise, after
a little practice, it was always possible to build a fire in the open (even in very wet
weather) for the purpose of cooking rice, — practically the only cooking that the habitual
camper-out need attempt. This with coffee and sugar and one or two kinds of tinned
meats (in addition to a tent, clothing and apparatus) will be found as much as the
collector will care to pack on his back in so rough a country, and I found the stove and
oil a sore burden, very reluctantly assumed. Except for very special purposes I never
took a native with me on these camping expeditions, partly because it was almost
impossible to get one man to go without companions and partly because the impedi-
menta would be proportionately increased as the number to be fed and sheltered was
added to. In some of these untrodden forests many of the birds (excluding the most
wide-ranging species which seem generally to have more or less fear or shyness of man
and the little fly-catchers, which are everywhere very tame or inquisitive) were absolutely

xxxviii FAUNA HAWAIIENSIS

fearless, and it was only just not possible to touch them with the hand. Sometimes
it was quite impossible to shoot a rare species, since it would keep following up the
collector, as he moved away, perching overhead at only a gun-length's distance. Then,
its curiosity satisfied, it would fly off altogether and be lost in the density of the brush.
Excepting in the more open forest, in the neighbourhood of ranches, the woods are
quite uninhabited, and sometimes for weeks together I never saw a human being.
Occasionally a native would come up and leave letters for me or take them down from
my tent, but usually I was away collecting, when he arrived.

Hawaiian islands much richer in species than has been supposed, and
the scarcity of individuals of species exaggerated.

Oceanic islands are generally said to produce but few species of native insects,
but their unproductiveness has certainly been exaggerated, owing to the hidden life
and small size of so many of these inhabitants. It has also been supposed that
individuals of the species are as a rule and comparatively speaking rare. In the
case of the Hawaiian islands, and probably of most remote oceanic islands, the insects
and other animals are limited to a small variety of types compared with other lands,
but the types represented are often extremely rich in species, which, one might almost
say, do their best to fill up the vacancies caused by the absence of many forms of life
almost ubiquitous elsewhere, but which have never reached these remote islands.
When talking to the late Dr Ashmead, who visited the islands in 1900, he insisted
that certain large groups of parasitic Hymenoptera, of which he had a specialist's
knowledge, must, being of universal distribution elsewhere, be really well represented
in the islands, though no species (excepting a few evidently imported) had ever been
collected. But in reality it is not at all surprising that these do not occur. Firstly
the chances of any vagrant insect, carried across the ocean either by wind or wave,
happening to land on a few small spots in mid ocean must be very small, and then
the possibility of its acclimatisation has to be considered. We know from practical
experience that many insects, which it has been desired to introduce, fail to establish
themselves in this climate. If a plant-eating species, it may find no fit vegetable food,
if parasitic, no fit animal food. But in the case of such specialized creatures, as most
parasitic insects, unless either a number of the host, they feed upon, has arrived with
them, or previously, and become established, or unless there happens to be some other
insect present, which may serve as a new host, the chance of a successful occupation
by a parasitic insect is very small.

The paucity of individuals of a species is also, I think, much less than has
been supposed, this supposition being due to the small size, hidden life and special

INTRODUCTION xxxix

habits of many of the creatures. I do not feel sure whether the number of really
rare species is greater than is the case elsewhere over an eqiial area of land. On large
land areas a species may occur in very small numbers, but persistently, over a limited
portion of the area, while in other parts removed from this, it may be continually
abundant, and small islands do not afford these conditions. On a continental land
if one picks out a continuous area, equal in size to one of our islands, there will be
found large numbers of rare insects, even in countries much more collected over than
the Hawaiian group. It is natural that a collector in a country of great roughness
and with extensive virgin forests, collecting in a limited time not only all kinds of
insects, but all other land animals, will obtain many unique specimens and also species
represented by only one or two examples, both from lack of time to make special
search for each particular species and because many insects even though they have
no regular season, become more abundant at one period than another and the best time
may be missed in a particular locality. Also in pathless forests, where a species is very
local, and particular as to the exact condition of its surroundings, it is often not possible
to find again the exact place where it happened to be met with. In restricted localities,
that have been often visited and collected over, most of the species have at some time
or another been found in some numbers and many in abundance. Again the personal
equation comes in. The collector particularly fancies certain species and devotes much
time to these, while others he is liable to neglect, in so far that he picks up only a
few specimens. For this reason the number of specimens cited as captured, in the
systematic portion of this work, should not necessarily be regarded as showing the
rarity or otherwise of a species. For instance, the conspicuous dark-coloured, day-
flying moth, Dasyuris holombra, of which two specimens are recorded, I observed in
hundreds, if not thousands, on one occasion, flying in the forest on Maui, but being
always hampered with a gun and much occupied with birds, I neglected to catch a
series and did not again have the chance. A number of species of beetles, of which
I captured long series, are undoubtedly amongst the rarest Hawaiian insects. My
experience in this matter is different from Mr Blackburn's, who says " the very
common insects" are "few indeed and the rather common ones almost none at all."
We should rather say (speaking of course only of the endemic fauna) that the rather
common species are numerous, the excessively common ones, less so, though there
are a considerable number of these. He also remarks that " It is by no means an
unusual thing to pass a morning collecting on the mountains (at any rate on those
under 3000 ft. high) and to return home with perhaps two or three specimens secured,
and having seen literally nothing else except the few most abundant insects." I am
quite sure that this must be due to his having neglected to get beyond the range of
the small ant Pheidole mcgacephala, before beginning to collect. A coleopterist of
some experience in island work (and perhaps even without this) in the mountains
close to Honolulu may take about forty species of beetles in a fair day's work,

xl FAUNA HAWAIIENSIS

between 1500 and 2000 ft. elevation, though he has a considerable walk to and
from the collecting ground. Almost the last day I collected in that locality, I took
exactly that number of beetles (Cis 6 species, Proterhinus 10, Carabidae 5, Curcu-
lionidae 7, Histeridae i, Cerambycidae 2, Staphylinidae 1, Nitidulidae 7, Anobiidae i)
in addition to numerous other insects, and had it been a different season, stray species
of Elateridae would certainly have occurred. I do not doubt I must often have
exceeded this number of species, especially as on this occasion 1 was by no means
well and really unfit to attempt collecting in the mountains.

It has been suggested that close interbreeding may result in diminished fertility
and in a paucity of individuals of island species, and that such interbreeding is very
common there is no doubt. But whether in insects this inbreeding has any such
result is extremely doubtful. We can feel quite sure that some of the introduced
insects in the islands have originated from one or two, or very few individuals,
accidentally imported by man, and of others imported for economic reasons we
know this to be the case. Yet though some of the former were introduced at least
half a century ago and have produced probably at least several broods a year ever
since, and some of the latter complete a generation each month or even more quickly,
these all remain as common as ever and show no sign whatever of degeneration or
impaired fertility. Of imported insect pests it is sometimes said in a careless manner
that these naturally disappear or become insignificant in time from being "played out,"
but 1 do not doubt that careful investigation will show that in such cases the real
cause of decrease is that they become attacked, after a while, by other insects or
diseases, and especially by parasites and predators, which transfer their attack by
degrees from native species to the foreign immigrant. Deterioration in insects,
supposed to be due to inbreeding, is much more probably due to the ill-effects of the
unnatural conditions of captivity. The extreme sluggishness of so many of the insects
and Mollusca leading to great restriction of locality, which we observe also in the birds,
must lead to extreme inbreedino-. We have observed colonies of some of the fliohtless
beetles to persist for years in a single tree and where these colonies are isolated from
others, no doubt all the inhabitants have resulted from a few stray examples, probably
often from one. While the food remains in suitable condition these isolated colonies
thrive and become very numerous, but they are, doubtless, often totally exterminated
when it becomes no longer suitable, unless, by chance, individuals can reach some other
tree fit to supply a breeding ground. Obviously this sluggishness and restriction of
range must itself diminish the numbers of individuals of a species, and the tendency
of island creatures to limit their range and to specialize their habits is a striking-
feature of the fauna. Loss of the powers of ilight is a very common phenomenon
in this connection.

INTRODUCTION xli

Number of species of insects and causes of extinction.

The total number of Hawaiian insects known to me at the present time is about
3325, but of these only about 2740 can be considered as belonging to the natural
fauna. Owing to man's interference and his introduction of foreign creatures, I should
consider that about 300 species have been exterminated, without being collected.
Mr Blackburn's and my own collecting, together with some aid received from others,
has in my opinion resulted in the collection of about half of the e.xisting species of
native insects, so that a perfect collection of this section of the fauna, made before
man's interference, might have yielded about 5780 species. I may have somewhat
underestimated the number exterminated.

It is known that several species of Passerine birds, formerly abundant, had become
either totally or nearly extinct before I came to the islands, twenty years ago, and
there is reason to fear that several others may since have disappeared. At any rate,
we know certainly that some, which were abundant, have become much less so, and
have totally disappeared from localities where they were common enough. In my
paper on the birds (Vol. i, p. 393) I have referred to the causes which have brought
about this extinction or diminution in numbers. As with the birds, destruction of forest
has, doubtless, caused the disappearance of many local insects, but even of greater
importance has been the introduction of foreign carnivorous species, especially of the
dominant ant, Pheidole megacephala. There is no record of the time when this destruc-
tive creature was imported, but even during the last twenty years it has occupied some
considerable areas previously free from it. It may be said that no native Hawaiian
Coleopterous insect can resist this predator, and it is practically useless to attempt
to collect where it is well established. Just on the limits of its range one may
occasionally meet with a few active beetles, e.g. species of Plagithmysus, often with
these ants attached to their legs or bodies, but sooner or later they are quite ex-
terminated from such localities. It is quite certain that native beetles and many other
insects are absent from the localities occupied by Pheidole, solely on account of its
presence. In several instances, as the ant has been observed to occupy a new area,
this area having been collected over before it was present and yielding many native
beetles, the latter have entirely disappeared. In a few low-lying localities, even close
to the coast, there are some places, which from excessive dryness and other causes,
the Pheidole is unable to occupy, at any rate permanently, and yet unfavourable,
as these are, for insects of any kind, here only will native Coleoptera be found.
On one occasion I came across an instructive instance of the effect of these ants
on the native fauna. A more or less open piece of forest at an elevation of 1500 ft.
above sea-level, with a large variety of trees scattered in it, appeared at first sight
an excellent spot for collecting native insects. A number of native Hymenoptera
F. H. I. /

xlii FAUNA HAWAIIENSIS

were seen flying round the foliage, hardy insects which the ants cannot exterminate,
though they are often seen attached to them by the mandibles. Every tree trunk
was invaded by Pheidole, and beating the boughs dislodged them in thousands.
Not a single beetle nor any native insect was obtained from these trees. One
solitary tree, however, for some reason was quite free from ants. It was a large
Bobea, with hanging masses of ' Maile ' [Alyxia) dependent from the boughs. From
the dead stems of this were shaken hundreds, if not thousands, of one species of
Proterhinus, others also being present, as well as the large weevils, Rliyncogonus,
and other kinds of beetles. I visited this spot on many occasions for the sake of
a rare species of wasp, but never obtained a beetle except from this one tree, and
a year later it too was occupied by Pheidole and barren of native insects. Fortunately
Pheidole is not universal in its distribution. It can in some localities just attain
4000 ft. in the mountains, under certain climatic conditions. Below twelve or thirteen
hundred feet it often occupies most of the islands, excepting some extremely arid
localities. Though not so utterly destructive to other insects as to the beetles, yet
many of them are destroyed by it, and generally speaking, collecting is very poor,
where it abounds. Most of the native species taken in such places are vagrant, like
Lepidoptera, and have bred in some adjoining area, either free from this ant, or
where it is comparatively sparse. Miles of attractive forest in some parts of the
islands are almost devoid of native insects, through its destructiveness. A very few
endemic insects seem able to breed in its haunts, even where it is quite abundant,
but many of the foreign or imported insects flourish in spite of it. It is not probable
that it will spread to any great extent beyond the limits now occupied, for it has
long since filled all suitable localities. Here and there the opening up of limited
areas of forest may by change of conditions allow it to colonize these, but the great
bulk of the forest is now reserved and not likely to be opened up. There is no
reason to suppose that the endemic insect fauna will suffer any considerable further
diminution, and it may, so far as one can see, remain as it is for ages to come.
The chief danger would be in the introduction of some predaceous creature like
Pheidole, which would be able to occupy the great area of forest land and the country
above this, where Pheidole does not now exist. As no such insect has been imported
in the course of the last century, it is on the whole improbable that it ever will be.

Comparison of 'introduced,' 'immigrant' and 'endemic' insects etc.

In a memoir on the Hawaiian Coleoptera, published in 1885, by Blackburn and
Sharp, the beetles are divided into three classes : (i) 'introduced,' i.e. species imported
by man, (2) ' immigrant,' i.e. species occurring elsewhere, but which have reached the
islands by natural means, (3) 'autochthonous,' i.e. species peculiar to the islands, for
which I have used the older and more often employed term, 'endemic'

INTRODUCTION xliii

Owing to our very incomplete knowledge of the insect fauna of the world, some of
the introduced species and also some considered to be immigrant are not yet known
outside the islands. The ant Prenolepis sharpii for instance, which was imported years
ago in boxes of plants by the Commissioner of Agriculture of the islands, and soon
became established and very common, was described from descendants of these im-
ported examples.

In judging whether an insect has been introduced by man, when the actual fact of
its importation is unknown, I consider the following points.

(i) If solely attached to foreign vegetation or parasitic or preying on imported
creatures only, it is certainly ' introduced,' or (less probably) ' immigrant.'

(2) If, being a beetle or Heteropterous bug, it is found within the range of certain
foreign predaceous insects, it may in the case of the former be considered certainly and
in the case of the latter most probably 'introduced' or possibly 'immigrant' In
explanation of this I may state, that in the case of the truly endemic beetles, without
exception, and usually of the Heteroptera, the area of distribution is absolutely fixed
by the non-occurrence of imported predators. Owing to interference by man these
predators may come to occupy new areas, and then from these too the above-mentioned
endemic forms disappear. At first, in such cases, many of the endemic beetles will be
found actually being attacked by these enemies, but subsequently they will disappear.
Some insects, however, e.g. bees and wasps and some Lepidoptera, more or less
successfully resist such predators, and though endemic, can occupy the same area, as
also can others that rarely or never are attacked, e.g. certain Homoptera that excrete
honey dew.

(3) Doubtfully endemic insects may occur outside the range of foreign predators
and mixed with many truly endemic ones, but usually they also range into the territory
occupied by the former. If not, their habits should be considered and their food, and
the probability of their being imported by man, but if they do so they are most likely
' imported ' or ' immigrant,' and surely so if Coleopterous.

(4) Actual affinity to, or remoteness from outside forms must always be considered.

(5) Whether the species is isolated from other members of the fauna, or
whether one or more closely allied forms occur is most important. When several
closely related species are found in the islands the probability of their being endemic is
very great. Importations by man usually consist of very different insects and not of
closely allied species, and the same would be likely to be the case with natural immi-
grants.

A careful consideration of such points in the case of any insect that is fairly well
studied, will usually leave little doubt as to whether it is endemic or introduced. It is
perhaps more difficult to distinguish the immigrants from either the endemic or the
imported species. We must, however, except from this statement a number of species
of known migratory powers, well-known species elsewhere, with great powers of

/2

xliv FAUNA HAWAIIENSIS

flight, and clearly natural immigrants. Excluding these, the number of immigrants is
probably very small, for reasons hereafter given.

Whereas the imported species are in most respects of little interest as compared
with the immigrant and endemic, in one particular they are of considerable importance,
especially such species as have been established in the islands for many years. House-
hold pests, however, and some others, that we know have been imported again and
again, are of no interest. It is probable that such introduced species as the Longicorn
beetles Laoocheirus obsolehts and Astrvnus hirtus were established from a single
importation of these species. They are evidently not frequently carried by man, for
until recent years the former had not spread to the other islands and the latter has not,
as far as is known, yet reached them. Yet the former is known to have become so
plentiful, as to have been an injurious insect in Honolulu forty or fifty years ago, and
the latter has been established at least for thirty years. Though for all these years
inter-island traffic has been very heavy, and plants continually taken from one island, to
another, and especially from Honolulu, where these beetles are common, yet the spread
o{ Lagocheirus has been slow, and that oi Astrimus has not, so far as is known, occurred
at all, as stated above. It is, therefore, very unlikely that either of these beetles has
frequently or even occasionally been brought to the islands from outside countries,
seeing that the traffic between these and Honolulu has been, until recently, compara-
tively very infrequent. I suspect, too, that these beetles are likely to be more abundant
with us than in their native countries. Owing to the equability of the climate, on
account of which so many insects breed the year round, and often produce many broods
in a year, many species have passed through very many generations since their intro-
duction. Some of the imported creatures we know from observation complete their
life-cycle in three weeks, and brood follows brood without cessation. Yet, when we
examine examples of these species, we may well feel some astonishment at the fact that
they quite resemble those found in their original home, even though this differs greatly
in climate and otherwise, and they exhibit no particular variability. Some (e.g. certain
Coccinellidae) notably variable in their native homes, appear to exhibit even less
variation here than in their own country. Looking at the imported species as a whole,
we must allow that these show no tendency to special variation, and there is not the
least reason to suppose that the variability seen is greater than, or different from that,
which they exhibit in their native homes. One is struck with the stability of specific
characters, and a study of these imported insects as yet throws no light on the question
as to whether variation arises suddenly or by slow degrees in a species. One would
infer that much time is as a rule required for the appreciable modification of a stable
species.

The immigrant species are of two classes like the introduced ones: (i) those that
are, doubtless, more or less frequent \m^m\<gvA.x\\.s i^Pyrameis xar-diii, Nomophila noctuella,
large dragon flies etc.) and (2) those which are chance immigrants, of which no second

INTRODUCTION xlv

immigration would probably take place in ages, if at all. At any period of the history
of the islands these chance immigrants must be very few in number, for reasons stated
elsewhere, and owing to the obscure nature of the fauna (obscure insects being very
imperfectly known in other tropical countries) we cannot be sure whether certain species
suspected of being immigrants are really so, as they have not been detected elsewhere,
and they may in reality be endemic. This is unfortunate, because they are the potential
ancestors of future endemic forms. Thus the Cossonid beetles Deinocossonus and
Orothreptes are possible immigrants and so are such species as Prays fulvocanel/us in
Lepidoptera, but they have not been recorded from other countries. A very few
species, e.g. the Tortricid moth, Bactra stramznea, are almost certainly immigrant. If
we examine these supposedly immigrant species and in conjunction with these consider
those endemic ones, which are little modified from outside forms, and therefore are to
be considered as a development from the more recent immigrants, we find a very
different condition from that above noted in the case of introduced species. There
may be a few constant species amongst these, and this may be due to the fact that such
have been comparatively a short time in the islands and are the most recent natural
immigrants, but these are certainly very few. We at once note the large amount of
variability exhibited by the species. In this connection we may review a few species,
which are either the sole representatives of their genus (and not, or very little, different
from the outside forms) or at least have only one or two other species related to them
in the islands. In the Aculeate Hymenoptera, the small ant Ponera perkinsi, hardly
separable from foreign species is the sole native representative of its group. It is
widely spread, occurs in many localities from near the coast to above 4000 ft., and
exhibits considerable variation. There is sometimes a distinct tendency to specializa-
tion in variation in different localities. In the parasitic Hymenoptera, Echthroinoiplia
inaculipennis varies very greatly and individuals might at first be taken to represent
distinct species. The small cockroach Phyllodromia obtusata is notably variable, so as
almost to have given rise to a distinct species in parts of the island of Molokai. The
earwigs listed under the names of Anisolabis pacifica and inaritinta in the systematic
portion of this work, the former possibly endemic and the latter immigrant, are variable.
The forest-frequenting species of Caloternies, which I expect will prove to be peculiar
to the islands, exhibits notable variation in different localities. Bactra straininea, a
New Zealand moth, is excessively variable and I consider that some of its local forms
will probably prove to be distinct species. Another small moth Hypenodes altivolans,
some varieties of which differ very little from the widespread H. costaestrigalis, is
extraordinarily variable. The Pentatomid bug Oechalia grisea varies very greatly, and
there is at least one offshoot of this, of restricted habitat and forming a distinct species.
In birds the native duck, possibly a puny descendant ol Anas boschas, is so variable
that some ornithologists have supposed we have more than one species. In beetles
Pentarthrum prolixuvi and the Parandra are variable forms. It is of course possible

xlvi FAUNA HAWAIIENSIS

that all these may have been variable on their arrival in the islands, or are the
descendants of variable immigrant species, but the variability in this class (i.e. immi-
grant species or comparatively recent developments from immigrants) is so very
general, that this seems improbable, comparing them with the species accidentally
introduced by man.

The endemic fauna of the islands consists for the most part of genera containing
an inordinate number of species, evidendy allied to one another, e.g. Scotoiytkra and
Hyposmochoma (Lepidoptera), Proterhinus (Coleoptera), Nesoprosopis (Hymenoptera),
Anomalochrysa (Neuroptera), Paratrigonidium (Orthoptera), Drosophila (Diptera),
Achatinella (Mollusca), and many others. If the genera are weak in species they are
generally, if isolated in the fauna, highly peculiar in structure, or they are evidently
merely offshoots from some of the larger genera. In the Passerine birds the genera
are numerous, but they are mostly weak in species. The large genera of insects and
shells often consist of many variable species, though in these large genera some of the
species are generally stable. More rarely there are genera, containing many species,
few or none of which are conspicuously variable, at any rate not sufficiently so, as to
cause any serious difficulty in defining the species. Probably these genera of stable
species have reached the furthest point of development possible under the existing
conditions in the islands. If we examine the series of allied forms of the Passerine
birds, as they exist to-day, we, see that a large number of them have reached such a
stage of specialization for a certain mode of life, that we can hardly conceive that they
could under any circumstances give rise to new forms. These could at most arise from
some of the more generalized. Possibly the same is the case in the large genera of
insects, of which the species are in a stable condition, though we are unable to appre-
ciate the relationship of structure to habit as easily as we can in the birds.

Distribution of animals by natural agencies.

All the islands being volcanic and having been built up from a great depth of
ocean at various periods, their entire fauna naturally originated from immigrants derived
from other lands. These immigrants must have arrived either by flight, like the birds,
or in drift like the flightless insects and probably the land Mollusca. Some of the
flightless insects, however, that we now find in the islands, have no doubt lost their
powers of flight after their arrival, or more properly speaking are the descendants of
well-winged ancestors, and in this respect are similar to the little flightless rail iyPcnnula
ecaudala) now extinct, but others, for instance some of the genera of weevils were,
equally certainly, flightless when they arrived. These can only possibly have reached
the islands in drift. That insects can pass over enormous distances in floating logs of

INTRODUCTION xlvii

timber can be seen from the study of the little weevil, Diyotribns 7ninieticus, whose
natural home appears to be in drift-wood, and which not only occurs in Florida, but in
the Hawaiian group and in Australia. In the case of the Hawaiian fauna many of the
winged insects might quite possibly have been transported in this manner, for in their
larval stages they live in the wood of dead trees, or beneath or in the bark, or they
frequently, even if leaf-eaters as larvae, creep into the cavities of dead branches or
beneath the bark to pupate. It is only necessary to look through the various families
of insects, the habits of which are recorded hereafter, to see what a great proportion
might have been carried in this manner. As is well known the common drift of the
islands, derived from outside, consists of coniferous trees from North-West America,
but few and probably none of the elements of our fauna can have been derived thence.
Our insects have no relationship with those from that quarter, and it is unlikely that
such drift would bring insects that would become acclimatized in the islands. Roughly
speaking the Hawaiian fauna may be said to have been derived, so far as we can judge
from its affinities, from immigrants received from the warmer parts of America, from
the Australian and South Polynesian islands, and from the Oriental region. I do not
place much importance on the fact that there is certainly no regular deposit of drift
wood from any of these regions at present on the island shores, for with our scanty
representation of types, it is only necessary that once in thousands of years an immi-
grant-bearing trunk or log should reach them. Certainly a careful consideration of the
components of the Fauna would lead us to believe that this must have happened.
Dr Guppy places little importance on drift in his considerations of the origin of the
Hawaiian flora and very great importance on the birds ; but when I consider how often
1 have found great numbers of seeds held beneath the dead bark of trees in the
mountain forests, I cannot overlook the possibility of original components of the flora
having arrived this way, as have those of the fauna. Further when one considers that
even in our limited fauna, a single tree trunk may contain a score or more of distinct
species, beetles and their larvae in the wood and bark, caterpillars boring the wood or
living beneath the bark, well-sealed nests of bees and wasps, often in old beetle
borings, with possibly Mollusca adherent to the bark, or beneath it, or wedged in
crevices, besides other creatures and perhaps parasites of some of these, we may fairly
suppose that once in a long period, some such micro-fauna may have been washed out
to sea and stranded on these islands, and that some at least of the emigrants have
survived and become established.

Though the distance between the islands and other lands is so great, yet we know-
that, like the migrant birds of Alaska that regularly visit the islands, certain insects
of migratory habits like the large dragonflies, the butterflies, Pyrameis cardui and
Imntcra, the small moth, NoniopJiila noctttclla, and others have been able to reach
the islands, and probably still do arrive from time to time, so we need not feel any
difficulty in believing that at some j^eriod a lesser-sized dragonfly (Agrion) or an

xlviii FAUNA HAWAIIENSIS

ant-lion {For7nicaleo) — insects which could only have arrived on their wings — have
been able to traverse a similar expanse of ocean by some rare chance. In many
cases the winged insects may not have arrived this way, because in their earlier
stages they could well have been carried like the flightless beetles and wingless
animals. Over what distance minute and delicate winged insects can be wind-borne
is not known, but probably under favourable circumstances it is very great. Some
small moths, as reported by Muir and Kershaw, are able to rest on the sea and
again take wing, but such cases are probably rare, and I imagine this faculty would
not be of much aid in traversing such great distances as we require. High and
steady currents of air are probably most efficient. A number of the existing species
of moths are of powerful flight and are partial to wind-swept country, and it is a
familiar sight to see these, when disturbed, allow themselves to be carried far away
on the strong wind. Given this habit of allowing themselves to be thus carried,
small moths might even be able to pass over greater distances than heavier-bodied
species. In the interisland distribution of species whirlwinds may have occasionally
assisted. These are most frequently observed on the plains, and I have recorded
how even so strong a bird as the imported Acridotheres may be carried up many
yards before it can extricate itself. These whirlwinds have been seen to carry up
thick columns of dust to an elevation of over 2000 ft., and we have once or twice
observed them to originate at this elevation in the mountains. Small creatures
carried up in this way and meeting high currents of air might be borne for great
distances before alighting.

Flightlessness in Hawaiian insects.

Amongst the Hawaiian insects there is a very large number of species in which
either one or both pairs of wings are so reduced as to be useless for purposes of flight,
or the hindwings may be entirely wanting. These cases in which we may suppose
the loss of the powers of flight to have originated within the islands themselves
are of considerable interest, and we may briefly review the insect fauna from this
point of view.

In Lepidoptera one case of flightlessness only has been so far observed, that
of the large Gelechiid moth, Hodegia apatela, the female of which has all the wings
so reduced as to be quite useless for flight. The male is not known, but it is very
probably fully-winged. This genus is merely an offshoot of the endemic fully-winged
and dominant genus Thyrcopa.

In Diptera, flighdess forms are, so far as is known, confined to the Dolichopodidae,
several species (probably of two genera) having these organs reduced to mere filaments.
One of these, Emperoptera, is an active and brightly metallic little fly, living on the

IN TROD UC TION xlix

ground beneath forest trees ; the others are, I believe, sluggish, and Hve in very wet
moss, clothing tree-trunks in dense wet forests. These are, I suspect, derivations
of the genus Campsicnemus, and are undescribed.

In the Hymenoptera, apterous forms are mostly such as are found in other
countries, but the flightless Diapriidae were probably derived from allied fully-winged
forms such as still occur with them. In the flightless species intermediate conditions
of the abortion of the oro-ans of flieht are known.

In the endemic Heteropterous bugs, one species of Metrarga has become apterous,
and a large section of the genus Redtivioius (Nabidae) is quite flightless, as are the
terrestrial members of the family Emesiidae. The species of Acanthia have the
wings, so far as is known, always so reduced as to be useless for flight. In the
Homopterous bugs many or most of the endemic Delphacidae appear to be always
flightless, and if winged forms are produced at all, it must be at very rare intervals.
Some, however, are always fully winged, so far as is known.

The Neuroptera contain the remarkable endemic genera of Hemerobiidae Pseudo-
psectra and Nesothauma, both flightless, the former with minute hindwings and the
front pair not greatly modified, while the latter has these hardened and sculptured,
so as to resemble more nearly the elytra of beetles. These genera appear to be
derivatives of the more ordinary Nesomicromus, a dominant genus in the islands.

In the Orthoptera, the Locustid genus Banza {^Brachynietopa) are all flight-
less, while in the Gryllids all the little crickets of the genus Paratrigonidiitm
are wingless, and flying individuals are never developed as dimorphic forms, in the
way that we have observed in some Trigonididae of other countries. All the
prognathous crickets {Prognathogryllus and allies) are flightless, but the wings are
so far developed in some forms as to suggest that their present condition has been
reached in the islands, while others are without rudiments of wings and almost without
tegmina.

Turning to the Coleoptera, in the Curculionidae, the genera Oodemas, Heter-
amphns, etc., containing only wingless forms, are so isolated in structure that one
cannot tell whether their winglessness has originated in the islands or whether the
forms, from which they were derived, were wingless when they originally reached
the islands, but the latter may have been the case, as with Rhyncogvms, the foreign
species of which are also wingless. The extensive genus Proterkinns consists of
wingless forms, whereas the foreign Aglycyderes is winged. Unfortunately I did not
examine the unique example of Samoan Proterhinus, which possibly is a winged
form, and the specimen is not at present accessible to me.

Of the Cioidae many species are flightless and some of these have a remarkable

superficial form, and have been segregated under a new generic name, Apterocis, but

other species, still left in the genus Cis, are also flightless, and the wings appear to

be in different conditions of degeneration, though in most of the species they are

F. H. I. z

1 FAUNA HAWAIIENSIS

fully developed. It is not quite certain whether winged and flightless forms may
not occur even in the same species in one instance.

In the Elateridae of the subfamily Eucneminae, an uncertain number of the
species of Droviaeolus are flightless, while many of the genus are fully winged and
are occasionally taken in the act of flying. Of the true Elateridae Dr Sharp believes
that one form, Dacnitus cufrax, is flightless. It is allied to the endemic genus
Itodacnus, which flies freely.

The single Lucanid genus Apterocyclus, somewhat allied to Dorcus, is flightless
and endemic.

The Nitidulidae are mostly fully winged, but four genera, containing in all nine
species, are flightless, while the remaining 1 29 species in nine genera are fully endowed
with flight. The amount of degradation of the wings in the flightless forms varies
according to the genus or species.

The endemic Histeridae of the genus Acritus have flightless species, but these
are probably much less numerous than the fully-winged ones.

In the Staphylinidae some of the species of Myllaena are apterous, their congeners
being fully winged.

Of the endemic Carabidae 184 are flightless, the fully-winged species only 20.
Nearly all the flightless endemic insects are inhabitants of the forest, or if they
frequent exposed situations like some of the Carabidae, they are closely related to
species that frequent thick forests and are equally flightless. There is no ground
for supposing that in these islands, as has been suggested for flightless insects in-
habiting other Oceanic islands, the wings have been lost or degenerated through
the agency of natural selection, as being a source of danger, if used on small land
areas, where flying insects are supposed to be liable to destruction from being blown
out to sea. Only in the case of the moth, Hodegia apatela, could this theory be applied
by any stress of imagination. So far, Hodegia is at present only known from open
and wind-swept localities, and it inhabits these both above and below the forest
region. Practically it is a flightless species of Thyrcopa, and fully-winged examples
of this genus have been observed to flourish in the most wind-swept of all regions
close to the sea margin. Still more delicate Microlepidoptera are found in similar
open country, and many of these as well as the fully-winged species of Tliyi-copa
seem to be far more successful than the Hodegia.

All the cases of flightlessness in Hawaiian insects are, I believe, to be explained
simply by ' disuse.'

If we consider the case of the endemic Heteropterous bugs, we find that all the
flightless forms are either entirely or to a great extent of terrestrial habits. The
winged species of Metrarga though they may descend to the ground, yet habitually
breed on certain plants, often at a height from the ground, but the terrestrial
M. villosa is flightless. All the truly arboreal Reduvioli are winged and are

INTRODUCTION li

sometimes seen on the wing. Some may overlap with the flightless forms in their
habitat, but on the whole the two groups are quite distinct. The apterous
Emesiidae are also terrestrial. The Elaterid, Dacnitus, is terrestrial, as is the Lucanid,
Apterocyclus. Many of the flightless insects are conspicuous for their sluggishness,
e.g. the subapterous Nitidulidae, and amongst these we find the only terrestrial species
of this family. Many of the Carabidae that are flightless are arboreal in their
habits, but these are all able to run quickly, and many of them are extraordinarily
active. It must be remembered that in creatures inhabiting a dense forest belt, as
most Hawaiian insects do, many of these, when in search of new feeding grounds,
at most require to descend from one tree and ascend another. Predaceous creatures
like Carabidae and many of the feeders on dead wood, as we have often observed,
infest the same tree year after year, and probably only cease to do so as the tree
itself fails to afford suitable food for the creatures that it supports, both those
that feed on its substance and those which prey on these. Doubtless with very
sluggish, flightless beetles the death of a tree often entails the death of numerous
individuals, but during its occupation by generation after generation, individuals may
become dispersed and colonize adjoining trees. In the case of more active forms
like the Carabidae, the death of a tree, that is their home, need cause no loss of life
of the beetles. It is instructive to note that in the case of beetles, which require
for their food that a tree should be in a special state of disease or decay, lasting only
for a short period, e.g. the bark-eating Longicorn beetles, and the burrowing Scolytidae,
no case of loss of flight is known to occur. That many creatures, which find an
inexhaustible food supply within a very small area, should become more and more
sluggish or loth to fly, and finally by disuse lose their powers of flight, seems quite
natural. Natural selection may have prevented the loss of flight organs in some of
the island creatures, but it has probably had nothing to do with the degeneration of
the wings in the flightless ones. Had any of the Plagithmysine Longicorns or the
Passerine birds taken to a terrestrial life, we should probably find flightless examples
of these, as we do in the Nitidulid beetles and in the (now extinct) small rails of the
genus Pennu/a. On the other hand sluggish Nitidulid beetles that affect flowers are
never flightless for obvious reasons.

Except in one or two isolated and doubtful cases {Cis and Bembidmm) there
are no instances known in the endemic Coleoptera or Heteropterous bugs, where a
species has both fully-winged and flightless individuals. In fact the only case known
where, apart from the condition of the wings, individual beetles are apparently in-
separable, is that of Bembidium fnolokaiense (winged) and Nesocidium laeticulum
(flightless). In the Homopterous bugs, however, we have fully-winged and flightless
forms of some species, e.g. of Aloha ipomoeae and Nesosydne ipomoeicola, of which
fully-winged forms are only produced at times and are then less numerous than the
brachypterous. These species both occur outside the forest. Of those found only in

HI FAUNA HAWAIIENSIS

the forest on ferns or trees I know no such cases of dimorphism, so, if any exist, they
must be rare. Many species are only known as fully-winged forms, e.g. the several
species of Aloha that feed on the Myrtaceous tree Metrosiderus. Most of the species
of the extensive genus Nesosydne are flightless, but A^. koae appears to be always
fully winged. This latter, though it feeds on a common and gregarious tree {Acacia
koa), yet appears to have peculiar habits, so that few Koa trees, as a rule, are in a
condition to support it, since they bear no true leaves. Whether this fact concerns
the retention of the organs of flight is worthy of investigation. In fact a careful
study of the winged and wingless forest-frequenting species of Nesosydne would be
of considerable interest.

Probable origin of the existing fauna from very few immigrants, the large
genera, or group of allied genera originating from a single or few ancient
immigrants. Comparison with the Flora.

When we look at the Hawaiian fauna as a whole we cannot help remarking the
numerous genera, which comprise an inordinate number of species. Also, we note
that a tribe or subdivision of a family will be represented by a number of closely allied
genera, these together including many species. Or, as in the Drepanidid birds, a family
may contain many closely allied genera, though these have but few species. A few
characteristic examples may be cited. In insects, of the Lepidoptera, Scotorythra
(Selidosemidae) has more than thirty species ; Scoparia (Pyraustidae) about 60 ;
Thyrcopa (Gelechiidae) about 30 ; Aphtlionetus and Neelysia (Hyponomeutidae) each
about as many as the preceding, and Hyposmochonia of the same family about 1 80 ;
Heterocrossa (Carposinidae) contains more than 30 species. Of many of these, species
still undescribed are also known. In Coleoptera, Oodeiiias (Cossonidae) has 46 species;
Proterhinus (Proterhinidae) no less than 136; while the Cerambycid genus Plagitk-
mysiis has 2)2) ; Xyletobius and Mirostermis (Anobiidae) have 52 and 70 species. In
the Odonata or dragonflies, Agrioii has two dozen species, and the Neuropterous
Anomalochrysa (Hemerobiidae) thirty. The genera Nysuis and Reduviolus in Hemi-
ptera, together with about 50 species, form nearly 40 per cent, of the endemic
Heteroptera, while the Homopterous Nesophrosyne has a multitude of forms, 42 having
been described. In Hymenoptera, Odyneriis (Eumenidae) has nearly 100 species, and
Nesoprosopis (Prosopidae) more than 50.

The Molluscan genus Achatinella contains 107 species, as enumerated by Sykes,
Amash'a loi, and Leptachatina 75. Even allowing that many of the described species
may prove to be only varieties of others, the genera are of very large extent.

With regard to series of genera that are closely allied to one another, it will be
noticed that many of the genera already named as containing a great number of species,
have themselves given rise to offshoots of generic value, i.e. have produced species

INTRODUCTION liii

judged to be more different from the aggregate of species they contain, than are these
one from another. In the Carabidae, tlie Anchomenini contain 17 genera more or less
closely allied to one another, and the Pterostichini four, the latter tribe with 76 species,
the former with 106. The Plagithmysini of the Cerambycidae contain three closely
allied genera, and the Prognathogrylline crickets (Gryllidae) four.

It becomes of importance to consider whether these great series of congeneric
species and smaller series of allied genera have been developed in the islands from
a single anciently immigrant ancestor in each case, or have sprung from diverse ancient
immigrations. Are we to consider that Drepanid birds, Anchomenine beetles, moths
of the genus Hyposmochoina and Scotorythra, etc. etc., have more or less frequently
safely reached the islands in past times and become established ? If this be the case
the successful immigration of outside animals must have been of comparatively common
occurrence. If we are able to say in any instance that in the case of one of these
series, whether of genera or species, that one species or genus is more closely allied
to some foreign form while another is more closely allied to a second foreign form,
than are the Hawaiian species or genera to one another, we should naturally suppose
these to be of different origin. Thus the moths of the genus Margaronia are very
different, and clearly belong to quite different groups existing outside the islands, and
cannot be supposed to have developed within these from a common immigrant ancestor.
One in fact {J/, exaula) differs very slightly from foreign species, and the fact that its
caterpillars are sometimes found feeding on imported shrubs growing in gardens in
Honolulu renders the endemicity of the species very doubtful. It is probably an
importation by man and will be found elsewhere.

In a few cases, however, we can, from a study of the structures of the truly native
insects and a comparison with outside forms, be sure that the existing species are not
sprung from a single ancient immigrant species. This is the case with the great series
of Hawaiian wasps of the genus Odyneriis, one group of which [O. nigripennis and
its allies) is closely related to Oriental species, and entirely different from the other
members of the genus. I suspect that the endemic moths of the genus Agrotis are
similarly of diverse origin. If we consider the habits and distribution of these genera,
that both are dominant forms, almost cosmopolitan, that in almost every country species
of each of them are excessively numerous in individuals, we shall not be surprised that
individuals of more than one species of each have at different times reached the islands.
Moreover, it should be said that neither Odynerus nor Agrotis (s.l.) are the equivalents
of ordinary genera, but comprise a heterogeneous mass of forms, which either remain
unclassified or at least are imperfectly understood as to their relationships.

Many of the genera that contain a very long series of endemic species are them-
selves peculiar to the islands, many in fact are so highly endemic that their relationship
to outside forms is by no means close, or even so remote as to be involved in doubt.
The time that has been necessary for the isolation of such remarkable genera may well

liv FAUNA HAWAIIENSIS

be considered sufficient for the production of the long series of allied species that they
contain, without the supposition of several or numerous immigrant species. In compact,
smaller groups like the longicorn beetles of the tribe Plagithmysini, the probability of
the origin of the Hawaiian series from a single form is, I think, not likely to be
disputed by those who have studied the creatures. There are three genera, and the
differences between the extreme species is great. Supposing the existing species to
have arisen from diverse immigrant species, it would be natural to suppose that one
immigrant at least represented each of the three genera. When, however, we look
into the differences between these genera, we find that though the bulk of the species
are easily enough placed, each in its proper genus, yet some species, forming distinct
connecting links between the genera, are still existing. Thus oi Plagithmyszis immundus
Dr Sharp remarks : " It is a connecting link between Clytarlus and PlagitJmiysus"
while Callithmysus C7'istatus, once referred to Plagithmysus, shows evident relationship
to some species of the latter and also to Clytarhis.

It is when we come to examine the more complex groups of allied genera such as
occur in the Carabidae or the Drepanid birds, that there is greater room for diversity of
opinion as to the multiple or single origin of the Hawaiian forms, as they exist at
present. As to the Drepanididae, their case has already been considered in the part of
this work dealing specially with the birds. It is of some importance on account of the
fact that these birds may by some botanists, who consider the flora to have largely been
established through the agency of these creatures, be considered responsible for the
introduction of a not inconsiderable portion of the existing plants. If however, the
existing forms have all sprung from a single or dual chance immigration in long past
ages, the part that this dominant group of land-birds can have played in the establish-
ment of a flora will be necessarily very small, or possibly of no account at all.

It may be worth while to consider some points in connection with the two
important and quite distinct groups of endemic Carabidae, the Anchomenini and
Pterostichini. The 17 genera of the former group have been divided by Dr Sharp
into two divisions, one with ten, the other containing seven genera. The character
separating these divisions is derived from the structure of the tarsi, which in the one
case have a peculiar grooved structure, while in the other they are simple. Amongst
the genera with grooved tarsi, however, there exist species in which the sculpture is
very much reduced or indistinct, and in the genus Colpocaccus, some of the species
have the grooves much more developed than others. In Metromenus, one of the species
{M. politus) not only has the grooving of the tarsi very obscure, although it belongs
to a genus in which this sculpture is comparatively strongly developed generally, but
in other respects it bears considerable resemblance to members of the division with
unsculptured tarsi. The characters on which the individual genera are separated in
these two divisions of Hawaiian Anchomenini are chiefly (i) the condition of the wings,
whether rudimentary or well-developed, (2) the absence or presence of sensory setae on

INTRODUCTION Jv

the pronotum. In wing-development and in the setae the Hawaiian series are, as a
whole, remarkably deficient as compared with foreign forms. Three of the lo genera
in the division characterized by simple tarsi are fully winged and can fly, six have the
wings quite rudimentary, but in one of these, Barypristus, the one species {incendiarius)
has wings about twice the size of the other [j'ltpico/a), while one genus, Chalcomenus,
has large wings, only the apical portion being somewhat reduced. It is, however,
flightless, and no doubt represents an early stage in wing-degeneration. In the other
division one only (Colpocaccus) of the seven genera possesses functional wings, the
others having these organs quite rudimentary. The prothoracic chaetotaxy appears to
be in a more unstable condition than was supposed to be the case at the time this
character was utilized for generic distinction. Thus Barypristus incendiarius is now
known quite commonly to be devoid of any pronotal setae, or to have a seta developed
on one side only. Apteromesus macnlatus has sometimes a seta near the hind angles
of the pronotum. Mesothrisais vagans rarely develops a weak seta at the posterior
angles, so that certain examples might on this character be placed with the Hawaiian
Platynus. One example of a small batch of the very distinct Meiromenus fossipennis
was found to bear a well-developed seta on each side-margin of the pronotum near the
middle, so as to become a Mesothriscus. It is now known from the examination of
individuals taken in company, that some of the Pterostichine species also vary in the
setae, so that individuals of one would on this character be placed in two genera.
Apart from the variability in the chaetotaxy, it certainly appears to me that the use
of this character for generic separation tends to place in different genera species' that
are really closely allied. Excepting the Barypristus mentioned above and a few of the
Pterostichine Carabidae, it is proper to state that variation from the normal number of
setae is rare and exceptional.

The occurrence of endemic Hawaiian species referred to a foreign genus, Platynus,
needs special notice. The two known species of this genus (apart from chaetotaxy)
are not closely allied to one another, but each much more closely resembles species
placed in other Hawaiian genera. If they truly belong to Platynus, then it would be
necessary, if we maintain the view that the Hawaiian Anchomenini have been derived
from a single immigrant form, either to consider this genus (since it is the only one
known outside the islands) as having given rise to the other endemic forms, or to
suppose that Platynus has arisen independently in the Hawaiian group. The Hawaiian
Platynus is not central in the series of Hawaiian genera, this position being held by
such forms as Colpocaccus and Mysticomenus, both of which it may be noted are fully-
winged forms. It should have been noted above that these fully- winged forms are
very poor performers on the wing. I think it probable that the Hawaiian Platyni will
ultimately be found to be more closely allied to other of the endemic Anchomenini,
than to foreign Platynus, and will be separated from the latter.

' Some of these species are not only extremely similar in structure apart from the chaetotaxy, but
have peculiar and identical habits.

Ivi FAUNA HAWAIIENSIS

It must be confessed that the extreme forms of Hawaiian Anchomenini are very
unlilce one another, yet no single genus (as in the case of the birds of the family
Drepanididae) appears to be very isolated from its nearest ally. Probably each is more
nearly related to its neighbour than to any outside form, and this seems to me in favour
of the whole series having been evolved from a single form, anciently immigrant.
In any case the possibility of the series having originated from numerous Anchomenine
immigrants at various periods of time, each of these immigrants having been such as
to fit naturally into the existing series, or at least having given origin to forms that do
so fit in, seems very improbable. Should one even propose two ancestral immigrant
forms, one most like Colpocacctis or Mysticomenus (central in the existing series), a
fully-winged insect giving rise to the series of genera with simple tarsi, and now mostly
flightless, the other perhaps flightless and akin to Platynus, giving origin to the series
with grooved tarsi and at the same time all flightless, the great resemblance between
Colpocaccns and Mysticomenus, the one with grooved, the other with simple tarsi, and
the specific differences in the development of the grooves of the former, may cause him
to hesitate to admit even a dual origin for the whole series.

The case of the Hawaiian Pterostichini is much simpler than that of the Ancho-
menini. There are only four genera, intimately allied, and separated solely by the
characters of the pronotal setae. Several of the species are now known to be almost
certainly inconstant in these characters, since individuals, not otherwise different, have
been found in company (in a ' batch ') both with and without certain of these setae.
Consequently individuals of one species fall into two genera on the pronotal chaetotaxy.
As in the Anchomenini, there is a great diversity of appearance in the members of this
group, and here again the setal characters appear to sunder species that are really
allied. The large series of existing species do not seem to have required more than
a single immigrant species for their evolution. The less diversity of structure as
compared with the Anchomenini, I judge to be due merely to the fact that sufficient
time has not elapsed for its production. Whereas the Anchomenine Carabidae are now
spread over all the islands, the Pterostichines, whose head-quarters are clearly on the
central islands (Maui and Molokai) where probably they first became established, are
at present not known at all on Kauai (admirably adapted as is that island for their
occupation), and even on Oahu are sparsely represented by a few more or less common-
place forms. Looking at the most remarkable of the existing Pterostichines in the
islands, it does not require a great stretch of the imagination to see in these the
progenitors of future genera as distinct from the more commonplace forms, as are the
more remarkable Anchomenini, the genus Blackbui-nia, for example, from the more
commonplace Anchomenines. The Hawaiian Pterostichines, speaking generally, are in
a wide sense hardly more than flightless forms of Cyclotliorax, a genus of a few species
in the Australian region, a fact in itself opposed to the probability of their having arisen
from various immigrant species.

A comparative study of many groups of animals represented in the islands, and of the

INTRODUCTION Ivii

affinities of species to species, and genus to genus, in the groups of allied forms, has led
me to believe in the extreme rarity of a successful immigration from outside. The
extraordinary gaps in the fauna of whole families of wide distribution and containing
countless species, many of which no doubt would, and some of which, after introduction
by man, are known to thrive in the islands, show clearly how hardly and rarely have
immigrants reached them from without. A limited number of birds and insects, species
of well-known migratory habits, for which no seas are impassable, doubtless, arrive
continually, but these, only in the event of such migration ceasing, are likely to produce
new and endemic forms.

The phenomena exhibited by the Flora, appear to me to be extremely similar to
those of the Fauna. There may be seen the same notable absences of forms widely
distributed elsewhere, the same multiplication of allied species of many of the genera
that are present, the same groups of allied genera embracing many species. I believe
that the explanation of these facts is quite in accordance with that which I think to be
true of the Fauna, as above stated. Dr H. B. Guppy, who has paid much attention to
the flora of the Pacific islands and the dispersal of plants, as I understand his book,
takes a different view of these allied genera and species, and would consider them the
result of numerous immigrants.

He considers that there existed an ancient age of Conifers in the Pacific, thereby
accounting for the three genera Dammara, Dacrydiuvi and Podocarpus in the Western
islands. These three genera are entirely absent from Tahiti and the neighbouring
islands, and from the Hawaiian group, the explanation being that at the time these
conifers reached the islands of the Western Pacific, the Hawaiian and Society groups
did not exist. Later, he tells us, there was an age of Compositae and arborescent
Lobeliaceae, during which nine endemic genera of the former reached the Hawaiian
group, and one other (Fitchia) became established in Tahiti. There is no trace of this
era of Compositae in the Western groups (Fiji, Samoa) owing to the submergence of
the Western islands during Tertiary times, the supposition being that during the time,
when Hawaii and Tahiti were receiving their Compositae from America, the Western
islands existed above water at most as small islets formed by their highest mountain
peaks.

Two of the coniferous plants are said to possess seeds that could be carried across
wide oceans by the aid of birds, even to the Hawaiian group, and yet during the whole
period between the time when the Hawaiian group and Tahiti came into existence, and
the present, it does not appear that these have even reached the Samoan group, so
comparatively near to Fiji. One would rather suppose that the presence of the conifers
in Fiji, like its Cicindelid beetles and some other animals, is due to the continental
character of the group.

As to the era of Compositae in the Pacific, the presence of these in the Hawaiian
islands and their absence from the western groups does not seem to require the geological
F. H. I. h

Iviii FAUNA HAWAIIENSIS

explanation above mentioned. The fact of a few species of Compositae having reached
Hawaii in early times would account for what we now see. The Hawaiian Com-
positae are admittedly of American origin and it is natural that the Hawaiian group
and Tahiti, being nearest to the American continent, should have received thence
immigrants which much more distant groups of islands have not received. Nor need
we suppose that there has been any ' suspension ' of the means of dispersal of Com-
positae to Hawaii since, subsequent to the first few earliest immigrants, it must have
received the progenitors of Tetramalopiuni, Lipochaeta and Carnpylotheca, and probably
much later still, Artemisia.

Of the age of arborescent Lobelias and their absence from the western groups,
the explanation is similar to that given to account for the Compositae. They also
are said to be of American origin, and the island groups in which they occur are just
those which are nearest to the American continent. We may note that the Galapagos
Islands, less distant from the South American coast, also have their own endemic Com-
positae. Birds which are supposed to have been efficient in stocking the islands with
plants, still annually migrate in numbers (of many species) from the American coast.

It may be advisable to consider further and in some detail the endemic Ha.waiian
Compositae and Lobeliaceae, it being interesting to compare the facts in connection
with them with those that concern various elements of the fauna. It should be under-
stood that the Hawaiian Compositae as a whole (endemic and foreign) are to be
compared, not with a compact tribe such as the Anchomenine Carabidae, above
mentioned, but rather with the Hawaiian Carabidae as a whole.

The four genera Reniya, Wilkesia, Argyroxipliiimt and Hesperomannia are supposed
by botanists to be extremely ancient forms in the flora, and, on account of their having
only two^ species each, to be in a decadent stage and becoming extinct. Their antiquity
as elements of the Hawaiian flora is, I suppose, mainly based on their structural isola-
tion, as compared with foreign forms, but it is said to be also shown by the paucity
of the existing species and their restricted range in the islands. Although a limited
number of species in an endemic genus is sometimes found, where we suspect that
genus to be an ancient component of the flora or fauna, yet more often the oldest
elements of the flora are certainly those genera (or groups of allied genera) with the
most numerous species and the widest distribution, as is also the case in the fauna.
Therefore the primary consideration must be the structural peculiarity of the plants
themselves. But we must not altogether overlook the possibility of the discovery of
forms in America, more closely allied to these isolated Hawaiian species than those
yet known. Besides these supposedly ancient genera, we have Raillardia and Dubantia,
together comprising about a score of species, the genera being related to one another
and also allied to the genus Raillardella of the Sierra Nevada. Consequently these
genera and their species may well be supposed to have originated from an anciently
' According to Hillebrand's Flora of the Hawaiian Islands.

INTRODUCTION lix

introduced form, allied to Raillardella, if not actually of that genus. These Composites
are common and generally distributed, though Dubantia apparently is not known on
Hawaii, except from the most ancient part of that island, that part in fact which
originally formed the whole island

Next come the three genera Tetramalopiuni, Lipochaeta and Canipylotlieca only
"on the borderland of generic distinctness," the two former reputed to have species
existing in California and Mexico, and the latter practically equivalent to Coreopsis.
Finally we have Artemisia with two endemic species, each occupying a very different
station.

The era of arborescent Lobelias is supposed to exhibit much the same phenomena
as the Compositae. Dr Guppy says that some are in their prime, others on the point
of extinction, and that the distribution of genera and species within the islands shows
that the original immigrants were not contemporaneous. They are only found in the
Eastern Pacific Islands, chiefly in Hawaii, with a few species in Eastern Polynesia.
They are absent from the Western Pacific Islands for the same reasons, it is said, as
are the Compositae.

However, on an examination of the Hawaiian endemic Lobelias, we find that
there are five genera, all well represented with from half-a-dozen to about thirty
described species, excepting the monotypic Brighamia, of peculiar habits and occupying
stations impossible for most of the others to thrive or even exist in. But there is this
great difference between the endemic Hawaiian Composites and the tree-lobelias; of
the latter the genera are not only all endemic, but they are remarkably peculiar, so
much so that Hillebrand did not even hint at their affinities. The seven endemic
genera of Hawaii and Tahiti are placed by Engler "in a group by themselves"...
" and he does not approve of the endeavours of some botanists to isolate one of them
from the rest and to connect it {Brighamia) with the Australian Isotoma " (Guppy).

Now it seems much more natural to suppose that these allied genera of Hawaiian
Lobelias have been developed in the islands from some very anciently immigrant
species, than that all the genera (or their ancestors) were originally produced elsewhere
and have all become extinct in their original homes. Or if they have become in the
islands so greatly modified that their American ancestors can no longer be recognized,
the time sufficient to produce such modification would have been also ample to have
allowed the development of the large number of species (many being still undescribed)
and of most of the genera, even from a single anciently introduced form. One may
judge of the near relationship of these Hawaiian genera, when one studies the synonymy
of the species and notes how competent systematic botanists have constantly referred
identical species to different genera !

While the endemic Compositae may aptly be compared with the endemic Carabidae
in the beetles, the Lobeliaceae are comparable rather with the Prognathogrylline crickets,
though the evolution of species in the latter has been much less profuse.

h2

Ix FAUNA HAWAIIENSIS

Although endemicity of plant or insect, as represented by great peculiarity of
structure and usually by the occurrence of numbers of allied species, naturally indicates
a very ancient occupation of the islands by their immigrant ancestors, yet it does not
necessarily follow that paucity of species or the apodemicity of a genus denotes a com-
paratively recent immigration. A classification of the Flora, as belonging to a definite
age or era, based on such a supposition will certainly prove erroneous. It is not
probable that all immigrants, that arrive and become established, are able, even after
vast time, to become adapted to such diverse conditions as others, and some, doubtless,
are much more slow to do so than others. The evolution of new genera or species
would proceed in a very different manner in different cases. In judging the length of
time that any particular plant or group of allied plants has existed in the islands, the
botanist would be well advised to consider the fauna that is specially attached to these.
When one considers that trees little modified from foreign species, e.g. Acacia koa or
Sopkora cJirysophylla, possess a great endemic fauna, not only species, but even genera
of birds and insects, quite restricted to or dependent on them, and that some of these
creatures are certainly themselves not less remarkable in their peculiarities than the
most peculiar of the Composites or Lobelias, we may hesitate to attribute such plants
to a later era than many other elements of the flora, which at first sight appear far
more ancient. Again, while in the islands an abundant endemic fauna restricted to
a plant indicates an ancient occupation by the latter, the absence of such a fauna
does not necessarily imply the reverse. In a fauna of comparatively few types it may
happen that few or no species have reached the islands that could become adapted to
certain elements of the flora even after great length of time. I think that those who
are in favour of the comparatively frequent accession of immigrants to account for the
great series of allied species, or groups of allied genera, hardly make full allowance for
the great age of the islands. Hitchcock remarks in writing of the most recent portion
of the group, the still active Mauna Loa on Hawaii, "when one considers how little
the bulk of the mountain is made up of the few flows delineated on the map, and how
small a portion of the whole mass these can be, he is overwhelmed by the certainty
that there were millions of streams and that millions of years must be assumed in
order to say how old the mountain is. It must have commenced to build up long-
before the tertiary period." And here he is considering the most recent portion of the
group and not the vastly more ancient parts.

For my part, as I understand it, the present Hawaiian fauna is derived from
waifs and strays from all directions. At rare intervals from the Eocene till now
chance immigrants have arrived. Some have been able to establish themselves, many
more probably, even after a landing has been effected, have failed. Those that have
been successful and have found congenial conditions have often thriven amazingly,
giving rise to hosts of descendant species, as they have become adapted to, or become
modified by, diverse conditions. There has been no 'age of Conifers' any more than

INTRODUCTION Ixi

an age of Cicindelidae (of which also a few are found in Fiji), no age of Composites
or tree-lobeh'as any more than an age of Drepanididae (birds) or Plagithmysides
(beetles). Where conditions have proved favourable and remained so, and plant or
animal has become adapted to special conditions, an exuberance of distinct forms
has sprung from the ancient immigrant. Such cases are manifest in the Lobeliaceae
amongst plants, and in many groups of animals, the Drepanididae (birds), Plagithmysidae
(insects), Achatinellidae (moUusca) and many others. Such form the chief and most
interesting part of the native fauna and flora of the present day.

Species-formation in the Hawaiian animals.

As evidenced by the long series of closely allied endemic species of many kinds
of animals, it is clear that species-formation has been very active within the limited
area of the islands and there is no reason to doubt that this activity still continues.
Some insight into the possible modes by which this multiplication of species has
taken place may be gained by a consideration of the existing fauna. But what is
now needed is not so much general, or even special collecting of existing forms, as
years of e.xperimental work in breeding a well-selected series of animals in the field.
Unfortunately this cannot be done by residents in the settlements on the coast, but
needs a prolonged and continuous residence in the mountain forests. In few cases
can the mountain creatures be acclimatized to breed successfully in the lowlands,
and it would be folly to embark on a laborious series of experiments, destined to fail,
as soon as results were becoming interesting, if not sooner.

Geographical segregation we may judge to have been a most important factor
in the evolution of species within the islands. It is obvious that the magnitude of
the total number of species of animals is to a large extent due to the fact that,
instead of one continuous land area, there are six forest-clad islands, and that in
many very large genera very few identical species are found on more than one, and
many others in only two or three of these islands. Thus the bird genus Oreomyza
(Pis. XIII and XIV) has a distinct species on each island. These birds have mostly
very similar habits and feed on similar food, in fact it is known that on some of the
different islands a good deal of this food consists actually of the very same species
of insects. Having a very varied dietary on each island, we may consider that the
food of each species is practically the same. Moreover, as some of the species thrive
in different areas, each on its own particular island, these areas having quite different
climates, vegetation, rainfall etc., it is clear that it is not these conditions that
necessarily affect the species. This is a very important point to remember in con-
sidering the effects of isolation.

Again and again in insects we find a species inhabiting one island replaced on
several of the others by closely allied forms, so that we can feel sure these have been

Ixii FAUNA HAWAIIENSIS

derived one from another or at least from forms hardly different from either (PI. XVI,
figs. 8, 9 and lo). It might be supposed that the small distance between the islands
would not be sufficient for isolation, especially when we consider that the animals,
from which all the fauna is derived, must necessarily have traversed the vast distances
between the islands and other lands. This, however, is clearly not the case. Certain
species, of migratory instinct, amongst the birds visit the islands regularly, but do not
settle down and give rise to endemic forms, and the insects of known migratory habits,
like the butterflies Pyratneis cardtii and Anosia eripptcs, the foreign species of Plusia,
Sphinx convolvuli, Nomophila noctuclla, the large American dragonflies etc. we may
well suppose receive recruits sufficiently frequently from other lands to prevent any
true isolation. It is what we may fairly call the 'chance' immigrant that is the
potential producer of new species. It seems incredible that so strong-winged a
butterfly as Pyranieis atalanta, which has been established on the island of Hawaii
for over twenty years^ was, at least until a few years ago, certainly restricted to that
island, and has not even yet been recorded from any other. As is well known, this
same butterfly is supposed to be a constant migrant from the European continent
to England across a channel comparable with that between Hawaii and its next
neiofhbourinof island.

If we consider the endemic species, and examine the ' Cyclothorax ' group of
Carabid beetles (presumably derived from the Australian region) we find they are
very richly represented on the neighbouring islands of Maui and Molokai, central in
the group, relatively poorly on Hawaii, with its comparatively great area and varied
conditions, much more poorly still on Oahu, and, so far as is known, totally absent
from Kauai, the extreme island to the north-west. Though the ' Cyclothorax '
beetles have existed a sufficient time in the islands to become so enormously rich
in species and to occupy the most diverse situations, where they occur, yet they have
clearly been very slow to spread from island to island. The fan-tailed flycatchers
[Chasiempis) derived also from the Australian region, are totally absent from the
three intermediate islands, showing well the chance character of the interisland
immigration, in the case of birds, whose ancestors also must have traversed thousands
of miles of sea to reach the Hawaiian group. In the Drepanididae, Heterorliynchus
is unrepresented on Molokai and Lanai, Heniignathus on Maui and Molokai, and
Drepanis (incl. Drepanorhamphus) on Oahu and Kauai. Yet such forms must have
required enormous time for their evolution. In none of these cases can the nature
of the islands, from which the various animals above mentioned are absent, be for
a minute considered as the cause of their absence. In the endemic birds I have
elsewhere noticed that there are two elements, one consisting of a few wide-ranging
species, widely spread throughout the group (e.g. Hiniatione vestiaria and Psittacirostra

' Though abundant on Hawaii, in districts visited by him, this butterfly was not found by Mr Blackburn
some 30 years ago, so I suppose it reached the island subsequent to his visit there.

INTRODUCTION Ixiii

psittaced) and a second containing forms restricted to one, or very rarely found on
two adjoining islands. This latter group comprises most of the endemic Passerine
birds. Even the native crow and buzzard, birds of very great powers of flight, do
not occur except on the island of Hawaii.

In insects one notices the same phenomena. In this group, speaking generally,
the more widespread forms are usually endowed with powers of flight. Even in
the Carabidae, where the vast majority of the species are known only from one island,
it is mostly the winged forms that one finds on more than one island, either unmodified,
or with species hardly different from one another (cf. Bembidium teres, pacifiaun and
molokaiense, the species of Co/pocaccits, Colpodiscus hicipetens). The winged species
of minute beetles of the genus Cis are many of them of very wide distribution, so
are many of the Lepidoptera. Flightless species are rarely widely distributed. Those
species of the Cossonid genus of beetles, Dj-yophthorus, that live in logs, and are
extremely tenacious of life, however, are often of wide range. But, as in the birds,
hosts of insects with admirable powers of flight are quite confined to one island.
The Achatinelline shells, so richly represented on Oahu, Maui, Molokai and Lanai
are very poorly represented on Hawaii, and are nearly unrepresented on Kauai, where
the great genus Achatinclla is altogether wantiny.

These facts seem to me to show clearly that, with certain exceptions, it must be
very rarely that a species passes from island to island so as to become established, and
that when this does happen, the immigrant is likely to be isolated for a very long time.

Since in many insects amply endowed with powers of flight, and in the majority
of flightless species, there are closely allied but distinct forms in different islands, one
may consider that stray examples of a species have only to become separated from
the mass of individuals of that species and kept isolated, in order to become in time
so modified as to form new species. Where we find an endemic species spread over
each or several of the islands, we may suppose either that in such cases the species
in question, owing to powers and range of flight, or to other special facilities for
distribution, is carried from island to island sufficiently often to prevent isolation, or
that, if isolated, sufficient time for change has not yet elapsed. I have elsewhere
referred to the fact that there is good evidence to believe that owing to the stability
of species, even a great change of environment and isolation cannot be supposed as
a rule to affect a species after a few or even a considerable number of generations.
That isolation is a most important fact is evident from comparison of the fauna of
the several islands. In the Hawaiian group it may be roughly said that isolation
is directly proportional to the distance between these islands. If we consider a
large, well-collected and much studied genus, such as that of the wasps {Odynems)
we find that the comparatively approximated islands of Lanai, Maui and Molokai
have many species in common, while Hawaii has few such species, Oahu still fewer,
and Kauai, the most remote island, none at all.

Ixiv FAUNA HAWAIIENSIS

We may see forms on the different islands in various stages of becoming distinct
species, from the earliest stage, where merely the range of variation of a species is
different on two islands, to that where every individual is different, but the differences
are so slight as to be hardly specific, and finally to that where the separating characters
are too important to be considered racial or varietal, when we may feel fairly confident,
that even should a fresh immigration of the original species take place from the one
island to the other, interbreedino- would not follow.

Modifications following change of environment or isolation are of course subject
to the action of natural selection, which may expedite the formation or mould the
character of specific distinctions, but even without any selection the original species
will be changed if isolated and isolated long enough. It is not improbable that the
plastic condition of the species in so many genera, and the extreme difficulty that
exists in limiting the species, is really due to the slackness or absence of the agencies,
by which natural selection works, the struggle for existence in the case of many of
the island creatures having been much less severe than in a more populous and varied
fauna.

One might cite any number of cases to show the effects of geographical isolation
on specific characters in insects, but one or two simple ones are sufficient. The little
bee Nesoprosopis anthracina occurs on all the islands from Oahu to Hawaii. It is
a xerophilous species, frequenting the flowers of Sida, Vitex, Waltheria, Tribuliis etc.
as well as plants introduced by man. On Kauai only it does not occur, but is there
replaced by N. fiavifrons, very closely allied to it, but quite distinct, with the same
xerophilous habits, and frequenting the same food-plants. Another species, N. facilis,
also found on all the islands but Kauai, is there replaced by an extremely closely
allied form A', chlorostida with similar habits. This case differs from the preceding
in that both these bees on their respective islands are wide-ranging, and able to
thrive in localities very diverse in climate and conditions. They range from the
coast to a height of fully 4000 ft. in mountain forests, and yet do not exhibit notable
variation under these diverse conditions.

In cases where flightless and sluggish insects are found widely spread throughout
the islands, when one would naturally expect modification of specific characters to have
taken place on different islands, a careful study of life and habits will probably generally
show reasons for the suspicion that isolation is not complete. For instance we are
surprised to find a small, flightless and sluggish beetle like Proterhinus deceptor on
all the islands, little or not at all changed, but we search in vain for distinctions
between individuals taken on the various islands. Some variation there may be, but
this is no greater between examples from different islands than between others taken
on one island. In 1900, and subsequently, I paid some special attention to this case.
It was found that this small beetle breeds in profusion in dry regions below any
existing forest, in scattered trees, though it also occurs at high elevations in the

IN TROD UC riON Ix v

mountains and under very diverse conditions. It is clearly only restricted from
reaching the coast by the presence of introduced predaceous insects, which quickly
exterminate it, and doubtless it did once frequent the coastal region. It is one of
the few beetles found in the dry branches or stems of those trees, which form a
large part of the island driftwood, and being able to adapt itself to very varied
conditions of climate etc. and also breeding freely in those trees, which extend right
down to the coast, it must have had unusual opportunities for being carried across
the interisland channels and also for becoming established when so transported.
It even breeds abundantly in the dry, woody capsules of some xerophilous trees.
I should consider in this case that the interisland channels have not been sufficient
to isolate examples, that may have reached the different islands. Though flightless,
we may class such a species with the vagrant birds, Hmmtione, Psittacirostra etc.
elsewhere alluded to.

It is interesting to observe in animals in which secondary sexual characters of
the male are conspicuous, that when geographical isolation has taken place, these
are generally modified, in fact herein may apparently be the only modification, as
if these sexual characters were often the first to become changed.

It should be noted that specific change may be concurrent with isolation alone,
without any change of food or habits, so far as can be observed, though, of course,
whether there is really a change of habits is uncertain.

Quite apart from these cases, where isolation on separate islands has induced
specific change, we must consider the cases where extremely closely allied species
derivatives one from the other, or both from a form hardly different from either,
exist on the same island. Of these there are two classes, one in which the closely
allied species inhabit only different areas, and the other in which they occupy the
same area. In the first case the species are on the same footing as if they inhabited
different islands. The best illustration of these is shown by the land Mollusca, of
which it is often said that each valley on Oahu has its own peculiar species. It is
true that many of the valleys do apparently have their own species, or at least local
races, which do not pass beyond, but there are numerous species that have a much
more extensive range, either occupying several valleys or ridges, or even having
a still wider distribution. It is not accurately known how the Achatinella are
distributed, but it is quite clear that they can only pass from island to island by
a most rare and exceptional chance. This is shown by their poor representation
on Hawaii and Kauai, and the fact that of the arboreal species on such islands as
Oahu, Molokai and Maui (where they are well represented) there is on each island
a specific multiplication of only a few type forms, showing that the present numerous
species on a particular island are the produce of only a few earlier established forms.
The ' Apex ' group of Achatinella is peculiar to Oahu, and so with other groups.
The sluggishness of the animals would probably make any wide distribution of the
F. H. I. i

Ixvi FAUNA HAWAIIENSIS

Achatinella on any one island a matter of a very prolonged period were this dependent
on their own movements. We once found at the foot of the Waianae slopes a number
of one of the terrestrial species of Amastra, quite outside the forest, hiding in the
hollows of a large log on the bank of a stream. This log had clearly been carried
down in a flood, and probably for many miles before stranding, the stream arising
in the Koolau range of mountains, the forest of which was miles distant. Once, on
Molokai, a young living Achatinella was found attached to the feathers of the Drepanid
bird Chlorodrepanis. Frequently they become adherent to one's clothes in passing-
through the brush. Doubtless in high winds very young shells are sometimes carried
to a distance in curled up leaves, in which they often hide. Once or twice in an open
treeless space on Molokai I found shells which must have been carried this way or
with small branches of trees during a severe gale. We have known sluggish beetles
of the genus Proterhiiius to be so carried far from their food-plant, doubtless only to
perish of starvation.

In 1893 I took the opportunity of paying a good deal of attention to the habits
and distribution of some of the arboreal Achatinella on Molokai, the shells of that
island at the time having been less collected than those on Oahu. It was quite
impossible not to be struck with the effect of isolation on individuals of some of
these species. Achatinella macrodon (Vol. 11, PL XI, fig. 16) was very common on
a ridge close to my camp, but very local, for the next ridge to the west had none
of it, nor did I see it on any ridge in that direction. After one had crossed one or
two deep gulches eastward, an allied form appeared on the ridges, but with remarkable
variations, tending to albinism. On the first-mentioned ridge it was comparatively
constant, singularly so for an Achatinella. Whether it had once occupied the area
between these localities and subsequently died out, or whether by some such means
as I have indicated above, it had passed over this area, cannot be known.

Another instance of discontinuity of distribution was examined into, over a large
area, in the case of the common and widely-spread Achatinella tesselata. This species
I found abundant over an extensive irregular plateau, where I had occasion to collect
often, at some distance N.W. of my camp. Here the shell was somewhat variable,
of good size, and a striking albinoic form occurred. On this same area nine years
later I found the shell much scarcer, but again the albino shells occurred. Away
from this area and close to my camp on one ridge only, and only on part of this
ridge, A. tesselata was found in large numbers, but of smaller size than the others,
and very uniform both in size and colour, excepting that here it was strictly dimorphic,
with two closely similar but easily distinguished and constant varieties. I was not
able to find any continuity of distribution between the two areas mentioned, in fact
I am sure that such did not exist.

When we consider the sluggishness of these molluscs, it is certain that the
individuals of a species on two such areas, though the distance between them in

INTRODUCTION Ixvii

mileage is small, would, but for some chance, remain isolated for ages, if not for
ever. How stationary some of these land-shells are, I had many chances of observing,
for in some cases I had the same individual under observation for weeks together.
A white variety of Achatinella redfieldi, which I had occasion to pass by almost daily
for many weeks, was always seen at rest just below the fork of a large branch of a
lichen-covered Ohia tree. Though there were many showery or wet days, it was
never absent from this spot by day, though it may, of course, have moved at night
and returned. This was a healthy animal, the shell not at all worn by age. A small
dead lichen-covered tree, supporting individuals of A. theodorei in 1893, ^'^-S still
occupied by these or their descendants three years later, the adjoining bushes being
unoccupied. These shells had the appearance of being a stunted, depauperated form
of A. proxvna, produced by isolation on a wind-swept ridge with its stunted vegetation.
In 1902 I looked in vain for this particular colony. To causes, as here given, is due
the multiplicity of species or local forms of the Achatinellidae.

Probably few insects are so restricted in range, or so easily kept isolated, as are
many of the Achatinellidae, for many of the most sluggish insects are, I think, likely
to be more frequently distributed by accidental means than the Mollusca. Still in
the insects there are cases known both of distinct species of similar habits and having
the same food, which merely occupy a different area of the same island, and of a single
species, which, occupying different areas, exhibits different variation in these two areas
— or in fact is on the way to form two.

Very often, however, we find species, extremely closely allied, occurring habitually
in the same locality and not geographically isolated. Thus, even within a few
square yards, the three species of Longicorn beetles, Plagithinysus darivinianus,
P. lamarckianus and P. varians occur. It is hardly conceivable that species can
be more closely allied than these and remain distinct. Though so similar, the
species keep quite apart. Each keeps to its own food-plant, and though occurring
on adjoining trees the species do not mix nor interbreed. P. darwinianus has been
found chiefly on Sophora, lamarckianus on Pipturus, varians on Acacia. We have
observed great numbers of all these species in the field, but have never found even
a stray specimen of one frequenting the tree affected by another or in company with
it, even though these trees grew side by side. Thus these three species, though
not geographically isolated, are isolated by their habits. I know no insects that
could be more profitably experimented with by breeding in the field than these and
other species of Plagithmysus.

It is certainly quite e.xceptional for a species of these beetles to forsake its
proper food-plant and attach itself to quite a different tree, as is evident from the
fact that a species in most cases has been found on one kind of tree and only one.
It would be of great interest to know whether individuals, bred for the first time
on a tree other than the normal food-plant, remain attached to that tree, or wander

12

Ixviii FAUNA HAWAIIENSIS

partly or wholly back to their original food. If we look at the case of P. vitticollis
and its van longulus, we find a great change of habits concomitant with so little change
of the insect that the two are considered to be varieties of one species. The var.
longulus is the common form, and is attached to a forest tree [Bodea), and, as usual,
the larva burrows beneath the bark, but vitticollis bores out the stems of a species
of Riibus. Most of the individuals of the latter, so far as the evidence goes, are easily
distinguished from the var. longulus, so that the two may be considered on the verge
of becoming distinct species. It is quite possible that when a Plagithmysus first takes
to feeding on a new kind of tree, the females, though they may remain attached to
the new food-plant, would attract males that have bred on the original one, but when
one considers the entirely different nature of the food-plants of such varietal forms
as P. vitticollis and var. longulus, or again of such closely allied species as P. lamarcki-
anus and darwinianus, the foods of which are trees of quite different orders, with
different odour and taste, the one an acacia and the other Urticaceous, one cannot
overlook the possibility that this may aid in the isolation of the individuals on different
trees. It is a familiar fact how quickly these beetles scent out and arrive at a tree
that is their special food-plant, if it be by injury placed in a condition suitable for their
oviposition.

In the case of Plagithmysus bishopi, of which quite identical examples have
been obtained and bred from Pelca the normal food, and Zanthoxylum as an excep-
tional occurrence, where these trees grow side by side, the food-plants are much more
nearly related and isolation might be less easily attained. Where isolation is complete,
in another district of Hawaii, P. bishopi becomes P. vicinus, though still feeding on
Pelea, the normal food-plant, but these two species have never been found in one
locality. Why certain individuals of a Plagithmystis occasionally, but apparently very
rarely, leave their proper food-plant to attack some quite different tree, is quite obscure.
But on all such matters much further observation in the field is needed.

Sometimes we may find species as closely allied to one another as those above
referred to, living actually in company and apparently having similar habits, but it
is quite possible that special investigation will show important differences in habits.
In the case of the flightless species of Reduviolus in the Hemiptera, for example, of
which two slightly different forms, probably really distinct specifically, were found in
the same habitat, a decided difference in the habits of these forms was observed.
The case of the small crickets of the genus Paratrigonidium is more similar to that
of the beetles of the genus Plagithmyszis, referred to above, the distinction of habits
in these being, as one might say, far more striking than the specific differences.
I place the greatest importance on these changes of habits, leading to isolation, in
the production of new specific forms.

The extreme variability of many of the insects and mollusca, whether in structure
or colour, the indefinite character of the species in many of the genera, e.g. in the

INTRODUCTION Ixix

Achatinellidae (Mollusca), the Proterhinidae (Coleoptera) and many other insects, might
be considered due to the absence or slackness of those agencies, which elsewhere cause
individuals less fitted to the environment to become eliminated. But it is obvious
that the lack of definiteness of specific characters may be due to lack of time. When
we consider that some of the creatures, which show the greatest individual variation,
form a large part of the food-supply of the once extremely numerous insectivorous
birds, and therefore might be supposed to have undergone a very rigorous selection,
it would appear either that this selection has been singularly ineffective in producing
uniformity of appearance in a species, or that the very great variability must be itself
advantageous. It is interesting in this connection to compare the great variability of
the underside (i.e. the parts exposed when at rest) of the native Pyram&is with the
usual great constancy of those parts in the immigrant and allied P. cardiii and
P. atalanta, in explanation of which it may be urged that these, in their usual
localities, undergo a hibernation for many months of the year and requiring therefore
a more complete protection, when resting, have arrived at a constancy of markings
that suit their resting places. P. tammeamea, on the other hand, is active all the
year, and brood follows brood without any dormant period of the adult. Spiders of
species most liable to be found by birds are often beautifully protected by their
resemblance to their environment.

Species which exhibit an extraordinarily wide range of variability, form an
interesting study in the islands, for we often find one or more distinct species so
closely allied to these as to lead to the suspicion that they actually have been derived
from the others. These probable offshoots from variable species are generally much
rarer and less widespread than the latter, and probably generally, if not always, differ
in their habits. In this case the causes, which have produced them, are similar to
those mentioned above of other insects. They have the appearance of being extreme
forms of the variable species, as though they had overpassed the limits of variability
and become distinct. Their constancy is probably correlated with uniformity of
habits.

There are some striking examples of discontinuous variation amongst the island
insects, and the same have been noticed in the case of the Achatinellid Mollusca.
The di- and tri-morphism in the colour of the legs of certain species of Plagithniysus
is of a very conspicuous nature, owing to the large development of the femora in
proportion to the body, these beetles in a slight degree having a cricket-like ap-
pearance. Even more striking are some of the dimorphic forms of the endemic
Locustidae {Ba7iza — Brachyniietopa). There is no evidence to suggest from a
comparison with allied species that these variations are likely to lead to distinct
species, the different forms pairing indiscriminately and not differing in habits. In
the case of one species of Banza (blackbiirni) a very remarkable form of sexual
dimorphism is seen to be resulting from the two forms, but not a differentiation of

Ixx FAUNA HAWAIIENSIS

species. The pairing of the AchatinelHdae seems to have been very little observed,,
and I myself have only three times seen these animals in copula. Two of these
cases were pairings between extreme varieties of Achatinella redfieldi, and in each
case the individuals in copula were of exactly the same colour-form, one pair being
the albino variety. The other case was that of another Molokai species, A. macrodon,
the individuals being identical in colour. No importance can be attached to these
few instances.

Reviewing the whole fauna, the widespread effect of segregation in species-
formation becomes evident, whether the segregation is brought about by geographical
isolation, or by change of food or habits. In the case of very sluggish animals, like
the Mollusca, a mountain valley or ridge may prove an . effectual isolating barrier,
or in fully-winged insects a narrow interisland channel. Exactly how far modification
is due to the direct effect of food or difference of habits and how far to the mere fact
of segregation is not known, but it appears to me that segregation is the most
important. The extraordinary series of well-defined but closely allied species of
Homopterous insects, each attached to its own special food-plant, are very interesting
in this connection. Considering the fact that individuals frequenting the same food-
plant, but geographically isolated, are so often modified as to form distinct species
or races, isolation appears the most important factor. The little Drepanid bird,
Himatione sanguinca, of vagrant habits and inhabiting all kinds of stations throughout
the main group of islands, on remote Laysan is replaced by the allied H. freethi.
A few individuals of the former, chancing to reach that remote island, would probably
remain isolated for ages, and this is probably what has happened in the past, the
modified H. freethi being the result.

Summary of general part of the Introduction.

The Hawaiian fauna cannot be said to belong to any of the great faunistic regions
of the globe, it contains most important elements derived from the Oriental region,
from the Australian and from the Neotropical or at least from the warmer parts of
America, and it cannot be considered as even belonging chiefly to any one of these
regions. On present information it is decidedly not Polynesian, but a proper study
of the Samoan and other groups may show greater affinities with these than is apparent
to-day. The Fijian fauna is extremely unlike the Hawaiian in nearly every respect.
The small islands (Christmas, Fanning, etc.) that lie nearly midway between Hawaii
and the Samoan group are in sad need of exploration, as also is the latter. Many
of the most important components of the fauna are so remarkably isolated (e.g. the
Achatinellid Mollusca and many groups of insects richly represented in species) that we
cannot even conjecture whence they have been derived. Even the family Drepanididae
in the birds has somewhat doubtful affinities, as also has the genus of thrushes Phaeornis.

IN TROD UC TION Ixxi

The antiquity of the group must be extremely great. The possibiHty of an ancient
continent, even were it probable geologically, cannot for a moment be entertained by
the student of the whole fauna. We should require connection with or approximation
to the Oriental region, just as much as to the American continent and Australia.
There is no possibility of an ancient land connection having existed even between the
islands of the group themselves during the period in which they became colonized by
the progenitors of the present fauna. Some groups of insects, considered by themselves,
may show nothing actually opposed to this supposition, but others prove it to be
quite untenable. Of those who have worked on the material collected by me, I think
Lord Walsingham alone has favoured the idea of an ancient continuous land area. But
the study of these winged insects is not favourable for forming a conclusion on this
point. If we consider other of those that are evidently amongst the most ancient
inhabitants of the islands, we see the impossibility of such a theory. The absence of
Achatinella, s.L, from Kauai at one end of the group, and its almost total absence from
the great forests of Hawaii at the other (where only a single type represented by two
or three species is known), the presence of Carelia on Niihau (until recently) and
Kauai, but absent from all the other islands, may be noticed in the Mollusca. The
development of highly specialized endemic genera of Finch-like Drepanididae on Hawaii
and their entire absence from the other islands, except for a vagrant, ubiquitous form
{Psittacirostra) and one other {Pseudouestor) peculiar to Maui, the island nearest to
Hawaii, are noteworthy in the birds. The vast development of species of the endemic
flightless genera of Carabidae, allied to Cyclothorax, on Maui and its neighbouring
islands, their poverty in Oahu, and total absence from Kauai, may be cited in insects.
The lack of a single individual of great groups of animals containing countless species,
ubiquitous in every land, except very remote Oceanic islands, not only forbids the idea
of any continental area, but leads us to conclude that the islands have never been even
in past ages much less isolated from other lands than they now are. We have elsewhere
shown the difficulty that creatures, whose ancestors must have traversed thousands ol
miles to reach the islands, have had in spreading throughout the group, and even after
ages many have not achieved this. This is certainly more or less attributable to that
sluggishness which appears so generally to overtake the descendants of animals that
reach the sparsely inhabited forests of these remote islands. On Hawaii we observe
even in birds so powerful as the native buzzard and the crow, an unreasonable restriction
to that one island, and even to parts of that island. In the Hawaiian islands and else-
where, the loss of flight of so many insects and less frequently of birds follows disuse.
Given sufficient time (and the extraordinary antiquity of the archipelago is manifest) aU the
phenomena of the fauna are readily explicable on the supposition that a comparatively
small number of immigrant species have at various periods been able to reach and
establish themselves in the islands. With a disinclination to wander, as seen in the
case of the crow and buzzard, above mentioned, it has often taken the descendants of

Ixxii FAUNA HAWAIIENSIS

these immigrants ages to spread over the whole group. Some like the Pterostichine
beetles have apparently not yet fully done so. Peculiarity seems often in proportion to
the isolation, this roughly depending, in the case of the different islands, on the width
of the channels between them. Where we study allied species, Kauai has these as
a rule most highly modified. Its ' Oo,' Acrulocercus, is almost generically distinct
from the others, its Loxops is the most aberrant, it alone has two species of Phaeornis,
one being by far the most aberrant, its ' Elepaio ' {Chasievipis) is the most different,
it alone has two distinct species of Chlorodrepanis, the one structurally at one end
the other at the other extreme of the series, these birds hardly differing on the other
islands. Its Amastrae in the land-shells have produced the most remarkable of all
forms in the subgenus Kauaia, and probably from a still earlier immigrant Amastra
(or antecedent of Avmslra) has developed the remarkable series of Carelia, the young
of which are in many ways so like Amastra itself. I have reason to believe that in
many cases, where we now find the greatest variety of allied species of any group of
animals, that island is the place whence all the species originated, or in other words the
place where the original immigrants became established. It is difficult to compare one
group of animals with another, as regards the importance of the modification that exists,
but I cannot see in the existing Achatinellidae any greater modification to have taken
place than is observable in the present components of the Hawaiian Nitidulidae, or
Anchomenine Carabid beetles, or in the Drepanid birds. It is interestmg to note that
the island of Hawaii, which is sometimes loosely stated to be the ' youngest ' island, is
in my opinion the one on which the last-named birds were first established. But it
must be remembered that Hawaii is a composite island, and its northern part is of very
great age and existed long prior to the bulk of the island, and coincidently with the
oldest of the other islands of the group, so that the Drepanid birds may have reached
the northern portion, before the rest rose above the sea. The more recent parts have
themselves existed for ages and, when their forests became continuous with those
of the original island, it would take a comparatively short time for the whole to
be occupied by birds. There is no existing genus of Drepanididae which does
not occur on Hawaii (unless the Molokai 'mamo' be considered generically distinct
from Drcpanis), excepting the parrot-billed Psendoneslor on the next island, Maui, and
the crested Palvieria of that island and Molokai, a form allied to the vagrant Hiniatione.
But Hawaii itself, in addition to all the other Drepanid genera, alone has the specialized
Ciridops and Viridonia, as well as the three more allied genera, Loxioides, Rhodacanthis
and Ckloridops, indicating excessive antiquity of its avifauna.

INTRODUCTION Ixxiii

Review of the Hymenoptera.

The Hawaiian Hymenoptera are remarkable for the extreme paucity of the number
of families of this vast Order, that are represented by endemic species. The saw flies
or Phytophaga, considered by some as a sub-order, are totally unrepresented. Ashmead
in 1900 recognized 94 families in the Hymenoptera, and this number may be taken as
approximately correct, for while some of these groups are in our opinion unworthy to
rank as families, yet others are formed of discordant combinations of genera, which he
freely admits are of quite different ancestral origin, and a proper classification of these
will make good any loss in number caused by the sinking of groups, that he considered
as distinct families.

Excluding forms that are known to be introduced, or from various kinds of
evidence are almost certain to prove so, the endemic Hymenoptera represent only the
following families : (i) Prosopidae, (2) Crabronidae, (3) Pemphredonidae, (4) Eumenidae,
(5) Bethylidae, (6) Poneridae, {7) Proctotrypidae, (8) Diapriidae, (9) Scelionidae,
(10) INIymaridae, (11) Figitidae, (12) Miscogasteridae, (13) Encyrtidae, (14) Pteromalidae,
(15) Eulophidae, (16) Ichneumonidae. (17) Braconidae. Moreover of these 17 families
four are only represented by a single species that can really claim endemicity (Poneridae,
Proctotrypidae, Pteromalidae, Braconidae), so that these can be looked upon as com-
paratively recent additions to the endemic fauna. It will be seen that I have excluded
a number of families, which contain species not at present known outside the islands,
and it is possible that a few of these species are really endemic, though I think this
is unlikely.

I will now refer to those more or less doubtful species which cannot positively be
considered as foreign importations, as well as to some of those that are without doubt
of human introduction. In the latter class are Xylocopa brasilianornvi (aeneipennis),
RIegachile palmarttm^ and M. scJiaiiinslandi^, and Apis mellifica amongst the bees.
Only two of these insects, the Xylocopa and Apis, occurred to Blackburn, when collecting,
and as the two Megachilc are very common Honolulu insects and, further, have spread
widely thence in the last 1 7 years, we can be sure they have been imported and were
not present in the islands even 30 years ago. Apis and Xylocopa are of earlier intro-
duction, the latter being well known to have been non-existent here till long after the
settlement by foreigners. It was no doubt brought from the warm parts of America,
when formerly ships visited the islands frequently from that region. In the Fossorial
group an American Stigmus was once taken in the middle of the town of Honolulu and
appears to have not established itself while a Sceliphron of early introduction from
America (known, however, not to have been present before the foreign settlement) and
a Trypoxylon of recent importation from China, are now both widely spread and
thoroughly naturalized. Both these insects are semidomestic in habits.

' The former of these is now known to me from California, the latter from China.
F. H. I. k

Ixxiv

FAUNA HAWAIIENSIS

The two species of Pison, mentioned in my account of the Hymenoptera, published
in 1899, have now a third congener of quite recent introduction, it having first appeared
in 1903. All these frequently breed in or on the woodwork of houses, in cavities in
chairs or furniture, etc.

The two Asiatic wasps, Polistes macaeiisis and liebraeus, of wide distribution, and
the American P. aurifer are also certainly importations by man, being quite unknown
in the earliest days of foreign settlement ; in fact of the two former species P. hebraetis
was of late introduction, not having occurred to Mr Blackburn, nor was it generally
spread over the islands 20 years ago.

Several Bethylidae are more or less frequent household insects, being doubdess
parasitic on others, which attack grain and other produce, or burrow in woodwork.
Such are the species of Epyris and others undetermined.

Of the ants, 1 think all those now existing may be considered as importations,
excepting a variable Ponera, chiefly found in the forests, and clearly intolerant of the
presence of most of the foreign forms. It is, however, quite probable that other endemic
ants have previously existed and become totally exterminated before collections of
insects were made.

It is not necessary here to detail the minute species of the Chalcidoid and
Proctotrypoid series that are clearly introduced, but I will now turn to several
Hymenoptera that are not so clearly introductions by man.

Of the bees we have Megachile diligens, a species found by Blackburn in Honolulu
more than thirty years ago and still occurring in gardens in the town. Now, however,
it is widely distributed over all the islands, but shows no noticeable variability, and, so
far as I have observed, forms its tubular leaf-cells always from plants of foreign origin.
It will almost certainly be found elsewhere. Clearly the Megachilidae are easily
imported in lumber or furniture, as since Blackburn's time M. palmariun and
M. schauinslandi (both of which commonly nest in houses or furniture, the latter not
using leaves, but filling the key-holes of the doors with resinous wax) have appeared,
and later still (in 1900) the black Lithurgiis albofiiiibriahts was established.

In the Chalcididae, C. polynesialis is a doubtfully imported species, which still occurs
in gardens in Honolulu, but its presence is now masked by the swarms of C. obsairata,
introduced for economic purposes. It appears to show considerable variability.
Epitramis lacteipennis still occurs rarely in Honolulu, where its habits are not known.
Another Chalcidid is of late introduction, having appeared about 1900.

The Evaniid, E. sericea, will almost certainly prove to be foreign ; it is bred from
the ootheca of foreign cockroaches.

The Braconidae, excepting the Spathiine, Ecphylopsis nigra, are almost certainly
all foreign, though some were taken by Blackburn more than 30 years ago. The two
of these that seemed most likely to prove endemic were Ischiogomis palliaiits, which
so often attacks the endemic longicorns, and Microdus hawaiicola, but the former,

INTRODUCTION Ixxv

which also destroys larvae of Imported longicorn beetles and apparently those of other
families, is now known elsewhere, and the latter is a parasite of introduced Tineid
moths and known also from Fiji.

To return now to the families that are represented by positively or probably
endemic species, we shall see that though the number of species is frequently large in
these, proportionately to the size of the islands, the number of genera represented is
very small.

The Prosopidae are represented by 53 described species oi on&'gtmi's, Nesoprosopis.
which is not endemic, since an European' species agrees with the Hawaiian series in its
essential characters.

The Crabronidae contain five genera closely related, as it appears to me, to one
another, but sufficiently distinct from foreign forms to be separated generically. The
European Crabro vagus is related to the least remarkable of the Hawaiian species.
None of the other diverse groups of Crabronidae have any representatives in our fauna.
There are 18 Hawaiian species.

The Pemphredonidae have two well-marked genera in the sub-family Pseninae.
They are intimately related to one another and no doubt of common origin and are
allies of the widely spread genus Miiiicsa. There are 10 species, equally divided
between the two genera.

The Eumenidae are represented by 104 species, included in the almost ubiquitous
genus Odyncrus together with three other genera that are endemic. These three
genera, however, are intimately related to some of the island species assigned to
Odynerus itself and are evidently local derivatives from the same stock, produced
within the islands. Those assigned to Odynerus, on the other hand, are, I now think,
clearly descendants of two quite distinct forms of original immigrants, one of which
gave rise to the bulk of the species, as well as to the endemic genera that I have
separated from these, while the other has produced but four distinct species, as at
present discovered, and its origin was Asiatic.

The Bethylidae (incl. Dryinidae) have four genera represented, none of these being-
endemic. Scleroderma has 10, Sierola nine, Pseudogonatopus two, and Echthrodelphax
a single species. The latter may not impossibly prove to be specifically apodemic, as
well as generically. It is of Australian origin, as also is Sierola.

The Poneridae are represented by one endemic species of Ponera, which exhibits
much variability, the variation being apparently due to local influences to some extent.

The Proctotrypidae have but a single species of Proctotrypes, parasitic on endemic
Diptera in the forests. It is said to be allied to a North American species.

The Diapriidae are represented by three described genera, one of which is not
endemic and the other two appear to me to be derivatives of the latter. One in tact

^ A species, N. chiiiemis, is now known from China.

k2

IXXVl

FAUNA HAWAIIENSIS

seems hardly more than a flightless form of the apodemic genus Phaenopria, under
which I have described species. Probably, however, Hawaiian Phaenopria will prove
orenerically distinct from species in other countries. There are nine described species,
and doubtless a good many more remain to be discovered.

The Scelionidae are represented by six species of Anteris, and a single one of
Baeus, which belongs to a different sub-family. All are truly endemic, as also may be
one at least of the genus Telenoiims, representing yet another sub-family.

The endemic Cynipoids belong all to the family Figitidae, and to one sub-family
of this. Though placed in a number of genera, one of which was described as new, by
Ashmead, the rather numerous species that are known appear to me to be all related
to one or two types, and probably should be assigned to not more than two or three
genera, a view taken by Kieffer without examination of specimens. They present
great difficulties in determination, but 23 species have been described without dealing
with male examples, which cannot certainly be referred to species of the other sex.
I here treat the Hawaiian forms as belonging to only two genera.

The Mymaridae are represented by 15 species of the genus Polynema, other groups
(sub-family and tribes) being unrepresented.

In the Chalcidoid series the Miscogasteridae have 10 species, placed in four genera
and two sub-families, but the characters distinguishing these sub-families are very slight,
and I have even had some doubt whether there is any real generic difference between
some of the Hawaiian species referred to, the chief genera representing the two
sub-families. Some undescribed species are known to me, and doubtless a good many
more remain to be discovered. Two of the genera representing the sub-family Lelapinae
are endemic. The Encyrtidae is perhaps the most important family of the Chalcid
super-family, the sub-family Eupelminae being represented in all by four genera, one
of which is supposed to be peculiar {Solindenia). The single Anastattis is clearly
imported, being parasitic on eggs of a Locustid, known to have been introduced, nor is
it very certain that E2ipelminus, represented also by one species, is really native.
Solindenia, the endemic genus (also with only one species), is less liable to suspicion,
but not altogether free therefrom, for it certainly occurs, where no endemic host is found
for it to parasitize.

Ejipehnns, on the other hand, contains a large number of endemic species, 54
having been described. They are of very varied habits, and as Ashmead recognized
but few in the large number of e.xamples that he handled, I fancy he must have
lumped together a number of distinct forms. Perhaps I have myself separated them
too minutely.

The Encyrtinae are represented by six species of the genus Anagyrns, which
appear to be endemic. This however is uncertain until their habits have been studied,
since in other countries the genus attacks Coccidae, and therefore numerous species
might easily have been imported with scale insects, accidentally, or perhaps in some

INTRODUCTION Ixxvii

cases intentionally by Koebele. The members of the tribe Mirini I look upon as
foreign, with perhaps one or two exceptions.

The vast complex of forms included in the Pteromalidae can only be said to
be represented endemically by a minute Spalangia, a true forest insect, allies of which
may be expected to be found.

The Eulophidae have a greater number of genera containing endemic species than
the Encyrtidae, but in most of these only one or two species have been described.
The Aphelininae and Tetrastichinae are foreign and need not be considered. The
Entedoninae, Elachistinae and Eulophinae must be considered as having endemic
species. These include seven genera and only eight species, as described. This,
however, gives an erroneous impression of the group, for a good many more species
have been collected (in several of these genera). After death most of them rapidly
dry, and distort to such an extent as to utterly unfit them for description.

The vast group of Ichneumons are represented only by a single endemic species
of Echthromorpha and two of Glyptogastra (an endemic genus) in the Pimplinae ;
in the Ophioninae by three endemic genera Banchogastra, Pycnophion, and Pleiwo-
nciirophion (six species in all), as well as a large number of endemic species in
apodemic genera. Ophion has one species, Enicospilus 13, Eremotylus i, Atliyreodon 2,
Atrometus 11, Livineriwn (i), Lathrostizus^ -{■ Idecthis^ 2, Pristoniertis^ i. The claims
of the species in the four latter genera to be endemic are, however, more or less
doubtful, and one other species of Limnerium is certainly introduced.

The Alysiidae and Braconidae are, doubtless, all foreign, excepting only the
minute Ecphylopsis nigra (the genus being endemic) of the sub-family Spathiinae.

There are therefore 52 genera in the Hymenoptera represented by endemic
species (though in a few cases the endemicity of these is questionable) and these
species number 372, or seven species to a genus on the average. If we exclude those
questionable species, the average would be rather higher still.

Comparing the Aculeate Hymenoptera, i.e. ants, bees and fossorial wasps, with
the remaining families or 'Parasitica,' we find in the former only 13 genera with
1 86 species, an average of about 14 species to the genus; in the latter 39 genera
also with 186 species, an average of 47 to the genus.

This very great difference in the average of species in the two groups will no
doubt be subject to considerable alteration and will not prove so vast, as now appears,
though I believe it will remain considerable. In many cases, owing to their specialized
habits, the parasitic forms have less scope for a great increase of species owing to
their dependence on a limited number of hosts. Thus the Eulophidae, several of
which are parasitic on leaf-mining caterpillars, are limited in species by the comparative
scarcity of species of Lepidoptera having these habits.

' Further observations render it certain that these have been introduced.

Ixxviii FAUNA HAWAIIENSIS

On the other hand we find that the genus Eupebmis, which can adapt itself to
very varied hosts, attacking eggs, larvae, and pupae of other insects, and various
orders, e.g. Coleoptera, Hymenoptera, Diptera, Orthoptera and Neuroptera, in the
small limits of the islands, has produced an exuberance of species.

But we must also make allowance for the minute size and hidden life of most
of the Parasitica, as compared with the comparatively obtrusive presence of the
Aculeata, rendering the latter so easy to collect. And still further, while the bees
and wasps are comparatively of large size, presenting obvious characters for specific
separation in sculpture and general appearance, as well as others afforded by the
genitalia, mouth parts etc., which are easily examined in larger insects, the minute
forms, included in the Parasitica, are much more difficult to discriminate. The closely
related species of Odynerns, inhabiting different islands, if reduced to the size of
Mymarids, and subject to post-mortem distortion, like these and the smaller Chalcidoids,
might in many cases prove impossible to separate.

Of the 52 genera, that contain presumably endemic species, 17 are, so far as our
present knowledge goes, themselves endemic. While 10 of the 13 aculeate genera
are considered endemic, only seven of the 39 parasitic genera are so. This, however,
is not of any great significance, but merely indicates that in the larger Aculeata it
is possible and convenient to distinguish groups of Hawaiian species from one another
or from allied genera in other countries.

Prosopidae. — All the Hawaiian species belong to a single genus NesopTOSopis,
which I made for these island forms, not knowing at the time that similar characters
existed in foreign Prosopis. Subsequently by a curious coincidence, when collectino-
in England, I discovered a bee, new to the English fauna, having the essential
characters of Nesoprosopis. This species is the Prosopis kricchbaiimeri of the
European lists. Although 1 have examined the structures in numerous European,
Australian and American' Prosopis, I have not yet found any other species allied
to this European form, nor, consequently, to the Hawaiian ones. It is greatly to
be regretted that the terminal segments, which exhibit such fine characters for specific
and generic separation, are generally entirely neglected by describers of Prosopidae,
so that for American and Australian species I have had to rely entirely on my own
observations. Possibly it will be found that the European P. kriechbauiueri, or others
allied to it, extend their range, like other insects, across Asia, and this would point to
an Asiatic' origin for the Hawaiian A^esoprosopis. There is no doubt that had
P. kriechbauiueri been handed to me amongst a collection of Hawaiian species, as
coming from the islands, I should not have hesitated to consider it as an endemic

^ An excellent paper on these has been published by Mr C. W. Metz (Tr. Am. Ent. Soc. x.xxvii, p. 85)
since this paragraph was written.

^ A species has now been discovered in China by Mr J. C. Kershaw.

INTRODUCTION Ixxix

form.^ It is most nearly allied to the Hawaiian species of the N. longiceps group.
The Hawaiian N'esoprosopis form a very varied assemblage, tending to split up into
a number of genera or sub-genera. The superficial differences between such extremes
as N. crabronoides and N. paradoxica are extraordinary, but throughout the whole
series of forms the essential characters of the genital armature and seventh and eighth
ventral segments remain the same, and bear strong evidence to the taxonomic value
of these characters.

The Nesoprosopis are almost the most ubiquitous of any Hawaiian insects.
They are found in the hottest and driest coastal regions, when vegetation springs
up after the rains, and in the mountains extend their range far above the forest line
to the limits of vegetation. Some of the species frequent the most different stations,
e.g. N. volatilis, which has been found on the hottest coasts and at all elevations
in the mountains to a height of 9000 ft. in the region of snow in winter time. Many
range from the coast to about 4000 or 5000 ft. above the sea, especially N. facilis
and allied species. Others are purely littoral or range but a short distance inland,
e.g. N. longiceps, blackbtn-ni, hilaris etc. The members of some of the groups,
however, confine themselves to similar stations. Thus the small or moderate-sized
short-faced species of the N. laticeps group are only found in more or less dense
forests, where there is much shade and constant dampness. The large forms with
punctate abdomen are also true forest insects. Some species exist in, and in fact
favour, the wettest and densest forests in the islands, where the ground is always
saturated with rains or in the condition of a bog. N. laticeps and N. satelles seem
to thrive in such situations.

In their nesting habits there is considerable variety. On the coast or lowlands,
or where the soil is sufficiently dry or sandy in the mountains, many form their burrows
in the ground, often, however, availing themselves of the pith cavities of dry branches
or twigs. Those frequenting denser and wetter woods in the mountains, of necessity,
burrow in dead tree stems or in hollow branches. Some affect the hardest tree-trunks,
e.g. of Ohia {Metrosidenis), sandal-wood, Mamani {Sophora) and utilize, when they can,
the borings of xylophagous beetles. Trees like the Lobeliaceous Clernwntia, the
dead branches of which are hollow, and afford a fine protection against the damp,
are frequently colonized by the larger species, such as N. Juscipennis. Some ot the
species seem to be of solitary habits and are rarer, while others sometimes form
great colonies, whether in the ground (e.g. N. difficilis, facilis, and many others)
or in dead tree-trunks, hard or rotten (e.g. N. paradoxica, melanothrix, etc.).

Being so widely distributed, naturally a very great variety of plants are visited
by the different species in search of honey and pollen. On the coast and lowlands,
foreign, immigrant plants are mostly visited. The chief of these are Sida, Waltheria,
Vitcx, Capparis, Scaevola and Tribulus. In the same situations, where the forest
trees do not extend to the lowlands, a few endemic plants are also visited such as

Ixxx FAUNA HAWAIIENSIS

Hibiscus brackenridgei, composites such as Lipochaeta and depauperated forms of
Santahwi. These lowland bees have taken freely to many introduced plants, such
as Pj'osopis and other acacias amongst trees, as well as garden flowers of various
kinds. In the mountains the Ohia tree in general is visited by all species of the
genus, as it affords abundance of nectar easily reached by these short-tongued bees.
Many other flowers are attractive in their season, Acacia koa, Stranssia, the mountain
species of Scaevola, Rubus viacraei, etc. In the regions of frost and snow, A'', nivalis
and others are partial to the flowers of Cyathodes. In some forests, where a foreign
Rubus has become a pest, they visit these flowers in great abundance. The different
species of these bees by no means restrict their attention to one kind of plant, but
collect from the most diverse kinds.

The most interesting fact in connection with the Hawaiian Prosopidae is that
a small group of five species of Nesoprosopis has become inquilinous or parasitic
on their industrial congeners. As is well known, amongst bees in general, parasitism
of this kind has arisen independently in various groups. Thus the Megachilidae
(sens, lat.) have given rise independently to the Coelioxys group of parasites
(Coelioxinae Ashm.) through forms allied to Megachile itself, and to the Stelis group
of parasites through forms allied to Anthidiiini (Anthidiinae Ashm.). The Antho-
phoridae have given rise to the parasitic Melecta group (Nomadidae partini Ashm.)
while the origin of some other parasitic forms is still involved in doubt. The case,
hitherto known, in which the least modification has taken place between host and
parasite in bees is that of Bonibus and Psithyrus, where the males differ very slightly
in structure, although Ashmead has gone so far as to make these genera represent
distinct families. In all these cases the main difference between the parasite and
the industrial form, from which it has sprung, lies in the disappearance of such
structures as are concerned in the gathering of food for the nurture of its young,
and therefore the female parasite is chiefly affected in most cases. This is likewise
the case in the parasitic Nesoprosopis, the distinctive curved hairs of the front tarsi,
whereby the pollen is swept towards the mouth, having undergone obvious modification.
I cannot, however, see the slightest character, whereby the males could be separated
generically from the industrial forms ; some of them indeed are not too easily separated
from the latter specifically. It may be supposed that these Hawaiian species show
the earliest stage in modification of industrial bees into parasitic, as at present known.
Their parasitic habits are complete, that is, the parasitic forms never store their own cells.

The cells of N'esoprosopis are translucent and of dry gelatinous appearance, being
impervious to the fluid honey stored therein. Such pollen as is mixed in this honey,
is regurgitated with it, since the Prosopidae possess no external arrangement for
carrying a load, as do most industrial bees. Rapid inward strokes of the front feet,
which, as has been said, are provided with special hairs, sweep the pollen grains from
the anthers of the flower towards the mouth.

INTRODUCTION Ixxxi

A good many of the species of Nesoprosopis exhibit considerable variability and
this not merely affects superficial characters, such as the facial or other markings, but
important structures are involved. Thus in Nesoprosopis flavifrons I have noticed
variation in the amount of dilatation of the scape of the antennae, so that, in this
respect, some examples more nearly resembled the allied A'', anthracina than did
others. -^ Similar variation has been noticed in other species having a strongly dilated
scape. The small median facial plate above the clypeus sometimes varies in its relative
length and breadth. In the case of N. difficilis and N. volcanica, two very similar
species, often occurring together, I found that the majority of many specimens that
I examined could be distinguished by the shorter supraclypeal plate of the former,
but that examples occurred in which this distinction was not maintained. These two
species, I should add, are perfectly distinct by other constant characters.

Some of the parasitic species are especially variable in size, and this variation
is often striking, when examples from different localities are compared in series.
It is due entirely to the amount of food supply consumed, and this amount depends
on the species of the host, in the nest of which the parasite is nurtured. On one
occasion I obtained specimens of N. volatilis of gigantic size for this species, these
having been bred in a colony of N. assiinit/ans var. oa/mensis. The same species
when obtained from colonies of N. /acta or N. difficilis is much smaller. In some
localities one may find very large and very small examples of N. hilaris in the same
station, the former being bred on the store of N. assimulans and longiceps, the latter
on that of N. blackbtirni. As will be seen from these remarks, the parasitic Nesoprosopis
are not at all confined to one species of host. However, they only infest the nests
of such species as burrow in the ground. Those that burrow in the trees have never
been found to be affected.

These latter, however, have their true parasites (i.e. not inquilines, as the others
would be more correctly called) in the shape of the Encyrtid Chalcidoids of the genus
Etipclmus, which are bred from the cocoons of some of the larger species, and very
probably affect the smaller also. On one occasion I saw an extraordinary congregation
of males of one of these Etipclnms, forming a complete circle around the entrance of
the burrow of Nesoprosopis setosifrons, the heads of all the parasites resting on the
edge of the mouth of this burrow. Their antennae were kept in constant vibration
and those of each individual were continually crossed with its neighbour's, evidencing
great excitement. No doubt the burrow, which was one of several in a very hard
dead tree, would, if opened, have revealed one or more females of the Eupelinus ready
to emerge. A^. fuscipennis, a species common in the mountains near Honolulu, is
attacked by the same or an allied parasite, as also is its var. obsctiripes on Maui.

Many of the species of Nesoprosopis are extraordinarily abundant and I doubt
whether any species is really rare. Some of them appear at irregular intervals and
so in any locality are easily missed. My experience with the remarkable litde

F. H. I. !■

Ixxxii FAUNA HAWAIIENSIS

N. crabronoides well illustrates this point. Originally, with difficulty, I obtained a
few females, and on various other occasions at the same place and time of year
failed to find even one. Yet on another occasion, also at the same season, I observed
many scores in a few hours in this same spot. Similar instances have frequently been
noticed, and a species which is abundant one year in the summer months may on
another occasion appear at quite a different season in the same locality. It is in
some respects rather interesting to note that the Hawaiian Nesoprosopis most nearly
allied to the one apodemic species are the littoral species of the N. blackbzirni group,
while the forest-frequenting forms include those most extremely divergent from these.

Comparatively few of the species are distributed over many of the islands of the
group, but N. facilis and difficilis are found on all the islands excepting Kauai, where
the former is represented by an extremely closely allied form, and N. laeta occurs on
all. Several species are common to the three neighbouring islands Lanai, Maui and
Molokai. Many are peculiar to a single island and further investigation is not likely
to prove this incorrect in the case of a good many species. Thus N. setosifrons is
represented on Oahu by N. anomala and on Kauai by N. perspiaia, while at present
no corresponding form has occurred on the other islands. N. insignis of Hawaii is
represented on the three intermediate islands by N. satelles, and probably on Kauai
by AT. andrenoides, while no corresponding form has so far been found on Oahu. The
N. dunietorum group has an allied species peculiar to each island, excepting Oahu and
Molokai.

As far as our present knowledge goes, the endemicity of the species as regards
islands is as follows: Hawaii has iS species endemic, Maui 6, Molokai i, Lanai i,
Oahu 3, Kauai 8. It is clear that the interchange of species between the three
neighbouring intermediate islands is much easier than between others of the group,
although Maui, a large island, with great variety of natural conditions, contains six
endemic species. If we treat these three islands as one we find that together they
have 13 that are not found on other islands, each in fact being well endowed with
species of the genus. Thus the small island of Lanai has no less than 14 species,
while but one is endemic, and even that one is likely to be found on Molokai.
Oahu seems to be poor in its Prosopid fauna, only 1 1 species being at present
known (or three less than on little Lanai), but of these three are endemic. Kauai
is poorest of all in number of species, only nine being known, but eight of these
are endemic. Hawaii stands alone in the richness of its species, which number 24,
and no less than 18 are endemic. These figures no doubt are subject to slight
alteration, for in one or two cases species described as distinct in Vol. I, pt. i of
this work are likely to be sunk, as being merely varieties. I should add that since
this part was published several species have been found to have a wider distribution
than is indicated therein, and in the figures given above these new localities have
been taken into consideration.

INTRODUCTION IxxxHi

XvLOCOPiDAE. — Xylocopa brasi/ianoruni (or aeneipeimis) is an abundant and even
injurious species, since it does considerable damage by riddling fence-posts, telephone
poles and other wood with its borings. It also burrows in living trees, but I think only
in the dead parts or such as are nearly dead, choosing generally the softest kinds of
wood. I think there is no doubt that it was imported by man in lumber. It was
unknown until after the islands were settled by foreigners. It is interesting to note that
its habits are such, as might have enabled it to reach the islands by natural immigration,
for it is particularly fond of breeding in dead logs on the sea-beaches, especially in the
very light, dry logs of the ' wiliwili ' [Eryihrina). It is also very partial to the dead
branches of this tree, when still growing. This Xylocopa chiefly inhabits the littoral or
low mountain regions. It visits many kinds of flowers, especially papilionaceous ones.
The larvae and pupae are often destroyed wholesale by the foreign ant Plieidolc mega-
cephala, which enters the burrows in swarms, and we have seen a whole colony of the
bee eliminated by this minute enemy.

Megachilidae. — ^The three Megachile are probably all introduced, two indeed
are of recent importation and have increased their range and numbers enormously in
the last 1 6 years. M. diligens is widely distributed over the islands, but shows no
local variation. It was found by Mr Blackburn in Honolulu more than 30 years
ago, but we have no record of its distribution at that time. It still is found in the
gardens in Honolulu. In the country it is generally found along the coasts or lowlands.
Its nests are formed of leaves of various imported Acacias. On sandy coasts we have
observed the bees very plentifully in the flowers of Iponioea pes-caprae, but it visits
those of other naturally immigrant or native plants, and in gardens in Honolulu has
been taken on Cosuios, Plumbago and various introduced flowering shrubs.

M. schauinslandi is, I have little doubt, an Asiatic importation. It is not a leaf-
cutter like its two congeners, but seals up keyholes and cavities, in which it breeds, with
masses of resinous matter. It is extremely abundant in gardens in Honolulu, visiting
many kinds of flowers of cultivated plants as well as weeds.

M. palmai'iini was probably introduced about the same time as the preceding and
is also very common and now widely distributed. Its nests of the usual leaf-formation
are often found in houses in holes or crevices, e.g. between the slats of window blinds.
They have been found in large numbers concealed in leaves of various palm trees,
which had been rolled and spun together by the caterpillars of Omiodes blackburni, an
injurious Pyralid moth. It visits many kinds of flowers, cultivated and other.

A still more recent importation, at present found only on Oahu, is a species of

Lithurgus'^, which was first noticed in some numbers in 1900. It is locally abundant

and widely distributed over this island. In some remarks that I published elsewhere

on this species I stated that the labial palpi were four-jointed, in error, for there are but

' Determined for nie by Prof. Cockerell as Z. albofimbriaius^ found in Tahiti. Probably an introduction
into both countries from the Oriental region, whence I have seen forms hardly different.

/2

Ixxxiv FAUNA HAWAIIENSIS

three joints, the terminal one having in some aspects an appearance of forming two. The
mouthparts of Lit/iiirqus are, as I have pointed out, extremely unlike those of ordinary
Megachilidae, the tongue being extended far backwards along the breast. This species
nests in wooden posts, sometimes forming extensive colonies. We have seen such a
colony in the upright posts supporting a house in the Nuuanu valley, and others else-
where. The bees are very partial to the flowers of Iponwea pes-caprae and other
Ipomoeas. Sometimes many examples may be found asleep in these flowers, after they
have closed up for the day. This species is I believe of Asiatic origin.

Pemphredonidae. — The Mimesidae, which in the systematic account I considered
a family, are perhaps better treated as only a sub-family of the Pemphredonidae.

The two genera represented have I think certainly originated from one ancestral
immigrant form, the home of which is quite uncertain, as the genus Mimesa, to which
they are allied, is of wide distribution, inhabiting both the new and old worlds.

The Hawaiian forms are easily distinguished by the great length and slenderness
of the basal joints of the antennal funicle, the long petiole, and the remarkable head
structures of the females. In the one genus these consist of a remarkable genal spine,
in the other of a peculiar modification of the clypeus.

In most of the species of Ncsoniimesa the genal spines vary much in development,
but the form in examples, in which they are fully developed, is more or less character-
istic of the species. This great variability renders their specific separation difficult and
the males are extremely similar in all the species. In Deinoniimesa on the other hand
the clypeal structure does not appear to vary to any noteworthy extent, though some of
the species vary a good deal in other structures.

It seems quite certain that both these peculiar structures are in some way connected
with the capture of their prey ; in the one case [Deino»ii)uesa) the effect is to produce a
kind of large spurious mouth opening, in the other [Nesomimesa) the long fringed
mandibles, when agape, and the pendent spines also form a sort of trap for the seizure
of the prey. The variation in individuals in the development of these spines is very
remarkable, for they are frequently extremely reduced in size. One would suppose that
a structure of this nature and importance would be quickly brought to a state of great
constancy by the operation of natural selection. On the supposition that I am correct
as to the use of the.se spines, and it is difficult to doubt this, the variation exhibited by
most of the species is very surprising. I believe the Kauai species, which is more
distinct from the others, than they are from one another, is nearly constant in the form
and development of its genal spines.

As in the other endemic species of Aculeate Hymenoptera, occasionally one meets
with specimens of these insects in which the abdomen is of a reddish colour instead of
black, a familiar variation in many kinds of Aculeates in other countries, and apparently
due to the adults having preserved the coloration of immaturity.

INTRODUCTION Ixxxv

All the Hawaiian species of both genera are true forest insects and most of them
may be seen in large numbers, where they occur, flying round ferns and bushes in
sunny places. The males are often much more numerous apparently than the females,
but this is due to the more retiringr habits of the latter, which, when thev have begun to
provision their nests, frequent dark, shady and damp places in search of their prey.
This consists of the endemic Limnobiidae or daddy longlegs, which live in such places.
On one occasion I saw a number of N^esoniimesa hawaiiensis endeavouring to catch
Fulgoroid leaf-hoppers, that were running on a small tree-trunk, but they were quite
unsuccessful in their attempts, the hoppers when pounced upon always hopping off in
safety. Although I have often watched females of these wasps returning with prey to
their burrows, it was always Tipulidae that they carried to the nest. Their burrows
are usually made in the ground and are often drilled down from beneath a stone, this no
doubt serving to keep the burrow sufficiently dry. Sometimes numbers form their
burrows close together and I have found such colonies of N^esoiniviesa and Deinomimesa
mixed, a favourable slope and soil attracting both alike. On a few occasions Nesomi-
viesa has been observed to form its nest in tree trunks, probably utilizing the boring of
coleopterous insects.

The parasitic Chrysididae, which so often attack Pemphredonids in other countries,
are wanting in our fauna and, so far as is known, the Hawaiian Mimesae have no parasitic
enemies. On one occasion I took the male of Nesomimesa nitida from the stomach of
a thrush {^Phaeornis) on Lanai. The comparative scarcity of prey appears quite suffi-
cient to prevent their becoming more numerous than we find them, in fact one is rather
astonished that they can procure sufficient to become so common as they are.

Excepting Nesomimesa nitida, which is found on each of the three adjoining islands
Maui, Molokai and Lanai, all the species of the genus and Deinot)iii)iesa are confined
each to a single island. The latter genus is at present unknown on Oahu, Molokai,
Lanai, but has two species on both Kauai and Hawaii. N^esomi?nesa has two species
on Kauai, and one on each of the other islands.

Crabroxid.\e. — The Hawaiian Crabronidae are represented by 18 described
species, which I have distributed in five genera. All these forms appear to be closely
allied and, as it appears to me, might well be the descendants of one original immigrant
form, allied to Crabro vagus. To this latter there are closely allied species in China
and America, and for this reason the Hawaiian forms may be either Asiatic or American
in origin. The Australian forms are very different. Of the 18 species represented,
three represent each one a distinct genus, while another genus, N^esocrabro, contains four
species, so that the greater part of the known forms fall into one genus, Xenoci-abro, of
which the others appear to be simply derivatives, and it is to species of Xenocrabro that
the European Crabro vagiis is most nearly related.

Unlike the other endemic fossorial Hymenoptera (^Nesomimesa and Deinomimesa)

Ixxxvi FAUNA HAWAIIENSIS

the Hawaiian Crabronids are ubiquitous, occurring both on the coast, in open mountain
localities and in thick forests. Some species indeed, e.g. X. unicolor, occupy all such
stations, and I have found this to occur in wetter and denser forests than any other
wasp, and where only a few species of bees otherwise represent the aculeates. Many of
the species are extraordinarily numerous in individuals, and we have seen around a
dead cow, on which flies were abundant, a swarm of one or two species of Xenocrabro
almost as large as that of their prey. I several times noticed when I had shot a deer
on the island of Molokai, that one or more Crabronids would arrive and settle on the
body before this was even cold, awaiting the arrival of flies. One may well suspect
that at the present time the number of individuals of these wasps is much greater than
was the case under natural conditions of the fauna, unless, indeed, the endemic
Dipterous population has very much changed. The swarms of dung- and carrion-eating
Diptera, that now exist in the mountains, can have had no place in the original fauna,
and on many of these flies the wasps now largely prey. Even the common house fly is
not exempt, and at the Volcano-house hotel on Hawaii ^Y. atripennis has often been
seen entering the room and taking the flies on the window panes. If we consider such
flies as Sarcophaga pallinervis^ (described from the islands) to be endemic, even these
can now breed in numbers previously impossible, owing to the great number of cattle
that have been introduced, and furnish food for their larvae. Another favourite prey of
the Crabronids of to-day consists in two common species of parasitic Tachinid flies, both
foreign.

The natural prey of the species of Nesocrabro is certainly the remarkable and
comparatively rare Sarcophagid flies of the endemic genera Dyscritoinyia and Prostheto-
chaeta. They have several times been caught, when carrying these, and a burrow of
A^. stygius, that was opened, was found to be packed with a small species of one of them.
We have taken the same flies from nests of other of the Crabronid genera, but they are
not restricted to these. Hylocrabro tiimidoventris sometimes provisions its cells with a
moderate-sized species of Drosophila. Some of the smaller species of Xenocrabro are
fond of preying on the Anthomyiid Lispe, and we have found others carrying species of
Caenosia of the same family, all these being endemic species. One species of the wasp
by no means restricts itself to one kind of prey, nor even always to kinds at all similar,
for Xenocrabro hawaiiensis on one occasion was caught carrying off Lispe and on
another occasion a species of the Limnobiid Dicranoinyia ! This fact is of some interest,
because the latter is the habitual prey of Ncsomiiiiesa ; and it shows that the Crabronid
can successfully capture the same without the aid of special apparatus. Xenocrabro
unicolor has been seen to capture and carry off the recently introduced and showy
Neoexaireta spinigera, a Stratiomyiid. The burrows of the Hawaiian Crabronidae
are usually formed in the ground ; those of Nesocrabro have been found only therein.
Others sometimes burrow in dead tree trunks, using, in harder woods, the borings of

' This species is now known to be American.

INTRODUCTION Ixxxvii

xylophagous beetles. Hylocrabro often makes its cells in soft rotten wood of such trees
as the Kukui [A/curih-s) or the Hau (Hibiscus). Some of the species visit flowers,
e.g. X. distinctus and A', uiandibjilaris, on the coasts of Oahu, Maui and other islands.
In the mountains they are sometimes attracted numerously by the flowers of Wik-
stroemiafoetida, and also those of Metrosiderus. In general, however, they are observed
flying round and settling on the leaves of bushes and ferns in the sunshine. The
females penetrate into dark shady places, so dark that they can hardly be seen, in search
of prey. Some of the species of Nesocrabro emit a shrill noise, when on the wing,
which much resembles the note of the Tachinids they are seeking.

The series of species represented in the islands exhibits a great variety in appear-
ance, for some of them are much and conspicuously marked with yellow on all parts of
the body, the yellow markings becoming reduced in others, until in A', unicolor we have
an entirely black insect.

There is in the yellow-marked species much variety in the coloration, and the
variation exhibited is often of an interesting character. INIany years ago Smith described
a Hawaiian Crabro as C. distinctus, from a specimen brought back by the old Beechey
expedition in the early part of the last century. Smith's description, dealing mainly with
colour, seemed to me to represent an insect so different from any Hawaiian Crabronid,
that (in the absence of the specimen, which could not be found) I suspected a mistake had
been made in the locality, and omitted the species from the Hawaiian list. C. distinctus
is now well known to me, and is an extreme and rare variety of the species I called
C. notostictus, which typically is a black insect, with small yellow thoracic markings.
Intermediate specimens between the extremes are much commoner than typical distinctus.
This brightly marked form has so far only been found at or near the coast, where the
intermediate forms also occur, as well as the variety I called notostictus. In the moun-
tains in the forest region the latter is predominant and intermediates are rarely met with.
From these facts one might suspect that the hot dry climate of the coastal regions was
productive of the conspicuously marked varieties. The following considerations make
such an explanation improbable. In the genus Nesocrabro I described a species, gaily
marked with yellow as A^. bidecoratus, adding a remark to the effect that "In spite of its
extremely distinct appearance I suspect it may prove to be a variety of the following"
(A^. ridirocaudatiis). This now proves to be the case, intermediate varieties having been
secured. The variation in this case is even more extreme than in the other, since typical
I'ubj-ocandatus is an entirely black-bodied insect, whereas the var. notostictus of distinctus
has at least yellow thoracic markings. It is interesting to observe that the markings of
the most highly coloured N'. rubrocaudatus (var. bidecoratus) almost entirely resemble
those of Xenocrabro distinctus. Looking at the localities, where these brightly marked
varieties of Nesocrabro occur, we find that, far from living in hot and dry places, they are
found in the wet woods near Kilauea (4000 ft.), in the still wetter district of Olaa and
other localities of windward Hawaii. I think that these highly coloured varieties are

Ixxxviii FAUNA HAWAIIENSIS

' reversions ' to an ancestral style of coloration, and I believe this is borne out by an
examination of the varieties of other Hawaiian species. In these there is a general
tendency to blackness of coloration, some few retaining conspicuous yellow mark-
ings, while most have these reduced to inconspicuousness or they are entirely
absent. Xenocrabro haivaiiensis and fiilvicriis, Oreocrabro abnorniis and Hylocrabro
tiimidoventris, species with normally black abdomen, all become spotted, as excep-
tional and sometimes very rare varieties. Species like Nesocrabro stygius and
daemonius, with immaculate abdomen above, frequently retain yellow pigment spots
beneath, where they are concealed from view. Generally speaking yellow markings,
especially thoracic, are less easily lost in the female than in the male. The general
blackness of the Hawaiian Crabronids, as now manifested, has I think been produced
within the islands, and while some still retain more or less the colour of their ancestors,
the majority have greatly departed therefrom, though many of them in exceptional
individuals reproduce that coloration to a greater or less extent. Further, a study of
the case cited of Nesocrabro rubrocaudatus and Xenocrabro distinctiis lends strong
confirmation to the community of descent that is suggested by the consideration of their
structural characters. At least I find it difficult to understand how two species of these
distinct genera can, under totally different conditions of climate and environment, produce
remarkable colour varieties, totally dissimilar to their usual forms, yet almost identical
with one another, unless they be reversions to a former style of coloration.

As in the bees, Hawaii is also the richest island* in its Crabronidae, seven species
occurring there, of which five are apparently endemic and one of the others is almost
specifically distinct (//. tiiiuidoventris var. Icucognatlms). Maui has six species, but only
one is peculiar to it, whilst Molokai and Lanai have none endemic. Oahu, like Hawaii,
has seven, but only three are peculiar to it. So far as yet discovered, however, it alone
possesses the remarkable genus Oreocrabro. Kauai is poorest of all, with three species
only, two of which, Nesocrabi'o compact iis and Xenocrabro vionticola, both occur on Oahu
(the former also on Lanai and possibly other of the islands) and one only peculiar to
itself, X. affinis. These statements are likely to need modification hereafter, but are
based on the information accessible at the time of writing. They do not accord with
the facts given in 1899, as might be expected.

No parasites are known to attack the Crabronidae of the islands, though it is quite
likely that the Chalcidoid Encyrtidae may do so, nor did I find any specimens of them
in the stomach of the many birds that I dissected. They have a peculiar odour, like
members of their family in other countries.

Tkypoxylonidae. — A family of little importance in our fauna, the Trypoxylonidae
are represented by a recently introduced species of Trypoxylo)i, a native of China,
occurring also, I believe, in tropical Queensland, and by three species of Pison, of the
sub-family Pisoninae. One of these is of quite recent introduction, having become

INTRODUCTION Ixxj

XXIX

noticeable in Honolulu in 1903, but was not taken in 1900, when I collected a number
of specimens of the other two species in gardens there. This recently introduced
species now far outnumbers the other two combined, in Honolulu. It has different
habits, in that, instead of nesting in burrows or cavities in woodwork, it forms mud-
cells like those of Sceliphron, fixing these under ledges and on the walls of wooden
houses, etc. The other two Pison are older introductions, both having occurred at
Blackburn's period of collecting ; both are apodemic and of Australasian origin. All
the species, like Trypoxylon, store their nests with spiders. It is perhaps worthy of
note that the Trypoxylon was introduced first into Hawaii, and not through the port
of Honolulu, as has usually been the case with imported insects. It did not reach
Oahu until some years after it had become widely spread and abundant on the large
island.

Sphegidae. — Represented only by the imported American Sceliphron, an universally
distributed species in the islands, from the coast to 2000 ft. and sometimes higher
elevations. It varies much in colour, as is the case in its native home. It is an
injurious species, in that it disfigures the walls and ceilings of houses with its large
masses of mud-cells. In the country these mud-cells are placed on rocks and trees, and
whether in the houses or outside are frequently occupied by the introduced Pison or the
endemic Odynerus nigripennis, more rarely by other species, as nests for their young.
On Kauai O. radula also occupies the disused cells of Scelipliron.

EuMENiDAE. — This family is represented by a greater number of species than any
other of the indigenous Hymenoptera, and all, to the number of 102, belong to the
ubiquitous genus Odynerus, sensu latiori. From this interesting complex I have split
off some small groups of species and considered them as distinct genera, as indeed they
are, although they appear to be derivatives of the same stock, as the Hawaiian Odynerus
proper. Odynerus nigripennis and its three allies are of different descent from that of
all the others, and certainly are sprung from a quite different' ancestral immigrant. If
the classification of the Odynerus of the world were not in a chaotic state, these four
species would not be placed in the same genus as the others, and a number of genera or
sub-genera, allied to one another, would also be formed for the dispersion of the bulk of
the Hawaiian species. One might reasonably compare the Hawaiian series of Odynerus
with that of the Nitidulidae in beetles. Though the known species are less numerous,
and the specific characters much more distinct, they form a somewhat similar series
of generic or sub-generic groups. The preciseness of the specific characters is itself an
interesting fact, almost indeed unique in our Fauna, when large genera like Odynerus
are in question. I think this distinctness of the species is quite real, and not at all due
to the fact that the Odynerus have probably had more time given to their study than
' No doubt Asiatic ; since allied Japanese species exist.

F. H. I. m

xc FAUNA HAWAIIENSIS

any other large genus of the Hawaiian insects. It is sufficiently proven by the fact
that, except in a few special cases, the species have been accurately determined from
my tables by those who either have had no previous knowledge of Hymenopterous, or
even of any insect characters, after a very small amount of study. I do not think that
any such result is possible with most other large Hawaiian genera (or groups of allied
genera) such as are found in the Carabidae, Anobiidae or Nitidulidae for instance.

The Odyneriis nigripennis group is probably of Asiatic origin, and I suspect is an
ancient or primitive type, showing some affinity to the genus Rhynchium, in which the
species above mentioned was originally placed by Holmgren.

Species of Odynerus are almost ubiquitous throughout the islands, though some of
the densest and wettest boggy forests are absolutely devoid of them. At the same time
a slight change in these, made by the incursion of cattle, is sufficient to allow of some
species becoming established, where previously they could not exist. A minority of the
species such as O. nigripennis, O. obsctire-punctaius and others can occupy most diverse
stations, from the coast to the region of frequent frosts in the high mountains. Some
others thrive equally on the coast or in open areas in the forest region, or above the
forest, but not in the thick forests. On Hawaii some of these pass from above the
forest to the lowlands through the midst of the densest woods by means of the almost
bare lava flows, by which the woods are intersected, but do not enter the forest on either
side of the flow. Some, like O. nigripennis, are not affected by the diversity of station
occupied, but others, like O. scoriaceus, have a tendency to local variation in colour,
when subject to great difference of climate. Many of the species are true forest insects,
some being confined to the drier and more open woods, others are only found amongst
denser growths, with heavier rainfall. Some species occur high above the forest limit
in the region of frequent frost, and of snow in winter time. Many are fond of frequenting
the rocky mountain streams, not only for the purpose of drinking the water, but because
they are enabled in dry weather to find there earth sufficiently moist for forming (in
some species) or for closing their cells. At one time when camping on Maui at an
elevation of about 9000 ft., where owing to the black lava sand and the bright cloudless
sky the heat was intense by day, though below freezing point at night, it was interesting
to watch two or more species of Odynertis visiting one of the water-holes, situated in so
perfectly shaded a spot, that the water retained an icy coldness. After a copious drink
of this water, each wasp would fall into a state of complete insensibility by the side
of the water-hole, and as many as a score were observed in this torpid condition at the
same time. After a considerable period, sensibility would return, and the wasps fly ofi"
without apparent injury.

In the forests these wasps are frequently taken on flowers, especially those of
Metrosiderus, but they have been noticed on many other native trees. In general,
however, they will be observed flying round foliage of trees and ferns, the females more
slowly, while seeking for their prey, the males more wildly, in search of their females.

INTRODUCTION xci

On the coast and lowlands they visit exactly the same plants, as I have mentioned
in the case of the endemic bees {Nesoprosopis). In places where they breed some may
be observed in the greatest abundance flying about rocks, especially where these are
piled up to form rough walls, up and down which they are continually coursing.

Their choice of nesting places is very varied. Some (like O. sociabilis) burrow in
the ground, especially in dry sandy lava. Others always form their burrows in dead
tree trunks, and many (e.g. O. obscure-pimctatus) are indifferent, breeding freely in posts
and dead tree trunks, or in the porous cavities of lava rock, which latter appear to be the
sole or chief nesting place of others. O. nigripenms and the allied O. 7'adula occupy
all sorts of nesting places, such as all those mentioned, and often the empty mud-cells of
Sceliphron. These and others (e.g. Nesodynerus rudolphi, O. montamis, hiloensis, etc.)
freely enter the verandahs and even the rooms of houses, where they make their cells
in cracks or holes in furniture, in the cavities of bamboo, and other situations.
O. nigripennis is so common about many houses, that it cannot fail to be often carried
on ships with furniture, from one island to another. It has been taken as single
specimens on Kauai, but whether it is really established there, I do not know. A few
species, Odynerus oahuensis being one of these, have abnormal nesting habits, forming
complete mud-cells, which are attached to the leaves of trees or to other objects. They
are generally placed in sheltered situations, sometimes for example in a curled up leaf
of Pelea, wherein a spider has made its nest ; and as various other creatures, including
young moUusca, seek the same shelter, we have several times found quite a collection
of animals around the wasp's cell. On one occasion this wasp was watched bringing
caterpillars to store an open cell, which was (with several already completed) suspended
from the rootlets of a large fallen Ohia tree, bridging a small mountain stream. On
other of the islands, where O. oahuensis does not occur, similar nests have been found,
but the makers have not been identified.

The prey of Hawaiian Eumenidae, so far as is known, consists entirely of
caterpillars. The number of these contained in a single cell varies according to the
size of the species of wasp and according to that of the size of the caterpillars. A large
variety of caterpillars are employed, and a single species of wasp is not only not constant
to the use of one kind of caterpillar, but sometimes even mixes the species in a
single cell.

On the whole it may be said that Pyralid and Microlepidopterous caterpillars are
the favourite prey and that Geometridae are rarely utilized. It is most remarkable,
seeing that the latter are occasionally taken (e.g. by O. montanus, eucharis, etc.), that
this should occur so rarely, for the Geometrid caterpillars are so very numerous that
they could be often obtained in any quantity. It is amusing to watch the common
O. nigripennis hunting the caterpillars of Omiodes, which shelter themselves by spinning
together the leaf or leaves of their food-plants. On Molokai a large ' wiliwili ' tree
{Erythrina) was the home of hundreds of the caterpillars of O, monogona and was

m 2

xcii FAUNA HAWAIIENSIS

constantly visited by the female of this wasp. She would keep running from one end
to the other of the gallery of the caterpillar, as the latter retreated to and fro, until
perhaps after dozens of these pursuits, the prey would drop down into the herbage
below, to be at length found, stung into paralysis, and carried away to the cell. Several
species of the wasps have been seen to carry off the grass-eating enemy of sugar-cane,
O. accepta, and O. epipsetistes preys on that of O. cofitinuatalis. In fact no doubt almost
any Omiodes caterpillar is acceptable to many of these wasps, for we have seen them
visiting the plants of Astelia near the volcano at Kilauea in search of the species that
feed on these. Of other Pyralid caterpillars various species of Phlyctaenia, Pyrausta
litorea, and others, Mecyna, and the foreign Hymenia recurvalis are all well-known prey,
so that it is probable that most Hawaiian species of this group fall victims on occasion.
Of smaller moths the caterpillars of Tortricidae and Carposinidae are favourites.

It is a common sight to see Nesodyjierus rudolphi and other species that are
common on the lowlands, extracting the larvae of Crocidosevta plebeiana from the flower-
buds of Sida ; in fact this Tortricid now furnishes an important food-supply of the
larvae of various littoral and sub-littoral species of wasps. In the mountains Eccoptocera
foetorivorans is a common prey. Besides these and other Tortricids, endemic and
foreign, and various Carposinidae of the genus Heterocrossa, members of the Tineina
are also preyed upon, e.g. the Gelechiid Thyrcopa, as well as introduced forms. With
this range of choice in the nature of the prey, the number of caterpillars stored in a cell
varies very much ; over thirty of a Carposinid or small Tortricid (I failed to note which)
were once found in one made by O. oahuensis.

In many localities at favourable seasons the number of individuals that are seen is
extraordinary. On one occasion I visited a mountain gulch on Molokai nearly every
day for three weeks and I estimated that in a length of a couple of miles (below the
line of forest) the population of adult wasps in this length was at least one million.
Five or six species were represented, but two or three were much more numerous than
the others. I have noticed an almost similar abundance in other localities. As may
readily be imagined, the economic value of these wasps is consequently very great.
This is the more true, since they readily prey on the most injurious imported Tortricines,
such as Archips postvittanus and other harmful caterpillars. It is probable that very
few of the large number of species existing are really rare, though of some only a few
specimens or even single examples have been taken. The Oahuan forms have been
much studied, and the only one that has been found once only is Nesodynerus optabilis,
and it must be remembered that the general appearance of this insect is exactly that of
several of its commonest allies, so that it may readily be passed over. Excepting the
littoral or sub-littoral species and the one just mentioned, every known Oahuan Odynerus
has been found in the mountains within three or four miles of Honolulu itself, as one
might say in one spot. Some, however, are of course much rarer than others, and their
apparent rarity is increased by the fact that, like Aculeates in other countries, they are

INTRODUCTION xciii

much rarer in some years than others, and further they appear at irregular times, so that a
species may be abundant one year in March for instance, and another year in August, and
in some years may hardly be seen at all. Consequently during any year unless one is con-
stantly collecting at all seasons in a fixed locality one may easily miss the period of greatest
abundance of any species or fail to find it at all. With experience and close attention in
the field it is fairly easy to discriminate between species that are exactly alike superficially,
owing to indescribable differences in appearance, often due to mode of flight and posture.

Only in exceptional cases do the Hawaiian Eumenidae exhibit important variation,
and in very few cases is this more than of a trifling character, affecting the colour.
There is, however, great variation in the size of individuals of a species, and this is due
usually to the amount of food supplied to the larva, but sometimes to the fact of two
eggs being laid in a single cell, so that the food supplied normally to one, has to nourish
two larvae. To this constancy of structure is partly due the ease with which the many
species can be discriminated. A common variation, which occurs again and again and
in the most diverse species, is the occasional assumption of a feeble yellow band or
traces of such a band on the first or first two abdominal segments in species which
typically have an entirely black body. Examples of this are Nesodynenis rudolphi,
Odynerus venator, O. heieroc/u-otmis, to instance only species very widely separated in
structure. Sometimes the yellow band appears only on the ventral surface. The
phenomena are precisely identical with those observed in the Crabronidae, and I think
are explicable in the same way. The blackness of so many Hawaiian Eumenids has
been produced in the islands, and the abnormal individuals are reversions to a former
general condition in colouring. These too, like the Crabronids, have retained in some
species the original yellow-banded colouration.

The general tendency to blackness of the Hawaiian Aculeata as a whole is one
of their most remarkable features. The blackness of these insects is increased by the
dark colour of their wings, which in a large number of the species exhibits striking blue
or purple reflections. The result of this is to produce a great superficial resemblance
between many of the bees, wasps and fossorial wasps. Though similar phenomena
appear in the Aculeates of other countries, I know no case quite comparable in extent
with that observable in this fauna. We are not able to suggest any satisfactory
explanation as to the cause of this widespread melanism. Were it universal it might
certainly be considered protective, for the result is conspicuousness, but the allied
species that lack the blackness thrive as well as those that possess it.

If we now return to the consideration of the Eumenidae by themselves, we again
find most interesting facts in connection with their colouration. It may be said in brief
that the Hawaiian Odynerus (s.l.) have become divided up into a number of colour
groups, and that these are entirely different from groups based on structure and real
affinity. As these colour groups occur on each island, and some of them indeed are
only found on one of the islands, we may review the species on each island separately.

xciv FAUNA HAWAIIENSIS

On Kauai are two colour groups, one of which contains only two known species.

Group I.
Insects with much red marking, wings shining fuscous, when spread.
O. blackburni and soror, allied species.

Group II.
Black insects with two conspicuous whitish or yellow bands on abdomen ; wings
dark and with conspicuous blue or purple reflections. Fourteen species of diverse
structure. (Plate XVI, fig. i.)

On Oahu are four colour groups, two of which may be said to be peculiar to
this island.

Group I.
Black insects with dark wings, showing conspicuous blue or purple reflections.
O. nigripennis, epipsetistes, erro, lopteryx, montanus, konanus, unicus. Nesodynerus
optabilis, rudolphi.' (Plate XVI, fig. 3.)

Group II.

Generally small species, black with shining fuscous wings, no blue reflections. In
this group some species show feeble and variable pale abdominal bands, and others
some red markings, apparently tending to disappearance and not conspicuous.

O. dubiosus, threnodes, pterophaennes, tvaianaeanus, palndicola, paraiiaias. Neso-
dynerus oblilus, acyanus. (Plate XVI, fig. 4.)

Group III.

Insects usually much marked with red, and the body with appressed fuscous
tomentum. Wings to a large extent hyaline and with no blue reflections.

O. pseudochi-omus, pseudochromoides, leiodemas, homoeophanes, eucharis, oahuensis.
(Plate XVI, fig. 2.)

Group IV.
Insects with usually two pale abdominal bands, the wings more or less infuscate
and with blue reflections, body generally with pale tomentum.

O. xerophilus, nautarum, acoelogaster. Pseudopte^'o-cheihis relictus.

On Maui, Molokai, and Lanai, the fauna of each of which is largely the same,
we have three groups.

Group I.
Identical with I on Oahu.

O. nigripennis, purpurifer, instabilis, ecostatus, laaisukatus, camelinus, brevi-
costattis, aprepes, lanaiensis, konanus. Nesodynerus eupie7yx, paradias. Pseudoptero-
cheilus congruus. Chelodynerus chelifer.

INTRODUCTION xcv

Group II.
Identical with IV on Oahu.
O. niolokaiensis, sociabilis, sinithii, insiibicola, nubicola nivtcola.

Group III.

Insects with red thoracic or abdominal markings or both, the wings dark and with
blue reflections.

O. frater, monas, cephalostictus, naiadum, tempe, dryas, potaniophilus, microdemas,
monobius, erythrosiactes, montivagus, sandwichiensis, petrobius, deinogaster, homoeogaster.
(Plate XVI, fig. 6.)

On Hawaii there is a general tendency of the above three Maui groups to become
fused into one large group, all representing I. O. obscure-punctatus and riibropustu-
lahis and one or two others may be recognized as obscure members of Group III.
O. newelli, sociabilis, sco7'iaceus, represent II.

Speaking generally of these groups, I find that in the field, the members of each
are easily enough distinguished. There are, as might be expected, some cases of
species that are intermediate in appearance and which might be placed in either of
two groups, but these are very few. On Kauai Group II stands out remarkably from
all others, since nearly all the Kauai species belong to it, while it is only approached
in appearance by a few species in Group IV on Oahu. The tendency of the species to
become red-marked on the intermediate islands is very striking, nearly half the known
species being so coloured.

Group IV on Oahu ( = Group II of Maui, etc.) is not very clearly marked off from
its Group I, when the insects are seen in flight, but as they usually have a characteristic
grey or hoary appearance they may be kept apart, especially as they represent species
mostly peculiar to open country or open spaces in forest country. When their represen-
tatives on Hawaii are considered, they become much less distinct from those representing
Group I on that island.

Groups II and III on Oahu are peculiar to itself, the dull red markings, clear
wings and body clothing of the former giving its members, dead or alive, an appearance
unlike anything else, while the shining fuscous wings of the latter render that group
equally unmistakeable.

In a few cases, isolated species have been found on islands, where they ill accord
with the groups there represented, but one cannot overlook the probability of these
being recent immigrants. Thus O. frater, a widely distributed species, has been found
very rarely on Oahu, where it does not fit into any colour group, as it does on Maui,
where it abounds. Excepting on Kauai, the Group I of Oahu is well represented on
every island, besides tending to absorb all others on Hawaii, so that nearly half the
known species of these wasps may be referred to it. The dominance of this group
increases the blackness of our series, for it contains species almost or entirely black and

xcvi ' FAUNA HAWAIIENSIS

with dark iridescent wings ; and, when other groups of Hymenoptera are considered, is
swelled by species of bees, of fossorial wasps, and even of parasitic Ichneumonoids.

It is clear thdt the colour phenomena exhibited by our Hawaiian Hymenoptera are
similar to those seen in other countries (whether in the Hymenoptera or in other orders)
where such colour groupings are explained as being associations of inedible species,
which are easily recognized by predatory enemies from their similarity of colour.
Whether this explanation is true in the Hawaiian case is, I think, very doubtful, though
I do not doubt that a satisfactory explanation of this would also explain the others.
The Australian Eumenidae, Prosopidae and Fossorial wasps furnish instances very
similar to the Hawaiian, and in the same groups, as I have myself observed in the
field, in that country. I feel considerable difficulty in the existence of four well-defined
colour groups, the members of which more or less intermingle in locality on the small
island of Oahu. Were each of these groups composed of members the most closely
allied structurally to one another, the difficulty would appear less ; but it is far otherwise,
for the species of the distinct genus Nesodynerus are divided amongst Groups I and H,
containing structurally diverse forms of Odynerus, and the remarkable Group HI
contains three quite different structural groups of the latter genus. On one occasion
all the six members of this group were taken in the same spot and on the same day, and
it is common to find two or three of the species flying in company, the number of
individuals of each species varying according to place and season. In all the groups
some of the species are always very much less numerous in individuals than others.
Instead of becoming split up into four colour groups on Oahu alone, one would have
supposed that it would have been more profitable and easy for one group only to have
formed, as being more easily recognized. As it is, one certainly cannot say that one of
these groups is more successful than another, for each contains extremely common and
comparatively rare species. It may be noticed that, excepting two species (hardly to
be reckoned as forest-insects, being probably recent derivatives from very similar forms
on other islands) the Kauai wasps have practically become superficially all alike, and,
as has been remarked, there is a strong tendency in the direction of a single colour
group on Hawaii.

If we assume that these colour groups are formed by processes of natural selection
and are indicative of inedibility, we are perplexed as to the immunity of insignificant
forms, which do not attain notably iridescent wings or any markings, and yet fly around
in company with these others and are equally or sometimes even more plentiful. For
if these are successful, why should colour groups occur at all ? It is fair, however, to
say that the one instance in which an aculeate was taken from the stomach of a bird,
was that of a diminutive male of Nesomimesa, one of the most inconspicuous forms,
extracted from the thrush Phaeoj^nis lanaiensis. It should be added that the writer
collected series of nearly every land-bird on each island, and so was able to examine
the stomach contents of a large number of birds in all, and the finding of a solitary

INTRODUCTION xcvii

Mnnesa only, would not tend to show the Hymenoptera, as a favourite food, in any
shape or colour. As a matter of fact, an Aculeate Hymenopterous insect (with rare
exceptions) is so unlike that of any other order by its general appearance in life, that
one can hardly imagine any vertebrate enemy with sense enough to distinguish between
colour groups of these and without the sense to distinguish the class as a whole. If
colour groups in Hymenoptera have arisen as a mark of inedibility, the latter quality
can I think have nothing" to do with the possession of a sting.

At one time I supposed that the Hawaiian colour groups might be the result of the
action of climatic differences, at least in so far as these groups were special to certain of
the islands. This seems very doubtful, for we find the nearest approach to the colour
group of wasps living in the forests of Kauai, in those living on the driest coasts of
Oahu, and quite absent from its very similar forests. In fact a satisfactory explanation
of the colour groups of Hawaiian Hymenoptera is wanting, and, when found, will no
doubt explain some of the similar phenomena elsewhere.

It is interesting to trace the structurally allied forms on different islands and see
how their superficial appearance is changed by entering different colour groups.

Odynenis eutreius of Hawaii is a black insect with dark blue-iridescent wings ; on
Maui it is represented by O. homoeogaster, a red-marked wasp ; on Kauai by O. viimus,
a conspicuously white-banded species. The obscure-t>7uictatiis group on Hawaii is
replaced by the redder species O. sandzvichiensis and its allies on the intermediate
islands ; on Oahu the blue iridescence of the wings is lost as well as all the red markings
{p. dubiosus and allies), while on Kauai the red markings remain, but the wings are of
a shining fuscous [O. blackbiirni and soror) as in the Oahuan allies. Odynerus nigri-
pennis, ubiquitous over all the other islands, is replaced on Kauai by the banded
O. radii la.

From what has been said above, it appears that Hawaiian Odynerus have little to
fear from vertebrate enemies, but in all localities (more or less), at times, a failure of
food supply occurs. This is of course most marked in dry coastal districts, where, in
some unusual seasons, vegetation never advances sufficiently, for a whole year or more,
to furnish food for the caterpillars, which are the prey of these wasps. The same
climatic causes, however, which retard the emergence of the Lepidoptera, until suitable
weather returns for the growth of the food plant, cause the Odynerus to lie dormant in
the larval stage and await the same conditions before pupation takes place. But for
this, many of the littoral species would, no doubt, be quickly exterminated by occasional
unusually dry seasons. The larvae of the Odyneri are attacked by a minute Mirine
Encyrtid of the Chalcid series, and since such different species as O. nigripennis,
montanus and oaliuensis have been found to be destroyed, it is quite likely that many
others are subject to its parasitism. This parasite was not noticed until 1901, when it
was bred from O. oaliuensis from the Makaha valley, but there is no good reason to
suppose it to be of recent introduction, as up to that time few Odynerus had been bred.
F. II. I. n

xcviii FAUNA HAWAIIENSIS

It is now probably of universal distribution over the islands. Scores of individuals
emero-e from a single wasp-larva. Doubtless the anomalous, polyphagous Eulophid
genus Melittolna, now present in the islands, will be found to attack many Odynerus.
Though not noticed in Honolulu till 1903, in 1906 it was already found far in the forest
on Hawaii at Kilauea. It is not yet certain whether it is an importation, but it
probably is so. The wood-boring species of Odynerus and the builders of mud-cells
((9. oahucnsis) are parasitized also by Eiipelnms, but whether those that burrow in the
soil are similarly attacked is not known.

In spite of the fact that the island wasps are insects of strong powers of flight, and
further that many form their nests in dead branches or trunks of trees, and even in
some cases in those light-wooded trees, which frequently are conspicuous in the inter-
island drift, yet they are quite remarkable for the large percentage of species peculiar to
a single island, or, in the case of Maui, Molokai, and Lanai, to a group of adjoining
islands.

Thus all the species known from Kauai are peculiar to it, excepting that isolated
specimens of O. nigripennis have been once or twice found there, probably imported
with furniture from Oahu. The latter species is ubiquitous throughout the other islands,
and O. /rater and O. konanus, though they are much less numerous than nigripennis,
occur on all these. Apart from these three, Oahu has 25 species, all peculiar, except
that one has once been recorded from Maui, perhaps wrongly. The three neighbouring
islands Maui, Molokai, and Lanai, in addition to the three species above named, have
two only {Chelodynerus chelifer and O. sociabilis) identical with Hawaiian species,
leaving thirty peculiar to them.

Kauai, with all its species endemic, is far poorest in the number of known species,
only seventeen having been described, Oahu the island nearest to it having no less
than 28.

As the Odynerus (s.l.) are so easily collected, more accurate figures can be given as
to the endemicity of the species of each island, than is possible with most Hawaiian
insects. No doubt the figures are subject to alteration, but probably the percentage of
endemicity will not be greatly affected. It is therefore worth while to tabulate the facts,'
as they exist according to my present information.

Island Species found

on

Species

endemic

on

Per

centage of endemic

Kauai 1 7

17

100

Oahu 28

25

89

Maui, Molokai and Lanai 35

30

85

Hawaii 32

27

84

The close relationship between the three intermediate islands (here treated as
one) is seen from the fact that the insignificant island of Lanai, with some ten
species of Odynerus, has apparently nothing endemic, its most distinctive forms
being only small colour varieties of those known from Maui or Molokai or both.

IN TROD UC TION xcix

The percentage of endemicity of species on the islands, exckiding Kauai, is,
as shown above, extremely close, and, as more new forms are likely to be found
on the other islands than on Oahu, this percentage may become still closer.

Vespidae. — The three species of Polistes, two of them introductions from China,
viz. P. hebraeus and P. macaensis, and one from California, P. aitrifer, are all very
abundant insects. P. macaensis and aurifer were present in the islands more than
thirty years ago, but P. hebraeus is of later introduction and was not generally
distributed over the islands in 1892, nor did it reach Hawaii till some years later still.
Although treated as varieties by most authors, P. macaensis and hebraeus are quite
distinct by the different processes of the sixth ventral segment of the male abdomen.
The Polistes are now nearly ubiquitous, from the coast to six thousand or more feet
above the sea. On the central plateau of Hawaii I have noticed nests built in the
bleached skulls of cattle and sheep, that are thickly spread in some parts of that
desolate country. These wasps are beneficial in destroying numbers of harmful cater-
pillars, but are otherwise a nuisance. They are affected by the Stylopid parasite Xenos,
and the Pjralid moth, P. maziriiialis, breeds in the nests.

Bethylid.ve. — The species of Scleroderma present feeble specific differences, so
that the number recorded (10) is subject to change, for little is known as to their
variability, etc. We have, however, noticed in bred examples of one species a very
decided individual variation in the shape of the propodeum, an important character.
Their habits are not well known. One or two species have been bred from dead wood,
yielding various beetles (Anobiidae, Cioidae, Cerambycidae, Proterhinidae) and Tineid
Lepidoptera mixed, and the possibility of other insects being represented, but failing to
emerge, is, of course, great. It is, however, known that one or two of our species
attack Microlepidoptera, so probably many have this habit. Male examples are very
rarely met with in the field and not often bred, so that it is probable that Scleroderma
like the apterous females of Dryinidae are often parthenogenetic.

Sierola differs greatly from Scleroderma in the fact that while individuals of the
latter are not generally common, those of the first genus are quite the most plentiful of
the parasitic Microhymenoptera. They are essentially forest insects, though one or
two of them are occasionally found without the forest. Their habits are quite different
from those of Scleroderma, for they are commonly seen running on the leaves of the
' Ki ' {Cordyline terminalis), of Pelea, Acacia koa and many other trees and shrubs.
They are parasitic on various caterpillars, but chiefly, I think, those of the Micro-
lepidoptera (Tineina and Tortricina) from which I have occasionally bred specimens,
but they also attack those of larger moths, for Swezey has bred S. dichroma from
the caterpillar of Oiuiodes asaphombra. A former remark of mine that Sierola was
parasitic on Cioidae is certainly incorrect, and it was, no doubt. Scleroderma and not

c FAUNA HAWAIIENSIS

Sierola, that I bred from dead wood attacked by these and other Coleoptera. The
species of Sierola are apparently somewhat variable and not always easily distinguished,
and I rather suspect that they were more numerously represented in my collections,
than is shown by Ashmead's discrimination of them.

These two genera embrace all the truly endemic Bethylidae, but in addition to
these there have been described from the islands two semi-domestic species of
Holepyris, as well as a species of Sierolomorpha (probably better referred to the
Cosilidae). Of little importance, and at present undetermined, are a species of
Ateleopteriis parasitic on some of the insects (probably Coleopterous) that destroy
stored seeds and grain, and a minute Cephalonomia that attacks the ubiquitous Scolytid,
Hypothene^nus erzidihis.

Dryinidae. — This family is represented by a single species of the Australian genus
Echtlirodelphax, and one, or perhaps two, species of the widely spread genus Pseudo-
gonatopus. The former is likely to be found elsewhere, being indeed extremely closely
allied to an already known Australian species. It attacks Delphacid leaf-hoppers
of various kinds, but apparently only on the lowlands or at low elevations, not being
a true forest insect. The larval sac is placed beneath the lobe of wing or tegmen and
a hopper frequently carries two of these parasites. In some cane-fields this parasite
has reached extraordinary numbers at certain seasons, attacking the swarms of nymphs
of the imported leaf-hopper of the sugar-cane. The larvae of Echtkrodelphax like
those of many other Dryinidae, are themselves attacked by chalcidoid parasites, which
are almost certainly of foreign origin.

The Hawaiian representative of Pseudogonatopus is an anomalous representative of
the genus and shows the most extraordinary variability in colour, some examples being
nearly black, while others are quite pallid and in parts almost whitish. They vary both
individually in one locality, and also very greatly, when taken in different localities-
There are all sorts of intermediate conditions between the extremes. Ashmead
recognized two species, but was doubtful as to their distinctness. Labco hawaiiensis is
the male of Pseudogonatopus perkinsi, the sexes having been bred several times. This
Dryinid is found in the forests of all the islands, in very diverse localities, and attacking
species of several genera of the endemic Asiracid leaf-hoppers. It is subject to the
attacks of chalcid parasites of the Mirine group of the Encyrtidae, which attack its
larvae, while still adherent to the leaf-hopper. Possibly owing to these parasites, the
adults of Pseudogonatopus are less common than would be expected from the number of
parasitized hoppers that are frequently seen. We have bred this insect from eggs laid
parthenogenetically, although males appear to be constantly produced by the species.

PoNERiDAE. — The exponents of the genus Ponera are no doubt introductions,
■excepting the forest-haunting P. perkinsi, which is rarely found on the lowlands. It

INTRODUCTION ci

lives in very small communities, usually of four or five to a dozen individuals, in woody
places, where the ground is covered with dead leaves, or in more open places under logs
or stones. It is often common under stones on the edges of the mountain streams.
Throughout great areas of forest land, where the fauna is chiefly endemic, it is the sole
representative of the Ants. It varies much in colour, and in some localities the majority
of the individuals observed were conspicuously reddish.

The leptogenys is possibly a natural immigrant, frequenting the lowlands and low
mountain elevations. It nests both in tree trunks and dead wood, and in porous
cavities of lava blocks. Its prey consists of Isopod Crustaceans, the remains of which
are nearly always to be seen in heaps about or within the nest. It is fond of migrating
from one spot to another, especially during the rainy season, and processions of these
ants carrying their cocoons are a familiar sight in gardens in Honolulu. Sometimes we
have found nearly every plant of a group of bananas to be occupied by colonies of the
Leptogenys, these being disclosed when the leaves are stripped from the stem. No
winged female has ever been found, though winged males are numerous. All the
wingless examples are very similar, a slight difference in the length of the sting being
the only distinction noticed between individuals. The winged male has, however, been
taken in copula with one of these worker-like examples.

MvRMiciDAE. — This family is represented by a number of widely distributed or
cosmopolitan forms of no interest in our fauna. I believe nearly all have been imported
by man, and se\eral new species have appeared since Prof. Forel's paper was published.
Some of these ants are frequent inhabitants of houses, though they all flourish outside,
e.g. Pheidole megacepha/a, Monomorium vastator, M. Jioricola, and Cardiocondyla
■wroiighionii, the latter breeding freely on some of the steamships plying between
Australia and California, or Australia and Vancouver.

Cardiocondyla nuda is found in the mountains and on the coast alike. It is
abundant in Honolulu, but was not collected by Mr Blackburn, so is probably of recent
introduction. It varies a good deal in colour.

Solenopsis geniinata and Pheidole megacephala have their nests infested by the
Myrmecophilous cricket, M. qiiadrispitia, and in that of the latter small Lepismidae are
of frequent occurrence. Neither these nor the crickets, however, are confined to
nests of these ants, for they equally infest those of some of the foreign Formicidae
{Prenolepis).

Pheidole megacephala is the most abundant of all the foreign ants. In many parts
it occupies not only the whole open country, but also the forests to a height of about
2000 ft. in the mountains. In open country it sometimes becomes established as high
as 4000 ft., and may be numerous at three thousand. Usually, where forests are dense,
it ceases to range above about 1200 to 1500 ft. of elevation, while in its range, no
matter how fine or how dense the forest may be, the endemic fauna, save for a few

cu

FAUNA HAWAIIENSIS

forms, that can resist, or are tolerated by the ants, is entirely exterminated. This native
fauna, especially of beetles, appears as if by magic, the moment the limit of range
of Pheidole is reached. In some places on the coast there are localities so dry and hot
that Pheidole cannot occupy them permanently, and here a remnant of a lowland
endemic fauna persists, unsuitable as are the conditions for insects in general. Of the
native insects that are attacked by Pheidole, the Aculeate Hymenoptera are the least
injured. Even in the case of large Crabronids and wasps of the genus Odynerus it is
common enough to find specimens with one or more workers of Pheidole, or with
the great head of the soldier-form attached to their legs or antennae, and we have
noticed instances where these strong insects have been entirely overcome by their
assailants.

DoLiCHODERiDAE. — Represented only by the introduced American form of Tapinoma
7nelanocephahmi. This small ant flourishes best in dry hot localities on the lowlands or
lower mountain slopes. It is very common.

FoRMiciDAE. — The three species of Prenolepis and one Camponotus, that represent
this family, are no doubt introductions and of no interest. The latter is to a large extent
domestic, breeding in incredible numbers in the walls of the wooden houses in Honolulu.
In some of these (even in houses only a few years old) this Camponotus (C maculatus)
is an intolerable nuisance. Swarming takes place on dark still nights, when all forms
of the ants issue from their nests, covering the floors, walls and tables and even entering
the beds. Though partial to houses, C. maculatus thrives well enough in the open, but
only on the lowlands, or at low elevations in the mountains. Prenolepis sharpii was
imported in a box of plants from Hong Kong, the earth, in which the plants were sent,
containing a great nest of this species, including hundreds of winged males and females.
It quickly became naturalized.

Ceraphronidae. — There are no endemic species in this family, but three species of
Ceraphron, two of which have been described, are known to occur. All are found
in Honolulu itself, and will no doubt become general in distribution. Ceraphron
abnormis appeared in 1903 and subsequently became abundant. It is a North American
species and has been swept from grass in California. Swezey has made known its
habits, it being a hyperparasite of leaf-hoppers, through the Dryinidae, Echthrodelphax
and Haplogonatopus.

ScELiONiDAE. — There are several species of the ubiquitous genus Telenotnus, some
being no doubt introductions, e.g. two that have been bred from the eggs of the foreign
bug, Rhopalus hyalinus. Others, however, have occurred in the forest region and their
habits are uncertain. One rather remarkable species is found numerously on Hawaii

INTRODUCTION ciii

in company with Asiracid hoppers, a small Capsid and Rediiviohis, and is likely to be
parasitic in the eggs of one of these Hemipterous insects.

A species of Baeiis is found in wet places in the mountains, and no doubt will be
found to be parasitic in spiders" eggs, and could be bred from these. We have only
found single specimens of this minute insect, and they are generally lost from being
mixed up in the killing bottle with larger forms.

Two allied genera Pseudobaeus and Dyscritobacus are described for insects occurring
in gardens in Honolulu, where they frequent foreign grasses in company with apodemic
insects, such as Rcdnviohis capsiforniis, Orthoea vincta, etc., but their habits are not
known. They are most likely parasitic in the eggs of .some of the insects occurring
with them. With these also occurs a species of Opisthacantha, doubtless an imported
species, now widely distributed. It is probably parasitic in eggs of grass-frequenting
Hemiptera, as it has been noticed in numbers in places too dry for the occurrence of
Orthoptera, but where Reduviolus, Orthoea and Nesomartis are found. Two species
of Calotcleia are also recent importations, one first appeared in 1903, the other still
later, in Honolulu. The genus Anteris, on the other hand, though itself apodemic,
contains only endemic species, true forest insects, the hosts of which are not known.
There are si.x described species, all excessively closely allied, and perhaps not all truly
distinct. It is possible that they parasitize the eggs of the Locustids of the genus
Brachymetopa, some of the species of which are unaccountably rare.

Platvgasteridae. — A single species of Inostemma, no doubt introduced recently,
is the sole representative known of the above family. It has occurred only in the
vicinity of Honolulu.

Proctotrvpidae. — A single species of Proctohypes is common on the higher
mountains of Maui and Molokai'. We have bred it from malodorous decaying fern-
stems, infested by the larvae of Drosophila, and other Diptera. It also frequents
Astelia veratroides, at the base of the leaves of which decaying vegetable matter
accumulates, and forms a breeding ground for small flies.

DiAPRiiDAE. — The species of Phaenopria are endemic forest insects, and the
endemic genera, Zacraniiim and Platymischoides, seem to be derivatives of these. In
fact, I have described species of Ashmead's last-named genus, as simply flightless forms
of Phaenopria, considering the two hardly generically distinct. The species are no
doubt numerous in the islands, closely allied, and difficult to distinguish, and some of
them show considerable individual differences in the shape of the head. All (except
Zacranium, the habits of which are unknown) are parasitic on 'vinegar-flies' of the
genus Drosophila, from which several have been bred. Owing to sexual differences,
and the fact that closely allied species live in company, I have not been able to associate

' It is also found on the other islands.

civ FAUNA HAWAIIENSIS

the males with their proper females, and until this can be done the former are better left
undescribed.

Two species of Diapria are of comparatively recent introduction, found in gardens
in Honolulu, and becoming more widely distributed. One of these is a common
parasite of an imported species of Drosophila.

FiGiTiDAE. — The parasitic Cynipoids are represented only by members of the sub-
family Eucoilinae, and, adopting the views of Kieffer as to their definition, by only two
genera. Ashmead, however, recognized six genera in the nine endemic species, that
he described. I have increased these to twenty-three, without describing males. The
latter cannot without special observations be referred to the other sex. All these
Hawaiian forms appear to be related to one another, in the genera, in which they are
placed, viz. in Cothonaspis and Eiuoila. Even the distinctions between these genera
seem to be broken down to some extent by some of the Hawaiian species. Some
species in both genera have been bred, and they are parasitic on the larvae of small
flies of the genus Drosophila. Some, like Pj'octotrypcs, are found at the base of leaves
of Astelia, where decaying vegetable matter collects and small flies breed. Some
frequent bushes or small trees such as Myoporum, flying round the foliage, and it is
possible that they will be found to parasitize small Diptera, the larvae of which feed in
fruits and berries of various native trees. In general, these parasites prefer damp shady
places in the forest, where is a dense undergrowth of fern. When largely collected,
I anticipate that great difficulty will be found in distinguishing the island species, which
may be very numerous. In addition to the endemic species, a single Etuoilidea is
found on the lowlands in Honolulu, and elsewhere. It is parasitic on small leaf-mining
flies of the genus Agromyza and certainly introduced.

Mymakidae. — Apart from introduced species of Alaptus, Anagnis and Leimacis,
of no interest in our fauna, the genus Polynenia alone represents the Mymaridae.
There are, doubtless, many species, fifteen having been already recognized. So far as
is known these Hawaiian Polynema parasitize the eggs of Hemiptera only, both the
Heteroptera [Reduviohis] and the Homoptera i^Nesophrosyne, several species, in the
Tetigoniidae, and Nesodryas and Nesosydne in the Asiracidae). It is probable, however,
that they have other hosts, since we have bred a large species from branches of trees,
killed by the borings of one of the endemic Tortricid caterpillars of the genus Archips.
Eggs of the Hemiptera above specified would not be very likely to occur in such a
situation.

Chalcididae. — Four species only of this family occur and one of these. Chalets
obscurata, has been imported for economic reasons. It is now one of the most abundant
insects in our islands, and serves to conceal the presence of C. polynesialis, which still

INTRODUCTION cv

occurs, but is rarely noticed amongst the swarms of its economically important congener.
C. polynesiale, though occurring in Blackburn's period of collecting, is almost sure to
prove an introduction, and recently a third species (though of another genus, Hockeria)
has become perfectly naturalized on Oahu. Chalcis obscurata is interesting, otherwise
than economically, owing to the fact that it frequently attacks insects already parasitized
by some other insect. Consequently it has even been bred from the pupa of other
parasitic Hymenoptera (e.g. the Ichneumonid Echtlii^omorpha niaculipeniiis) and Tachinid
riies. It seems deficient in its instincts, for we have observed one ovipositing in the
pupa (concealed of course between the layers of palm leaf) of Oniiodcs blackburni, when
examination showed that the pupa had previously been squashed flat, and was quite
dead and dry. Nevertheless in productiveness it is one of the most successful of insects.
Epitramis /acteipeitnis^.discov&'CG.A by Mr Blackburn, still occurs on Oahu, but is rarely
met with. Its habits are not known, nor has it been found except in the neighbourhood
of Honolulu.

EuRYTOMiDAE. — Represented only by species of Eurytoina and one or two of
Isoso77za, all of recent introduction. The former is hyperparasitic, attacking Braconids,
especially Bracon omiodivonis, a common parasite of Pyralid caterpillars, and less
frequently Apanteles. Its presence was not noted until 1903, when it was already
numerous. It is very widely distributed, and in Honolulu we have found it on the dry
coast of Waikiki, as a hyperparasite of Omiodes blackburni, as also in the wet valley of
Nuuanu. It is common in some of the cane-fields of Hawaii, where Omiodes accepta
is an abundant host of Bracon, and on one occasion at Pahala we observed countless
numbers of the males flying round and running on the leaves of cucurbitaceous plants,
growing in waste places. The 'joint-worms' or larvae of species of Isosoma are
attached entirely to imported grasses, and are abundant in Honolulu and no doubt
elsewhere. There appear to be two species, which are parasitized by an Eupelmine
Encyrtid, and I think also by a Pteromalid.

MiscoGASTERiDAE. — This family is chiefly represented by a number of species of
Toxeuma all endemic, and by the endemic genera Neolelaps and Mesolelaps, the former
with several species, though only two have been described. These are all true forest
insects and usually sparingly met with. Though we have bred one or two species,
their habits are not certainly known. They appear to be associated with the caterpillars
of microlepidoptera or small beetles that attack stems or fruits of native trees. The
species of Toxeuma are likely to prove very difficult to distinguish. They are bred
from twigs containing small beetle larvae, Proterhinus, Cis, etc.

Encyrtidae. — The sub-family Eupelminae is chiefly represented by about fifty
described species of the ubiquitous genus Eupehmis, forming a remarkable series, diverse
in structure and in habits. The specific value of a good many of those that I have
F. H. I.

CVl

FAUNA HAWAIIENSIS

described is uncertain, since some of them are variable and the species are no doubt
very difficult to determine. It is impossible to correlate the sexes, unless a species has
been bred. Most of the known species are found in the mountain forests, but some
have occurred on the lowlands and it is possible that some of these are not endemic.
Some are egg-parasites of various orders of insects, e.g. E. axestopsi^) bred from eggs
of the Locustid Brachynietopa, and E. rhyncogoni from those of the Otiorhynchine
weevil, Rhyncogonus. Others attack larvae of various Coleoptera, or of Neuroptera of
the Hemerobiid family {Ano7)!aloch)ysa). Some are frequent parasites of several of the
larger bees included in the genus Nesoprosopis, and also of certain Odyneriis, while
some are parasitic on Diptera and others of Lepidopterous larvae, both case-bearing
and others. The genus Solindenia, described as peculiar to the islands, is a common
insect, and will almost certainly be found elsewhere. It is parasitic in the egg capsules
of cockroaches of the genus Phyllodroniia and is found to attack foreign species, as well
as the native P. obtusata. The single Aiiastahts is quite certainly an introduction, and
thouo-h now widely spread, is a common garden insect in Honolulu, where it parasitizes
the eggs of the introduced Locustid Eliviaea appendiculata. The habits of the one
described Eiipelniinus are not known.

Of the Encyrtinae, Encyrtus fusciis, one of the most abundant insects in parts of
Australia, as we have found it, is no less common in the islands, being introduced and
parasitic on various species of scale-insects of the genus Lecanium, also introduced.

The members of the tribe Mirini include some common parasites of foreign scale-
insects, Microterys flavus e.g., and Blepyrus insularis { = B. niarsdeni How.) which are
clearly introduced. .Others, however, are likely to prove endemic, e.g. the parasites
of the Dryinid leaf-hopper parasite, Pseudogonatopus, and a species, which infests the
larvae of various kinds of wasps of the genus Odynerus. Aphidencyrtiis on Aphidae
is of course introduced, as also is a species, for which the late Dr Ashmead proposed
to characterize a new genus, Aniicroterys, common in gardens in Honolulu, where it
parasitizes an abundant scale-insect of Cynodon dactylon.

The habits of several other species are at present unknown.

The tribe Ectromini includes six species of the genus A»agy7'Hs{}) described by
myself, but whether these are all really good species is doubtful. Their habits are
not known, and until these are ascertained, I feel doubts as to the endemicity of the
species. They occur near the coast, as well as in the mountains. Should they prove
to be parasites of foreign Coccidae, we may be sure that they are themselves foreign
and either have been introduced accidentally with their hosts, or in some cases, possibly,
for economic reasons by Koebele. He, as I know positively, attempted to introduce
Anagyriis from China and Japan.

Pteromalidae. — The great complex of genera here included, is almost unrepre-
sented by endemic sjoecies, for of the very few known to exist in the islands, only one,

INTRODUCTION cvii

Spalangia lanaietisis has any claim to be considered indigenous. This is a true forest
insect and has been bred from more than one of the smaller endemic species of Drosophila.
Two other species of Spalangia are known, but they are clearly importations, parasitizing
the puparia of various common introduced Hies, the larvae of which feed in cow dung
or other excrement. One of these was identified as ^. liirta, and in fact it is practically
identical with specimens of a Spalangia from Europe and China, and hardly different
from a Mexican form. Still it does not agree with Haliday's description in the length
of its antennal joints, and so we have considered it to be distinct from S. hirta.

One or two species of Pteronialus, one of which has been bred from a. foreign
Tortricid, are not likely to prove endemic, and one or two of the genus Pachyneuron
or allied forms connected with foreign Diptera, are likewise introductions.

The scale-insect parasite Tomocera californica is an introduction from Australia,
where we have seen it, and other species of the genus, in abundance. It was found
commonly by Mr Blackburn, and described as a new genus Moranila. Although it
bears the .specific name californica it is of course an introduced species in California,
as into the islands. Owing to other parasites and predators, introduced to destroy
Lecaniuni, the Tomocera is now far less plentiful than it was some fifteen years
ago.

EuLOi'iiiDAE.— In this family the sub-families Aphelininae and Tetrastichinae, the
former with numerous species parasitic on introduced Aphidae, Coccidae and Aleyrodidae,
are all probably introduced, the only species that are at all likely to prove endemic are
in the Tetrastichinae, viz. the polyphagous Melittobia and an undescribed forest-
frequenting species of uncertain genus and habits. I believe, however, that these are
also introductions, like Tetrastichus hagenotvii, which is hyperparasitic in cockroach
egg-cases, wherein it attacks Evania. Paraphelinus xipkidii is an Aphelinine of
rather ordinary structure, but most interesting from its habits. It parasitizes the eggs
of the common imported Locustid, Xiphidiutn varipenne, and also is a hyperparasite
of leaf-hoppers, breeding in the cocoons of the Dryinid Haplogonatopus, as recorded by
Swezey. This diversity of habits in a member of a group so constant otherwise in the
limits of its parasitism, is of great interest.

The other members of the Eulophidae must, in the present state of our knowledge,
be considered specifically endemic, though none of the genera are peculiar to the
islands. They include in the Entedoninae the genera Astichus and Oniphale ; in the
Elachistinae Ophelinus ; and in the Eulophinae Heniiptarsenus, Necrenimis, Sympiesis
and Eidophus. In some of these genera several new species (at present undescribed)
are known, but they preserve very badly and offer small attraction to the collector or
describer. Many of them are familiar parasites of leaf-mining microlepidoptera and
they are commonly bred from mines of Philodoria in leaves of Pipturus, Metrosiderus,
etc. and from the common circular mines that so often disfigure the foliage of Pelea.

2

cviii FAUNA HAWAIIENSIS

The species of Oniphale is (if indeed there be only one) remarkable for its extreme
variability in size, colour and sculpture. It attacks various leaf-mining caterpillars,
those of Gracilaria being commonly parasitized on the lowlands, and those of Philo-
doria in the mountains. It is, however, known to attack species other than leaf-miners,
e.g. various microlepidoptera, whose larvae live in fruits, etc.

Trichogrammidae. — It is doubtful whether there are any species of this family
endemic, and highly improbable that any of those hitherto discovered are other than
introduced. IVesizuoodel/a hilaris is found on foreign grasses in gardens in Honolulu
and itself is clearly foreign. Of Pentarthron (which appears to be a synonym of
Trichogrammd) several species occur. P. flavum is a parasite of lepidopterous eggs
and is often seen running on foliage, as also is P. seniifumatum. P.flavutn may be
no more than the widely distributed Trichogramnia pretiosa, which attacks many kinds
of insect eggs. The eggs of Ano^nalochrysa are parasitized by the same genus,
possibly by the same T. pretiosa (or P.flavmn) or by a variety of this. Eggs of the
introduced Locustid, Elimaea appendiadata, are attacked by another species, apparently
undescribed, many individuals of the parasites emerging from a single egg of the
cricket.

EvANiiDAE. — One of the two species of Evania, both of which are very common
insects on the lowlands and lower mountain slopes, is of wide distribution outside
the islands, being carried in ships ; the other is only known at present from the
islands, but is certainly foreign, and will be found elsewhere. It is, like the
common E. appendigaster, a parasite of foreign cockroaches, not of the one endemic
Phyllodromia. Both these Evania are attacked by the hyperparasitic Tetrasticlms
hagenoivii.

IcHNEUMONiDAE. — Ichneumoninae are entirely wanting, except for a species of
Ichneumon, introduced for economic reasons by Koebele, and the Cryptinae have three
species of Hemiteles, as recognized by Ashmead, but all the Hawaiian specimens of
the genus that I have seen belong to one variable species, presumably He>nite/cs
tenelius, a common parasite of Chrysopa, introduced from N. America. The Pimplinae
are more interesting, for we find here an endemic genus, Glyptogastra, with two
described species. The habits are not certainly known, but we have found one species
flying about twigs bored by caterpillars of a large species of Archips, the pupae of
which it may parasitize. Echthromorpha maculipennis is remarkable for its great
variability in details of colouration, size and otherwise. It is doubtful whether all the
Hawaiian specimens are not referable to one, though extreme variations might be
described as forming several distinct species. This parasite is almost ubiquitous, being-
found in gardens in Honolulu and throughout the mountains, and in cultivated places

IN TROD UC TION ci x

on all the islands. It is often extremely numerous in individuals and parasitizes many-
very different kinds of Lepidoptera. Chrysalides of Pyrameis tavnneaniea, found in
the forests, more often produce this parasite than the butterfly, in my experience. All
pupae that are moderately exposed, such as those spun up in cocoons on leaves of
trees, or between layers of leaf are sorely attacked by this parasite. Plusia, Omiodes
and other Pyralidina, as well as the Pyrameis, are favourite hosts. It abounds in
localities with excessive rainfall. Pimpla hawaiiensis is an apodemic species, which
we have bred from a Mexican Tortricid. In the islands it is often bred from pupae
of introduced Tortricina, as well as from native Pyralidina. It is very abundant.

The Tryphoninae are represented only by two widely distributed European species,
both of course introduced, viz. Metacoelus fefnora/is, which seems barely to maintain
its foothold, and Bassiis /aefatoruts, the too abundant parasite of the introduced Australian
Syrphid fly, Xanthograninia grandicornis.

The sub-family Ophioninae is by far the most important section of the Hawaiian
Ichneumons. At the present time I recognize forty species of this group distributed
in eleven genera, Idecthis and Lathrostizus being considered synonymous. One species
of Limneriutn is certainly foreign, being a common insect in cabbage gardens, where
it parasitizes Plutella criiciferariim. The single Idecthis and Lathrostizus are also
subject to great suspicion, as introductions, and also the Pristomcrus, though at present
they have not been identified from other countries. The bulk of the species, as will be
seen, if we subtract these dubious natives, belong to the true Ophionines and the genus
Atrometus of the Anomalines. Of the former the genera Banchogastra, Pycnophion
and PletironeiwopJiion are endemic, the two former indeed are amongst the most
remarkable of their group. Most of the species of the Ophionines are absorbed in
the genus Enicospilus. These are remarkable for the variability of important characters,
as well as superficial ones, so that sometimes individuals are met with, which have lost
the generic distinctions. In consequence, the status of the species is by no means
settled, and the more the specimens are collected the more difficult is it to define the
specific characters. One striking character, in which variation is shown in some
species, is the transverse propodeal carina, while in others it appears to be quite
constant. In some variable species it may be present and distinct or largely effaced,
according to the individual. In some species the carina is normally well-developed
in the female and wanting in the male, as in the case of Enicospilus kaalae, but in this
species a proportion of the males have the carina strongly developed like that of the
female. The spots in the discocubital cell also are subject to variation and may be
distinct or effaced in different individuals of a single species. In some species they
appear to be normally or always absent, decharacterizing the genus.

Many of the Hawaiian Ophionines may be seen flying freely in the forests in the
day time, especially in places where ferns grow freely. They are also on the wing at
night and are sometimes attracted to lights. Many are of social habits and crowd

ex FAUNA HAWAIIENSIS

together in numbers, when at rest. We have seen dozens of examples of a species
resting beneath one or two adjoining leaves of a large-leafed tree, so thickly indeed as
to hide the surface. At other times they form great flocks in dead hanging fern fronds.
These assemblies are sometimes all of the male sex, but sometimes mixed. Sometimes
too the species are mixed in these assemblies. So far as we know only Enicospilus
and Pkiironetirophion congregate in this way, the others being more solitary. Individuals
of many of the species are very numerous. Even within a mile from Honolulu, on the
fore hills, we have seen hundreds of examples of Enicospihis inolokaiensis (? Ophion
/meatus Cam.) flying about together in the sunshine, in an area of a few square yards.
Geometers, Pyralids and Noctuids have all been found parasitized by Enicospihis,
but though many members of the large genus Scotoiytlira (Geometridae) have been
bred, they have very rarely been found to be attacked. Consequently I suspect that
the caterpillars of the genus Agrotis, when occurring in localities, where the parasites
are common, will be found more subject to their attack. The smaller Athyreodon
attacks Pyraustid caterpillars of the genus Phlyctaenia.

Limnerium blackburni is one of the commonest Hawaiian insects, of universal
distribution in the islands, and exhibiting slight variation in superficial characters. It
attacks so many of the Pyralidina that it is useless to specify particular species para-
sitized, but Omiodes and Phlyctaenia are favourite hosts. We have known Phlyctaenia
stellata, for instance, to suffer from its parasitism to such an extent that about 90 per
cent of the caterpillars were destroyed. It also attacks Scoparia as well as Tortricina
and Tineina, and parasitizes foreign as well as endemic caterpillars, being notably
polyphagous. Pristomerus, I think, has but one variable species, not two, as described
by me. My original specimens coming from different islands and differing greatly in
superficial appearance were not recognized as belonging to one species. It parasitizes
the caterpillars of various Pyralidina, while Lathrostizus is often parasitic on some
domestic caterpillars, probably Phycitidae. The small Anomalines of the genus
Atronietus are met with much more sparingly than the Ophionines. They are found
only in the forests, flying over ferns, or round bushes, especially Myrsine, Pelea, etc.
They have been bred from the larvae of endemic Tineina or Tortricina feeding in
shoots of native trees.

Alysiidae. — Aphaereta muscae is an introduction from N. America, and a common
parasite of various foreign flies, the larvae of which live in cow dung. Aspilota has
been bred from similar Dipterous insects and is also probably foreign. There are no
certainly endemic Alysiids known.

Braconidae. — The Aphidiinae are represented by a single introduced species,
which destroys the cabbage Aphis, the Euphorinae by ' Centistes' aniericana, a common
parasite of the imported ladybirds Neda abdominalis and Coelophora inaequalis. The

INTRODUCTION cxi

Cheloninae have three species ; Chelomis blackburni, occurring also in Australia, is a
very common parasite of various foreign Lepidoptera of different families, sometimes
attacking native species also. Phanerotoma kaivaiiettsis, which first appeared between
1897 and 1900, and is now common, was probably introduced by Koebele from Japan,
while quite recently another species has appeared in Honolulu. The Agathidiinae are
represented only by Microdiis haivaiico/a, not a true forest insect, but which, being
polyphagous, has been bred from caterpillars of foreign Tineina of various kinds, the
imported cotton-boll Gelechiid {Gelechia gossypiella) being one of these. It does,
however, attack endemic Tineina, e.g. Hyposjnocotna. The Microgasterinae contain
several species of the ubiquitous genus Apanteles (s.l.), two at least of which are known
to be parasites of apodemic Tineina and Tortricina. No doubt all are introductions.
The Braconinae, quite unrepresented in Blackburn's collection, now have several species
of Bj-acon, one [B. omiodivoni»i) being a most abundant parasite of the Pyraustid
caterpillars of the genus Omiodcs. It was introduced, I believe, by Koebele and has
spread and increased greatly during recent years, having now entered the mountain
forests. Another species is an abundant parasite of a Trypetid fly of the genus
Tephi'itis. A species of Habrobracon is often found in houses, being parasitic on
caterpillars that attack articles of food. It is also common enough in the open, where
it frequently parasitizes Phycitidae that infest the pods of the algaroba tree, Prosopis.
Ischiogonus palliatus of the Rhogadinae was discovered by Blackburn, and is probably
now more abundant than formerly, attacking larvae of Longicorn beetles, whether
native or foreign. It is also found in Fiji, and was no doubt introduced into the
islands. It exhibits a good deal of variation, this apparently depending to some extent
on the species of its host. It appears to attack some Curculionidae as well as Ceram-
bycidae. A second species has more recently been introduced and freely parasitizes
Clytarlus and Plagitlwtysns, the endemic Longicorns, as well as some imported genera.
The insect described as HormiusiJ) peregrimis^ is parasitic on xylophagous beetles
of the family Bostrychidae, and is of recent introduction, being sometimes found
commonly in Honolulu. This insect is no true Hortniits and seems to be related to
the Helconinae, and perhaps should be transferred to that group. It also occurs in
F"iji. In the Spathiinae, Ecphylopsis nigra, a minute flightless insect, is no doubt
endemic, and is the only known Braconid that has any claim to be considered so. It
is known to me from all the islands (except Lanai) and is a true forest insect.' It is
bred from dead wood containing larvae of minute beetles, e.g. Proterhinus. A minute
species of Spathiiis has once occurred in Honolulu and is certainly introduced. It was
found flying about some boards, that were infested by countless individuals of a
probably foreign Dryophthorus. One or two other species of Braconidae of recent
introduction are not included in this account, as they have not yet been examined.

' This is probably Eiiscelinus of Westwood.

cxii FAUNA HAWAIIENSIS

Review of the Coleoptera.

Forty-three (or if the Lyctidae be considered as a group in the Bostrychidae 42)
of the 85 families of Coleoptera, as enumerated by Sharp in the Cambridge Natural
History, have representatives in the Hawaiian islands.

Of these families, however, 26 are, as I believe on various kinds of evidence,
entirely foreign to the natural fauna, being introductions by man, and four others
(Hydrophilidae, Dytiscidae, Anthicidae and Coccinellidae) are represented by either
imported or naturally immigrant species, likely to be found elsewhere. Excluding
these, the real Hawaiian fauna of beetles represents only 17 families.

The total number of species described or enumerated' is 1288, these being included
in 229 genera.

The 26 families above mentioned as being foreign to the natural fauna are
represented by only 71 species and these are scattered in no less than 57 genera.
However, as many of the families belonging to the true native fauna are represented
not only by species and genera that are really native, but also by introduced ones,
it is necessary to analyse these 1 7 families in order to understand the true nature of
the fauna. Thus in the Cerambycidae 10 of the species, each belonging to a different
genus, are importations by man, leaving five genera with 52 species native.

The Curculionidae have 14 foreign species (one or two, however, being natural
immigrants) in nine genera; 132 species in 12 genera are of the true fauna. The
genus Pentarthruni contains imported and a native species.

The Scolytidae have seven foreign species in three genera ; 1 7 apparently native
species of Xyleborus, which also contains foreign forms.

There are 136 endemic species of Proterhinidae, at present all included in the
genus Proterhinus.

The Cistelidae are represented only by endemic forms, the two genera containing
12 species.

The Tenebrionidae have eight foreign species in six genera ; one genus with a
single species is possibly endemic, but will quite probably be found elsewhere.

The Cioidae have three probably foreign species in one genus, leaving 39 truly
endemic forms in two genera.

The Anobiidae have four foreign species in three genera, and 134 endemic in
the same number.

The Elateridae have five foreign species in five genera ; the native fauna has
also five genera with 76 species.

The Lucanidae have one genus endemic, with seven species.

This does not include a number of species introduced for economic reasons, nor a number of
recent casual introductions, now well established.

INTRODUCTION cxiii

The Dermestidae have three foreign genera with five species ; three genera with
2 1 species are endemic.

The Cucujidae have lo foreign species in seven genera; there are lo native
species in two genera.

The Colydiidae are represented by three foreign species, each in a different genus,
and a single endemic genus with one species.

The NitiduHdae have six foreign species in two genera, and 136 native ones in
13 genera.

The Histeridae have five foreign species in three genera, and 34 native in a
single genus.

The Staphylinidae have 24 foreign forms included in 16 genera, and 95 true
members of the fauna in 13 genera.

The Carabidae have six probably foreign forms in three genera, and 204 endemic
species in 36 genera.

If we remove from the above families the introduced species and the few natural
immigrants, either known to be found or likely to occur elsewhere, and add these to
the 71 species found in families that contain only foreign forms, we find that the
foreign element consists of 181 species distributed in 131 genera. The truly native
fauna on the other hand consists of 1107 species distributed in 102 genera. Thus
in the foreign element these genera contain rather less than i -4 species to each genus
on the average, while in the other group the species are lO'S to the genus. Perhaps,
however, the few certain natural immigrants should be rather added to the truly native
species, but as these immigrants number in all less than a dozen, the striking contrast
between the natural and imported coleopterous fauna would be only slightly changed
thereby.

We must also notice an essential difference between the native genera and the
imported ones. Thus the latter are rarely or never closely related one to another,
while many of the former are formed for species which are clearly closely related to
other endemic species, so that the genera are frequently very closely allied to one
another, and in fact difficult to distinguish by trenchant characters. For instance,
many of the genera of Carabidae are excessively closely allied and the distinguishing
characters are not always constant. The three allied genera of Cerambycidae,
Plagithmysus, CallUJunysus and Clytarius, contain species that show characters
connecting one with another.

In some of the genera the species are remarkably restricted in their range over
the islands. This is notably the case with the Cerambj'cidae above mentioned, for
not one species is known to inhabit even two of the islands. The fact is the more
remarkable as these beetles possess strong organs of flight and in fact fly strongly
with the wind. Moreover they could also be carried in the larval and pupal state
from one island to another in floating trees or their limbs. The Carabidae and

F. H. I. p

cxiv FAUNA HAWAIIENSIS

Proterhinidae, the former usually and the latter always flightless, are also mostly of
different species on the different islands, but the species of Cis on the other hand
are generally widely distributed throughout the group.

Many of the species of Cerambycidae, Curculionidae, Carabidae, Cioidae, and
Anobiidae exhibit much variability in structure in individuals. Owing to their generally
distinctive appearance this leads to no particular difficulty in the separation of the
species of Cerambycidae, but in nearly all the other families many of the larger
genera are extremely difficult to deal with. Probably no more difficult study in
systematic entomology could be found than the working out of the Hawaiian
Nitidulidae, Anobiidae, and some other groups.

The following 80 genera are, so far as is known, endemic : Plagithinysus,
Cal/ithmysns and C/ytarhis (Cerambycidae) ; Chaenosternum {^\ Orothreptes (?),
Deinocossonus, Nesotocns, Dysomvia, Heteraiiiplms, Oodemas, Anotheoriis (Curculio-
nidae) ; Labetis (Cistelidae) ; Apterocis (Cioidae) ; Holcobius, Xyletobius (Anobiidae) ;
Eopenthes, Itodacnus, Dacnitiis, Cerat ataxia (Elateridae) ; Apterocyclus (Lucanidae) ;
Labrocertis, Ai'gocerus, Eocerus (Dermestidae) ; Brontolaemus (Cucujidae) ; Antilissus
(Colydiidae) ; Goniot/iorax, Gonioryctus, Nesapterus, Eunitidula, Orthostohis, Cyrtos-
toliis, Apetasiniis, Apetinus, Eupetimts, Nesopeplus, Nesopetinus, Notopephts, Cillaeopepltis
(Nitidulidae) ; Lispinodes, Nesoniedon, Lcjtrocoi'ynus, Xanthocoryims, Holocorynus,
Liophaena, Eiidicstota, Eusipalia (Staphylinidae) ; Blackbiirnia, Deropristus, Atra-
chycnemis, Anchoiejflics, Pseudobroscus, Derobroscus, Brosconymits, Anchonymus, Mauna,
Disenockus, Chalcomenus, Barypristus, Baryneus, Co/podisc7is, Prodisenochus, Aptero-
mes2is, Mysticomenns, Colpocaccus, Atelothrus, Mesothrisctis, Mecostomus, Mecomemis,
Metroniemis, Mecyclothorax, Thriscothorax, Atelothorax, Metrothorax, Gnatholymnaeuni,
Nesolyninacu77i, Nesocidiitm, Atelidiiun, Metrocidiiun, Nesornicrops, Macranillus
(Carabidae).

Proterhinus, representing the fam. Proterhinidae with its very numerous species, is
only known at present by a single Samoan species other than the Hawaiian series.

One or two genera, though described from the islands and not at present known
elsewhere, are, doubtless, introduced. These are not included in the above list. It
may be noted that the greater number of new genera are found in the Carabidae,
Nitidulidae, Staphylinidae, Elateridae and Dermestidae, groups classified by Dr D.
Sharp. It is therefore quite possible that had the abundant species of the families
Curculionidae, Cioidae, Proterhinidae, and Anobiidae, groups worked out by myself,
been described and arranged by him, his profound and special knowledge of the
Coleoptera would have led to the formation of many genera in these families
likewise.

Chrysomelidae. — This family is represented by the introduced pest of the tobacco
and various Solenaceous plants, Epitrix parvula. Probably it has not existed in the

INTRODUCTION cxv

islands for more than 30 years, since it was not collected by Mr Blackburn. It is
very abundant in some localities on the ' Poha ' or ' Cape gooseberry,' Phy salts
peruviana, riddling the leaves, as it does those of the tobacco. One or two other
Chrysomelidae have lately been introduced, but are not included in this work.

Bruchidae. — Bnickus prosopis is now an excessively common beetle, and very
injurious to the seeds of that most important tree the 'algaroba' {Prosopis). Four
or five other species of Brtichis are likewise more or less common, the B. chinensis
being frequently seen in vast numbers in stores, being more domestic than the others.
The larger Caryoborus gonagra is also highly injurious to the seeds of various
Leguminous trees.

Cer.ambycidae. — The single species of each of the genera Parandra and Aegosonia
are apparently endemic. The former often breeds in great numbers in large, standing,
but dead or partly dead, Koa trees, though by no means confined to these trees.
Very minute examples, not one quarter the bulk of ordinary individuals, were found
in small decaying logs of Myrsine and Straussia on Molokai, and very large ones in
very wet logs of entirely decayed wood on Kauai. When mature the beetles may be
sometimes found beneath close-fitting bark, their flattened form allowing of this mode
of concealment. When disturbed, they will feign death. Sometimes they are attracted
to lights at night. The larvae vary greatly in size according to the condition and
nature of their food. They have small but quite well-developed thoracic legs. The
ovipositor of the female is a very strong and hard organ, so that on casual inspection
it might be mistaken for an aedeagus, and this sex wrongly supposed to be the male.
The Aegosonia has much the habits of the Parandra, and is often found in company
with it. Larvae are frequently found in the wettest and most rotten logs or even in
the soil beneath these. They also attack healthy living trees of Myoporum, and in
fact are polyphagous, though usually confined to dead wood. In tracts cleared of
forest and planted with sugar-cane or coffee, they have been known to attack these
beneath the soil. Aegosoma is very readily attracted to light.

Xystrocera globosa has been introduced within the past 20 years and is now
very common in Honolulu. It breeds especially in the wood of some of the foreign
Leguminous trees, that are such an ornament in the city. The beetle may often
be seen resting on the trunks of affected trees in the daytime, or flying round
electric lights at night.

Astrinius kirtus is a common species in and around Honolulu, but has not been
noticed elsewhere. It particularly affects the old ' Hau ' trees on the coast and may
be found resting in the crevices of the bark by day, or seen running rapidly and
in numbers over the surface after dark. It follows the Hau trees to an elevation of
some 1200 feet up the mountain slopes, but is much less common there than near the

P2

cxvi FAUNA HAWAIIENSIS

beach. Widely distributed outside the islands to the west, it was probably an early
introduction from Fiji or Tahiti.

Ceresium simplex is much more abundant and widely distributed than the
preceding. Though most common amongst the algaroba trees of the lowlands, it
has been occasionally bred from native forest trees at an elevation of 1500 ft.
It sometimes swarms around the electric light at night. Ciirtomerus pilicornis is
an introduction from the New World, now very common round Honolulu and
occasionally found as high as 1500 ft. in the mountains. The larva is found in
dead stems of various trees. We have observed it very commonly in the planted
forest of Eucalyptus, immediately behind the city. It is also found in dried stems
of some low-growing plants. The larva is parasitized by Ischiogonus palliatus and
/. pallidiceps. Clytus crinicornis is e.xcessively common throughout the islands on
felled trees of Prosopis, and some of the larger Leguminous species, and does damage
to the wood, if it is left lying exposed to its attack. It is not known to be attacked
by parasites, and is confined to the lowlands and lower mountain slopes. The beetle
is also frequently seen on various flowers.

There are 14 species of the endemic genus Clytarhis, which is closely related
to the larger-sized PlagitJimysus. Excepting C. abnormis, which perhaps is not a
true member of the genus, all the species are attached either to Sophora chrysophylla
or Acacia koa. No species are known from Molokai or Lanai, the almost total
destruction of the native acacias on these islands being no doubt responsible for
their absence. Most of the species are attached to the twigs and small branches of
the trees, whereas the larger Plagithmysi feed usually beneath the bark of the trunks
and larger limbs. The larvae of Clytarhis are now much destroyed in some localities
by the comparatively recent introduction of the Braconid, Ischiogonus pallidiceps, and
/. palliatus also attacks them. In one case we noticed about 90 per cent, of the
larvae of C. fragilis to be destroyed by these parasites. On Maui, the remarkable
bird, Pseudonestor, is continually hunting for the larvae and those of Plagithmysus,
and its stomach is often entirely filled with this food.

Plagithmysus is a genus of larger and more conspicuous beetles than Clytarhis.
There are 33 described species, and one or two still undescribed are known to me,
as well as the larvae of several others distinct from these. They are of very
remarkable appearance and often mistaken by non-entomologists for crickets or
grasshoppers. Their wings are partly exposed, continuing the outline of the elytra,
their folding being abnormal. The hind-body is extremely small, either in both sexes
or at least in the males. Many of the species are able to produce a sound by the
rubbing of the basal part of the hind legs, which are tuberculous, along the sculptured
margin of the elytra ; and some have stridulating organs on the middle and hind coxae,
the middle ones operating on the adjoining edge of the thorax, the hind ones on a
ridge on the basal segment of the abdomen. All have the usual stridulating apparatus

INTRODUCTION cxvii

on the scLitellum. The more slender-legged species run with extraordinary rapidity
on the trunks and branches of the forest trees, and they often perform curious
evolutions, running in short curves or zigzags, and at times almost leaping. Some-
times the hind femora are notably spread outwards and kept well away from the
elytra, as if to avoid their rubbing together. Individuals of many of the species
exhibit great variability. Variation in size is very striking in many species, and
there is very noticeable variation in structure of some, apart from size, e.g. in the
form and development of the pronotal crest. The most conspicuous variability occurs
in the colour of the legs of some of the species, which in this respect are dimorphic
or trimorphic. (Plate XV, figs. 5 — 11.)

Thus in P. aequalis the hind femora are either red or black, and of 181 examined
70 had red legs.

In /*. blackburni of 68, five only had red legs.

In P. lamarckianus black and red-legged forms are both common, the red femora
of the latter usually being black or dark apically.

Of 98 P. variatis 41 had black legs, 53 had black or dark legs with the apical
part conspicuously red, while four were of a nearly uniform reddish colour.

P. varians, P. lamarckiatius, P. blackburni and P. dariviniamis are excessively
closely allied species, and but for the fact that they have been carefully studied in
the field, many might doubt their claim to be distinct. P. c/afivitiianus is very
constant in its uniformly red femora, which are merely of a darker shade in some
than in others.

It is interesting to note the very different nature of the variation in these
species. Thus da7-i.mnia7ius is constantly red-legged, blackburni is black-legged, rarely
with red legs ; lamarckiamis has commonly either red or black femora, varians has
a very common form quite unlike any of the others, a very scarce red-legged form
like dartvinianus or some lamarckianus, and a common black-legged form like
blackburni and some lamarckianus. Other species, like P. giffardi and P. bishopi,
with red femora black or dark apically are extremely constant and no noticeable
variety has been found.

As with Clytarlus, the two native acacias. Acacia koa and Sophora chrysophylla,
are favourite foods of Plagithmysus, for six species are found on the former and
three on the latter tree.

The remaining 25 species are attached to a very varied list of food-plants
(with the rarest exception each being confined to one). Thus Urticaceae, Myrtaceae,
Myrsinaceae, Rubiaceae, Rosaceae, Rutaceae, etc., are attacked. In this connection
it is interesting to refer to the closely allied species of the P. darwinianus group
above mentioned. All these are common species and have been much observed in
the field, and in some spots P. darwinianus, lamarckianus and varians have been
found in numbers within a few yards of one another. Yet in spite of this and the

cxviii FAUNA HAWAIIENSIS

fact that the females of Plagithmysus readily attract the males, not one example of
either of these has ever been found to attack the tree affected by the others, varians
being restricted to Acacia koa, lamarckianns to Pipturus, and darwmianus to Sophora
chrysophylla. It is pretty certain that, however slight be the characters that separate
these species, no interbreeding takes place between them, each remaining constant
to its own food-plant. In fact, almost all the known species of the genus remain
equally attached to their special food-plant, and as it might be supposed that change
from one food to another may have in some of these cases led to the formation of
species, we must refer to the case of P. vitticollis and its van longulus.

The van longtilus is one of the most constant in a general way of the species of
the genus and its larva lives beneath the bark of Bodea, a Rubiaceous forest tree.
P. vitticollis (typical) affects a native species of Rubus (Rosaceae). Some of the
examples (perhaps most) exhibit pallid colouring on the elytra, which is never the
case with the var. longulus. Where the latter form occurs we have not found
individuals attacking Rubus, though it grows there. The true vitticollis, found on
Rtibus, were a few miles from the locality, where the van longulus occurred, and
perhaps no Bobea grew there.

The case of P. bishopi is also remarkable. This is attached to Pelea, a
Rutaceous tree. On one occasion near by some Pelea trees, affected by bishopi,
I found a different tree, Zanthoxylon sp., on which were specimens of this Plagith-
mysus. This particular tree had been known to me for years, when it was in sound
condition, but had now been injured and attracted the beetles. There were many
larvae feeding in the bark and the larger ones were taken and subsequently bred,
yielding perfectly typical examples of P. bishopi. It may be noted that a curious
variety (var. gracilis) of P. bishopi was previously found in the same locality on an
unidentified tree other than Pelea, and I have some suspicion that this tree may have
been of the same species as the one above mentioned. Although the individuals that
were bred proved to exhibit no variation, yet it would have been very interesting to
have continued this breeding, as in course of time it is by no means unlikely that
variation would have shown itself It remains to notice the case of P. sulphurescens
and giffardi. The first specimens of sulphurescens were taken on the Urticaceous
tree, Urera sandtvichensis, and are described as having the base of the elytra fulvous.
Some, captured on the wing I believe, had this part black. P. giffardi shows no
variation and has the elytra black at the base. It is attached to My r sine (Myrsinaceae),
and this may have been the case with examples, taken flying, in my early collections.
It is therefore uncertain whether the two are really distinct.

Whereas most of the species of Plagithmysus attack only unhealthy trees or such
parts as are in unsound condition, some affect those that are apparently quite healthy.
Thus P. perkinsi, as evidenced by the exit holes of the beetles, sometimes breeds
numerously in trees of Myoporum, without noticeably injuring the tree,, and the larvae

INTRODUCTION cxix

of P. speculifer live in the stems of Urera, which appear quite sound. Many of the
species can be obtained in any number by felling the kinds of trees that they affect,
in many cases the beetles appearing in numbers two or three days after a tree is
.cut down and continuing to be found for weeks. P. perkinsi, spectdifer, vitticollis
and others, when in the larval condition, often feed in the actual wood or in the pith
of the trees, but most of the species feed in or just beneath the bark, leaving long flat
grooves, where they have fed. Before pupation, however, these usually enter the
wood for that purpose. A few of the species are much more sluggish than the very
active majority, though even these (e.g. P. puherulenttis and perkinsi) can run with
speed on occasion. In dull weather the beetles are found with difficulty, in fact at
such times and at night they appear generally to leave the trees they affect. In the
very early morning we have several times seen individuals rise out of the underbrush
and fly to the tree trunks, as the sunshine became warmer, they having evidently
rested during the night amongst the lower-growing plants.

Like the common introduced Clytns crinicornis, the males are very active in
pursuit of the females, and both sexes copulate with different individuals. Where
there is conspicuous di- or trimorphism the females will pair successively with males
of each form. The male often accompanies the female as she oviposits, holding on
with the front and walking with the hind legs, and every now and then copulating
afresh.

Plagithniysus is attacked by the two Braconid parasites of the genus Ischiogonus,
one of which first appeared about 15 years ago, while the other (which also inhabits
Fiji) is a more ancient introduction. Several parasites may be bred from a single
partly grown larva. On one occasion, of over 80 larvae of P. solitarius taken on
the mountains just behind Honolulu only two small individuals had escaped these
parasites.

The species of Callithmysus resemble those of Plagithnysus in habits, and the
two genera are intimately connected. The three species inhabit only Oahu, and one
of them, C. cristatus, was formerly considered to be a Plagithmysus. This species
seems closely connected with P. rolnistjis {pidvernlentiis), and the Maui species
P. fimebris is also somewhat similar to these. It would appear that all or most of
the known Oahuan Plagitlmtysus have a tendency towards the Callithmysus form,
the thickness of the hind legs being very noticeable as compared with those of allied
species from the other islands. C. cristatus is attached to Acacia koa and is often
found in company with P. pidverulentus, but C. koebelei is found on Pipttirus and
C. viicrogaster on Bobea, all of which trees are favourites of Plagithmysus.

CuRCULiONiDAE. — The 24 described species of Rhyncogonus are endemic with the
possible exception of one or two, which may be natural immigrants. These R. vestitus
and R. extranetis live outside the forest region and are attached to apodemic plants.

cxx FAUNA HAWAIIENSIS

The former has been observed in enormous numbers, frequenting Vitex trifolia on
the sandy isthmus on Maui, the latter affects verbenaceous weeds on Oahu. The
forest-frequenting species are rather diverse in habits, some moving around freely in
the daytime, others resting at that time beneath bark, in moss, or amongst the foliage.
Many are gregarious or sub-gregarious, so that occasionally a number of examples may
be found resting side by side. Although many are more or less rare insects, there is
evidence that some of these occur in great numbers at times, or at least have been very
numerous, since in some localities we have found the soil full of the detached elytra,
when living examples were not to be found. Many of the species are very imperfectly
known, and in spite of their considerable size are not easily distinguished, being notably
variable both in superficial appearance, and in points of structure. Their headquarters
are apparently on Kauai and Oahu at the one extremity of the group ; none are known
from Hawaii at the other end and but few at present from Maui. There is no doubt
that many of the species are very local or restricted in range on the island that they
inhabit, so that many more species, or at least varieties of known forms, should be dis-
covered in the future. While some like the dense and wet forests, others inhabit very
dry localities, with scattered brush or small trees. Some of the species, such as the
well-known R. blackburni and koebelei, are known to be polyphagous, frequenting
various forest trees and even some species of ferns. The life-history of the former is
to some extent known and no doubt others will be found to resemble this in a general
way. The eggs are laid in numbers between two leaves of Acacia koa (and no doubt
of Straussia, Bobea, etc.) which are glued together. The young larvae on emergence
drop to the ground and no doubt feed on the decaying vegetable matter contained in
the soil. The eggs of R. blackburni are parasitized by the Chalcid, Eupehnus rhynco-
goni, one parasite emerging from each &gg. No doubt other and rarer species will be
found to have similar parasites, the number of eggs laid being out of all proportion to
the number of adult beetles that are found. On Kauai the scarce little thrush,
Phaeornis palmeri, is a most successful hunter of Rhyncogomis, for in all cases these
beetles were found in the bird's stomach, even to the exclusion of all other food, while
they have been found in no other bird.

Pantomorus fulleri is an injurious beetle, imported, doubtless, with hot-house
plants from California. It was not known in Mr Blackburn's time. It first became
conspicuous on Maui, but it is now injurious on Hawaii, Oahu and Molokai. Of the
forest trees it is very partial to Acacia koa, the eggs being laid in masses in cracks of
the bark or in swellings caused by a Tortricid caterpillar. The young larvae fall to
the ground and feed in the soil, the habits being much like those of Rhy7icogonus.
The beede itself defoliates the rose, fruit-trees, and other plants, and in default of other
food it will attack young sugar cane. Being apterous, it could probably have been easily
controlled, if not exterminated, in the first period after its introduction.

Cylas formicarius is another introduction, which still occasionally reaches the

INTRO D i XTION cxxi

islands in consignments of sweet potatoes. The larvae is common not only in these,
but also in some of the wild Ipomoeas, especially /. pes-caprae.

The 21 species oi Acalles are all endemic. They are difficult to collect and very
imperfectly known at present, and being often variable, with great sexual differences,
are still more difficult to separate specifically. Moreover examples in different condition
as to freshness have a very different appearance. Some of the species can, however,
be easily bred from dead wood, and until long series of many species are obtained in this
way their number will remain quite uncertain. With the exception of A. tuberculatus
found beneath small logs lying on the ground, all the species frequent standing trees.
They breed in dry dead branches, and are apparently absent from the wettest forests.
No parasites are at present known to attack this genus. The unique type of Chae-
7iosterniim has much the appearance of an abraded Acalles. Hyperomorpha sqiiaviosa
described (from a single specimen found near Honolulu) by Mr Blackburn, is probably
an introduction. I have felt some doubt whether this may not be Cryptorkynchus
batatas, an insect now common and attacking the sweet potato and other Ipomoeas,
and itself not a true Cryptorkynchus . Another recent introduction is the mango weevil
C. mangiferae, already after a few years' occupation, only too abundant on Oahu.

Sphenophorus obscuriis is the well-known 'cane-borer' of the Hawaiian islands, a
most injurious species to sugar cane, but breeding also occasionally in bananas and
various palm trees. The Hawaiian and Tahitian form, introduced originally into
Maui from Tahiti, and later still reaching Fiji, is a different race from that found
in New Guinea and the Moluccas, the New Guinea form having also been imported
into Australia. The three species of Calandra are introduced, and include the common
rice-weevil, the tamarind weevil (C linearis var. striata) and a more remarkable species,

C. remota. This latter is usually found in banana stems but also sometimes occurs in
those of coconut trees on the coast near Honolulu.

The Cossoninae contain the most important and numerous genera and species
of Hawaiian weevils. The genera Deinocossonus, Nesotocus, Dysonima, Hetiramt)hus,
Oodemas and Anotheorus are endemic, while Orothreptes though not at present known
from elsewhere, will probably prove apodemic. There are 1 7 species of Drophthorus,
one of these D. distingiiendus being probably apodemic. The rest are true natives.

D. distingucndiis is common in the town of Honolulu, often riddling boards, or wood that
is laid upon the ground in gardens. It is also very widely distributed throughout the
forests. Most of the species are polyphagous, their larvae attacking many kinds of dead
wood, either that of still standing trees, or of rotten logs lying upon the ground. Some
species, however, are more particular. D. oahuensis is usually found in the dead wood
of standing trees o{ Piptjcrns, and D.pnsillus inhabits decaying tree-ferns. D. viodestus
is also rarely found in the latter, as well as in many kinds of dead wood, hard or
decayed. The species are difficult to separate, and frequently colonies of several species
are found mixed. The remarkable little insect, for which I made the genus Thalattodora,

F. H. I. q

cxxii FAUNA HAWAIIENSIS

supposing it to be a natural immigrant, proves to be such, and is elsewhere known from
Florida and Australia. It is Dryoiribus viimeticus of Leconte and Horn, It is inter-
esting to find that this beetle has presumably at some distant time reached the small
and remote lying island of Midway, and there has given rise to an allied species. It
is not known whether typical D. mimeticus occurs there also. Examples from the
main islands of the Hawaiian group are in no way distinguishable from American
specimens.

Of the three described species of Pentarthrum, P. obscurum and blackburni are
certainly introduced, the latter attacking boxes of foreign wood in Honolulu, and the
former is, I believe, also known from Fiji. It attacks trees of foreign origin. Another
species of Pentartkrum has recently been imported and lives in the stem of sugar cane.
P. prolixuni on the other hand is truly endemic, found only in the mountain forests, and
confined to the native tree-ferns. It exhibits considerable variability. Orothreptes
callttkrix is widely distributed in the islands, and the genus, if not the species, will no
doubt be found elsewhere. It is attached to the naturally present, but not endemic
tree, Pisonia umbellifera. The minute weevil, Deiiiocossonus nesioies, is found on various
kinds of dead wood, Metrosideriis, Alyxia etc. It is confined to the native forests,
from 1500 ft. to 4000 ft, and shows considerable variability. The natural immigrant
in driftwood, described by me under the name oi Haloxenns immigrans (Vol. 11, p. 148),
belongs to the genus Macrancylus, originally described from Florida. Pseiidolus
longiilus, which we have found in consignments of plants from Fiji, is no doubt an
imported species. P. hospcs, of later introduction, and first found in the boards of the
floor of a room in Honolulu, is now far commoner in the mountains round the city than
P. longuius. Where the latter was once common one now finds only P. hospes, as if
the latter had in some way dispossessed the other. Phlaeophagosoma tenuis is also an
importation, which in recent years we have found amongst Fijian plants, when inspecting
these on their arrival at the wharf. The genus Nesotocus, with four species, is a very
remarkable endemic form, included by Champion in a small group of Central American
genera, distinct from, but allied to the Cossonini. Sometimes these insects are not
rare beneath bark or in crevices of the limbs or trunk of Cheirodendron. Whereas in
drier districts, e.g. at Kilauea, Hawaii, the beetles remain concealed and at rest during
the day, in very wet and dense forests, like those of some parts of Puna and the
Kohala mountains, they are active by day, running rapidly over the tree trunks like
many Longicorns. Dead branches of Cheirodendron are often riddled by the borings
of these species. Individuals vary greatly in size, and, in accordance with this, the
structure is much modified in the small examples, the form of the rostrum, antennal
joints etc. becoming affected. N. kaiiaiensis is remarkable in having the antennae of
the ^ inserted in a different position on the rostrum from that of the others, though
otherwise excessively closely allied. Dysomma sylvicola, only once found amongst dead
leaves, is of uncertain affinity.

INTRODUCTION cxxiii

The lo species of the genus Heieraniphus are of great interest. They seem to
be best represented on Oahu, which yields five of the known forms. H.filiciim is
common in decayed parts of the stems of tree-ferns in the mountains near Honolulu.
It exhibits a good deal of variation, and different colonies apparently sometimes differ
considerably in appearance. H. zvollastoni, foveatus and cylindricus are all common
on the liliaceous plant, Astelia ; sometimes all are found in company on a single plant,
sometimes two of the species are mixed, sometimes only one occurs. On one occasion
a single plant yielded not only these, but H. hirtelbis as well ! It is very remarkable
to find all these species living absolutely together, and with perfectly distinct specific
characters, when we must suppose, that all originally were the product of a single form.
In spite of apparently an identical mode of life, species formation of the most distinct
kind has taken place. Of the four species, H. cylindricus exhibits much variation,
the others are much more constant. H. haleakalae and H. frater are found beneath
rotting logs in the same locality and may not be distinct species ; kaiiaiensis has the
same habit, and violokaiensis was found in wet moss on tree-trunks.

Oodenias is a remarkable endemic genus with 48 described species, with others
known, but undescribed. The species are extremely difficult, many of them being
variable, while some exhibit marked sexual differences and others little or none. The
larvae of all feed on dead wood or ferns, excepting borrei, which is common beneath
stones, where only a scanty vegetation of grass-tufts and a few low plants exist.
O. brunnetmi is found in dry frond-stalks oi Pteris. Many of the species, like O. aenescens,
are polyphagous, attacking the dead wood of many kinds of trees. In fact this species
and some others are even found in stems of low plants. Others, however, are either
solely attached to one sort of tree, or, at least, are rarely found on more than one.
Some of the species, e.g. O. corticis, O. nivicola and O. midtiforvie, are very numerous
in individuals and many of the species are gregarious, so that a number of examples
may be found in proximity. Many, however, are difficult to collect and are still very
imperfectly known. No parasites of these beetles are at present known, but they are
a favourite — perhaps the favourite — food of several species of the remarkable birds of
the genus Heterorhynchus, and the allied Hemignathus also devours large numbers of
them.

A^wtheorus with three species is allied to the preceding. A. montanus breeds in
the dead wood of Aleurites, Acacia koa, Pisotiia etc. in the mountains just behind
Honolulu and elsewhere on Oahu. It appears to have become very much more abundant
of late years than was formerly the case. Once difficult to obtain, it is now a common
beetle, and is sometimes found in company with the introduced Pseudolus hospes and
Dryopkthorus distinguendus.

ScoLYTiDAE. — Three genera with 24 species are considered in this work, but one
or two other genera are now represented by recently imported species. Of the 19

q2

cxxiv FAUNA HAWAIIENSIS

species of Xyleborns two of the most abundant, A', confusus and X. ptibescens, are
introductions by man, and one or two of the other species are very Hkely to prove to
be foreign. X. pubescetis {immaiurus Bl.) is an injurious species, attacking trees that are
temporarily unhealthy, and in that case sometimes causing their death, when otherwise
they would no doubt recover. It may be seen in vast numbers breeding in trees that
are scorched by forest fires, and is sometimes common in the city of Honolulu. It has
also been introduced into Queensland, where it was observed in myriads in felled timber
in one locality, and no doubt it will become ubiquitous throughout warm countries,
wherever the climate is suitable. The native species are very difficult to distinguish
from one another, and there is great sexual dimorphism, so that it is not possible to
associate the sexes in the present state of our knowledge. The males are usually much
rarer than the females, and large colonies of the latter may be found without a single
example of the former sex. One group of large-sized species is attached to the tree
Cheirodendi'on. Others attack Acacia koa, Piptjirus and other trees, while the intro-
duced species are partial to Aleurites triloba, the apodemic 'Kukui' tree. For most
of the endemic species a tree has to be in a particular condition of decay or disease in
order to be attacked. The species of Hypothenenms are, doubtless, all introduced.
H. eruditus is sometimes found in the covers of books, as in other countries, but it
also breeds very freely in the open, in dry stems of many plants, and in the twigs of
many bushes and trees. It is parasitized by a minute Bethylid, probably a Cephalonoiiiia.
H. insularis and H. ruficeps, described by me, are varieties, I believe, of this variable
species. H . viaculicollis is often found with H. eruditus and is very common in twigs
of tamarind. Hibiscus, and many other trees and plants. It is also fond of boring in
the trunks of large avocado pears [Persea) when these are not quite healthy, and
aggravates their condition. Crossotarsns externedentatus sometimes joins in the attack
on this tree and becomes very numerous. The species of Hypothenenms are mostly
confined to the lowlands or lower elevations rarely attaining an elevation of 2000 ft. in
the mountains.

Anthribidae. — Represented by only foreign forms, unless, as is improbable,
Araeocerus constans, which is very closely allied to the introduced A. fasciculatus, should
prove to be endemic. It is very common in the Kona district of Hawaii, frequenting
the flowers oi Argemone mexicana. A. fasciculatus is one of the commonest of beetles,
breeding in immense quantities in the fruits or seeds of many native and foreign trees,
and also in dead wood, dry stems of sugar cane etc. It is occasionally parasitized by
an Etipelmus. It ranges from the coast, throughout the mountain forests of all the
islands. Of recent years two or three exotic Anthribids have become imported and
established. These belong to the common tropical genera that have the antennae
greatly elongated. One of them we have found swarming in consignments of coconut
drupes imported for seed.

INTRODUCTION cxxv

Proterhinidae. — This family, excepting for a single species, which inhabits Samoa,
is at present only known from the Hawaiian group. Here about 130 species have
been recognized, and these form an assemblage exhibiting great variety of structure.
The discrimination of the species is a matter of very great difficulty owing to the
variability of many of them, and which are true species and which mere local forms or
varieties is very incompletely understood. It is quite certain that many of the species
apart from great variability in examples taken in the same locality, also exhibit local
variation, and further some are known to vary according to the nature of the food-
plant. There is often great variability in the size of the individuals of a species, and
concomitantly with this, the structural characters become modified. Some of the species
are polyphagous, feeding in the dead bark of widely different trees. Thus P. vestitus,
which may be considered the type of the genus, is found on the Kukui, Aletn-ites
(Euphorbiaceae), o\\ Pipturus (Urticaceae), on Charpentiera (Amarantaceae), etc. This
species does not show any particular variation in accordance with the food-plant. Other
species, on the contrary, such as P. oscillans and P. laticollis, are attached only to one
species of tree, those just mentioned breeding only on Acacia koa. Stragglers may be
found accidentally on other plants, having become dislodged from their proper habitat ;
and even at some distance, when, after high winds, by which branches or twigs are
detached and carried to a distance, the beetles leave these in search of a proper breeding-
place. Several species, e.g. P. longtihis, are found only on tree-ferns, while P. pteridis
is attached to Pteris and P. s/iarpi to an undetermined, but not arboreal, fern. A few
species leave the stems to feed on growing leaves of the trees they affect, and some
form burrows in the leaf stalks. Many of the species are gregarious and it is a
common occurrence to find a dozen or even many more individuals resting side by side
beneath dead bark. Sometimes quite different species are associated together in these
flocks. The apodous larvae are often found feeding in the bark, beneath which the
adults congregate, but some enter the solid wood of hard trees, while some breed in
the leaf-stems of ferns. Proterhinus is ubiquitous throughout Hawaiian forests, where
any native Coleopterous fauna remains, and ranges above these to a height of 9000 ft.
or more on the higher mountains, affecting the shrubs that grow at high elevations.
They entirely cease to exist in the lower forests, where these are well occupied by the
ant Plicidole megaccphala, which rapidly exterminates them. Doubtless, there has once
been a considerable number of species, inhabiting areas at lower elevations, which are
now extinct. Not a single species is now known from the coastal region of the islands,
though the Samoan species was found in coconuts, that had been grown on the coast,
in that group. It is probable that numerous species remain to be discovered outside
the Hawaiian islands, and possibly some forms will be found connecting Protcrhimts
more closely with the New Zealand Aglycydercs.

Apart from size, colour and clothing, the variation that has been noticed to exist
in individuals of colonies of Proterhinus affects the size of the eyes, length of antennal

cxxvi FAUNA HAWAIIENSIS

joints, the shape of the pronotum and the development of the humeral angles of the
elytra. As all these characters have to be used for the differentiation of the species,
it may readily be understood, that years of study may be necessary before a satisfactory
elucidation is attained. With regard to the variation in the individuals of the colonies
mentioned above, it is worthy of note that we have found in the case of some species
that whereas the individuals of one colony exhibit no variation of note, in another colony
may be found examples so variable that, had the extreme forms been found apart, one
would have hesitated to consider them as belonging to a single species. Whether this
is due to the mating of similar parents in the one case and of dissimilar ones in the
other can only be settled by experimental breeding in the homes of the insects. They
do not thrive if removed from the forests, and may even be affected in superficial
characters, when bred on the lowlands. Thus a series of P. vestitus reared in Honolulu
could not be matched in colour by any of many specimens gathered from the very same
trees at an elevation of about 2000 ft. in the mountains.

Oedemeridae. — Oxacis collaris described from the islands, is certainly an importa-
tion and has often been seen in great numbers on foreign trees and shrubs about the
town of Honolulu, and of recent years has spread throughout the island of Oahu.
Doubtless, it will reach the other islands, if it has not already done so ; sometimes it is
extremely abundant at light. It sometimes visits certain flowers in the daytime, and at
a time when many of the shrubs in Honolulu were covered with the Coccid, Ceroplastes
rubens, it literally swarmed over the foliage, probably attracted by the excreted honey-
dew. Quite recently one, if not two other Oedemerids have been imported into the
islands, but have not yet become generally abundant.

AxTHiciDAE. — The two species of Anthicus, which frequent the neighbourhood of
the coast may be natural immigrants, being widely distributed in the islands, and one of
them, at least, is very abundant. A. oceanicus has been recorded from the Marquesas.

CiSTELiDAE. — The genus Cistela contains seven described endemic species, and
Labetis with five is supposed to be endemic. The species of Cistela are closely allied
and difficult to determine and as a rule not numerous in individuals, so that they have
been imperfectly studied. They appear to be diurnal as they are found on the foliage
of trees and on ferns in the daytime and occasionally are seen on the wing, as is the
case with the Labetis of Kauai. The species of the latter genus that occurs on Hawaii,
however, is nearly always found resting beneath the bark of Acacia koa in the daytime,
several examples being sometimes found in company and we do not remember seeing it
active in sunshine like the others. The species are extremely closely allied and the
larvae are not at present certainly known, but Tenebrionid-like larvae, superficially
somewhat similar to those of some Eucnemidae and found with these are probably to
be referred to the Cistelidae.

INTRODUCTION . cxxvii

Tenebrionidae. — The seven genera recorded are of little interest, most of the
species being certainly importations, but four Epitragus diremptus, Platydema obscurum,
Opatrum seriatum, and Sciophagtis pandanicola are possibly natural immigrants. The
latter now seems to be rarely or never found. There are a few other Tenebrionids
now present, of quite recent introduction. Alphitobius lateralis appeared on Oahu
about 20 years ago, and has since spread and become one of the commonest of insects.
The larva of Opatrum is not infrequently found in the soil beneath the droppings of
cattle, and is probably predaceous on the Diptera so abundant in these.

CioiDAE. — The 42 species representing this family have been placed in two genera,
the apodemic genus Cis having 29, and the endemic Apterocis 13 species. They are a
varied assemblage of forms, and will probably at some time be split into more numerous
genera. Cis paci/iats is a very commonplace species, as compared with its congeners,
and resembles foreign forms. It is very common in foreign fungi growing on trees that
are not endemic, and I suspect it will itself prove to be foreign or an importation. One
or two other species are likewise doubtfully native. Very few of the Hawaiian Cis are
found in the larger fungi that grow out from the trunks of trees, but Cis roridus and
bimaatlatics are found in these, though not confined to them. Most of the species live
beneath bark of trees, feeding on the smaller or microscopic fungi that grow in this
situation. Cis laetiailns we have found, both mature and larval, on dead fallen leaves of
Freycinetia, the larvae no doubt feeding on the fungi growing on these. Many of the
species are widely distributed throughout the islands and very numerous in individuals,
and they also exhibit much variability. Some of the species of Cis, as also all of those
belonging to Apterocis, are flightless. With regard to the former it is not certain whether
some may not have fully-winged and flightless individuals as well. One or two of the
species referred by me to Apterocis, I believe, from more recent examination, to be fully-
winged and they should be transferred to Cis. The Hawaiian forms are a very interest-
ing series and particularly require close observation in the field and need still more to
be bred in captivity, in order that the limits of variation of the species may be correctly
determined. Some of the wingless Bethylids {^Scleroderma) are sometimes bred from
wood containing these beetles, but it is not certain whether they are parasitic on
them, or on other insects (especially caterpillars) found in the same wood. The minute
Braconid, Ecliphylopsts nigra, is also obtained from wood in which these and other
small endemic Coleoptera are breeding. The abundance of the beetles and the com-
paratively great rarity of these parasites show that, if parasitic on Cis, the latter are of
little effect in reducing the numbers of the former.

BosTRiCHiDAE. — The six species, each belonging to a different genus, are all intro-
ductions by man. They are none of them forest insects. Some of the species are very
injurious to felled timber, whether destined for fire-wood or for other purposes, reducing

cxxvni

FA I 'XA HA J J A/IEXSIS

the wood in time to a powdery condition, by their numerous burrows. Bosfn'ckus
mi<rrator Sh.. a species we have found in Mexico, has proved destructive to wooden
tanks and even to the wood of some houses. Xylothrips religiosa and, I beHeve, some
of the other species are attacked by the introduced Braconid, described by me as
Hormius (?) peregrimis, which apparently really belongs to the little known Helconine
srenus Euscelinus of Westwood.

LvcTiDAE. — Two imported species of Lyctiis, one being the well-known European
L. bmrnneus, are of no particular interest. V<& have seen L. brunneus in great numbers
beneath the bark of large trees injured by fire.

Anobiidae. — The imported insects of the genera Catorama, Anobium and Lasio-
derma are importations by man and of no special interest, except to the economic
entomologist. Hokobius with 12 and Xyletobius with 52 species are endemic and allied
to one another. The species of the former are nocturnal, those of the latter diurnal and
sun-loving, and often seen in numbers basking on the leaves of forest trees. Hokobius
may be found sitting near their burrows on the trunks of dead trees after dark. Some
of the species of Xyletobius are ver)^ abundant and of wide distribution. They breed in
dead wood as a rule, but some of the species have been taken ovipositing in sickly trees,
which, however, were by no means dead. It appears that some and perhaps many of
them are particular in their choice of food, feeding only on one species of tree. Some
of the larger species are known to be parasitized in the larval condition by the Encyrtid
genus Eupebmis, and they are occasionally found in the stomach of insectivorous birds.
They do not thrive in the densest wet forests and sometimes are quite absent from
these, but are most abundant in more open and drier woodlands. In their company one
frequently finds the endemic Dermestidae which seem very regularly to be associated
with them, and sometimes considerably resemble them in superficial appearance. The
definite variations in the pattern of many Xyktobius is of an interesting nature\ Some-
times these distinct varieties of a species are all found in company, but sometimes they
appear to be of local occurrence. The larger insects of the genus Hokobius are some-
times found on tree ferns, but it is not known whether they breed in these. Some
species have been bred verj- freely from very dry dead wood, e.g. from posts used as
supports of an outhouse. Occasionally examples are attracted to light at night.

The species of Mirostenius are very numerous, no less than 70 apparentl)- distinct
forms having been distinguished. The discrimination of the species is extremely
difficult, since man)- are closely allied to one another, some are variable, and whereas
some present extreme sexual differences, others hardly differ in external sexual characters.
Consequently the number of species given is likely to need some modification. In their
habits the Mirostenius resemble Xyktobius, being sun-loving insects, and very sparsely
represented in the wettest or densest forests, but in more open woods some species are
' See Plate XVI, figs. 11 — 16, for varieties of X. proteus.

INTRODUCTION cxxix

very numerously represented. Many of the individuals, that are dislodged by beating
bushes, take wing and may sometimes be seen beating up against the wind to regain
their position. They are often observed in numbers on the upper side of the leaves,
remaining motionless, rarely active. Only a fraction of the number of known species,
however, occurs in profusion, many being very scarce. They breed in dead wood, and
when the bark is stripped from dead Koa trees, one sometimes finds the remains of
thousands of examples beneath this. They chiefly affect the same trees as the species
of Xyletobius, and in fact are generally taken in company with these. It is not definitely
known whether they are attacked by parasitic Hymenoptera, but it is most probable
that the small Chalcids of the family M iscogasteridae, which parasitize other small
Coleoptera, affect them also. They are sometimes found in the stomach of native
Drepanidid birds, but not as commonly as are the brassy weevils of the genus Oodemas.
Species of endemic Dermestidae are very commonly found in company with Miros-
ternus, and some of them superficially resemble the latter in appearance. Although
described first from the islands, Mirosternus is now known to inhabit tropical America,
and the Hawaiian forms are probably derivatives from a very ancient introduction from
that region.

Cleridae. — Represented only by three widely distributed species, introduced, no
doubt, by man. The two species of Necrobia {rujipes and ruficollis) are often abundant
in the remains of dead animals, but Tarsostenus univittatus does not seem to flourish in
the islands. It is generally found on dead posts bored by various xylophagous beetles,
and we have only seen it at large at night time.

Malacodermidae. — Helcogaster pectinatus has been found only in and around
houses in Honolulu, and we once observed a small swarm of males, entering a room
through the meshes of the mosquito blinds covering the window. Probably they were
attracted by a female somewhere within the room, but the latter was not observed.

Caccodes debilis is likewise a Honolulu insect, generally found in or close to houses,
but once observed in a plantation of foreign trees a few miles from the town. Both
these species, sole representatives of the Malacoderms, are, doubtless, importations,
though not yet known elsewhere.

Elateridae. — Five genera, each represented by a single species, are certainly
importations. Of these Melanoxanihus melanocephalus is often seen in the windows
of stores in the town of Honolulu, but is also found in the country. Adelocera
modesia is common on Oahu, but during the period of my systematic collecting was not
observed on the 6ther islands, though it may now have reached some of these. Simo-
dactylus chinamonieus is generally distributed throughout the group, the beetles being
often observed in numbers at the bases of leaves of liliaceous and other plants, and also

F. H. I. . r

cxxx FAUNA HAWAIIENSIS

on flowers, while the larvae are found in decayed wood, stems of sugar cane, &c., and
are known to be at least partly carnivorous. The large Chalcolepidius erythroloma is
sometimes numerous on Oahu, especially near Honolulu, but has not, so far as is known,
yet reached the other islands. It is commonly seen at the sap oozing from fungus-
attacked trees in the lower forest, especially on the Koa and Kukui, and the larvae
occur in the dead wood of the latter. We have also found these in the wood of living
orange trees, once in such numbers as to be apparently doing injury, but the trees were
sickly.

Monocrepidius exsul is the latest importation in the Elateridae, it having been first
noticed in 1900, and now is the most plentiful of this family on Oahu. It is attracted
to light on dark nights in extraordinary numbers, especially in the vicinity of cane-fields,
where it breeds in the trash.

Eopenthes is an endemic genus with 2)2^ described species, many of which are rare
and imperfectly known, the species being extremely hard to distinguish. Some have a
constant colour pattern, while others are very variable. In the latter case individuals of
one species may be of two or three quite distinct patterns of colour, these same colours
being of specific value in other species and not varying. These beetles are remarkable
amongst the Hawaiian Coleoptera for several reasons. They are almost entirely
summer insects or at least do not occur between November and March. They are
almost the only native beetles found visiting flowers for the sake of the nectar, being
especially fond of the blossoms of Metrosideriis. They are also largely of diurnal
habits. Unfortunately many of them appear to be rare or this may be partly due to
their comparatively short season, on account of which the travelling collector does not
happen to be in the right place at the right time.

Eopenthes koHae, a very variable species, is very abundant and widely distributed
on Hawaii and is found in all sorts of situations, even under stones. The larvae are
common objects in the forests of all the islands, being found in rotten wood, and are
often seen in numbers, when adults are rare, or not observed at all. No parasites
were obtained from the few I was able to rear.

Itodacims, another endemic genus with eight species, is nocturnal in its habits,
or at least some of the species are so, and /. gracilis may be seen on the wing in
numbers at dusk. In the daytime they hide beneath the bark of trees, sometimes
a considerable number in company. The larvae also have been found beneath bark,
and the adults are attracted by light. Dacnitus, with a single species, is probably
a terrestrial species. It was only once found beneath a log on very wet mud, in a
boggy forest. It is allied to Jtodacnus.

The Eucneminae are represented by 33 endemic species of Dromaeohts and a
single one of an endemic genus Ceratotaxia. They have been even more imperfectly
collected than the true Elaters, and as in these, the larvae are more numerous than the
adults. Unless found full grown, these larvae generally die if removed to the lowlands,

IN TROD UC riON cxxxi

and no beetles are raised. They are, however, easily reared in the forest region and
until this has been extensively done, the species are likely to remain uncertain. The
adults are usually found beneath the bark of trees, or, when just freshly emerged, in logs
or the dead stems of growing trees, where the larvae have fed. Some like D. perkinsi
can bore into the hardest wood, others like D. obscitrns have been found in the wettest
and softest of rotten logs. Some occur in the moss on tree trunks, and a few species
are, but very rarely, taken on the wing in the sunshine. Some of the species are wing-
less. They are not partial to flowers, like Eopenthes. Acacia koa is a favourite tree
with this genus, and a number of species are attached to it. On old koa trees great
quantities of the remains of these beetles are often seen beneath the bark, probably in
evidence of many generations having bred therein.

BuPKESTiDAE. — Unrepresented in the native fauna, but with three imported species
established. Two of these are common North American species of Biiprestes and
appear not to thrive in the islands. Perhaps they are not really established, but are
brought in from time to time with the heavy shipments of lumber. An obscure
Agrilus attacking leguminous trees, probably more or less unhealthy, was so abundant
in 1900, as to appear to be an injurious insect near Honolulu.

ScARABEiDAE. — Trox scaber, Aphodius lividus, three species of Ataenius and
Saprosites pygniaeus, an undetermined Psaitmiobius and Adorettis temdmaculatus, all
imported by man, alone represent this large family. The latter, introduced from Japan
about 1896, is an injurious insect, and for a time defoliated many ornamental plants,
and threatened to destroy some of the forest trees. Afterwards becoming attacked by
a fungous disease, and this being artificially spread, it ceased to become so serious
a pest, though always numerous. Subsequent to its introduction, we have found the
larva abundantly in soil contained in boxes of plants brought from Japan, when inspect-
ing introduced plants just landed from a steamer from Yokohama.

LuCANiDAE. — Represented only by the endemic genus Apterocycltis, found only on
Kauai, where seven forms have been distinguished. All these forms were collected
within an area of a few square miles and their specific distinction seems uncertain.
The larva has been found in and beneath rotten wood, and a newly emerged beetle was
once taken in a rounded cavity in the soil beneath cow-dung in an open place away
from trees or fallen wood.

Dermestidae. — The allied genera Labrocerus with 18, Argocerus with two, and
Eocenes with a single known species are all endemic and of considerable interest.
Some of the species are quite common and we have always found them in places
frequented by, and usually in company with, Anobiidae, and there is probably some real

r2

cxxxii FAUNA HAWAIIENSIS

connection between the two, though their habits are not known. Like the Anobiidae
they sometimes frequent the foliage of plants, and some of them have a striking super-
ficial resemblance to certain species of the former. These superficially similar species
in the two groups are sometimes actually found in company. On^one occasion an
Anobiid was found far below the usual range of these insects, near the coast, and even
in this case a Labroceriis i^L. airtico'nis) was found on the same tree. It seems possible
that the larvae of these Dermestidae prey on the Anobiidae. Larvae of Dermestids
beaten from dead branches of trees in the forests, no doubt belong to Labrocerus,

Attagenus plebeius is often found in houses, and is certainly introduced, as also are
the two species of Crypiorhopalwn, both of which are found in Honolulu and probably
all over the islands, on the lowlands. The larva of one species is often noticed on
the sheath of dead palm leaves, when these fall from the trees. The two species of
Dermestes, common introduced species, are abundant in carcases of dead animals, and
range to high elevations in the mountains.

CocciNELLiDAE. — Only four species of this family occurred in the islands twenty
years ago, but since that time numerous genera and species have been imported for
economic reasons. These have now, many of them at least, become the commonest
and most ubiquitous of insects. The four species found by Mr Blackburn, all still
occurring, are, doubtless, importations by accident, excepting perhaps Scyninus ocellatus,
which might be an immigrant. I have been told that this species is identical with a
species in the Galapagos Islands. S. discedens Sh. appears to be the »S. debilis of
Leconte and S. vividus Sh. is said to be S. loewii of Mulsant. Cycloneda abdominalis
is certainly much less numerous than was the case twenty years ago, but now it has to
compete with a number of other introduced species, which have the same food and are
far more successful.

Erotylidae. — Represented only by Euxestus minor not known from elsewhere,
but probably an importation, as it has only been found on Oahu, and by Eidoreus
minutus, which has been found actually in Honolulu, and is very unlikely to be
endemic.

CoRYLOPHiDAE. — The five genera of this family contain, so far, only six species,
which are all known only from the islands at present, and four of these have only been
found on Oahu, mostly near Honolulu. Sericoderus piibipennis and Orthoperiis
aequalis are of wide distribution throughout the group, in the mountains, and are found
in fungi on Koa and Kukui trees, but it is probable that these, as well as all the others,
will be found elsewhere. These others belong to the genera Sacium, Anisomeristes and
Corylophodes, the latter with two species.

INTRODUCTION cxxxiii

Mycetophagidae. — Of the two species of Lihirgus, L. balteatus is American, and
L. vestitiis, though described from the islands, will doubtless prove to be foreign, as it
has been found out of the range of endemic beetles on foreign trees. I think that
both species occur in the town of Honolulu at times, and one or other species of the
genus sometimes abounds in decayed stems of sugar-cane. Propalticus oculahis is
also certain to prove an introduction, for though it occurs in the forests, we find it in the
town of Honolulu,, sometimes in dead stems of introduced Hibiscus. TypJiaea ftimata
is of course an importation.

Mycetaeidae. — Represented only by the introduced Mycetaea hiria, and it is
uncertain whether this has become established.

Lathridiidae. — Only represented by the foreign Lathridius nodifer and Colovocera
maderae, the latter first observed in 1900 in foreign ants' nests, in and close to Honolulu.
L. nodifer, though widely distributed, only occurs in very small numbers, usually
amonofst fallen leaves in the forest.

&

Cryptophagidae. — Cryptophilus integer an introduced species, found in Honolulu,
and the European Henoticus serraius, also, no doubt, imported, are the only repre-
sentatives of this family.

Cucujidae. — This family is of more importance than the several preceding, though
six of the eight genera represented are represented probably by only foreign species,
importations by man. Bronto/aetnics is an endemic genus with four closely allied
species, showing considerable variation, and they are mostly difficult to distinguish.
They are nearly always found on trees affected by the longicorn beetles, especially
Clytarhis and Plagithmysus, occasionally on the Kukui tree [Aieurites) when the foreign
longicorn Oopsis nutator is breeding therein. The six described species of Parandrita
are still more difficult to separate and are imperfectly known owing to the rarity of most
of the species. They apparently have the same habits as Brontolaetmis, but usually
occur singly or only one or two examples together, whereas e.xamples of the latter are
frequently found in some numbers together.

Laeinophlaeiis minuius is an imported species and may be found in Honolulu
beneath the rind of Hibiscus and other trees attacked by other beetles. It is often
very common in stores in Honolulu, being numerous in rice and other produce, in
company with the usual insects affecting such produce.

Psammoechus insularis and other species of the genus as well as Monanus have
been found in plants imported from other countries and, doubtless, are all introductions
by man, while Cryptotnorpha desjardinsii comes under the same category. It is an

cxxxiv FAUNA HAWAIIENSIS

extremely common beetle, very partial to banana plants. The representatives of
Cathartus, Silvanus and Nausibius are also importations and of no interest.

CoLYDiiDAE. — Antilissiis is an endemic genus with only one species {^A. aper). It
is an abundant forest insect, and very widely spread throughout the islands, found
usually beneath bark of Straussia, often many individuals in company. Glyptoma
blackbiinii, a Staphylinid, frequently lives with it, and the larvae of both occur with the
mature beetles. It shows some variation, but being so different from any other
Hawaiian insect, this is not usually noticed. This is the only native Colydiid.

Minthea rugicollis and Colobicus parilis have been found in or near Honolulu
beneath bark. The latter first appeared about 1 900, and became very numerous on the
trees killed or injured by fire in the conflagration that took place in cleaning up the
city, during an epidemic of plague. The minute beetle Derolathrtis was first found
about the same time, but only in trees on the edge of the road round Mt Tantalus,
where house-building was being actively engaged in, and much lumber carried up. It
was common, and has since spread to some extent.

DiscoLOMiDAE. — The single species of Fallia, very closely allied to a Central
American species, will probably prove to have been introduced. It has been found in
the common hard fungus on trunks of Aleiirites (though not confined to these), and
like the fungus itself and the few other beetles found therein is no doubt foreign.

Trogositidae. — Represented only by Tenebroides mauritanicus a cosmopolitan and
imported species.

MoNOTOMiDAE. — Represented only by Hesperobaemis capita, usually found in the
mountains, but once found in Honolulu in decayed sugar-cane. It occurs all over the
islands and is sometimes numerous in the inflorescence of Freycinetia, in company with
foreign Nitidulidae {Haptoncus tetragomis) and also with native species of that family.
The larvae occur on the Freycinetia with the adult.

Nitidulidae. — This family is extremely richly represented by 138 species that are
endemic, and a few introduced forms. Excluding the latter there are 13 genera, all
endemic, mostly evidently related to one another. Those of which the relationship to
the others is doubtful {Notopephcs and Cillaeopepliis) contain only three or four species
in all. A considerable variety of habits is exhibited by the Hawaiian series, so that the
allied forms have occupied most situations in the islands, that are affected by these
insects in other parts of the world. A few species are terrestrial, living amongst
decaying leaves. These are excessively sluggish, and have the size of the eyes reduced
and are flightless [Apetiniis explanatus). The four flightless genera have arisen

INTRODUCTION cxxxv

independently from winged forms, and are not closely allied to one another. So far as
at present known they contain few species, only nine in all having been discovered.

The species of Goniothorax and Gonioryctus, with nine and twenty-four species
respectively, show considerable diversity of habits, some frequenting the fleshy in-
florescence of Freycinetia, others living at the base of the leaves of this plant or
Astelia, the fresh flowers of which are attractive to the adults ; some are found in
flowers of Lobeliaceous plants, and breed in the almost liquid, decaying stems of these
trees, of Cheirodcndron and others ; some live and breed beneath the bark of hard-
wooded trees like Acacia koa, and others in decaying tree-ferns. The flightless species
of Nesaptcriis have the habits of the latter. The species of Orthostolus breed in the
semiliquid mess or exudations beneath the bark of Lobeliaceous trees or others.
Several are attached to Acacia koa and usually a number of examples, from three
or four to a hundred or more, are found in company. Apetimis is either terrestrial, or
found beneath bark of decaying branches. Eupetiniis contains 24 species, and is allied
to the preceding, but fully winged. Many of the species are very common insects and
the individuals vary much, .so that the specific distinctions are extremely difficult to
make out. I spent a great deal of time in the collection of colonies of species
of the ' impressus ' group in order to try and understand the limits of variation of
these, but owing to apparently distinct species being found together and the variability
of all, I was not able to arrive at any satisfactory conclusion. The individual species
show a good deal of variation in their habits, breeding in quite different plants. Most
of them are attached to dead wood, or to fleshy flowers and decaying inflorescences,
and a few to tree-ferns. All are very sluggish, and it is seldom that one is seen on the
wing, but possibly they are nocturnal in their activities. The large genus Nesopeplus
with 32 and Nesopetiims with 25 species seem closely connected by some of their forms,
and the latter has species evidently connecting with Gonioryctus, so that in collecting
I always supposed them to be small species of the latter genus. This is the case with
the common N. tinctus, which is sometimes found with Goniorycttis on flowers of
Astelia. Some of the species of these large genera have habits like those of Eupetinus
and are found in company with them on Lobeliaceous flowers and Freycinetia and also
in fruits of forest trees, but others frequent small inconspicuous flowers, e.g. those of
Kadua, and even the larvae have been found in these. Some are evidently very
particular as to the kind of tree they frequent, or are entirely restricted to one kind, but
others are much less fastidious. Some breed in rotten stems of tree-ferns. Many of
the flower-frequenting species do not breed in the flowers, but only resort to these for
food, apparently eating the pollen, with which they are sometimes quite covered. The
Ohia flowers, with their abundant nectar seem to be rarely or never visited, though the
beetles may be obtained from the dead wood. Many species are very abundant and
they are very difficult to determine and will no doubt be much more so, when all that
exist have been collected. Notopeplus reitteri is an isolated form, attached to the

cxxxvi FAUNA HAWAIIENSIS

banana plant, in which it breeds, and is widely spread over the islands. It has been
taken from tree-ferns, but its occurrence there may have been accidental. The minute,
elongate and flattened species of Cillaeopephis are found on various trees, beneath the
bark. C. infiimts, the best-known species, is not attached to one plant, as we have
found it breeding in decayed parts of Pisonia and on the Urticaceous Piptiirus and
Urera.

The four species of Carpophilus are all importations, and are either domestic, or
found in decaying flowers or fruit. C. humerahs and others are sometimes very
abundant in rotten sugar-cane stems. Both the species of Haptonciis are also found in
the latter and also in flowers and fruits, and are certainly introductions. No parasites
have been obtained from any of the Nitidulidae, but they are sometimes killed by
fungous disease, which is rarely epidemic. I do not remember to have ever found any
Nitidulidae in dissecting the native birds.

HiSTERiDAE. — The single species of Carcinops and two of Saprinns are certainly
introductions, and the very minute beetles, Bacanius atomarius and confusus, found only
near Honolulu by Mr Blackburn, may also be so. The species o{ Acritus 34 in number
are probably all endemic, with the possible exception oi A. insularis, which, found only
near Honolulu, belongs to a different section from all the others. These are all found
in dead wood or generally beneath dead bark, especially where there is moisture and
decay. It is not known whether they are carnivorous, like most Histeridae, but as
larvae of Mycetophilidae and Drosophilidae occur in the same places, it is quite likely
that they prey on these. Some of these beetles are flightless, having rudimentary
wings, others are fully winged, though we have never seen them expand these. It
is usual to find several examples in company and these companies sometimes consist of
two (and possibly more) quite distinct species. Owing to the nasty mess in which they
often live, I have no doubt I neglected to take nearly as many examples as I might,
because they foul and stick to other cleaner insects, and such creatures would be better
collected apart or in alcohol. They are not really uncommon and are ubiquitous
throughout the islands in the forests. Aleurites, Acacia, Pipturns, and especially
Cheirodendron are some of the trees that they affect.

ScAPHiDiiDAE. — A single Scaphisoma, found only in the Waianae mountains of
Oahu, represents this family. It is very doubtfully indigenous.

SiLPHiDAE. — A single individual of Clainbus found near the active volcano, to
which there is much traffic, alone represents this family. It is probably an intro-
duction,

Trichopterygidae. — I suspect that all the members of this family are foreign, for
I have found two species in the town of Honolulu (one in decayed cane and one beneath

INTRODUCTION cxxxvii

bark ot foreign Hibiscus) which are certainly importations. Some doubt may attach to
the species of Ptiliodes, but two of these have only been found near Honolulu and the
other which is found beneath Koa bark in the high forests of Hawaii and elsewhere,
also occurs close to Honolulu. The other genera represented are Actidiuni, Ptinella
and Tric/iopteryx, each with a single species.

Staphylinid.ae. — Of the tribe Piestini the genus Thoracophorus has two endemic
species, one common and variable, ubiquitous over the islands, beneath dead bark of
Straussia and sometimes on Bobea, the other apparently very rare and its habits not
known, except that it is also found beneath bark. T. blackburni is excessively sluggish
and often occurs in numbers together, in company with Antilissiis aper. The single
representatives of Lispiniis and Ancaais are both foreign, found in or near Honolulu,
and, no doubt, introduced by man. Lispinodes, an endemic genus, is evidently rich in
species, ten having been described by Dr Sharp, but individuals seem to be extremely
rare. We have always found these in company with Thoracophorus blackburni, or more
rarely with species of Diestota and Myllaena, but have only observed one example of
Lispinodes to scores or hundreds of individuals of the other genera, on an average.
They are always found beneath bark, generally where there is much moisture and
decay.

The Oxytelini are probably unrepresented in the native fauna, unless one or other
of the species of Trogophloeiis prove to be endemic or naturally immigrant. From the
habits of the Hawaiian species I do not feel sure that these could have been imported
by man. On the other hand the four species of Oxytelus have certainly been imported.

In the Paederini Lithocharis vilis and the two species of Medon are probably
importations, less probably natural immigrants, but the two Ophioinedon probably and
three Nesomedon certainly are endemic. N. brunnescens is found in wet boggy forests
under moss or bark and the others are true forest insects, probably of similar habits.

Of the Staphylini the four Philonthi, Creophilus maxillosus, and Cafius nauticus
are foreign, whereas the three allied genera Leurocorynus, Xanthocorynus and
Holocorynus are endemic genera, together containing only four species, all of which
excepting the variable Leurocoiynus cephalotes appear to be rare insects. I fancy that
all are attached to the tree Cheirodendron, under the bark of which they live, sometimes
larvae and adults together. Leptacinus flavipennis is an imported insect, found by
Blackburn in Honolulu. Other Staphylinidae which prey on Dipterous larvae in cow-
dung, like some of the Philonthi above mentioned, have been introduced for economic
reasons, but it is not known whether these are established.

The greater part of the Staphylinid fauna is found amongst the Aleocharini,
Myllaena with eleven species, Oligota with 28, Liophaena endemic and allied to the
preceding with three, Diestota with 29, and Eudiestota and Eiisipalia endemic and
allied to this, with one each. All, or almost all, these species are endemic and of great

F. H. I. s

cxxxviii FAUNA HAWAIIENSIS

interest. There are two species of Atheta, one imported, the other possibly so, though
not known elsewhere. The species of Phloeopara, Xenusa and Stenagria are not likely
to be endemic and are very probably importations.

The native Myllaena, Oligota and Diestota all exhibit much variety in their habits,
but species of all of them are found in decaying trees beneath the bark, and we have
found all together in a single tree Lobelia. Some of the species of Myllaena only
occur under stones, especially on the edge of streams, others are found in the flowers
of Freycinetia or Lobeliaceae with Diestota, Nitidulidae, etc. Some are only found
beneath large decaying logs. The Oligotae besides occurring under bark of various
trees are some of them specially attached to the foliage of plants, e.g. trees of the
composite genus Dubautia. Liophaena appears to be partial to dry, or moderately dry,
dead branches of trees especially Acacia koa.

There are a good many common species amongst the three large genera above
mentioned, but they require special collecting and the very minute Oligotae are easily
lost, unless a special bottle is carried for their reception. I have no doubt that I lost
many individuals that I came across in general collecting. Some appear to be always
found singly or one or two together, while some living beneath bark form little colonies.
I once found a score or more of a brightly metallic species beneath a small piece of bark
of Acacia koa on Kauai, but these must have been lost, as the species is not amongst
those described. It is probable that the species of Myllaena found beneath logs and on
the ground are flightless, excepting those that frequent the margins of the running
streams and are very active.

Hydrophilidae. — It is doubtful whether any of the few known representatives of
this family are really native, though the genus Oniicrus was described from the islands,
and Hydrobius nesiticus and seniicylindriciis also are riot known elsewhere. It is note-
worthy that two of these species have only occurred on Oahu. Cyclonotuvi extraneum is
certainly an imported species. The two species of Dactylosternwn are also, doubtless,
importations. The species of Hydrobius are of interest from the fact that the fresh-
water fauna of the islands is so very scanty.

H. semicylindricus is a very abundant beetle and I think is sure to be found
elsewhere. The fact that it has been found in artificial water-containers led to the
suspicion that it was an importation by man, but the occurrence of a second species, far
in the native forests, renders it possible that it is a natural immigrant.

Dytiscidae. — A single species of Rhantus and one of Colyinbetes are ubiquitous in
the mountain streams. Both exhibit variability and it is doubtful whether they are
natural immigrants or whether they are really endemic. On the whole the former is
the more probable ; a closely allied species of Rhantus is found in the far distant island
of Tahiti.

INTRODUCTION cxxxix

Carabidae. — This is one of the most important families of Coleoptera represented
in the islands, no less than 210 species having been described, of which one only is at
present known from elsewhere.

There is not the least doubt as to the endemicity of any of these species (excluding
the introduced Plochiomis pallens) excepting the other Lebiine, Saronychmm incon-
spicniDU, which I have no doubt is an importation, and the four species of Tachys, which
are probably introductions by man. All of these latter are found on the lowlands
amongst foreign insects, or else have only occurred in low mountain forests close to
Honolulu. Of recent years at least two other Bembidiine Carabids have been imported
and become fully established, and also another Lebiine.

Deducting all these, the native Carabid fauna consists of 204 described species all
of which are endemic, while a good many additional species, as yet undescribed, are
now well known. Restricting our remarks to this endemic fauna, we observe that all
the species belong to the subfamily Harpalinae, and to three tribes in this subfamily,
viz. Pterostichini, Anchomenini and Bembidiini. These are represented respectively by
76, 92 and 16 described species. The species of Anchomenini are distributed very
unevenly in 24 genera, the Pterostichini in four genera (but of one only a single
species is known), the Bembidiini in 8, but one of these contains 10 of the 16 species.

Many of the interesting features of the Hawaiian Carabid fauna are detailed by
Dr Sharp (Vol. iii, p. 175 et seq.) and, as I have had occasion to refer specially to
these elsewhere, they need not be reconsidered here. The diminished chaetota.xy,
predominance of flightless forms, and the relationship of the genera one to another in
each group are of particular interest.

The adoption of the chaetotactic characters and those of the wings for the formation
of genera is largely responsible for the large number of these that have been described.
As Dr Sharp remarks (/. c. p. 186) "had I not adopted the condition of the wings and
the thoracic setae as a basis for genera, our Hawaiian Carabidae would have appeared
as members of only three or four genera. The other structural characters I have used
for discrimination are extremely slight. This should be borne in mind, as the picture
thus presented of three distinct groups, each consisting of a considerable number of
closely allied forms, is fairly correct."

In the Anchomenini the genus Blackbiirnia, represented by only a single species
and peculiar to Oahu, is remarkable for its sculpture. It is a heavy-bodied form, less
active than most species, and is one of the comparatively few Anchomenines that is
found beneath stones.

Deropristiis has three species, one each on Oahu, Molokai and Maui. The two
latter are not rare and are found beneath prostrate stems of tree-ferns or under logs,
but the unique example of the Oahuan species is said to have been found beneath
a stone. I once found a single individual of this or an allied form under a stone on
a ridge in the mountains near Honolulu, but being called from my room, I left the

S2

cxl FAUNA HAWAIIENSIS

beetle on the table and when I returned after a short absence, it had been carried off by
that household pest, the ant Pheidole megacephala, and I was unable to trace it or to
find another specimen.

Atrachycneniis is only known from Maui and Molokai, and has the habits of the
Deropristns of those islands ; in fact they are sometimes found in company, but
individuals are not numerous. Anchotejflus is only known from Kauai and Oahu,
a species on each island, and neither seems to be common. A. gracilis was found on
the rocks in a mountain stream after a heavy spate, and probably lives beneath stones
on the margins of these streams. Pseudobroscus lentus is only known from near the
summit of Haleakala, Maui, where it was found under stones, a few weeks after the
disappearance of the snow-cap.

The metallic and rather elegant, punctured, narrow species (four in number) of the
genera Derobroscus and Brosconynnus are only known from Oahu, where they are found
in holes in the trunks or branches of trees, or beneath close fitting bark. In very wet
forests we have once or twice found specimens on dark rainy nights, no doubt lying in
wait for their prey, outside their burrows. I suspect that they may be common in the
cavities in the higher branches and twigs of Koa trees, as the bird Paroreomyza
macjilata often contains fragments of many examples of these beetles, when it is shot
while feeding amongst these branches. DerobrosciLS politus was wrongly recorded from
'leaves' of trees, I should have written 'twigs.'

Anchonymus agonoides was found very locally on Haleakala, inhabiting cavities in
the trunk or branches of the Koa. When found, a considerable number of individuals
is liable to occur, whereas of Derobroscus we never found more than two or three
together. The larvae of both these genera were noticed in company with the adults.
Mauna frigida is one of the most abundant species on Haleakala, Maui, and is found
beneath stones in the open country above the forest from 5000 — 10,000 ft.

There are twelve described species of Disenochus, none, at present, being known
from Hawaii or Oahu, but on the latter, doubtless, the genus is to be found. They
occur beneath bark of trees, or rarely under logs lying on the ground, and several
are only found in very wet moss, growing upon tree trunks. A good many of the
species are rare or at least difficult to collect. D. cit-rtipes in general form greatly
resembles Atrachycjieinis, to which genus I supposed it to belong. It also has the same
habits. As a rule the species of Disenochus are remarkably constant in their exact
habitats, the variable D. aierritmis, however, exhibits some inconstancy in its choice of
these. Chalcomemcs with three species occurs on most of the islands ; the form on
Hawaii seems to be practically the same as the Molokai species. It is remarkable for
the fact that it roams about in the daytime, though usually this is only noticed in deep
dark gulches. In more exposed and open situations many examples may be found
hidden beneath stones or elsewhere, but none seen at large till after nightfall. The
large beetles of the genus Barypristus are confined to the open country of the high

INTRODUCTION cxli

mountains of Maui and Hawaii above the forest line, or on the edges of the region of
large timber. Both species are found beneath stones, B. rupicola almost entirely so,
but B. mcendiarius on Hawaii, on the edge of the forest-belt, also occurs low down
under bark of Koa trees, sometimes even beneath the level of the soil. Both are
common beetles in suitable localities. Barytietis sharpi, differing from the preceding in
its well-developed wings, is of far more arboreal habits and may be obtained high up in
trees from beneath bark, usually of Acacia koa ; but it is not restricted to that tree.
Very rarely it is seen at large during the daytime, ovipositing in the chinks of the Koa
trees. Colpodiscus contains two species, one of which is common to Maui and Hawaii,
and is often extremely abundant, flying in numbers to light at night. On Hawaii it is
usually found amongst dead leaves or fallen stems of tree-ferns, or beneath logs, but in
the lao valley it was found beneath stones or shingle on the banks of the stream, where
C. lahainensis also occurs. Once we found a specimen devouring an Oniscus, a creature
usually avoided by Carabidae, so that where it abounds under stones, ground-beetles
are usually absent. Prodisenochus terebratus is found only on Haleakala, Maui, beneath
or in decaying logs and appears to be rare. It is sometimes in company with
Atrachycnemis, but is I think rarer than the latter. Apteromesus maciilatus is restricted
to Kauai, where it is common locally. Mysticomenus with two closely allied species is
only known on Oahu. AI. niysticus is said to occur beneath stones, but M. tibialis is
common under bark in both mountain ranges.

The genus Colpocacciis, with six described species, contains some of the commonest
Hawaiian Carabids, and most of the species are excessively closely allied, so that
I suspect the number is liable to be reduced. They all are attracted by light at night
in the forest region, to which they are restricted. They are remarkable for the in-
constancy of their habits, not one of the forms being restricted to a special habitat.
They may be found beneath stones, under or in logs, under bark of trees, in the stems
of tree-ferns or amongst the dead fronds, in decaying vegetable matter on the ground,
at the bases of leaves of Freycinetia, etc. and in other situations. Colonies even of
hundreds of individuals are sometimes found together, and sometimes other rarer
Carabidae are found mixed in these colonies. At night they may be seen at large on
trees, or running about on the margins of mountain streams or on the ground beneath
the forest trees. The fifteen species of Atelothrns are mostly found on the neighbouring
intermediate islands of Maui, Molokai and Lanai, only one having been found on each
of the islands Hawaii and Kauai, and that from the former island is of somewhat
doubtful status (as to whether it is not a sport of Mesothriscus or Metromenus) and that
from the latter is an aberrant form. Though none are recorded from Oahu, I have for
some years known two remarkably distinct species from this island. Some of the
species of Atelothrns, e.g. the very abundant A. erro, are not constant in their habits,
since they are found both under stones, etc. on the ground and beneath bark of trees at
a considerable height from the ground. Others like A. platynoides and transiens.

cxlii FAUNA HAWAIIENSIS

I believe, have only arboreal habits. The fourteen species of Mesothriscus and twenty-
six of Metromenus in general resemble Atelothrus in their habits, some being arboreal
either living beneath bark or in moss or in cavities in rotten wood or in tree-ferns, or on
the ground, in or beneath logs of wood, and but rarely under stones. A few species in
both genera are found in wet forests by day on the flowers of Astelia, and some, like
Metromenus mutabilis, hide in numbers at the bases of the leaves of this plant or (like
M . palmae) o{ Ffeycinetia. Occasionally at night we have seen some of the Anchomenine
Carabidae devouring caterpillars, and it is probable that these form a large part of their
tabulum. Their fondness for Acacia koa, which so generally is attacked by caterpillars
of Scotorythra, leads me to suspect that this genus supplies many of them with food.
The beetles themselves are in some cases very long-lived, even under unnatural conditions
in captivity, and I have been struck with the fact that while the larvae of many of them
are found in the same situation as the adults, the latter generally are much more
common. The species of Mecostomus and Mecomenus are not well known, but they are
apparently terrestrial species.

That the Oahuan bird Oreomyza maculata apparently hunts specially for the
Carabidae of the genus Derobroscus has been mentioned above, and I have found
remains of Colpocaccus hatvaiiensis in dissecting the rarer bird Viridonia on Hawaii,
and this latter genus of beetles and some allied genera in other birds. Metromenus,
Colpocaccus and other of the genera emit an unpleasant odour, and when a colony
of C. tantalus is disturbed, under certain conditions of weather, the vapour given off
becomes easily visible, and in ammonia gas produces dense white fumes.

Generally speaking one may say that of these Carabidae those species with the
most diverse habits are the most abundant, but a few that are more constant in habits,
e.g. Metromenus palmae and M. mutabilis, are also very common. It seems clear that
the scarcity of some species is due to the fact, that they are very particular as to the
condition of their habitat, and that these conditions can rarely be found. Such species
cannot but be individually weak, even though they are generally present, when the
right conditions occur. Others like M. paltnae and mutabilis above mentioned, though
restricted to certain environments, find the right conditions commonly. Yet other species,
which apparently are rare, and yet, so far as one can judge, affect conditions that are
commonly met with, may be thus rare because the conditions which are really suitable
are not common, but we are not able to distinguish between the suitable and unsuitable.

The four genera of Pterostichini cannot at all be distinguished from one another by
their habits, but there is much difference between some of the species in this respect.
Generally speaking they agree in these with the Anchomenini. Many are arboreal
being found only under bark, or moss, or in dead branches of growing trees, and usually
those of terrestrial and arboreal habits are quite constant in these habits. Some of the
ground-frequenting species are not uncommonly found in decayed stems of tree-ferns,
and a few, like Metrothorax deverilli, are found beneath bark or moss on trees, in hollow

INTRODUCTION cxliii

decayed stems, and amongst decaying leaves upon the ground. Quite a few of the
species occur beneath rocks or stones, chief amongst which is the extremely abundant
Mecyclotho7'ax montivagiis of Maui, replaced on Hawaii by M. pele, of which some
specimens seem intermediate in appearance. The Pterostichine beetles are almost
ubiquitous throughout the forests of the islands, excepting where these are invaded by
the introduced ant Pheidole niegacephala, and those of Kauai, where not a single species
has been discovered. On Oahu they are much more poorly represented than on the
other islands with equal forest area. On the highest mountains a number of species are
found in the open country above the forest-belt, but not one (nor any other endemic
Carabid) is known below the forest, since every moderately damp situation is there
occupied by the foreign ants. Probably all the species are nocturnal in their activities,
since only on the rarest occasions has an individual been seen walking in the open
or on the leaves of trees in the daytime. Apart from the question of the thoracic
setae, some of the species are notably variable and varietal differences are sometimes
considerable between individuals actually taken in company. A few species are remark-
able for the peculiarities of their sculpture, as also are a good many of the Anchomenine
series. Occasionally, as with the latter group, remains of Pterostichines have been
observed in the native Drepanid birds.

The Bembidiini differ considerably from the other two groups of endemic Carabidae
in the fact that no arboreal forms are known, though individuals have been met with on
rare occasions in decayed parts of fern stems, and further, many of the species, that
inhabit moderately damp situations, are found roaming about in full daylight.
Occasionally we have noticed specimens feeding on minute larvae of other insects and
once a number of individuals together were observed feeding on a dead hive-bee. The
flightless GjiatholyDinaeiim was found in or beneath large stems of tree-ferns and is only
known from Kauai, where the Bembidiine fauna is most richly developed. Nesolyumaeum,
also containing only one species, has, I believe, similar habits, but is fully winged. It is
widely distributed occurring from Oahu to Maui, though rare. Bembidium teres is
already known on all the islands from Kauai to Maui and is sometimes numerous
amongst the small stones or shingle on the edge of mountain streams. B. pacificiun is
more often found amongst dead leaves and is fairly common locally on Oahu and
occurs on Kauai. B. molokaiense another winged species is found from Kauai to Maui.
Nesocidmm as a genus is only distinguished from some of the species of Bembidium
[B. molokaiense) b)- its vestigial wings. N. laeticuluvi is found from Kauai to Maui or
with the same range as B. molokaiense, suggesting the idea that it is a dimorphic form
of this, as does its structure. The other species of Nesocidium are at present known
each from only one island, but they have mostly been so rarely collected, that not very
much weight can be attached to this. The genera Atelidium, Metrocidium, Nesomicrops
and jMacranillus, each monotypic and endemic, are only known from Kauai. Their
habits are the same as those of Nesocidium.

cxliv FAUNA HAWAIIENSIS

Excepting that two species of Hawaiian Carabidae are referred to the widespread
genus Platynus and five to the ubiquitous Bembidiimi, all the certainly endemic species
are placed in genera that are also endemic.

Review of Lepidoptera.

Up to the present time' 764 species of this Order have been described or
enumerated from the main islands, but of these at least 61 may be considered as
foreign. Many of the latter are obviously importations by man, while a minority are
equally certainly natural immigrants from other countries ; a few cannot with certainty
be assigned to either of these classes, but almost certainly belong to one or the other.
Seven hundred species, or 92 per cent, of the Lepidopterous fauna, are therefore
endemic.

Of all the families of the Order twenty only are represented in the islands, and
three of these contain each only one species and that certainly imported by man. The
Pierid, Pieris rapae was imported with cabbages from California some 1 2 years ago ;
Meliphora grisella (Galleriadae), no doubt, with honey bees ; Ethniia colonella
(Oecophoridae), appeared in the islands a good many years ago, but is known to
have been of comparatively modern introduction. Other two families, Nymphalidae
and Lycaenidae, are represented by only one endemic species each, supposing Lycaena
blackbiirni to be truly endemic, which is by no means certain.

If we leave the foreign element in the different families out of consideration, we
find that nine only contain fifteen or more species. These are the Caradrinidae with
34 species, Hydriomenidae 17, Selidosemidae 39, Pyraustidae 172, Gelechiidae 41,
Hypomoneutidae 270, Carposinidae 2il>^ Tortricidae 47, Tineidae 15. Consequently
nine families contain no less than 668 of the endemic species or 95 per cent, of the
whole.

The 764 species of Lepidoptera are distributed in 117 genera, of which 37 are
supposed to be endemic. Generic endemicity is much greater in the smaller moths
(i.e. in the Tortricina and Tineina together) than in the aggregate of other great groups
or superfamilies, in fact it is nearly twice as great in the former, which have 24 of the
58 genera endemic. The larger moths and butterflies on the other hand have only
13 endemic genera of their total of 59. Thirty-three genera contain only apodemic
species, these being either introductions by man or in some cases natural immigrants,
while thirty-three genera, though themselves apodemic, contain only endemic species.
Fourteen genera contain a mixture of endemic and apodemic species. The 61 foreign
species are therefore distributed in 47 genera, or average about 1-3 to a genus, while
the 702 endemic species are placed in 84 genera, an average of 8-3 to each genus.

' In this account the famiHes and genera adopted are as in the Systematic part of this work. In
a few cases the number of species is slightly changed to bring this up to date— June 1909.

INTRODUCTION cxlv

Many of the endemic genera, that contain a single, or only a few species, are clearly
offshoots from other of the larger endemic genera, or as one might say, they are species
of these genera, which have diverged more widely in structure than the average. Such
are Sisyrop/iyta, Nesochlide, and Acrodi'epanis, derivatives of, or at least of the same
original ancestors as, Scotorythra, the formation of such genera having no doubt taken
place within the islands. Similar groups are Mestolobes, Promylaea, Oi'thomecyna and
Protaulacistis ; Thyrcopa, Catamempsis, Psychra, Ptycothrix and Hodegia, and others.

While therefore the apodemic genera are usually very distinct or remote from one
another, the endemic are often closely allied to one another, in such a way as to form
aggregates of several allied genera, these aggregates being generally remote from one
another and more nearly corresponding to the apodemic genera than do the individual
genera composing them.

These preliminary remarks will show the restricted nature of the indigenous
Lepidopterous fauna, and from how few original ancestral immigrants it might have
been derived.

Caradrinidae. — There are five genera, three, Heliothis, Caradrina and Spodoptera,
containing only foreign species, and two, Agrotis and Leucania, with both endemic and
apodemic species. The two very widely distributed Agrotis, A. ypsilon and A. saiicia,
though they may have reached the islands by natural means, are equally likely to have
been imported in their earlier stages by man. This is also true of Leucania uni-
piincta. This latter and A. ypsilon both occurred to Blackburn during his residence in
the islands, but A. saucia is apparently a more recent introduction. In the winter
months it is often common in gardens in Honolulu, as well as being abundant in
mountain localities at other seasons, yet it would appear not to have reached the islands
up to the time of Blackburn's departure.

Apart from all these foreign members, Agrotis has 26 and Leucania 8 endemic
species. Meyrick considers these endemic Agrotis as probably of American origin and
forming a group of allied species, but Hampson scatters them in five genera {^Feltia,
Epipsilia, Agrotis, Agrotiphila and Euxoa) these being themselves all of wide distri-
bution. Similarly the eight endemic Leucania are referred by Hampson to three genera,
Cirphis, Eriopygodes and Hyssia. Meyrick recognizes two " quite independent and
dissimilar groups," the first four species forming an endemic group of unknown origin,
while the others are allied to L. tmiputicta. It is the first of these two groups that
contains the species referred to Eriopygodes and Hyssia by Hampson.

Heliothis armigera is no doubt a natural immigrant, as also are the two species of
Spodoptera, while Caradrina reclusa is a recent importation (first appearing in 1902 but
now fully established) and the other Caradrina (C. examinis) will also probably prove
to be foreign.

Leucania euclidias is one of the most variable of Hawaiian moths ; some of these

F. H. I. t

cxlvi

FAUNA HAWAIIENSIS

varieties are figured in Volume i. pi. 3. The most extreme varieties are found at the
same time and place, but it would appear that in some localities the species exhibits
a much smaller proportion of extreme aberrations than in others. It is extremely
abundant in the wet woods of the Hilo and Puna district, where L. iiiphadopa, compsias
and anthracias are found with it, but in much smaller numbers. There the caterpillars
are common on ferns, and the pupae in decayed wood or beneath moss. All of these
species are attracted by light and in some localities L. eitclidias appears at all hours,
but on the lower edge of the forest at Waialua on Oahu, we observed on several
occasions, that no more than a straggler or two were ever attracted until 11.30 p.m. or
later, when scores would arrive in quick succession, till hundreds in all were present.
No matter how favourable the earlier hours had been for the cajDture of other moths,
L. eticlidias never put in an appearance in numbers until near midnight, and striking
varieties were in small proportion to the more usual forms, certainly far less numerous
than in some of the wetter districts. All the species of this group are true forest insects
and most abundant in wet forests. During the daytime the moths hide amongst dead
leaves and are sometimes very numerous in the masses of dead fronds that remain
attached to tree-ferns.

The remaining group of Leucania contains species very similar to the widely
spread L. iinipjincta which are less special in their habitats. L. amblycasis, even in dry
localities, is not infrequently found on the lowlands in company with L. imiptmcta. In
the forest region it is much attracted by the flowers of Metrosideriis, of which a small
tree may yield hundreds of examples of this moth. When disturbed they fall to the
ground and make no attempt to fly, being gorged with the copious nectar of the flowers.
The moth has great powers of flight and we have known it attracted to the lights of an
interisland steamer, when this was in midchannel. This and L. pyrt'hias in the larval
state feed on grasses, attacking imported species and sugar cane, but the natural food of
the latter species is more probably the common sedge Bamnea nieyeiiii, in the debris at
the roots of which Swezey has found it hiding. The caterpillars of this uniptmcta group
of Leucania are very different from those of the euclidias group.

The endemic species of Agrotis are of diversified habits, some being true forest
insects, while others are to be found rather in the open country, whether this be at low
or high elevations in the mountains. A. microreas flies freely in the morning sunshine
over the low growth of Vacciniiivi, Cyathodes etc., which covers the ground in open,
upland forest-land of Hawaii. At certain seasons we have observed it on the wing in
great numbers, reminding us very strongly by its flight and appearance of the well-
known European Charaeas graminis.

Some species are littoral or sublittoral and attached chiefly to dry sandy localities.
Agrotis cremata and photophila are notable examples. Others, such as A. arenivolans
and dislocata frequent the coastal districts, lowlands and lower mountain elevations and
then reappear above the forest-line or in extensive open places in the forest. A. dislocata

INTRODUCTION cxlvii

is one of the commonest species, and its caterpillar sometimes does much damage to
farm produce, stripping the potato, tomato and many other plants of their foliage, as
well as gnawing through the stems. In this work it is frequently aided by the cater-
pillar of the very dissimilar moth A. crinigera, both being truly 'cut-worms' and in the
larval state remarkably similar to one another. Sometimes one and sometimes the
other is the most injurious, but dislocata appears to thrive at higher altitudes in the
mountains. On the uplands of Hawaii, as at Waimea, where A. dislocata sometimes
does much injury to cultivated plants, the moths are noticeably different from those
taken on Oahu, Molokai, etc. They are greyer or whiter in appearance and this gives
them a distinctive look, when series of examples are placed side by side. These two
injurious species are a favourite food of the golden plover, which catches the moths,
as well as their caterpillars.

On the high mountains above the forest-line and in open forest A. crinigera seems
to be replaced by allied forms, A. mesotoxa, epicrenina and baliopa, which never descend
to the open country below the forest. Similarly, at great elevations, A. dislocata is
replaced by A. aulacias on Maui and on Hawaii by an undescribed species.

At present little is known as to the parasites of Agrotis and Leucania, except that
some of the species are much destroyed by the Tachinid Chaetogaedia monticola and to
a lesser e.xtent by Frontina archippivora.

A species of Enicospilus has been bred from A. dislocata, and it is therefore likely
that the Ophioninae will be found to attack many of these caterpillars, as they are
partial to the endemic Leucaniae.

All the endemic Agrotis have great powers of th'ght, and many of them rise so
readily in the daytime, as one walks along, and travel at such speed with the wind, that
even where individuals are very numerous, it is often difficult to capture many specimens.
This is especially the case with those that frequent the open and exposed parts of the
higher mountains, where strong winds are prevalent. Many of the species are very
strongly attracted by the juices exuding from decaying fern leaves, and also by artificial
lieht, while some visit the flowers of Metrosiderus and sandal trees, and no doubt others.

Heliothis ai-miger, though a common insect, does not appear ever to attain here the
extraordinary abundance that it reaches in other countries. The larvae, often lying
exposed in the flowers of Sida, or on other plants, are very subject to the attacks of the
two Tachinid flies mentioned above, as being parasites of Agrotis, and in some seasons
nearly all the specimens found are parasitized. The colour variations of the moth are
numerous, and are not of local occurrence. Thus eight examples taken together on
Molokai varied from the palest yellow form to the darkest suffused one, not two indi-
viduals being alike. On the dry lowlands H. ariniger is rare, except during the winter
months, or when Sida and other lowland plants spring up afresh after heavy rains.

The two species of Spodoptera are doubtless natural immigrants, 5. exigua being
practically cosmopolitan in warm regions, while S. mauritia is one of the few insects

t2

Iviii FAUNA HAWAIIENSIS

CXlVIll

that have always been well known to the natives, on account of the periodical abundance
of its larvae. These are truly ' army-worms ' marching over great areas of pasture land
and devouring all the herbage on their march. Of late years these great armies have
been much less frequently noticed, though formerly of annual occurrence at the season
of the growth of fresh grass. There is no doubt that this diminution of the ravages of
the grass army-worm was due to the excessive multiplication of the imported Indian
mynah bird [Acridotheres tristis), great flocks of which visited the pasture lands to feed
on the caterpillars. Of late years it would appear that the mynah bird has become less
numerous, owing to the failure of lantana berries, which formed its chief supply of food
throughout the year, and it is said that, coincidently with this decrease, the army-worm
has again occasionally become conspicuous in some pastures. Previous to the great
multiplication of the mynah bird, this Spodoptera was a favourite and important food-
supply of the golden plover during the winter months. It is well known that, when
feeding on the hordes of caterpillars, these migrants from Alaska arrived at their finest
condition, before leaving the islands for their distant breeding grounds.

Of the two species of Caradrina, C. rechisa is a recent importation, no doubt from
Fiji, as we have seen its larvae on consignments of plants from those islands. It was
first found in Honolulu in 1903 and soon became common, and extended its range to
other of the islands. C. exaininis, once found on the island of Hawaii, is probably also
a foreign species.

Plusiadae. — The two genera Simplicia and Adrapsa are each represented by an
introduced species, both of them occurring in Fiji, and we have found the larvae of both
swarming on plants imported from that group. The Simplicia was imported long before
the Adrapsa, which was not noticed until after 1902.

Nesamiptis, with two species, was described from the islands, but I believe exists in
tropical Australia. One of the species (A^. obsoletd) is extremely common and most
variable in colour and pattern of markings. Its caterpillars feed very freely on the
imported ' Hilo' grass. The other, N. plagiota, is much more local, though sometimes
common, and appears to vary very little as compared with its congener. Hypenodes,
with seven species, has one which is very widely distributed and abundant, and also
very variable (//. altivolans). It is freely attracted by light and to sugared trees and
may often be observed in great numbers flying at dusk in marshy places in the
mountains amongst sedges. Most of the other species frequent very wet forests, and
are much less numerous and less commonplace in appearance.

Of the two species of Cosmophila one is probably introduced, as we have found its
caterpillars on plants brought from Fiji. Both exhibit much variation, but in the case
of the foreign C. sabulifera, variation is local or irregular. In one instance a number
of caterpillars, taken on a native Hibiscus (?) in a mountain forest, produced a very
variable series of adults, including some remarkable aberrations. On another occasion

INTRODUCTION cxlix

a very large number of moths bred from caterpillars, that were injuring a fine hedge of
a foreign Hibiscus, showed no remarkable varieties. Sometimes the foliage of the 'Hau'
tree (//. ii/iacciis) is much injured by these caterpillars. C. noctivolans is sometimes
found commonly in dry places amongst Sida, on which the larvae feed, as well as on
some of the plants affected by C. sabiilifera. The latter is much parasitized by the
common Tachinid flies, Chaetogacdia and Frontina, so that hedges of Hibiscus, very
badly defoliated, may become entirely freed from caterpillars by their means.

Of the two species of Hypocala, H. andremona is, doubtless, a natural immigrant,
these insects being endowed with great powers of flight. H. velans, considered by
Meyrick as a variety of andremona, is, I think, clearly a distinct species and presumably
derived from the latter. It appears to be much more numerous than andremona in most
parts of the islands. In the daytime it often secretes itself amongst the lava, which
is piled up to form walls in various parts of Hawaii, and from these it is very easily
disturbed in the daytime. It also frequents the caves and cavities in the sides of
precipitous gulches, issuing from these in great numbers, as we have noticed on Molokai
and elsewhere. It freely enters houses, much more often than H. andremona. Both
feed on Maba sandivichensis, and their earlier stages have been studied by Swezey,
confirming their distinctness. Although most abundant on the lowlands and lower
mountain slopes, we have noted the occurrence of H. velans in a well-known cave at
an altitude of nearly 9000 ft. on Haleakala.

Plusia chalcites and P. biloba are, no doubt, natural immigrants, the former
ubiquitous and very numerous, often indeed injurious, being polyphagous, the latter
most partial to the uplands and generally scarce. P. chalcites occurs also on Midway
Island. In the wettest districts of the islands the caterpillars are sometimes destroyed
wholesale by epidemics of a fungous disease, while another fungus attacks the moth.
The pupae are much parasitized by the endemic EchthromorpJia and the imported
Chalcis obscurata, and the caterpillars by the Tachinid flies. But for these restraining
agents, P. chalcites would prove one of the worst of pests. P. pterylotis is a very remark-
able endemic species of rare occurrence, but widely distributed, as it has been found on
Oahu and Hawaii. It is replaced on Maui by an allied, but very distinct species.
These endemic forms have no connection with the apodemic ones named above, nor
are they apparently closely related to any known species of the genus. The cause of
their rarity is not known, but, no doubt, they will be found to be heavily parasitized by
the Echthromorpha, which is always very numerous in the localities where they occur.

Hydriomenidae. — The greater number of the species belong to the genus
Eucymatoge, with 10 described forms and, doubtless, others to be discovered.
E. monticolans is ubiquitous throughout the forests, and is remarkable for its great
variability. Extreme varieties are often found in company, but in some localities
(notably, e.g., on the summit of the small island of Lanai) there is a tendency for some

cl FAUNA HAWAIIENSIS

particular variety to predominate or become conspicuous. Some of the variations have
been figured in the systematic portion of this work. The Hawaiian species, Hke
others, rest during the daytime with outspread wings on the trunks of forest trees.
E. monticolans on various trees and E. craieinas on Acacia koa are very often obtained
by examining the trunks. The latter also rests on the surface of rocks. One or two
species are found above the elevation of the true forest-belt, and some are restricted
to very wet woods. E. monticolans has been bred from a full-grown larva found on
Metrosiderus polymoj'pha. The species of XanthorJioe appear to be all rare insects
in the imaginal state, and their earlier stages are not known. X. insularis is found
above the forest-belt on Haleakala, Maui, from seven or eight thousand feet above sea-
level upwards. The other three species are forest insects. Progonostola cremnopis,
forming an endemic genus, is widely distributed, and occurs on Oahu, as well as on the
windward islands. Near Honolulu it may be found resting on tree-trunks or the stems
of tree-ferns on Mt Tantalus, and on the decomposed lava of steep cliffs at Nuuanu
Pali. It bears a considerable superficial resemblance to Xanthorhoe caustoscia. The
single species of Dasyuris was found on the upper skirts of the forest on Haleakala,
Maui, where it occurs periodically in extraordinary numbers, flying by day. On several
visits to the locality not a single example has been observed, but on one occasion it was
swarming over a limited area. Though not a rapid flier, it was not very easily captured,
being expert at keeping just out of reach. The smaller Hydriomena aplioristis appears
to have similar habits, being also a day-flier, though also attracted by light at night,
but is usually seen singly, and we have never seen it in numbers. It has so far only
occurred on Hawaii.

Selidosemidae. — The Selidosemidae with about forty known species, and, doubt-
less, others undiscovered, are a most important element of the Lepidopterous fauna.
Most of these are absorbed in the genus Scotorythra with 34 species, and the other
four genera may be looked on, for the most part, as merely more modified forms of the
large genus. All five genera are endemic. The forms included in Scotorythra itself
are of varied structure, as if tending to break up into several groups or genera, and
these distinctions in the adults appear to be to some extent correlated with corre-
sponding differences in larval characters. The smaller species of the genus, belonging
to the group of .S". corticea, for instance, have a characteristic appearance and pattern
(or form of the second line of the forewings), tending at the same time to differ in
character of neuration, and also in the length of the tibial spurs from the others. Some
of them, and perhaps all, rest at times with spread wings, Boarmia-like, on the trunks
of trees. On the other hand the numerous species, large and small, of the S. rara
group, rest, Anisopteryx-like, with the wings unspread, so as to form an elongate triangle,
creeping into holes in trees or beneath bark, or lying hidden amongst masses of dead
fern leaves during the daytime. Sisyrophyta is remarkable for the secondary sexual

INTRODUCTION cli

characters of the male, the wings being more or less distorted in this sex by a special
clothing of the under-surface, which in 5. goviphias has the appearance of a dense felt.
Nesochlide has a group of specially modified scales on the underside of the forewings
in the male. The great Acrodrepanis and small Tritocleis lack the modified hind tibiae
and the characteristic hair-pencils of the other forms.

Some of the species of Scotoiythra are amongst the commonest of moths, and
some have been able to adapt themselves to great changes in their environment. Thus'
Scoto7yth7-a rara and h'achytarsa sometimes become very numerous, their caterpillars
feeding on the introduced guava trees, in localities whence all native vegetation has
disappeared. We have even found caterpillars of this genus feeding on the strong-
scented imported Lantana. Sisyrophyta gomphias can also maintain itself away from
native vegetation.

Many of the species of Scotorythra are polyphagous, but even these seem specially
to favour certain plants. Acacia koa is attacked by numerous species, and certain of
these become locally and periodically so numerous, that great areas of ' Koa ' forest are
entirely denuded of their phyllodes. When this denudation is long continued we have
known trees to be entirely killed, not perhaps altogether directly owing to the attacks
of the Scotorythra, but because, after a sickly condition had been induced by the
denudation of foliage, other insects (e.g. the longicorn beetles of the genus Plogithmysus
and the small, boring Scolytidae) joined in the attack. Scotorythra idolias on Hawaii
and 5". pahidicola on Maui were responsible for two of the most severe attacks that we
have witnessed. Native birds attracted in thousands by the abundance of this, one of
their favourite foods, were gorged to repletion, and the starving caterpillars formed
writhing masses on the ground beneath the tall Koa trees. The dropping of excrement
from the trees on the dead leaves beneath made a rattling noise as of a hailstorm. In
one instance it was noted that these pests of caterpillars were destroyed by an epidemic
fungous disease, which attacked the full-grown larvae after their descent to the ground
for pupation, as well as the pupae themselves.

In open spaces in the forests at nightfall one may see large numbers of the moths
flying slowly overhead and often out of reach, traversing these spaces and all or nearly
all travelling in the same direction. Sometimes they congregate in hundreds within some
hollow tree-trunk or amongst the pendent masses of dead fronds of tree-ferns. In some
cases all the individuals so congregating are males, even in one case where several
hundreds of examples were taken together. Many of the species are attracted by light,
in some of these the males and in others the females are much more numerous. Thus
but one female of Nesochlide epixantha was attracted amongst scores of the other sex.
The males of this pretty species also freely visit the flowers of Metrosiderus, and they are
abroad on the most windy nights, to which, no doubt, is due the fact that one occasionally
meets with a strasgrler on the lowlands, and even in the town of Honolulu. The female
of this species is remarkable in that it is occasionally found flying freely in the sunshine.

clii FAUNA HAWAIIENSIS

No doubt, formerly, numerous species have existed on the lowlands, but these have
mostly disappeared owing to the attacks of foreign predaceous insects, especially ants.
In very dry localities, where that destructive little ant Pheidole megacephala is unable
to exist, or is hardly present, species of Scotorythra still flourish. This is the case with
6'. paratactis, the caterpillars of which are very numerous on the scanty vegetation that
grows near the coast on the driest parts of the west side of Oahu. The exposed cater-
pillars of this species would be quickly exterminated by Pheidole in most parts of the
coastal region of this island.

The caterpillars of some of the species of Scotorythra appear to be nocturnal in
their feeding habits, and during the daytime hide beneath the bark of the trunks of the
trees, on whose foliage they feed. In this situation considerable numbers may be found
at rest, ranged side by side. They form a most important j^art of the food supply of
the endemic birds, and are supplied by the parents to the young of nearly all the species,
while they are a favourite food of many adult birds as well. On the other hand they
are very little attacked by the many species of wasps of the genus Odyjierus, and it is
most remarkable that, since these do occasionally store them up in their cells as food
for their young, they should not more often avail themselves of so abundant a prey,
when more favourite caterpillars become scarce or fail. The ubiquitous bug, Oechalia
grisea, also destroys great numbers of the larvae of many Scotorythra. The variation
in colour and markings of many of the species of Scotorythra (as well as of Nesochlide
and Acrodrepanis) is very great, and some idea of this variability may be gathered
from the figures accompanying the systematic descriptions in this work. In most
species, that show much variation, the extreme varieties are taken in company. It is
not known whether difference in the food plant is to any extent the cause of variation,
but it is certain that it is not so in some cases, where variation is very great, as several
species have been tested in this respect. It is very noticeable how frequently species,
that are quite distinct, yield similar varieties, and a character which appears as a
variation in one or more species may be a constant character in another. As an
example of this one may mention the presence, as a constant character, or merely as
an infrequent variation, of a conspicuous pale costal streak. In some species the males
and in others the females appear to be more subject to variation, and some, of which
large numbers have been examined, exhibit very little variability.

The pupae of Scotorythra are very commonly found when one is searching for
other insects, under wet moss, in damp rotten wood, under logs, and in other situations.
Most of them, however, as well as the caterpillars, are difficult to breed, when removed
from the wet mountain forests to the lowlands, even though great pains are taken to
keep them as nearly as possible under natural conditions. Some of the large species
have been observed laying their eggs in the bark of trees, the ovipositor being of great
length when fully protruded.

INTRODUCTION cliii

Sphingidae.- — Only six species of this family are at present known, and of these
three are known elsewhere, being natural immigrants. The widely distributed Sphinx
convolvuii is more abundant than its congener, Sphinx ce/etis. The latter is usually
found in the larval state, feeding on the tobacco plant, or on some of the species of
Soiajium, while the former is not only extremely common on many species of Ipomoea,
as well as on other plants, as a caterpillar, but is also an abundant moth, readily at-
tracted by flowers or electric lights. In the morning large numbers may sometimes be
found attached to the flowers of the wild ginger, which they have visited during the
night, and from which they have been unable to withdraw their proboscis. Examples
so caught are often devoured by ants during the course of the day. The caterpillars of
5. convolvuii are very variable in colour, and all sorts of varieties of these may be found
at the same time and place. Sometimes they do considerable injury to the sweet
potato {Ipomoea batatas). The eggs are subject to the attacks of the small parasite
Peniarthron. The third immigrant, Deilephila lineata, is also a most abundant species,
and ranges to much greater elevations than the species of Sphinx, for we have found
the caterpillars entirely stripping certain plants at a height of 5000 ft. in the mountains,
and at still greater altitudes. In dry districts near the coast it appears in abundance
periodically, after or during the rains, and is polyphagous. The moth may be seen on the
wing sucking the blossoms of lantana or other tubular flowers, even during the hottest
sunshine, though usually more active towards night.

Three closely allied endemic species of Deilephila are of more interest. They
are chiefly forest insects, though they range over the dry forehills down to the coast.
D. wilsoni [pyrias) is at present known only from Hawaii, where it is generally
distributed, the polyphagous caterpillars feeding on many forest trees of different
families. In wet districts the moth is freely on the wing at all hours of the day, visiting
the flowers of Metrosidertis, as well as those of cultivated plants, nasturtiums, canna, etc.
In drier localities it flies more freely at dusk. We have seen hundreds together rising
straight up from the rough lava flows, that intersect the dense forests of the Hilo
district of Hawaii, till they reached the height of the tall tree-tops on either side of
the flow. D. calida is generally distributed on Oahu and Molokai and its caterpillar
is polyphagous like that of wilsoni. It varies much in markings, sometimes having
a pair or a number of eye-spots present, and these eye-spots may differ in number
on either side of the body, and in different individuals may occupy entirely different
segments. In many examples they are altogether wanting. Sometimes they are
present only towards the head end of the caterpillar, sometimes only on the segments
near the caudal extremity. The moth itself exhibits a good deal of variability, as
does D. ivilsoni. On Hawaii in addition to the latter there exists a second species
or local race, much more nearly allied to D. calida. No representative of these has
yet been taken on Kauai, but caterpillars similar to those of the others have frequently
been found there, so that at least one additional species is to be expected, unless

F. H. I. u

cliv FAUNA HAWATIENSIS

these caterpillars prove to belong to the remarkable green-coloured D. smaragditis.
Probably other species allied to D. calida remain to be discovered. We have found
many larvae of the last named marked with black scars, showing the attack of some
parasitic or predaceous insect, but nothing was bred from these.

PiERiDAE. — Pieris rapae first appeared in 1897, having been, doubtless, introduced
with cabbages from California. On the lowlands it abounds chiefly during the winter
months and becomes to a considerable extent injurious. All the butterflies produced
are of the European summer form, there being no seasonal dimorphism. In dry hot
coastal districts the eggs are laid very freely on Capparis sandwichiana of the Cappari-
daceae, so that the butterfly is often very abundant in localities, where, at first sight, no
suitable food-plant appears to be present. The eggs of Pieris are in some places much
destroyed by the little ant Pheidole megacephala, and the caterpillars are preyed on by
introduced wasps of the genus Polistes, which strip and carry off portions of them to
feed their young. It would appear that as Polistes increases in numbers in the summer,
after new colonies have been started by the hibernated females, the Pieris becomes
much less numerous, while as soon as the nests of the wasps are deserted and the state
of hibernation is begun, the butterflies increase very rapidly and their caterpillars
become very troublesome. The well-known parasite Pteroviahis pitparimi, which has
several times been imported in great numbers, as an enemy of the Piej'is, is apparently
unable to establish itself here.

Nymphalidae. — Anosia eripptis is no doubt a natural immigrant, which has
established itself in the islands since the introduction of the milk weed, on which it
feeds, by foreigners. It is found wherever the food-plant grows, and, being a very
powerful flier, often in places far distant from this plant. Though very common, it is
not, as has been reported by a visiting entomologist, the commonest butterfly in the
islands, being much less numerous, for instance, than Lycaena boetica. It is not very
variable, though once or twice we have noted melanochroic and albinoic examples on
the wing amongst the large numbers seen. The caterpillars are attacked by the
common Tachinid fly, Frontina archippivora.

Vanessa cardiii and Imntera are both natural immigrants, the former feeding mostly
on malvaceous plants and introduced thistles, but also on Gjtaphalium, on which the
latter habitually feeds. In dry districts on the lowlands both these species become
abundant on the appearance of a fresh growth of vegetation following copious rain, but
disappear with the di-ying up of low plants. V. cardui sometimes entirely strips the
common weeds on which it feeds, so that we have even seen the caterpillars perishino-
of starvation. It is sometimes much parasitized by the Tachinid, Frontina. A con-
siderable percentage of the Hawaiian cardin are intermediate between the var.
kershawi, which has been considered by some a distinct species, and typical cardui.

INTRODUCTION civ

while some are typical kershawi. Eggs laid by the same female may produce both
forms and intermediates.

V. atalanta has only been found on the island of Hawaii, where it is sometimes
abundant in the mountain forests. It was not noticed by Mr Blackburn during the
period of his collecting, and is probably a recent arrival. It is quite doubtful whether it
is a natural immigrant at all, and we suspect it may have been introduced by man. It
is at least remarkable that in the past i8 years it should not have spread to the other
islands. We have found it very numerously in Olaa, Hawaii, flying freely even in the
heavy rains of that rainy district, and visiting the flowers of Rubus. Sometimes also it
was attracted at night to the lights in the house. It is abundant too in the Kona district.

V. taviuieamea is by far the most interesting of the few Hawaiian butterflies, being
found throughout the forests of all the islands, and at times it is even seen in gardens
in Honolulu. Such visits, however, are accidental, and usually occur during or after
stormy weather in the winter months. The butterfly itself is remarkable for the great
variation of the under side of the wings, whereas the coloration of the upper side varies
but little. The sexes are easily distinguished by the difference in colour of some of the
small spots in the black apical part of the front wings, these spots being pure white in
the female. The flowers of Broussaisia are often very attractive to this butterfly, as are
those of an introduced Rtibus, but more often it is found feeding on the exuding sap of
Acacia koa, Myoporum, and other common forest trees. Having a very powerful flight
it is sometimes met with far from its usual haunts, as for instance on the tops of the
highest mountains or near the sea-coast. The caterpillars are very variable, being some-
times green or purplish or particoloured. When young they fold back a small part of
the leaf and thus conceal themselves, but when larger often feed exposed. Their food
consists of various urticaceous plants, especially Pipturus albidus, but Urena and other
genera are also attacked. On one occasion a female butterfly was observed near the
coast at Honolulu ovipositing on young plants of the common malvaceous weed, on
which V. cardui is so abundant. By following this female as it flew from plant to jolant,
a number of eggs were collected, as they were laid. The caterpillars however, when
they hatched out, refused to eat the young growing plants on which they were placed,
and, after crawling about these for a day or more, died of hunger. Others from the same
lot of eggs, being given leaves of the native ' mamake ' i^Pipturus\ survived. It would
therefore appear that the butterfly, when driven from the mountains to the lowlands,
where the usual Urticaceae are absent, will select as a food-plant for its caterpillars
or rather for ovipositing, one which is freely fed on by allied species of its genus
(e.g. V. cardiii), although its own caterpillar is not able to subsist on this. Possibly
the instinct of selecting this malvaceous plant is an ancestral one, still retained, though
now fatal to the progeny.

The chrysalis of V. tatmneamea is occasionally found suspended from the leaves of
various trees or plants in the forest, but we have more often found parasitized examples

u 2

clvi FAUNA HAWAIIENSIS

than sound ones. From the former one breeds the Pimpline Ichneumon, Echthro-
morplia luaculipennis, and of late years, occasionally, the imported Chalcid, Chalcis
obscurata. In spite of these enemies, and, sometimes, of Tachinid flies, the Kameha-
meha butterfly is a common insect, and at the same time the finest and most conspicuous
in the Hawaiian fauna. As many as a dozen or two may at times be seen flying around
some injured Koa tree, from which sap is exuding, or resting on its trunk or branches.
On such occasions it is sometimes possible to place a net over some half-dozen individuals
at once. Only a small proportion of examples caught in the field are in perfect condition,
the wings, though strong, being apparently very brittle. Although the butterfly bears a
general resemblance to other species of Pyratneis, the caterpillar is so very distinct, that
it would be taken to belong to some other genus. The very numerous stout spines with
which the head is set, the absence of any mediodorsal line of spines, and the enormous
development of two apical abdominal ones, give it an extraordinary appearance.

Lycaenidae. — L. boetica is ubiquitous throughout the group, feeding on many
leguminous plants in the open country, and we have found it at an elevation of some
7000 ft. in the mountains frequenting the flowers of Sophoi-a chrysophylla. It is
apparently free from the attacks of parasites, but both larvae and eggs are destroyed
by the ant Pheidole megacephala. The date of its importation is not known, but it has
been present for more than thirty years.

L. blackbiirni is not at present known outside the islands, though it will quite
possibly be found elsewhere. Though chiefly found in the mountains, it is also
frequently common on the lowlands, sometimes occurring commonly in gardens in
Honolulu. In the latter, the caterpillar^ feeds on various foreign trees that bear pods ;
in the mountains it infests the pods of Acacia koa and the leaves and capsules of
Dodonaea viscosa. This species is not known to be attacked by any parasites, nor does
it exhibit any striking variation.

During recent years other two Lycaenidae have been imported, as destroyers of
the flowers and seeds of Lantana camara. They are natives of Mexico, where they are
so greatly attacked by parasites, that fully 90 per cent, of the larvae were destroyed by
these in their native country, and the butterflies rarely seen. In the islands they become
excessively numerous, whenever the Lantana flowers freely enough to admit of their
multiplication. They are apparently exempt from parasites, though the eggs are often
much destroyed by Pheidole.

Phycitidae. — The few Hawaiian representatives of this family are small, obscure
species, all but three or four being introductions imported with articles of food.

' Mr J. C. Kershaw informs me that this caterpillar is devoid of the usual glands found on the
abdominal segments of Lycaenid caterpillars. If the butterfly is really endemic, this fact in connection
with the absence of any native ants, except the entirely terrestrial Ponera perkinsi, is interesting, since
the excretion of these glands is habitually eaten by ants.

INTRODUCTION clvii

Genophantis, however, is an endemic genus (liable to prove apodemic on further
research in other countries) and the species of Homoeosoma are also endemic. All these
insects are attracted freely by light and all the species are common in their proper
haunts. Genophantis is attached to Euphorbiaceous, Homoeosoma to Composite plants.
The larvae are sometimes found stored up in the cells of Odynerus, and they are para-
sitized by the Ophionines of the genus Limnerium and Lathrostiziis and sometimes
by Che/onus blackburni.

The most interesting species of this family is one whose caterpillar is excessively
abundant in the flowering stem of Argyroxiphumi, the silver sword plant, a composite
found plentifully near the summit and in the crater of Haleakala. Probably this insect
will form a new genus, the species being as yet undescribed. Of many hundreds of
caterpillars brought down from the crater to Honolulu in 1896 only one or two produced
moths.

Galleriadae. — The single representative, Meliphora grisella, is of course an
importation with honey-bees, and of no special interest.

Crambidae. — There are half-a-dozen endemic species of Talis, small obscure grass-
moths, some of which exhibit a good deal of variability in markings and colour. They
are able to flourish in the driest localities near the coast, and also frequent open parts of
the forest region in the high mountains. Most and probably all the species are under
favourable circumstances very numerous in individuals. They are easily disturbed in
the daytime and are attracted very readily to light at night. The larvae of one or more
species have been found at the roots of tufts of grasses. Of the habits of the single
Prionopteryx nothing is known and its claim to be endemic is quite uncertain.

The Euchromhis is a foreign species, now fully established on several of the islands,
frequenting the lowlands and lower mountain slopes, below the line of forest. We have
seen it flying in numbers in the daytime amongst grass and Sida rhombifolia on
Molokai at elevations below 1000 ft. during the cooler months of the year.

Pyraustidae. This is by far the most extensively represented family of the larger
Lepidoptera. Eighteen genera are at present known, but of these four — Nymphula,
Evergesiis, NomopJiila and Hellula — contain each a single foreign species only. On the
other hand five genera — Hyperedis, Projiiylaea, Meslolobes, Ori/iotnecyna and Pi'otaula-
cistis are endemic. Hyinenia is represented by one apodemic and widely distributed,
and one endemic species. The remaining eight genera, though apodemic, contain only
endemic species. Hellula unda/is, the caterpillar of which is the well-known ' Cabbage
web-worm ' of America, has of course been introduced by man, and Evergesiis anastom-o-
salis is a still more recent introduction from the oriental region. It is injurious to the
sweet potato, in the stems and tubers of which it burrows, and has already spread from

clviii FAUNA HAWAIIENSIS

Oahu to other of the islands. The moth, first noticed in 1900 as a great rarity, is now
common in Honolulu, coming to the lights at night. Nomophila nochiella is probably a
natural and not infrequent immigrant, being abundant locally some years and not noticed
at all during others. N'yvipkti/a is either immigrant or more probably introduced.
Hynienia recut'va/is is almost the most abundant moth in the islands, and not only occurs
on the main islands of the group, but also on the small and far distant outlying ones.
Its polyphagous larva is a common prey of various wasps of the genus Odyneriis. Not
only foreign weeds and economic plants, but the endemic Nototrichium is riddled by
these caterpillars. Locally, remarkable aberrations are met with, but always rarely and
exceptionally, and it is questionable whether the supposed second species' of the genus
is an extraordinary aberration or really distinct.

The caterpillars of the genus Ovtiodes have been specially studied by Swezey, who
of late years has applied himself to the investigation of the early stages of the native
Lepidoptera with great perseverance and success. The larvae of all the species of this
genus that are known, with the exception of O. vionogona, feed on monocotyledonous
plants. That species is attached to various leguminous plants and frequently quite
spoils the appearance of the clumps of ' wiliwili ' trees, that grow in gulches at low
elevations in the mountains. Most of the species feed on grasses, sedges, liliaceous
plants, palms or bananas. Oiniodes blackburni is responsible for the defoliation of
coconut palms throughout the islands. It attacks also various other palms and more
rarely the banana. On the latter are found several closely allied species, which, unlike
O. blackburni, are restricted to the mountains. It would be premature to state that
these banana-feeding species O. meyricki, O. niaia, and O. uiusicola have no other food-
plant, but they have not so far been found on others. If it proves that these (and
certain other insects) are really restricted to the banana it would strongly influence us in
the belief that this plant is a truly native component of the flora and not merely an
aboriginal introduction, a belief further strengthened by the fact that one of the most
peculiar Hawaiian varieties of banana is said to sometimes produce seed. Another
interesting group of species is formed by O. antidoxa and its several allies, but the food-
plants are more varied in this group, Liliaceae, Flagellariaceae and Cyperaceae being
affected. By far the commonest and most ubiquitous species of the genus are those
feeding on grasses, e.g. Omiodes localis, continuatalis, demaratalis and that pest of sugar-
cane O. accepta. These are very abundant, and are seen on the wing or are readily
disturbed from the herbage, as one walks along in the daytime. Almost all the species
of the genus are attracted by light, and some, unless captured this way, or bred from the
caterpillars, are not likely to be met with except by the rarest chance.

Though living in the concealment of retreats, formed by rolling up the leaves of
the plants on which they feed, or otherwise hidden, the caterpillars are attacked by
many natural enemies. A Pentarthron destroys the eggs of some species and the

' This or another allied species has now been found on Maui by Mr J. F. Rock.

INTRODUCTION clix

caterpillars are now greatly attacked by Bracon omiodivor'uni (an introduced species)
and the Ophionine Linmeriuvi blackburni, sometimes also by a species of Enicospilus in
the latter group. The two common Tachinid flies, Chaetogaedia monticola and Frontina
cxrchippivora, also parasitize the caterpillars. The Pimpline Ichneumons, Eckthromorpha
maailipennis and Pimpla hawaiiensis, as well as the very abundant, imported Chalets
obscurata, are bred from the pupae. From one of the forest-frequenting species (C. asa-
phoiiibni) Swezey has bred the Bethylid, Siero/a diclwoiiia, and it is likely that others of
this genus will attack other Oniiodes larvae. In addition to these parasites, various
species of Odynerus carry off the caterpillars to store their cells. Odynerus nigripennis
is a constant enemy of Omiodes accepta and other grass-eating species, as well as of the
leguminiphagous O. vionogona. The rarer wasp Odynerus cpipseitstes has been noticed
hunting for the caterpillars of Omiodes continuatalis. The imported social wasps of the
genus Polistes also use those of various species, as food for their young, while various
other polyphagous predators feed on them when opportunity offers.

The species of Phlyctaenia are numerous, twenty-six having been already described,
while others have since been discovered. In their larval habits they much resemble
Omiodes, and some of them are amongst the most abundant of moths. They differ,
however, in the fact that the caterpillars are entirely or almost entirely attached to
dicotyledonous plants for their food supply, though I have some suspicion that the
Omiodes-like P. heterodoxa will be found to live on SisyrincJiiuvi or some other mono-
cotyledon. In the forest region of the islands many trees or shrubs are attacked by
the caterpillars of Phlyctaenia. Some species attack very different food-plants, e.g. the
common P. despecta, which is extremely abundant on Ipomoea and various composite
plants and occupies with equal success stations near the driest coasts or high up the
mountains, where it can thrive in the wettest forests. Such species exhibit considerable
variation as is natural, but it is not clear to what extent this is due to climate and to
what extent to food-plant. Some of the species, e.g. P. monticolans and eucrena, vary
greatly even when taken in the same station. Many of these moths are easily disturbed
in the daytime, as one walks along, or are even on the wing naturally. P. pyranthes
sometimes flies freely in the sunshine in open places in forests amongst Vaccinium
reficidatum, on which the caterpillar feeds, being much more abundant than the moth.
Like all the other members of the genus this day-flying species flies also by night and is
attracted by light. P. calliastra was noted as flying freely at the approach of darkness,
soon after sundown, then remaining quiescent till midnight or later, the period of
activity of this, as of other species, being evidently very short. P. micacea may be
noticed flying from tree to tree in wet forests, growing on rough lava flows, and settling
on the mossy tree trunks. When at rest it raises the abdomen and has in consequence
a peculiar appearance.

The natural enemies of Phlyctaenia are much the same as those of Omiodes, and in
addition to these, P. despecta is attacked by the Braconid Chelonus blackburni. Probably

clx FAUNA HAWAIIENSIS

the predaceous Odynej-i ■axv^ the parasitic Lininerium are their worst enemies. In one
case a large number of caterpillars of P. stellata (a species extremely common on the
urticaceous tree, Pipturus a/bidiis) were collected, but only four moths were reared,
85 per cent, having been parasitized by the Lunneriutn, an exceptional death-rate.

The Hawaiian species of Pyrausta appear to resemble the Phlyctaenia in habits,
and are mostly found in the mountain forests, within the rain belt. P. litorea, however,
frequents dry sandy coasts, the caterpillar feeding on the leaves of that common
immigrant plant, Scaevola koenigii. The commonest species is P. constricta, the
caterpillar of which is comrrion in the mountains, feeding on Scaevola chamissoniana.
The moth is rarely seen on the wing, but is readily attracted to light, on the lower
edge of any of the forests of Oahu, where the food-plant abounds. P. litorea, on the
contrary, is very easily disturbed from amongst the leaves of its food-plant. The latter
species is attacked by Limnerium and the introduced Chalcis obscnrata and no doubt
all the others will be found to be parasitized by these and other natural enemies that
attack Phlyctaenia.

Mecyna aurora is a widely distributed species in the islands, but its endemicity is
doubtful. Its habits are like those of Pyrausta and it feeds on various Compositae,
native and introduced. Like the others it is attracted by light. M. virescens has all the
appearance of an endemic insect. It is extremely variable in colour and chiefly abounds
at high elevations, 4000 ft. or more in the mountains. It occurs in great numbers in
open places in dry forests composed of Acacia koa, Sophora chrysophylla, Myoporum,
etc., and flies readily by day, settling on the herbage, though it is also attracted to light.
It favourite food-plant appears to be Sophora, which is sometimes badly eaten by the
caterpillars. The latter are of bright colours, and were found to form a favourite food
of the fine endemic Passerine bird, Rhodacanthis palineri. These caterpillars also eat
the leaves of Acacia koa and the moth sometimes occurs in places, where no Sophora
grows, and at much lower elevations than 4000 ft.

The three species of Hawaiian Loxostege appear to be rare insects, probably owing
to the fact that their larval habits are not known. They are attracted by light at night,
but very rarely met with in the daytime. They are usually found in the belt of heaviest
rainfall in the mountain forests.

Hyperectis is an endemic genus with only one species at present known, this having
occurred on Maui and Hawaii. Probably this moth will be found to be quite variable in
its markings, as of the few specimens obtained on Hawaii one is a remarkable aberration.
It is attracted to light at night and was once taken on the wing in the daytime.

Margaronia is represented by two entirely dissimilar forms, the conspicuous green
M. exajila greatly resembling foreign forms, and it must be looked upon with suspicion
as regards its endemicity. The caterpillar is sometimes common on, or even injurious
to, foreign Apocynaceous trees, grown in gardens in Honolulu. In the mountains it
will no doubt be found to feed on trees of the same order, such as Rauwolfia, Ochrosia

INTRODUCTION clxi

and Vallesia, and I have seen the caterpillars numerous on what I was told was a
species of Euphorbia. This moth appears to frequent the lower borders of the forests
and is sometimes disturbed from amongst ferns, where it flies wildly and rapidly and is
generally difficult to capture. At night it is attracted by light. Margarofiia cyano-
michla is a widely distributed species throughout the islands, especially in the wetter
forest regions. It exhibits a good deal of variation, probably in part according to the
station it inhabits. It comes freely to light and is rarely met with otherwise.

Mestolobes and Orlhomecyna are extensive endemic genera, with 30 species in the
former, and 14 in the latter already known, and the two monotypic endemic genera
Protaulacistis and Pro77iylaea are offshoots of these. Some of the species of Mestolobes
(e.g. M. xauthoscia, mimisctda, etc.) are frequent visitors to flowers, flying freely in the
sunshine and also at night, while others appear to be entirely nocturnal, and come very
freely to light in company with the former. Some may be seen in numbers flying
over or settling on ferns in shady places. Most of the species are entirely confined to
mountain forests, but M. minuscnla is ubiquitous, occurring near the sea-shore even on
the leeward side of the islands, and thence upwards through the forest-belt. Not
infrequently a small swarm will buzz around and even settle upon the person of the
collector. In the forests it is usual to find several species in company, and individuals
of two or three may be sometimes noticed on a single flower of the Ohia tree. The
species that have been examined in numbers are generally very variable in coloration.

In general the habits of Orthomecyna are like those of Mestolobes, but in a number
of species there is a tendency to fly low and settle on the ground or near it. These
low-flying species are generally of obscure coloration, compared with the more arboreal
forms. Some visit flowers of forest trees and some come freely to light. O. epicausta,
exigua, and viesoc/iasma are excessively numerous in certain localities at proper seasons.
Some of these, like some of the Mestolobes, can be dislodged in extraordinary numbers
from bushy trees, in which they are resting during the daytime. Nearly all the species
are true forest insects, though they are sometimes found in the open country below or
above the forest-belt. None seem to occur on the lowlands, at least not on the leeward
side of the islands. Considered generally they do not seem to show any particular
liking for the excessively wet parts of the forests, which are frequented by many species
of Mestolobes. Like the latter, some are extremely variable in markings.

More than sixty species of Scoparia are already known, and no doubt many more
remain to be discovered. They occur from the lowlands on the windward side to an
elevation far above the forest-line on both sides of the highest mountains, but, except
accidentally, are not found on thfe lowlands of the leeward sides. They are most
numerously represented in the true forest-belt. As in other countries, they rest in the
daytime on the trunks of trees and on rocks, but are easily disturbed, as one walks
along. Some settle freely on the ground, in open parts of the forest, where there is
a great growth of lichens amongst low-growing plants, such as Vaccinium, Cyathodes,

F. H. I. X

clxii FAUNA HAWAIIENSIS

and Coprosma. Many match in colour the lichen growths, that cover the branches and
trunks of trees, on which they rest ; but, as stated, they are so easily disturbed in the
daytime that they are frequently snapped up by the fan-tailed flycatchers {Chasievipis)
which, but for this habit, they might elude. In dense damp forests, where moss covers
the trunks of trees, species with orange, yellow, or ferruginous colour (5. ianthes,
marmarias, nectarias, haivaiiensis, etc.) are conspicuous; in drier and more open places,
black and white species with sharply defined markings {S. balanopis, etc.) are often
numerous, mixed with the dull and difficult species of the group of 5. jueristis, and the
very distinct looking S. venosa.

The caterpillars of Scoparia feed on mosses and possibly also on lichens. Those
of species of the nieristis group are sometimes numerous beneath moss growing on
perpendicular banks or road cuttings. They are much attacked by Limnerium black-
burni, which may be seen flying along such banks in great numbers, and frequently
settling and thrusting its ovipositor through the moss. Other species feed on the
mosses growing upon the trunks of trees. Some occur above the forest-line on rocks,
on which mosses and lichens grow together. According to Meyrick, " not one of the
many species is even moderately variable," but possibly it would be more correct to say
that the variability, which exists, though sometimes quite noticeable, is not of such
a character as to obliterate the distinguishing specific characters. Apart from the
Linmeriuni, above mentioned, nothing is known as to the natural enemies' of the
Hawaiian Scopaina, but besides the flycatchers, Oreomyza and Heterorhynchus have
been seen to catch the moths. The great abundance of individuals of many species is
noteworthy, hundreds of specimens being seen around the lights at night in many places.
Equally plentifully others are disturbed in open places in the forest region, as one
walks along ; while in some forests they fly off from every tree-trunk.

The two species of Lineodes are widely distributed throughout the islands, but
usually not numerous. They are easily disturbed in the daytime from low plants, on
which they rest Pterophorus-like with folded wings, and they are also attracted by
light. Probably they are most common in the more open parts of the forest, where
Vacchmun or other low-growing plants cover the ground, yet we have even found one
of the species on the dry leeward coast of Oahu, and their endemicity is doubtful.

Pyhalididae. — The two species of Pyralis are introductions by man, and of no
particular interest. P. manihotalis is common in many houses in Honolulu, while
P. mauritialis is still more common, the caterpillar feeding on the nests of the intro-
duced social wasps [Poiistes). The latter moth is very readily attracted by light.

Pterophoridae. — Trichoptilus oxydactylus is throughout the group a very abundant
littoral or sub-littoral species, extending its range to the forehills. The caterpillar is

' Probably they are parasitized by the Bethylid Sierola, which has a wide range of hosts in Lepidoptera.

INTRODUCTION clxiii

found abundantly feeding on Bocrhaavia. This moth is probably a natural immigrant,
having a very wide range outside the islands, and it is found on the small outlying
islands of the group, e.g. on Midway Is. It comes freely to light.

There are four known species of Platyptilia, one of which, P. fuscicornis, is
probably an importation with plants. It is a very common insect, and the caterpillars,
which, like the pupae, vary in colour, are found on the flowers of the common weed,
Ageratum conyzoides. I have bred the same species with several others from flowers
of Lantana camara sent from Mexico. P. rhynchophora .is generally distributed
throughout the group, wherever Vacciniuni rcticulatum flourishes, at elevations of
from 2000 to 9000 ft. above sea-level. The food-plants of the other species are
not known.

Orneodidae.— Only two species of Orneodes are known, and these have only
been taken on Kauai and in the western mountain range of Oahu, but as they are very
rarely met with in the perfect state they will probably be found to be more widely
distributed. The Oahuan species, O. objtcrgatella, was once bred in large numbers from
the drupes, I believe, of Plectronia.

Gelechiidae. — Represented by 1 1 genera containing 45 species. Phthorimaea
opcrculella, the common pest of the tobacco plant, is of course an introduction, as also
is the cotton insect, Gelechia gossypiella, and the single species representing each of
the genera Stoeberhimis and Auiosticha are also importations, which, owing to their
habits, might very probably have been brought to the islands by the natives before
the coming of white races. Merininetria represented by a single species, only once
captured, is of uncertain status. Hodegia with one described species (but of which
others are known to occur), Ptycothrix and Catameynpsis also monotypic, and Psychra
with two species, are developments of Thyrcopa. The latter with 26 (and others
undescribed) and Aristotelia with nine absorb most of the species of the family. The
six genera Merimnetria, Hodegia, Ptycothrix, Catamempsis, Psychra, and Thyrcopa are
endemic.

The species of Aristotelia are found amongst Gozildia, and the swellings on the
twigs made by one of the species are very common objects. After the escape of the
insects these swellings are often the home of more than one species of Proterhinus
and other insects. Neolelaps is bred from these galls, but is probably parasitic on the
beetles. The moths themselves are not very often met with in general collecting.
The caterpillars are parasitized by the Chalcids of the genus Eupelmus. Stoeberhimis
and Autosticha are both common in Honolulu gardens and elsewhere, their larvae
feeding on all sorts of dried or dead vegetable matter. They are attacked by the small
Braconid, Microdtis hawaiicola. Both come to light at night, the former in very great
numbers, the latter less frequently, but it is often seen at rest on the sides of houses.

X2

clxiv FAUNA HAWAIIENSIS

It rests with the foreparts much elevated, and thereby has a very distinctive appearance,
quite unlike Stoeberhinus, some varieties of the female of which it much resembles in
superficial appearance. Gelechia gossypiella is of recent introduction, and quite injurious
to cotton-bolls. It first appeared in the grounds of the Department of Agriculture, and
was no doubt imported with cotton-seed. It is parasitized by the foreign Braconids,
Chelonus blackbtirni and Microdus haivaiicola. The tobacco pest, Phthoriniaea oper-
ciilella is also very numerous, and an earlier introduction, having been collected by
Blackburn. It is parasitized by the common Limnermni blackburni.

Hodegia apatela, a flightless jumping insect with abbreviated wings, is only known
in the female sex, the male probably being fully winged. It was found in the wind-swept
open country near the summit of Haleakala, and one or two similar forms have been
seen on the open lower slopes of Molokai, below the forest region, a locality also
constantly swept by strong winds, Catainetnpsis decipiens is very common in the larval
state, infesting the leie [Frcycinetia) and sometimes injuring the shoots, but the moth
is not very often seen at large. The numerous species of Thyiropa are mostly feeders
on dead wood, some occurring in the driest localities, living in the stems of both native
and introduced plants, and one of them is common around Honolulu, feeding on the
dried droppings of cattle. The moths are, many of them, very readily attracted to
lights, and are very numerous in individuals. The caterpillars of some species, however,
feed on living shoots, and some live in decaying logs so wet and rotten that the water
can be squeezed from the wood. Some of the species are very variable, and in some
there is a striking sexual dimorphism. The caterpillars in some localities (especially
on the lowlands) are a favourite prey of the wasps of the genus Odynerus and
Pseudoptei'ocheilus, and in mountain districts they are eagerly sought for on the dead
branches of trees by various Drepanid birds, e.g. Heniignathus and Hetero7-hynchus.
We have also found them in the stomach of the little flycatchers of the genus
Chasiempis, which may be seen investigating fallen decayed tree-trunks in search of
this food.

Oecophoridae. — Ethmia colonella, the solitary representative of the family, is
known to have been introduced. Its food-plant is the ' Kou ' {Cordia subcordatd), a
tree no doubt introduced by the natives themselves, who valued it highly. Since the
introduction of the Ethmia, this tree has been robbed of all its beauty ; many indeed have
been entirely destroyed, while others are either continually defoliated or have the foliage
so riddled by the attacks of the caterpillars as to be unworthy of preservation. The gaily-
coloured caterpillars seem to be remarkably free from the attacks of any natural enemies,
but sometimes the omnivorous ant Pheidole megacephala destroys numbers of them.
The moth itself is comparatively rarely seen, though it may be found resting on tree-
trunks and occasionally visits lights.

INTRODUCTION clxv

HvpoNOMEUTiDAE (including Elachistidae and Plutellidae). — Several of the eight
described species of Batrachedra are known to be attached to ferns, on which the larvae
feed. Some of the species are very numerous in individuals and they may be swept or
disturbed from ferns in any number during the daytime. Both the wiry Gleichenia
and soft ferns are affected by the caterpillars. It is possible that all the Hawaiian
species are feeders on ferns.

The habits of the three Hawaiian species of Agonisnius, an endemic genus, and two
of Elachista are at present unknown. Of Stagynatophora the three species, 6". incertu-
lel/a, S. honorariella and S. quadrifasciata, are no doubt introductions by man. The
latter is a common insect in some Honolulu gardens, and generally throughout the
islands, on the lowlands, being attached (as is 5. incertulelld) to Pandamcs odoratissimus,
and various cultivated species of this genus. The caterpillars feed internally in the
dead leaves and before pupation form a large oval case, which they usually drag inside,
between the upper and lower surface of the leaf, in which they have fed. The
dead leaves of the trees are often riddled with the holes, from which the cases have
been formed. These Pandanus-feeders would be very liable to have been carried
around from group to group of the Pacific by the natives in their migrations. 5". sordi-
della is doubtfully congeneric with the other species and its habits are not known.
Aphthonetiis with 29 species is endemic. The moths are common on tree-trunks or
hiding amongst the foliage of trees and ferns and are readily attracted by light. The
genus is connected with Neefysia, which contains 31 species, and probably has similar
habits, by Rhinomacirum (with two species), both these genera being also endemic.
Of the great endemic genus Hyposniocoma 177 species have been described, forming a
varied and probably heterogeneous assemblage of forms, with, evidently, a considerable
variety in habits. Many of the moths are extremely common, resting by day on rough
tree-trunks, from which some readily take flight on the approach of the collector.
Others are disturbed in quantities from amongst dead fern-fronds, or dry limbs of trees,
or from dense bushy trees or shrubs, especially certain varieties of the Ohia tree {Metro-
siderits). Many are readily attracted by lights. A group of yellow or orange-coloured
species are very conspicuous objects on the intermediate islands of Maui and Molokai.
Some of the species exhibit much variation in colour, and when series of individuals
have been collected from a great number of stations it is probable that the discrimina-
tion of the species will become a very difficult matter. Some of the caterpillars feed
in dead wood or bark of trees and are quite naked, while others form cases of silk
mixed with frass or ddbris. These cases exhibit much variety of form and appearance.
Some are acute and spiniform, while others are broadly oval ; some are dilated at each
extremity, or pointed at one end and broadly rounded at the other, others are dilated in
the middle. Some, found on lichen-covered trees, greatly resemble the surface on which
they rest. Of several species almost incredible numbers may be found attached to
rocks or bare vertical surfaces of decomposing lava, where the larvae no doubt feed on

clxvi FAUNA HAWAIIENSIS

the microscopic vegetable growths. They are parasitized by the Braconids Protapan-
teles hazvaiiensis and Microdjis haivaiicola and also by the Chalcid Ompliale vietallica,
which is so common on leaf-mining Tineina. Species of the Miscogasterid genus
Ncolelaps are also bred from wood affected by Hyposmocoiua, but it is not definitely
known whether they attack these caterpillars or other wood-eating insects found with
them. I believe they are attached to the Coleoptera. The moths are often caught by
the little fan-tailed flycatchers {Chasienipis) and by the native dragonflies. Though the
chief home of Hyposmoconia is in the true forest-belt, some occur both below and above
this belt. Even in the dry lowlands a few kinds are found, their larvae feeding on the
low forms of vegetable life, growing on rocks and tree-trunks. On the wet side of the
islands a once numerous lowland fauna has been, no doubt, well-nigh exterminated
by the ant Plieidole. The habits of the allied monotypic genera, Dysphoria and Biiba-
loceras, are unknown. The former comes freely to light at night. Eiipei-issiis cristahis,
the sole exponent of its genus, is very common in the larval state in the dead stems of
Freycinetia. Hyperdasys with four and Semnopj'epia with three species are found hiding
amongst masses of dead fern-fronds or are attracted by light. All these genera, like
Hyposmocoma, are endemic. Diplosara lignivora is a very common insect in the larval
state, the cases sometimes being found by scores or hundreds beneath the bark of dead
and fallen trees. The moth is freely attracted by light. Blastohasis inana is a foreign
species and has been bred from stored yams imported from the Orient, though it
had previously become established in Honolulu. Endrosis lactella and Oecia tnaculata
are imported domestic insects, the latter parasitized frequently by Protapanteles.
Mapsidius with three species is an endemic genus, the habits being unknown. The
moths appear to be very rarely met with, the very conspicuous M. quadridentata was
found in the bed of a mountain torrent, having been washed out by the heavy rains. The
very variable Prays fulvocanelhis is a common insect, often disturbed from the branches
of trees. It is a true forest insect and almost certainly endemic. Phitella maciilipennis
is a pest amongst cabbages and other Cruciferae, and is of course introduced, there
being no endemic Cruciferous plants in Hawaii. P. albovenosa, if it has the same habits,
will also prove to be an importation. The first-named species is much parasitized by
Limnermm po/ynesiale, and it is possible that this will prove to be the same as the
Limneriiim recorded as attacking the cabbage pest in North America, of which I have
seen no detailed description.

The Hyponomeutidae with their 276 species are such an important element of the
fauna that the following summary is of interest. Oecia, Blastobasis and Endrosis with
single species, which are domestic or semidomestic, are introductions by man. So too is
Phitella cruciferartmi and probably also its congener. Stagmatophora has three species
that are almost certainly introductions, and it is quite likely that the fourth may also be
foreign. Leaving out of consideration these five genera with their nine species, there
remain 15 genera with 267 species that must be considered endemic. Prays with one

INTRODUCTION clxvii

very variable species, Elachista with two (and no doubt others to be discovered) and
Batrachedi-a with eight allied forms, some, and perhaps all, attached to ferns, are apodemic
genera. The remaining 12 genera are all endemic and seem to be mostly intimately
related to one another. Thus Agonisrmis is said to be intermediate between Bah^achedra
and Hyposmocoma ; Rhinomactnim between the extensive genera N'eefysia and Aphtho-
netiis, while other genera represented by one or a few species seem to be special
developments of some of these larger genera.

Carposinidae. — Thirty-three species of the genus Heterocrossa have been
described, and doubtless many others remain to be discovered. The species appear to
be often variable and very difficult to separate, a difficulty which will be much increased
by the discovery of new forms. The moths are often very numerous, being attracted
by light or disturbed from amongst foliage, especially that of the Ohia tree. They are
also commonly found at rest on tree-trunks, and once, when sheltering from a heavy
rain storm, I remember noticing half-a-dozen examples all close together on a single
stem of a tree-fern, none of these individuals much resembling one another, and perhaps
each formed a distinct species. The genus is not endemic and a species that I found
resting on tree-trunks near Sydney (N.S.W.) had a very Hawaiian-like appearance.
The caterpillars attack many kinds of fruit of forest trees and shrubs, e.g. of
Clerniontia and other Lobeliaceae, of Vacciniu))i, Eugenia, Pittosporioii, Mahoe,
Sideroxylon and, doubtless, many others. Others live in buds, e.g. those of Metro-
siderns. These caterpillars are sought after by the wasps of the genus Odynerus, and as
many as three dozen have been found in a single cell. They are also obtained by the
native birds, while the moths themselves are often caught and devoured by the
' Elepaio' {Chasienipis) and by some of the Drepanididae, especially by those belonging
to the genus Oreoviyza.

ToRTRiciDAE. — The single species of Eccoptocera is one of the commonest of
Hawaiian moths and is extremely variable. It is especially attached to Metrosiderus,
and its caterpillars are much sought after by the wasjDs of the genus Odynerus. There
is no reason to doubt its endemicity. Crocidosema plebeiana is a natural immigrant,
attached to the immigrant plant Sida, in the buds of which the caterpillar lives. It is
an important food-supply of the larvae of many of the endemic wasps, that frequent
the lowlands and lower mountain slopes, since it is excessively numerous and ubiquitous,
wherever its food-plant flourishes. Near Honolulu, Nesodynerus rudolphi, Odynerus
niontanus, and other wasps are always to be seen searching the 'Ilima' buds in their
season for these small caterpillars. Gyisononia leprartim is less abundant and may be
an introduction. If not, it is probably a natural immigrant and will be found elsewhere.
Adeloneura with half-a-dozen species described and others existing, is an endemic
genus. The caterpillars live in the pods of the Acacias, Acacia koa and Sophora

clxviii FAUNA HAWAIIENSIS

chrysophylla, and are injurious. A. falsif alee Hum feeds on the beans in the pods of
leo"uminous plants and also bores in the stems, sometimes destroying the plant.

The endemicity of any of the species of Cryptophkbia is doubtful. CiyptopJilebia
illepida, of which long series have frequently been bred, is much more variable in the
males than in the females. It is extremely common, the caterpillars feeding in the
pods of the imported Acacia farnesiana but also on the very different (Sapindaceous)
Nephelmni litchi. It also attacks Cassia and other imported pod-bearing trees, in
which it resembles the allied C. carpophaga, which is known to feed on Cassia and
Nephelium. In the mountains C. illepida is injurious to the native acacias, and the
other two doubtfully-distinct species, C. tetrao and C viilpes, will no doubt also be found
on the same. There are five species of Enarmonia described. The status of these
species is uncertain, as the variability is excessive, being somewhat similar to that of
Adeloneura falsif alcelliini. Examples with very little resemblance to one another are
bred from the same brood of caterpillars. These feed in the pods of Sophora and of
Acacia koa in the mountains, and are numerous enough to be injurious in some localities.
Bactra straminea is a very widely distributed species in the islands and extremely
variable, examples differing greatly in size and pattern. Probably several species are
really included under this name, for we have observed scores of specimens in some
localities, without remarking any special variability. If there is only one species, then
the variation is to a large extent local or racial. Melanochroic forms occur and these
are sometimes of gigantic size. In some varieties there is constant and conspicuous
sexual dimorphism.

Of the subfamily Tortricinae, Pararrkaptica is represented by a single species,
which greatly resembles some of the species of Archips, and, though peculiar to the
islands, is probably an offshoot from the other. The species of Archips, nine in number,
are, excepting A. postvittanus, endemic, as also are the very similar species included in
Panaphelix (monotypic and endemic), Dipterina with one species and Tortriv with five.
So far as is known all these greatly resemble each other in habits, and the borings of the
rather large caterpillars in young shoots of Myrsine or other trees are often conspicuous
and numerous. The moths are not very commonly met with, but some species are
attracted to light. In the daytime we have usually disturbed them from amongst dead
leaves lying beneath the forest trees, or found some of the prettily coloured green-marked
species at rest amongst moss on tree-trunks in wet forests. The abundance of larvae
compared with the rarity of the moths is quite remarkable. I think that I have obtained
a species of the small Ophionine of the genus Atrometus from one of these Tortrices.
The imported A. postvittanus is an injurious insect and has been found, in company with
Amorbia emigratella, doing much damage to young fruits on orange trees, but both these
species are polyphagous. When inspecting importations, we have found A . postvittatms
on plants introduced from Australia, on hot-house trees from California, and on others
from Mexico. It first appeared on Kauai in 1896, having probably been brought from

IN TROD UC TION clxix

Australia with orange trees, as was the Australian Mantid Orthodera prasina, the latter
being still confined to Kauai. The other importation, Amorbia emigratella, was first
noticed in 1902, when the larva was already common on orange trees in Honolulu.
A. postvittaniis is a favourite food of Odynerus, especially of O. nigripennis, and its
pupae are parasitized by Pimpla hawaiiensis, an imported Mexican Ichneumonid, while
its eggs are destroyed by Pentarthron flavum {Trichogramma pretiosa ?). The other
pest is at present much less attacked by natural enemies.

There are 10 species of Capita, all forest insects and no doubt endemic. Some
of these are readily attracted by light, but very rarely found in the daytime, though
sufficiently common. Some are known to be extremely variable. One is abundant in
the drier forests, but the caterpillars', like those of Epagoge (with four species), have
not been bred.

It will be seen that the Tortricidae present a great difference from the Hyponomeu-
tidae in that there are no extensive endemic genera, the monotypic Pararrhaptica and
Panaphelix being closely allied to apodemic ones, while Adeloneura has only half-a-
dozen species, mostly small obscure insects, of which congeners might at any time be
found elsewhere.

TiNEiDAE. — The' two species of Opostega are endemic and the perfect insects are
probably difficult to collect. O. dives was found only once, the two individuals were
taken running on a leaf of Pelea in the sunshine and one was noticed ovipositing. It
is possible that the curious circular mines, that are so conspicuous in various localities
in the thick leaves, are formed by the larvae of Opostega^. From these mines one
generally breeds only Eulophid parasites. Opogona aurisquaniosa is an imported
insect, easily carried in the larval state with coconuts, sugar-cane, bananas and other
plants. It usually feeds on dead or dry vegetable matter and is polyphagous. One or
two other species, that have reached the islands on imported plants, have been inter-
cepted and destroyed. The imported larvae of a pretty species, infesting the drupes of
coconuts in Samoa, have more than once been bred to maturity. The species of Ereu-
netis are all no doubt introduced, their habits being in some cases like those of Opogona,
E. viinuscula and E. flavistriata being easily carried about with sugar-cane. In fact,
another species, that infests cane, has still more recently been imported and become
very numerous, even in some mountain forests. The dry leaf-sheaths of the sugar-
cane afford a favourite food for the caterpillars, which hide between the sheath and the
stem. Of E. zebrina little is known. Blackburn took it in Honolulu and I found my
specimen on a trunk of the Kukui tree, also on Oahu. E. simulans is very abundant,
the caterpillar feeding on dead bark of trees and the moth sometimes is common round
the lights or may be seen resting on tree-trunks. It is found from the coast to an

' Species have since been reared from sandalwood by Mr H. Swezey, and Opostega has been bred by him
from Pelea.

F. H. I. y

clxx FAUNA HAWAIIENSIS

elevation of about 1800 ft. in the mountains and occurs in gardens in Honolulu. The
caterpillar is sometimes parasitized by the Braconid, Rlicrodus hawaiicola, and I believe
also by a now very abundant species of Chalcididae {^Hockeria) of recent introduction
and not included in the systematic portion of this work. Philodoria is an important
endemic genus with seven species described. The mines are very conspicuous in the
leaves of the urticaceous Pipturit,s, many examples of P. niicropetala sometimes being
bred from a single large leaf P. splendida is attached to Metrosiderus (Myrtaceae). In
wet boggy forests we have noticed mines in quite different plants, amongst these being
Myrsine, but Piptnriis certainly is the food-plant of more than one species. Of Oraci-
laria epibathra the habits are not known, but G. inarginestrigata is a very common
insect, the larval mines in the leaves of Sida being very conspicuous. Besides this
malvaceous plant it also mines the solanaceous Datura siramonium and some others.
Other species of this genus are known, but have not been described in this work.
Both Philodoria and Gracilaria are frequently parasitized by Omphale meial/iai-s, and
other minute Eulophidae. The four species of Bedellia are of some interest. One
has been referred to the European sommilenlella, and one to the American minor.
The latter is very common, the larvae mining the leaves of Iponioea of various species.
The former, however, as well as the two species described as new, seems to occur in
localities quite beyond the range of any Convolvulaceae, and to- have some different
food-plant. Setomoipha dryas is an introduced insect, and Acrolepia aiLreonigrella may
come under the same category. The three species of Monopis and Tinea are of course
importations and without interest, while the unique insect, for which the genus Para-
phasis was made, is of uncertain status.

Review of Neuroptera.

One hundred and sixteen species of Neuroptera (s.l.) have been enumerated in the
systematic portion of this book, and these represent but six families of the Order. If
one excludes the Psocidae, of which very many species have been imported with plants
from other countries (these species, however, not having been enumerated in this work),
the Neuroptera are singularly free from artificially imported species, more so, indeed,
than any other Order. There are, however, several species, which, we can be sure, are
natural immigrants, viz. the three dragon-flies of very powerful flight, Pantala flavescens,
Tramea laceraia, and Anax Junius, all species of wide range and inhabiting the
American continent. A small white ant\ destructive to houses and woodwork all over
the islands on the lowlands, has been established for many years, having, no doubt, been
brought in with lumber. A few are of doubtful status, the Embiid, Oligotoma, and
the Hemerobiid, Megalomus hospes, being probably either natural immigrants or
endemic, while the ubiquitous Chrysopa microphya is more likely an importation. In

' One if not two other species of Termites have more recently been introduced into Honolulu.

INTRODUCTION cl

XXI

the Hemerobiidae, one genus, Ncsomicrovms, of the Hemerobiinae, contains 22 known
species, Anonialochrysa of the Chrysopinae 29, Agrion of the Odonata 26, Psoais of
the Psocidae 14, and Elipsocus 10. No less than loi of the species of Neuroptera are
consequently distributed in only five genera !

Many families or even greater groups are totally unrepresented. Thus there are
no Trichoptera, Perlidae, or Ephemeridae of the aquatic groups, no Mantispidae,
Panorpidae, Ascalaphidae, etc., of the terrestrial forms.

Hemerobiidae.^ — The single species referred to Megalo7mis is a rather common
forest insect throughout the islands, the habits of which are very imperfectly known.
It exhibits some rather remarkable variations, and though allied forms will, no doubt,
be found elsewhere, it may itself prove to be endemic. We have not seen species from
other countries having the same peculiarities of neuration, which will no doubt exclude
it from the genus Mega/onnts properly called. It flies at dusk and sometimes is
attracted by lights in the nighttime, hiding by day amongst dead leaves attached to
trees, and amongst dead fern-fronds. When beaten from these it feigns death like
others of the group.

The species of Nesomicromus exhibit a great variety of appearance, some having
the remarkable contour of the wings of D repanopteryx, though of course not allied to
this, while others hardly differ from some species of Micromus, described from other
countries. The more remarkable forms appear to be related to and connected by
intermediates with the more commonplace ones. They are a difficult study, since
many are so rare as to have been very imperfectly examined, and the difficulty is
increased by the variability of the neuration and other characters. With the exception
of N. vagus, which occasionally ranges to the coast, all are forest insects, many of them,
as has been stated, rarely or very rarely collected. On the other hand N. vagus is
often met with in great numbers. Mostly they frequent trees or ferns infested with
Psocidae, on which they prey, but some, and especially those which are found most
numerously, attack Aphidae. Amongst the latter may be mentioned N. vagus,
minimus, and fulvescens. One is tempted to think that the greater abundance of such
species is due to this habit, the large number of Aphidae, which have become imported
with various plants, affording a more abundant pabulum. Probably Aphidae were
entirely absent from the endemic fauna. //. vagus, the most successful of all the
species, now sometimes abounds outside the forest in fields of sugar-cane attacked
by Aphis sacchari, on maize, etc., and in the mountains we have found it in enormous
numbers on the rare tree Gossypiwn drynarioides infested by Aphis gossypii. On one
occasion the capsules of the latter plant were found full of the cocoons of N. vagus,
the larvae having crept within for the purpose of pupation. If, as is probable, the
Aphidae were absent from the fauna until they were imported by man, it is most
likely that the Psocidae and small Homoptera previously supplied the sole food of

y2

clxxii FAUNA HAWAIIENSIS

N esomicronms , and their present diet of Aphidae is a return to the normal food of the
family in other countries.

The genus Psendopsectra is clearly an endemic offshoot from Nesoniicromus, the
posterior wings having become reduced to lobes, and the insect itself flightless.
Nesothaunia is a still more remarkable form, the hind wings having entirely dis-
appeared, while the front ones have become hard like the elytra of a beetle, and
their fringes have also vanished. It is allied to Psendopsectra, and has been found
in company with it, on trees covered with dense growths of lichens and harbouring
many Psocidae. It varies much in colour, so that examples taken in the same locality
appear superficially distinct from one another. The insects comprising these two
genera are amongst the most remarkable of known Hemerobiidae.

Of the subfamily Chrysopinae one species of Chrysopa (C oceanicd) was brought
back by the Beechey expedition more than three-quarters of a century ago, and
has not since been met with. Probably it frequented the lowlands, and has become
exterminated. In this connection I may add that a species of this genus is known
to me from the far outlying island of Midway, but I do not know whether this is the
same as the other, opportunity for comparison of description or specimens not having
occurred.

Another species, Chrysopa microphya, now ubiquitous on the lowlands, and at
moderate elevations in the mountains, is, I feel sure, a comparatively recent introduction.
Its larva attacks many small insects, such as various scale insects or Coccidae, Aphidae,
young leaf-hoppers, etc., and being numerous, it is decidedly beneficial. The larva
carries the empty skins of its prey on its back in the usual manner, and the eggs are
of the usual stalked form. The pupae are parasitized by a well-known American
Hemiteles of the Ichneumonidae, but the proportion so destroyed is small.

Apart from these species all the Chrysopine Hemerobiids belong to the endemic
genus Ano7nalochrysa, itself no doubt capable of subdivision, and embracing a wide
variety of forms, 29 species having been discriminated. The eggs are simple, not
stalked, and several are frequently laid side by side. They are parasitized by a species
of Pentarthron, of the family Trichogrammidae (Chalcidoidea) which, however, may
have been introduced. The larvae, some of which have been found preying on
caterpillars, are often gaily coloured, the colouration sometimes resembling that of
the adults, being green or yellowish, with a crimson or bright yellow mediodorsal stripe.
The larger ones are able to give a sharp bite, when they fall on the bare skin. The
adults are mostly entirely nocturnal, I think, though some of them are very easily
disturbed by day. In open places in the forest, where the growth is short and scanty,
and also in some places above or below the forest, A. montana, a small fragile species,
often flies up as one walks along, and may even be on the move without being disturbed.
I have seen this or an allied species in incredible numbers, when on my way in the
early morning hours from the coast at Kawaihae to the uplands of Waimea on Hawaii.

INTRODUCTION clxxiii

Very few species, however, are found outside the belt of dense forest. A. ritfcscens
occurs on the lowlands, as well as in the mountains, and may even be seen in Honolulu.
W'e have found the females in numbers fluttering slowly about the foliage of Kukui
trees at dusk, and ovipositing on these. The male is one of those remarkable for the
extraordinary structure of the costa of the front wings. It and several others became
numerous in the upland cane-fields of Hawaii during the worst period of the attack of
the sugar-cane leaf-hopper {Perkinsiella), their larvae preying on this pest. No doubt
in the forests they likewise destroy the endemic leaf-hoppers, though as above stated
we have seen them sucking caterpillars of the genus Scotorythra. Many of the species
of Anomaloclwysa are remarkable for their variability in colour, and in characters of
neuration. This variability renders the distinction of the species more difficult, so that
the number of these may be subject to some correction, though probably the error is
not great. The females lack some striking characters shown by the males, and are
the more difficult to determine. Neither any of the species of Anonialochrysa nor
Chrysopa microphya possess the offensive odour characteristic of some of the Chrysopae
of other countries. Certainly Anomalochrysa is one of the most interesting components
of the Neuropterous fauna, and an exact study of the variations of some of the species
would be very desirable. Unlike Chrysopa microphya the larvae of Anonialochrysa
are quite bare, not covering themselves with ddbris nor with the skins of their prey as
the other does.

Myrmeleonidae. — The two species of Formicaleo appear to be allied to one
another, but to have rather different habits. F. perj'urus, the smaller species, is,
doubtless, much rarer than it formerly was, and has entirely disappeared from some of
the localities, where it formerly occurred. I have never myself met with this insect,
but I once found a solitary larva, which I suspect belonged to it, beneath a stone on
the edge of the stream in the lao valley, Maui. It might almost have been said to be
actually in the water. Three-quarters of a century ago this insect appears to have
occurred near Honolulu, probably in the Nuuanu valley. The larger ant-lion, F. ivilsoni,
is a common insect on the driest lava-fields of Hawaii, where there is a scanty vegetation
or the surface is barren. It occurs near the coast as well as at elevations of from
4000 — 6000ft. above the sea. It is readily disturbed, as one walks along in such
localities, by day, usually settling down again after no very long flight. We have seen
it taking more extensive and higher flights at nightfall. The habits of the larva are not
known, but probably it lives beneath stones or in cavities of the porous lava, as no
burrows have been noticed where the species is common. It cannot prey on ants, for
these do not exist in the uplands, where the ant-lion abounds. Some of its haunts are
so barren that one may well wonder what insects are numerous enough to support the
many larvae that must occur.

clxxiv FAUNA HAWAIIENSIS

Embiidae or Embioptera.

Oligotoma insularis, the sole representative of this small family, is a common
insect on the lowlands, and in dry places in the mountains to an elevation of some
200oft. above the sea. Blackburn reported it as occurring in the thatch of native
houses, but it also is abundant under stones, amongst ddbris of fallen leaves and twigs,
in the cavities of dead twigs and branches, and beneath the webs that it spins on the
exposed trunks of large trees, in fact in many situations. Frequently small colonies of
larvae, nymphs and adults are found in company. The winged males fly at night, and
are attracted by light, and their appearance somewhat suggests that of certain Perlidae,
their movements somewhat those of Raphidia, or still more of small exotic Mantidae.
In whatever situation they are found they spin galleries of silk, along which they can
travel rapidly either backwards or forwards. If the species is really endemic, which is
very doubtful, it is one of the very few native species, not specially protected, which
has escaped destruction from foreign predaceous insects in the lowlands. Possibly
the galleries in which it lives may have saved it from destruction. Though here
placed in the Neuroptera, Oligotoma would be less out of place amongst the cursorial
Orthoptera.

Termitidae or Isoptera.

Only two Termites of the genus Calotermes are recorded in this work, but during
the course of publication, one, if not two, other species have been imported, and are
probably established. The names assigned to the species by McLachlan and adopted
by me were given on the examination of winged examples only, and their correctness
is very doubtful. The smaller species is clearly introduced, inhabiting houses and
woodwork throughout the islands, but is not a forest insect. It has done much damage
in Honolulu and other settlements, attacking many of the more choice woods. On
the other hand, the larger species is a true forest insect, being particularly fond of dead
Koa trees or the dead parts of living trees. Communities, however, are also found in
detached logs of this and other wood, when lying on the ground. This species is
variable, and examples of the soldiers taken from communities on different islands
showed marked differences in the form of the underside of the head. The communities
are often very large, occupying all parts of the trunk and branches of a large dead tree.
The soldiers have distinct eyes, and a number of kings and queens may be found in one
colony. The latter do not exhibit any noticeable post-metamorphotic growth, such as
is so remarkable in the queens of many other Termites.

INTRODUCTION clxxv

Psocidae or Psocoptera.

The species of this family are numerous, and very imperfectly known. The
endemic forms appear all to belong to two types, each with numerous species, repre-
senting the genera Psocus and Elipsoctis. Many of the species are very variable
and also closely allied, and as they are fragile and often indifferently preserved, they
are difficult to study. They are common throughout the forests of all the islands, and
endemic species still occur near the coast in a few places. Of recent years great
numbers of foreign forms have been imported with living plants, so that these are now
found in every garden, and some, and probably many, of these have extended their
range into the forests, and invaded the habitats of the endemic species. No doubt the
existence of the native Psocids in the islands is very ancient, as they are well known
to form the prey of other endemic creatures, e.g. the representatives of the Hemipterous
family Eniesiidae.

Odonata.

The two foreign dragon-flies, Pantala fiavescens and Anax junms, are extremely
common insects, both being particularly abundant on the lowlands, and they range
throughout the islands. Tramea lacerata, though not a rare insect, has been much less
successful. It too is essentially an insect of the lowlands, or at least of low elevations.

Anax sirenuus, superficially similar to A. Junius, but much larger, belongs rather
to the mountains, and may be found five or six thousand feet above sea-level. At
moderate elevations of 1500 to 2000 ft., both these species breed freely in the pools of
the mountain streams, and we have taken the male of the one attached to the female of
the other on several occasions. I captured three such pairs in the course of two days,
when collecting in the mountains near Waialua on Oahu. Owing to the peculiar
method of copulation in dragon-flies, it is not possible to say whether this truly took
place or not. Apart from size, these two species of Anax are quite distinct by other
characters. As might be supposed the endemic A. streniiiis is a very powerful flier,
and on big streams and in open country is difficult to catch. Where they breed in
small streams flowing down narrow gulches, or in pools in small ravines, as they
continually pass and repass in their flight up and down, they may be easily taken.
On the larger Wailuku river near Hilo, where they were abundant, they were easily
killed with small charges of dust shot, as they flew over the surface of the water.

Nesogonia blackbitrtii, a somewhat remarkable endemic dragon-fly, occurs on all
the islands in the mountains. It is often observed in localities where very little water
is to be found. This is due to the fact that it breeds in the small temporary pools that
remain for a time after heavy rainfall, as well as in small and easily overlooked water-
holes, that are of a more permanent nature. We have sometimes seen it in large

clxxvi FAUNA HAWAIIENSIS

numbers together, but more usually few or scattered specimens are noticed. On one
occasion in a sheltered corner of a deep gulch on Molokai scores of examples could be
seen at once resting with expanded wings on the dried stems of some low plant, nearly
every stem having an occupant. Each day for a considerable period they were
observed congregated in this favoured spot, but only during the late hours of afternoon
sunshine. This dragon-fly exhibits much variation in colour, size, and other respects,
and both general variability and local are evident.

The twenty-six species assigned to Agrion form by far the most remarkable
portion of the endemic dragon-fly fauna. The variability of many of the species, in
characters that are considered important, is unusually great. In some species the
post-ocular spots may be conspicuous, reduced, or entirely absent, according to the
individual. Other varieties in colouration may be still more striking. A. anianrodytH))i,
for instance, may be an entirely blackish insect, with much bluish white pruinosity on
the head, thorax and the base of the abdomen, or it may be of a more metallic black
with conspicuous thoracic pale markings, or in addition to much pale ornamentation
the abdomen may be largely red. There is very great variability in size of the
individuals in many species. There is much general variation in examples taken in
the same locality ; in some cases there is sufficient difference between the aggregate
of individuals of a species from one island and those inhabiting another to form more
or less distinct races or subspecies. Thus the two species, A. amatirodytum and
A. calliphya, are of much smaller average size on Hawaii than on the intermediate
islands of the group, and their neuration is consequently affected.

The neuration of many of these Agrions shows much variation in detail, and this
not merely in small points, but the more important features are in a plastic state.
McLachlan, when he received material from Blackburn for description, some thirty
years ago, formed a new genus for the reception of two species sent to him, calling this
genus Megalagrion. This genus was essentially based on the neuration of the post-
costal area of the wings, a number of the cellules in this area being doubled, instead
of forming a single row. When, however, a more extensive collection of Hawaiian
species is examined, it is found that this duplication of cellules exists in all stages of
development. Species that normally have a single post-costal row of cells sometimes
have a number of these divided to form a double row. In some cases the post-costal
area is simple on the wings of one side of the insect, partially double on the other.
A similar phenomenon is also shown in the series of post-pterostigmatic cellules, where
a similar complication of neuration takes place, some species always having more or
less a double row, others having sometimes a single and sometimes a partially double
row, or the wings on either side may be different.

It is clear that increase of size of the insect favours duplication of the cellules,
though it does not always necessitate it. Thus the three large species, which would
more properly form McLachlan's genus MegalagiHon (if that be retained) always have

INTRODUCTION

clxxvi

the complicated post-costal area to a greater or less extent. Some division of the
cellules generally occurs in the large species A. kauaiense, on one side or the other,
or in one or other pair of wings (fig. i a, i b, post-costal area of right and left front-wing).
A large example of A. deceptor, as will be seen from fig. 2, has the post-costal area
between the 7th and i6th cellule considerably complicated by division, though typically
this species has a simple row of post-costal cellules. A small race of A. callipkya
(named van microdemas by me) is found on Hawaii. A dozen examples, taken at
random and examined, all have a simple row of post-pterostigmatic cellules (fig. 4a and
4b) in both front and hind wings, whereas a dozen examples from Molokai, Lanai,
and Maui, nearly all have this area more or less complicated by division of cellules
(fig. 3a, 3b). In some of the smallest species of the genus the post-pterostigmatic and
post-costal areas rarely, if ever, show any tendency to duplication of their cellules.

Fig. I a.

2

Fig. I b.

Fig. 2.

Fig. 3 a.

Fig. 3 b.

Fig. 4 a. Fig. 4 b.

In many of the red-bodied species a tendency to melanochroism is a common form
of variation. This tendency is particularly noticeable in individuals found in certain
localities. In dealing with the three large, allied species, A. blackburni, oceanicum, and
heterogamias, I remarked that the females of the latter were easily distinguished from
those of the other two by the fact that the abdomen was not at all red, but entirely
dark. At the time, I had seen a large number of examples of each of these species.
Subsequently, however, I found that in other localities on Oahu (to which island it
is confined) A. oceanicum also had a female entirely lacking the conspicuous red colour
of part of the abdomen, and further in some localities this form much predominates.

Still later, on the island of Hawaii similar dark-bodied females of A. blackburni
were observed, whereas those previously taken there (though in other localities) were
red-bodied, as were all those found on the islands of Maui, Lanai, and Molokai.

F. H. I. z

clxxviii FAUNA HAWAIIENSIS

Hitherto no dark-bodied form of the male of any of these species has occurred,
all being largely red, nor has any red-bodied female of A. heterogamias (which is
peculiar to Kauai) been found. Thus, it may be said that the females of A. oceanicum
and A. blackburni are dimorphic, whereas the female of A. heterogamias, so far as is
known, is not. Consequently A. heterogamias always exhibits striking sexual dimor-
phism. A. oceanicum and A. blackburni do so, when we consider the dark-bodied form
of their females ; but when we compare the red-bodied form of this sex with the other,
the sexual dimorphism in the latter two species is much less marked. In other countries,
Agrionids, the males of which are red-bodied, exhibit similar dimorphism in the females.
Cases wherein black-bodied species are dimorphic, having a red-bodied' form in the
male sex, are very rare, and I do not feel sure of having met with such, except in the
case of A. amaurodytum, and but rarely in that species.

Extensive melanochroism of the (normally) largely red-bodied male of Agrion
deceptor is common locally, and other species are affected less frequently, and in a
lesser degree.

Only the very driest coastal regions of the islands and the highest elevations in
the mountains above the region of streams and forest are devoid of any species of
Agrion. A. xanthomelas is a common insect in Honolulu gardens and in lowland
districts generally, not usually partial to the mountains, though in the Kona district of
Hawaii it is common about stagnant pools up to an elevation of about 3000 ft. It
is very numerous in individuals under conditions totally changed from the natural;
perhaps it now finds more numerous breeding places, and a more abundant prey in
the numerous insects that have been introduced by man in the region it frequents.
A. hawaiiense, another small species, is more local than the preceding, but also seems
to generally breed in stagnant water. Where it frequents streams, like that of the
lao valley on Maui, we have noticed that its chief haunts are quiet small pools, often
cut off, or at a distance, from the main stream. It also breeds numerously in upland
ponds of considerable size, where these occur. A. deceptor, viicrophya, and nigro-
hamatu7n also sometimes breed in stagnant pools of water, but more often in the
streams themselves, or at least in pools left standing in the beds of streams, when
these cease to flow. Most of the other species breed usually in running water, but on
one occasion we found the nymphs of the large A. heterogamias" numerous amongst
dead decaying leaves lying on the ground, and saturated with the wetness oozing from
a perpendicular bank, at the foot of which they lay. There was no standing water,
and the spot was at some distance from a river, and had no connection with this. From
this the transition of habits is not very great to what may be considered the true
terrestrial, or one might in some cases say, arboreal species. These {A. koelense,

Teneral or immature examples, which instead of having a black or metallic-black abdomen, have
this of dirty red or pitchy colour, are not to be confused with truly red-bodied examples.

^ The nymphs of the allied A. oceanicum are sometimes found in the wet moss on rocks in stream-
beds, and the young ones are preyed upon by the larvae of Rhatttus pacificus.

INTRODUCTION clxxix

A. asteliac, A. oa/mensis, and others) deposit their eggs amongst the leaves of various
plants which usually retain some moisture at the base, where they clasp the stem.
Such plants are the climbing leie {Freycinetia) and the liliaceous Astelia. Here the
nymphs, which are short and stout as compared with some of the slender stream-loving
species, are found in numbers, those of several sizes often living in company. In wet
weather, when a little water may collect at the bases of the leaves of the Astelia, we
have noticed that the nymphs will often be found to have crawled half-way up the leaf,
as if they actually disliked the wet ! Both the Astelia and Freycinetia being favourite
habitats of a number of native insects, it is probable that these nymphs fare fully as
well as those frequenting the water. Thus the bases of these same leaves, and the
decaying rubbish that accumulates there, are the haunts and breeding-places of various
Nitidulidae and Carabidae, of small Diptera and their Hymenopterous parasites, of
Lepidopterous larvae, of Hemiptera and other insects, as well as of others which
casually seek shelter, and of the young of small land Molluscs. In consequence of their
habits, these species of Agrion are frequently found in places quite remote from streams
or standing water. The caudal appendages of the nymphs and the mask are much
shorter than in some of the water-frequenting species, though there is much difference
between some of the latter themselves in this respect.

The food of the adult Agrions consists to a large extent of small moths. We
have also seen them take daddy-long-legs (Limnobiinae) and leaf-hoppers, and no doubt
they prey on any small insect that flies by. The larger species, A. oceanictim, etc., not
infrequently prey on the smaller, and themselves are devoured by the large endemic,
Anax streniius, and the immigrant, A. Junius. On one occasion I caught an Anax
jutmis devouring a male of Agrion oceanicum, which itself still retained hold of the
small and delicate species, A. leptodemas, partially eaten. Agrion blackburni has been
found devouring A. nigrohamatum, a species of considerable size, though much more
slender than itself.

Considering the apparent scarcity of food, owing to the absence from the mountain
streams and pools of more fragile water insects, such as Ephemeridae, Perlidae,
Culicidae, etc., the abundance of the Agrions is quite remarkable.

To what extent the species of Neuroptera (s.l.), at present known only from a
single island, are really confined to one, is at present in many cases uncertain, owing
to the fact of their rarity. There is little doubt that the endemicity of the Kauaian
species is in most cases real, for though the dragon-flies of Oahu have been much
collected, yet of the lo Agrion known from Kauai only two (which are generally
distributed over all the islands) have been found on the neighbouring island. Other-
wise the species of Agrion are frequently of wide distribution over the islands. Thus
Oahu has four species (40 per cent.) endemic, and ranks next to Kauai, while Molokai,
Maui, and Hawaii ' have each but one species endemic, and Lanai has none.

^ The species {A. nesiotes) supposed to be peculiar to Hawaii is now known from Maui.

z 2

clxxx FAUNA HAWAIIENSIS

The endemicity of the less easily collected Hemerobiidae cannot be properly
estimated till much larger collections are made ; but in its Chrysopinae there is no doubt
that the island of Hawaii is disproportionately rich. It is now well-known that some
species originally recorded from a single island are by no means confined to one, but
range over two or several.

Review of Diptera.

The Diptera (excluding the Pupipara) are represented by 26 families, 10 of which,
I believe, contain endemic species, and 13 only imported ones, the families Ephydridae
and Agromyzidae being doubtfully represented by endemic forms. Excluding these
latter, the native fauna belongs to the Mycetophilidae, Chironomidae, Limnobiidae,
Dolichopodidae, Pipunculidae, Sarcophagidae, Anthomyidae, Trypetidae, Drosophilidae,
Asteidae. In addition to these the Pupipara are represented by three species of
Olfersia (Hippoboscidae), one of which is described from the islands, the other two are
known elsewhere. Though found on the native Passerine birds, they also occur on
wide-ranging sea-birds, and can only be considered as immigrant species. Excepting
perhaps some of the metallic-coloured Sarcophagidae and a few of the largest Droso-
philidae, the endemic flies are all of small size and of the most obscure superficial
appearance. They have only been specially collected to a small extent and the number
of those described can be but a fraction of those that exist. The extraordinary develop-
ment of the Drosophilidae, in structure and in the number of species, is the most
striking feature of the Dipterous fauna. The number of described endemic species of
Diptera is only 135, while the introduced ones number 57. The former are contained
in 27 genera, the latter in no less than 46.

Mycetophilidae. — This family is probably represented by endemic species of
Sciara and Platyiira, and as its members have been little collected other species and
even genera are likely to be found. If preserved as dried specimens, these insects are
subject to much distortion after death and often become hardly recognizable. It Is prob-
able that the truly endemic forms are numerous, the larvae being very plentiful in
decaying vegetation, where they are preyed upon by the small Carabid beetles, and, if
they have been exposed, are also seized upon by minute carnivorous flies belonging to
the Dolichopodidae. A number of species have been imported with foreign plants and
have become very abundant, so that it may not be very easy to discriminate the foreign
from the native species in these obscure flies.

Chironomidae. — Chirononms Hawaiiensis is one of the commonest of insects,
especially near the coast or on the lowlands. Its status as a native insect is very doubtful.
Being freely attracted to light, it often swarms in the verandahs of houses, and forms a

INTRODUCTION clxxxi

considerable part of the food of some of the lizards that haunt the same situation. The
smaller Chironomids such as Tanytarsus and Cei-atopogon are found in the mountain
forests and the species may prove to be endemic. They have not been specially
collected and the number of species that exist is quite uncertain. Some are also found
on the coast, and about the salt marshes in the lowlands.

More interesting than any of these is an aquatic black insect, which often frequents
strong mountain streams like that of the lao valley in Maui. Mr F. W. Terry, who
has studied its life-history, informs me that this species is of an undescribed genus,
allied to Tclmatogeiton. I observed it in great numbers in 1894 in the above-men-
tioned locality, when the river being in flood the flies were usually to be found sheltering
behind large rocks projecting from the stream. They are also found on other of the
islands, and are almost certainly endemic and an interesting addition to the scanty fauna
of the freshwater streams. As a rule this insect preserves badly in dry specimens, and
probably for this reason was not described in the systematic part of this work. In life,
when I first observed it, it appeared to me one of the most remarkable of the island
Diptera.

PsYCHODiDAE. — Only two species of Psychoda have been recorded, though one or
two others have been observed. They are certainly all importations by man, and two of
the species have been bred from cow-dung and from wet soil. They are of no interest
in connection with the Hawaiian fauna.

CuLiciDAE. — The two species of Stegotnyia, fasciata and saitellaris, are well-known
to all inhabitants as the 'day-mosquito,' owing to the fact that they are active at
irregular periods between daybreak and dark, whereas the ' night-mosquito ' or Culex is
active at dusk and throughout the night. All have been imported by man and there is
no native mosquito known, nor any true native name for a Culicid. 5". scutellaris is of
comparatively recent importation, as it did not come under my notice during the earlier
days of my collecting, though now very numerous and conspicuous. Both it and 5". fasciata
are very troublesome not only on the lowlands but also in parts of the lower forests,
where in the absence of pools or streams they can breed in great quantities in the small
collections of water that form in hollows of the limbs of trees or where these join the
trunk, as well as in the centres of decaying stumps. They do not generally seem to
range upwards above an elevation of about 1500 ft. The Culex is also a species
frequenting the coast and lower elevations, though exceptionally it has been found as
high as 4000 ft. above the sea. 5'. fasciata is, as is well-known, a species of notoriety
from its connection with yellow-fever, a disease at present unknown in the islands', and
we suspect that S. scutellaris has a similar connection with the fever called ' dengue '
(which is sometimes epidemic), though others would attribute this to the Culex. For

' A case of yellow fever has since been reported.

clxxxii FAUNA HAWAIIENSIS

the latter, two specific names have been received from authorities at Washington and
a third from the British Museum, so we are doubtful as to which it really belongs.
Having no faunistic interest we have not specially inquired into this matter.

LiMNOBiiDAE. — The species o{ Dicranomyia are endemic, and to the five described,
others and perhaps many more will, no doubt, be added. They are common insects,
sometimes attracted by light and sometimes observed at rest in the daytime, or on the
wing in the dark cavity of some hollow tree. In the latter case a number are usually
seen flying together, rising and falling in their flight in the narrow space of a few feet.
We have bred one or more species from decayed wood, overgrown with damp moss.
These fragile flies are the favourite prey of the endemic predaceous wasps of the family
Mimesidae, and some of the Crabronidae likewise gather them. Consequently one may
find the females of these wasps investigating damp, dark places, where the Dicrano-
myia are likely to be found, but which ordinarily would have but little attraction for
such sun-loving insects.

The single species of Linmobia is common in Honolulu (and elsewhere) and is
I suspect introduced. It has been bred from damp moss. The Triviicra is also of
doubtful endemicity. Styringomyia didyina^ is extremely common near the coast
around Oahu and perhaps on the other islands. It sometimes swarms at night around
the electric lights, sitting quietly on the walls and ceilings, with the body pressed
closely to the surface, and the front and middle legs extended straight forward in front
of the head in a characteristic manner. We have found this or a very closely allied
species, as well as a much larger species, in Australia, and should its habits prove it to
be liable to be carried by ships, we should consider it an importation into the islands.

Stratiomyidae. — There are three species, all doubtless introductions by man,
though two have not been yet identified from elsewhere. Of the two smaller species
one a Sargus was already found in Honolulu 30 years ago, the other, Acanthina, has
been evident for only about 1 5 years.

The conspicuous Neoexaireta spinigera is also of recent introduction, not noticed
in 1897, but already common round Honolulu in 1900. It enters the lower forests and
the larvae abound beneath the bark of some of the native trees, when in a decaying
condition. This fly is now frequently carried off by the endemic fossorial wasps
(Crabronidae) for the provisioning of their nests.

ScENOPiNiDAE. — Like the above family this has no special interest to the student
of the fauna. It is represented by only one or two foreign species of domestic habits.

^ This species was subsequently bred by Mr F. W. Terry and I should consider it to be a probable
introduction by man.

INTRODUCTION clxxxiii

DoLiCHOPODiDAE. — The two species o{ Gnamptopsiloptis are no doubt introductions,
G. patellifer having been long established, and it is one of the commonest of flies.
G. pallidicornis is of recent introduction ; it was first noticed in 1896, was more
common in 1902 and is now still more frequently seen. Both are frequently bred from
soil in which young plants are being raised. On the other hand the species of Cafnpsi-
cnem is and Chrysotus are endemic, and no doubt many new ones remain to be collected,
as they are found throughout the forests, often in abundance. Unfortunately most of
the small and obscure Dolichopodidae have very soft integuments so that in a few days
or even hours after capture they become shrunken and distorted and almost useless for
descriptive purposes. They require special collecting and preserving, and it would be
safe to say that of this family at least 100 species might be procured in the
islands. Several species that frequent wet moss have the wings reduced to filaments
and are of course quite incapable of flight, but these interesting forms appear to shrivel
and distort after death and should be preserved in alcohol. Many of the smallest
species live on the ground beneath the shade of the trees, not only in wet but also in
dry forests, and if the dead leaves be swept aside and the damp earth exposed, they
are readily attracted thereto, and prey on the minute larvae of mycetophilids or other
delicate creatures, that are exposed amongst the disturbed humus. The little flightless
Emperoptera also has these habits, living in company with the small and equally active
Hemipteron, Nesidiorchestes, and other small insects, all flightless. The remark in the
systematic portion of this work that it was taken ' on Freycinetia ' is incorrect and no
doubt due to a wrong label having been attached to some of the specimens. It is
altogether terrestrial. Several commonplace Dolichopodidae found in and around Hono-
lulu are probably foreign {^Medeterus sp. ? &c.).

PiPUNCULiDAE. — About a dozen species of the genus Pipuncuhis are already known
and probably numerous additional ones remain to be discovered. These species are
difficult to discriminate being mostly closely allied to one another, and some of them
apparently vary very greatly in size, perhaps in accordance with that of their host.
Several, that have been bred, are all parasitic on Delplacid leaf-hoppers, chiefly those of
the genus Nesosydne. The one species P. rotundipennis belongs to a different section
of the genus from that, in which all the others are placed, and its host is not known.

Owing to the habits of the leaf-hoppers affected, most of the Hawaiian Pipunculus
are to be found flying round ferns or forest trees and shrubs, since most of their hosts
are to be found on these. They are never to be swept from grass, as is so often the
case in other countries. At least two species attack the common hopper of the Ipomoea
(^Nesosydne ipovioeicold) and are found flying round Convolvulaceous plants, on which
the host is so often found. Though all the species of Pipmiculus are certainly endemic,
yet two of them have attacked the introduced leaf-hopper of the sugar cane {^Perkinsiella
saccharicidd) which is widely separated generically from the endemic hoppers. Most

clxxxiv FAUNA HAWAIIENSIS

of the species of these flies are confined to the forests, but some stray below its limits
and some above. Some are found in plenty, and individuals are to be seen constantly
passing by on the wing, flying from plant to plant, the males in search of the females,
the latter more carefully scrutinizing frond, leaf, or branch, in search of their hosts.
Occasionally a pair are seen hovering in the air in copula, the larger male sustaining
the female. As in other countries, the size of the fly, when bred, often appears very
large as compared with the body of its host. So small a leaf-hopper as Nesosydne
raillardiae will produce a comparatively large Pipunculus. The puparia, so far as is
known, are always formed on or beneath the soil. They are never found exposed and
attached to the surface of leaves as is the case elsewhere with certain (but probably few)
species.

Syrphidae. — This important family is quite unrepresented by endemic forms and
the few introduced species, excepting perhaps Xanthogramma grandicorne, a common
Australian insect, are of quite recent importation. Volucella obesa, Eristalis pundulatus,
Syritta oceanica and Eumerus marginatus have all become established during the years
of my residence in the islands and all are now very common insects. The Volucella
was first seen in 1894, while the others appeared between 1897 and 1900. Eristalis
tenaxvj2£, already common in 1892. It thrives best at high elevations in the mountains.
The Xanthogramma is a very beneficial insect, but is unfortunately much parasitized
by the ubiquitous Ichneumonid, Bassus laetatorius, and sometimes by a species of
Pachyneuron, unless this latter proves to be parasitic on the Basstis. The Syritta
breeds in decaying vegetable matter, and has been reared from pots containing plants,
the soil of which had been mixed with horse or cow droppings.

Oestridae. — Represented only by three species, imported with domestic animals.
These are Oestrus avis, Hypodernia bovis and H. nasalis.

Tachinidae. — Represented by only three or four species, probably all foreign and
most likely importations by man. A small unidentified littoral species might possibly
prove to be endemic. Frontina archippivora is an extremely common fly, parasitizing
Anosia and Pyj'ameis cardui, as well as the caterpillars of many moths of various
families. It is of great economic value and is said to have been imported from America
by Koebele. It is known to be of recent introduction. Chaetogaedia nionticola is
another very beneficial species, which attacks many of the most injurious caterpillars.
Its habits have been studied by Swezey, and are of some interest, owing to the fact
that it is one of those which deposit their eggs on the leaves of plants, instead of on a
living caterpillar. It is of course largely a matter of chance whether the &gg is
swallowed by the latter, and hence the female fly is very prolific and the eggs minute.
This Chaetogaedia may be a natural immigrant ; at any rate it was universal throughout

IN TROD UC TION clxxxv

the mountain forests about 20 years ago. It would be interesting to compare a number
of Hawaiian examples with N. American specimens, to make quite sure of their
identity. It is a very favourite prey of the larger Hawaiian Crabronidae. Occasionally,
like other parasites of caterpillars, it is itself parasitized by the imported Chalcis
obscurata, though the latter is also normally a lepidopterous parasite. Like the
Tachinids it may vary greatly in size according to the nature of its host.

Sarcophagid.'\e. — The species of Sarcophaga are rather numerous and are all
unquestionably importations from other countries, and their number has doubtless
increased during recent years. Mr F. W. Terry, who has given much time to the
study of the species for economic reasons, finds that the male genitalia afford excellent
specific characters, but as these have been rarely described by systematists, the identifi-
cation of the island species is almost impossible. .S". pallinervis, one of the species
described by Thomson from Honolulu, is identical with a North American one, while
another is Chinese. S. barbata and 5. dux are also common, but there are now other
species present, so closely allied to the former that it is uncertain which of them is
really Thomson's barbata.

These introduced Sarcophaga are now more or less attacked by Hymenopterous
parasites, either casually or purposely imported, such as Eucoila, Spalangia, and several
species of Pteromalidae, as well as Alysiidae.

S. pa/linervis is the most ubiquitous of the island species, since the larvae live in
the droppings of cattle, and it thrives at all elevations. It is greatly attacked by
parasites, and is a favourite prey of the Crabronid wasps.

Apart from these foreign species of Sarcophaga, the family is represented by two
endemic genera, of very great interest, and the most striking in appearance of any of
the Hawaiian Diptera. These two genera are closely allied to one another and doubt-
less of the same origin, and it may even prove difficult, when all the species have been
collected and studied, to maintain the generic distinctions between them. The blacker
coloured species of the genus Dyscritomyia have in life a very Tachinid-like appearance
and their behaviour in the field is also much like that of some of those parasites. The
bright metallic green species of this genus and of Prosthetochaeta are in some cases
more Lucilia-like.

As the development of these genera with their rather numerous and often highly
remarkable species showed them, or rather their ancestors, to have been very
ancient colonists of the islands, it became a natural question as to what their habits
could be. Their Tachinid-like behaviour suggested that they might be parasites of
Lepidopterous larvae, but the fact that they were not ever bred from these, though the
latter were specially collected in a favourite locality for the flies, made this very uncer-
tain. Excrement or carcases of mammals was out of the question from the absence of
indigenous mammalia. So too with the birds, for the flies sometimes occur in dry,

F. H. I. aa

clxxxvi FAUNA HAWAIIENSIS

open, treeless localities, where are no birds. Many years of collecting had never
revealed a large-sized fly maggot in decaying vegetation, not even in the most evil-
smelling substances. Besides material of this sort is not found in the dry open country.
These flies, so far as is known, are larviparous, the maggot, when born, being already of
considerable size, so that there is some approach to the condition of the pupiparous
flies. Some years ago Mr Terry reared one of these maggots to maturity on a mixed
animal diet, including land molluscs. Later he obtained a new generation of flies from
captured specimens kept in large glass jars and supplied with living and dead molluscs.
Finally Mr D. B. Kuhns brought back Achatinellas (supposed to have been living
when taken, but more probably recently dead) containing maggots, from which the flies
were bred. Many shell collectors have noticed the occurrence of maggots in Achati-
nelline shells, found still fresh but not living, and we have ourselves sometimes picked
up a number so affected in a single day. When one considers the great numbers of
mollusca that exist in limited areas in the islands, it is certain that, even in a small
area, many individuals must be dying each day of the year, quite sufficient to supply
food enough to support the number of existing flies, especially as these when adult
are very long-lived. Considering the well-known and very strong odour of dead land
molluscs, these would not fail to readily attract creatures so keen-scented as Sarco-
phagous flies, probably long before the odour became appreciable to human senses.
No doubt many kinds of molluscs serve as food for the maggots, for the flies are
common enough in localities where only the thin-shelled Succinea is to be found.
Species of this genus are to be found in very dry localities, and would account for the
presence of the flies in such places.

The flies of both Dyscritomyia and Prosthetochaeta are difficult to determine speci-
fically owing to the variability of individuals, the variation affecting important structures,
e.g. the presence or absence of macrochaetae, which have been considered as of generic
importance. Some of the species have very remarkable secondary sexual characters,
and the male genitalia will evidently prove of great importance in the determination of
the species. These flies are rarely found on the coast in dry districts or on the open
forehills, but are common in open places in the forest, and occur also in dense forests,
and are frequent above the limit of compact forest. Whether all are feeders on
mollusca is of course at present uncertain. It is quite certain that they originally
formed the exclusive prey of some of the endemic Crabronidae, and even now some of
the latter have never been found to carry off any other kinds of fly. Some species of
Nesocrabro may be often seen on the wing hunting beneath masses of fern or
Freycinetia in damp shady places for these flies, which presumably are seeking there
for fallen molluscs. All the larger species of Hawaiian Crabronids have at times been
found carrying them off, and their burrows are frequently packed full of them to the
exclusion of all other species. Certainly Dyscritomyia and Pi'osthetochaeta are amongst
the most interesting constituents of the Hawaiian insect fauna.

I

INTRODUCTION clxxxvii

MusciDAE. — This family is not represented by endemic species, but owing to the
ease with which species are transported with stores of meat or in other ways on steamers,
there is now a considerable number of foreign representatives. Musca fiavineiins was
described by Thomson from Ross Island, with a variety from Honolulu, and is not
known to us. There is known, however, in addition to Musca domestica, a very
distinct Chinese species, probably of recent introduction.

There are several species of Calliphora, the date of their introduction being
uncertain, but the conspicuous Pycnosoma diix became common in Honolulu in 1900,
and was no doubt introduced a year or two previously. Lucilia sericata appeared about
the same time as the preceding, and spread very rapidly, and as the maggots seriously
infest living sheep, it sometimes does considerable damage. RJiinia testacea also
appeared first in 1900, and at once became very common. Haematobia serrata was
imported in 1896, and is probably a worse scourge to horses and cattle in these islands
than elsewhere in the world. It breeds everywhere in the droppings of cattle, and
brood follows brood throughout the year. Musca domestica is also bred freely from
cowdung found in open pastures. Stonioxys calcitrans is a common pest, of earlier
introduction, since it was noticed in numbers on Hawaii in 1892. The flies of the
genera Calliphoi^a and Lucilia are often carried off by the predatory Crabronidae ; so too,
occasionally, is the common house-fly. They are also subject to the attack of some of
the same parasites as the Sarcophagidae.

Anthomviidae. — The genera Hydrotaea, Ophyra, and Homalomyia contain only
imported species, as do some others yet undetermi"ned, but the several species of
Lispe are clearly endemic, and no doubt others will be added to these. They mostly
frequent the forest, and do not seem generally to be common. I have taken the
fossorial wasps, Hylocrabro tumidoveiitris and Xenocrabro inolokaiensis, carrying off one
of the species. Coenosia is an important genus with more than twenty species known
to me in the islands, but further collecting should increase this total to one hundred.
No doubt many of the species are rare. Nearly all are true forest insects, and they
are best represented in wet woods. Many of the species are known to be carnivorous,
preying on other weaker insects. The larger ones may sometimes be seen in some
numbers on the trunks of trees, having a bold appearance, as they stand ready to dart
off after some other insect. Sometimes the larger seize and devour smaller species of
the genus. Like so many other flies, they are themselves preyed upon by the Crabronid
wasps, the cells of which are sometimes found packed with nothing but Coenosia.
Both the black- and yellow-bodied species are taken by the wasps. Their earlier stages
are not known, but it is likely that some of the larvae that are found in the debris at
the bases of the leaves of Astelia or Freycinetia may produce these flies.

aa2

clxxxviii FAUNA HAWAIIENSIS

SciOMYZiDAE. — A single species of Sciomyza alone represents this family, and so
far it has only occurred on Oahu. Very probably it will prove to have been introduced,
though at present only known from the islands.

Ortalidae. — Eiixesta annonae is a very abundant introduced species, and is often
bred from sugar-cane that has been attacked by boring beetles, or which is in a state of
decay. It may have been imported with some of the varieties of sugar-cane brought
from America, though it might equally well have been introduced in other vegetable
matter. Acrosticta pallipes was probably of more recent introduction, as it has become
very much more numerous during the last 12 years than formerly. Like Euxesta it
also has been bred from unhealthy stems of sugar-cane, etc. A species of Chrysomyza
appeared first in 1900, and of late years has become very common.

Thus all the representatives of this family are without doubt foreign, though the
Acrosticta was described from Hawaiian examples, and the Chrysomyza is as yet not
identified with any described species.

Trypetidae. — Excluding Dacus cucurbitae, a very common oriental species, which
had become numerous in Honolulu in 1900, having been introduced, no doubt, some
years previously, the Trypetidae are represented by a number of endemic species of
Tep/iritis, and an endemic genus Phaeogramma. Dacus cucurbitae was originally
described as Hawaiian, and no remark was made as to its being an introduced insect,
though this fact was known to all in the islands, if not to the describer. It is, like other
fruit-flies, a very troublesome insect, attached chiefly to Cucurbitaceous plants, but also
attacking beans, tomatoes, and other plants.

Though only three species of Tephritis are enumerated in this work, they will, no
doubt, prove rather numerous, when the endemic Composite plants are thoroughly
examined. T. crassipes, though very similar to some of the other species, may prove
to have been really an early introduction by man. It is bred in great numbers from
the foreign weed Bidens pilosa, as well as from Cosmos and other garden plants.
T. cratericola attacks the Silver-sword [Argyroxiphium), in some cases every achene
being destroyed by it. It is equally numerous on Raillardia nienziesii. R. laxiflora
yields another species of the fly, as does Dubautia. T. cratericola is noteworthy for
the fact that there is a difference in the sexes in the dark pattern on the apical portion
of the wing. T. crassipes, above mentioned, is attacked by two Hymenopterous
parasites, no doubt introduced, one a species of Eurytoma (Chalcidoidea), the other a
Bracon (Ichneumonoidea). At present these have not been bred from any forest-
frequenting species of Tephritis, though both are very common around Honolulu.
Nor has T. cratericola, which lives above the forest limit, been found parasitized. The
Braco7t, however, is now found on other of the islands, and these parasites, if they
attack the true mountain forms of Tephritis, may diminish their numbers. New species

INTRODUCTION clxxxix

of Phaeogramnia also probably await discovery, their secretive habits causing them to
be easily overlooked.

Sapromvzidae. — Of this family, only a single species of Sapromyza has been
found, and that only in the immediate neighbourhood of Honolulu, rendering it highly
probable that the species is introduced.

PiOPHiLinAE. — Represented only by the introduced Piophila casei, the produce of
the cheese maggot.

Ephydridae. — Of the three genera enumerated, one, Brachydeute7-a, is represented
by a single N. American species. The other two, Notiphila and Scatclla, have each
a species not yet known from outside the islands, but their claim to endemicity is
uncertain. We suspect, however, that this family does contain endemic species.

Drosophilidae. — This family is a most important constituent of the Dipterous
fauna, with nearly fifty species enumerated. They are very unevenly divided between
three genera, Hypenomyia with one, Idiomyia with five, and Drosophila with the
remaining species. The two former are endemic, and Drosophila is represented by
an assemblage of species, exhibiting great diversity in structure and appearance, and
will, doubtless, hereafter be found capable of division into other genera. At present
these insects, many of which are obscure and minute forms, have been very imperfectly
collected. To make an approximately complete collection and thorough study of the
Hawaiian species would require the devotion of many years of special work. Not less
than 250 species must exist in the islands, and double that number may very probably
occur. Many of the species preserve very indifferently as dried specimens, and it is
necessary that material should be preserved in alcohol as well as pinned. Those found
in cool, wet forests often shrivel and distort, either soon after death, or when brought
down into the hot and comparatively dry climate of the lowlands. Some of the species
are quite conspicuous, and are readily attracted by the sap oozing from a broken limb
of a tree, or from exudations caused by decay or disease. Very many breed in stems
of trees or plants, which, when decaying, yield abundant moisture — such as those of
the arborescent lobelias, of bananas, tree-ferns, etc. The larvae abound also beneath
the bark of some forest-trees, which, when this is stripped off, reveal a semiliquid or
pulp-like material covering the wood. Some of the larger and very many of the
smallest and most obscure species live amongst the soft ferns, which grow in damp
places beneath the shade of the forest-trees. The larvae of these flies are very subject
to the attacks of Hymenopterous parasites, Proctotrypcs kawaiiensis, and species of
Phaenopria (Proctotrupoidea), several of the Eucoilinae (Cynipoidea) and Spalangia
lanaiensis (Chalcidoidea) having been bred from them. The common Crabronid wasp,
Hylocrabro tiimidoventris, often fills its cells entirely with species of DrosopJiila, but the
one which it most usually carries off is, I suspect, an introduced one.

cxc

FAUNA HAWAIIENSIS

Review of Hemiptera.

The Hawaiian Hemiptera present an interesting feature in the great difference
between the constitution and development of the Heteropterous and Homopterous

fauna.

Excluding the scale-insects (Coccidoidea) and the plant-lice (Aphidoidea), of which
it is doubtful whether there is a single native representative, the total number of
Hemipterous genera is 68, the species numbering 259'. Of these, 47 genera are
Heteropterous, 21 Homopterous, while 126 species belong to the former, 133 to the
latter division.

In the Heteroptera the following genera are represented only by species introduced
through human agency : Triatoma, Zelus, Alloeocramim, Clinocoris ( = Ciniex and
AcantJiia Auct.), Orthoca (with two species, O. nigriceps and 0. vmcta), Clerada,
Rkopalus, and Geotomus. Triph/eps of the Anthocoridae and Halticus of the Capsidae
are also certainly introductions, and one or two other Anthocorids and Capsids are also
open to suspicion. The Pyrrhocorid, Dysdernis peruviamis, should be altogether
expunged from the list, as, no doubt, having been brought forward on a wrongly labelled
specimen. There was nothing like it in the Blackburnian collection, and I can only
suggest Ithaniar hawaiiensis, as the species, therein contained, which may have been
supposed to be Dysdercus. Apart from these introduced species, the water-frequenting
bugs Arctocorisa blackburni, Buenoa pallipes, Merragata hebroides, Microvelia vagans,
and the pelagic Halobates sericeus, may be looked on as natural immigrants — the
Biienoa, possibly an introduction by man — the three last-named being already known
from other countries.

Excluding all the 15 genera and 16 species named, there remain to represent the
Heteroptera 32 genera and iio species. Twenty-one of these genera and all the
species but one (the widely-ranging Reduviolus capsiformis) are at present supposed to
be peculiar to the islands.

The indigenous fauna is made up of representatives of the following nine families
only: Anthocoridae, Miridae (Capsidae), Acanthiidae, Myodochidae (Geocoridae),
Lygaeidae, Nabidae, Reduviidae, Thyreocoridae and Cimicidae (Pentatomidae).
It must be remembered that of these the Cimicidae, Thyreocoridae and Lygaeidae are
each represented by only one genus that can claim to belong naturally to the fauna, and
that the total number of species is but four, so that these important families are almost
unrepresented. The Reduviidae have only a few species (in three genera) belonging
to the Ploiariinae. The Nabidae have a single genus with numerous species. On the
other hand the Capsidae (and in a less degree the Anthocoridae) are comparatively
rich in genera, the former having no less than 14, but in these the total number of
described species is only 24.

^ September, 1909.

INTRODUCTION cxci

The Nabid genus Reduviolus and the Geocorid genus Nysius contain no less than

50 of the 1 10 endemic Heteroptera, and both of these genera are cosmopolitan or
nearly so. The average number of species to a genus in the endemic Heteroptera
is only 3 '4, the many genera of Capsidae and Anthocoridae with few species, being
effectiv-e in the reduction.

If we analyze the Homopterous constituents of the Fauna and exclude the
following species, introduced by man, viz. Peregrmus maidis and Perkinsiella
saccharicida (Delphacidae), Siphanta acziia (Poecillopteridae), Centroiypus sp. ? (Mem-
bracidae) and Phiynomorphus hospes (Tettigoniidae), there remain 16 genera with
128 species.

The Delphacidae contain seven endemic genera, which are evidently allied to one
another, with 46 species in all, and one genus (not endemic) Kelisia, of independent
origin, with only three described Hawaiian species. The Tettigoniidae have four
genera represented, one of these, Nesophrosyne, and its offshoot, Nesophryne, containing

5 1 described species, while Nesosteles contains four species, one of which is certainly,
and one probably, foreign. The Fulgoridae have two genera represented, one lolania
with a single variable species, the other Oliaj'us (cosmopolitan or nearly so) with 24.
The Psyllidae have two genera with four described species, all endemic. Subtracting
the two probably introduced Nesosteles, we have 126 Homoptera distributed in 16
genera and four families, an average of nearly eight species to the genus. Twelve
of the 16 genera are endemic.

The contrast between the Homoptera and Heteroptera is therefore very great, and
one might say that the former, having a much smaller stock of ancient immigrants to
start with, has been far more successful in species-formation than the latter. Even
making all allowance for corrections and for additions to the fauna, this fact will
certainly remain true.

CiMiciDAE. — The Cimicidae are very poorly represented by the one genus Oechalia,
of which the Hawaiian species are considered to be sub-generically distinct from the
typical Australian form. The number of species existing in the islands cannot be
considered as definitely settled at present. Two only are readily distinguishable, but
others will probably prove to be distinct. O. grisea, as now considered, presents
extreme variation in colour and structure, and of these varied forms it is likely that
some are in reality good species, and may themselves prove to be less variable
than grisea, as appears to be the case with the second species, O. kaonohi, lately
described. At any rate the nymphs present noticeable differences, and, so far as my
limited experience goes, similar nymphs have not produced adults varying in any very
important manner. Oechalia grisea is one of the commonest Hawaiian bugs, and
occurs even on the hottest and driest coasts, when the vegetation is green, and above
the upper limits of the forest on the high mountains. It is, however, most abundant

cxcii FAUNA HAWAIIENSIS

in the forest-belt, and eggs, nymphs, and adults may be found on all kinds of trees, as
well as on ferns and low plants. It has even been found breeding in gardens in the
town of Honolulu. Its chief food seems to be caterpillars, especially those of the
genus Scotorythra, but those of a good many other groups are also attacked occasionally,
e.g. Plusia, and various Pyralidina. During the excessive multiplication periodically of
looper caterpillars, Oechalia sometimes becomes also excessively numerous, and we
have then seen eggs, nymphs, and adults in countless numbers on the forest-trees.
During the worst years of the attack of the leaf-hopper of the sugar-cane {Perkinsiella),
in some localities, in cane-fields adjoining the forest, numbers of Oechalia were to
be seen in all stages preying on the hoppers, and both species of the genus were
present.

During a visit to Australia I only noticed occasional specimens of Oechalia, and
do not know whether, though known to become very numerous, it ever occurs in such
great numbers, as its Hawaiian congener, nor whether it exhibits the same structural
variability. It is proper to say that in certain localities it is quite possible to collect a
fair series of the Hawaiian species, that does not show much variation. Dark metallic
green forms of grisea with blunt spines seem mostly to occur in wet localities at
moderate elevations, and have been noticed especially in the West Maui Mountains
and on Haleakala.

Thyreocoridae. — Geotomus pygniaeus is probably an introduced species, though it
would be of some interest to compare its variation with that of specimens from other
countries. It frequents open country, and is often found under stones, and thrives in
dry, hot localities near the coast, as well as in open spaces in the high forest, in the
regions where frosts occur. Nymphs are found in company with the adult at the roots
of herbage or beneath rocks.

Coleotichus blackburniae is the sole representative of the Scutellerine group, and
is by far the most showy member of the Heteropterous fauna. It is not known from
elsewhere, but its congeners are conspicuous in Australia and the Moluccas. Apart
from the fact that it is the finest Hawaiian bug it is interesting, in that it appears to
have two forms, usually distinct at a glance, the one appearing red, the other yellow.
It is very widely distributed, and is found in hot, dry localities near sea-level, and in the
mountains to five or six thousand feet above the sea. I have bred specimens from
nymphs found in a garden in Honolulu. Both adults and nymphs are frequently
gregarious, lying packed close together, when at rest. Great numbers are sometimes
in consequence found together, and a single tree may hold some hundreds of specimens
of adults and nymphs of all sizes, as well as many eggs. The adults appear to be on
the wing at night, and occasionally enter houses, attracted by the light. However,
they take flight very readily on slight disturbance in the daytime, especially during hot
sunshine, usually flying a short distance, and making a loud humming noise as they fly.

INTRODUCTION cxciii

Sometimes after a short circular Hight they return to the tree from which they were
disturbed. They are very partial to Koa trees {^Acacia koa), but feed, so far as I have
observed, only upon the pods of these, extracting their juices. Whether they will
attack other parts in the absence of pods is very doubtful. They breed likewise very
freely on a very different tree, Dodotiaea viscosa, and both eggs and nymphs are
occasionally found on other plants. The two mentioned trees are, however, their
favourite food-plants. They have also been found breeding on imported Acacias.
Usually from Dodotiaea viscosa I have obtained the yellow form, with clear yellow
dorsal stripe, untinged with red, from Acacia koa the red form. Whether these varieties
depend entirely on the food-plant is, however, uncertain ; it is perhaps more likely due
to climate, the yellow variety being chiefly found in the driest localities. It is a
remarkable fact that the little Lycaenid butterfly, Lycaena blackburni, which holds a
position in the Hawaiian Lepidopterous fauna somewhat analogous to that of Oechalia
in the Heteropterous, feeds either in the pods of Acacia koa, or on the Dodonaea with
equal readiness and, so far as is known, on no other native trees. The small, globular
nymphs of the first stage are very conspicuous objects from the strong contrast of their
colours, the abdomen being for the most part bright red.

LvGAEiD.\E. — If some doubt is attached to the endemicity of Coleotichus, this is
also the case with Itliamar hawaiiensis, which likewise is only known from the islands.
It abounds on the coasts of some of these, especially frequenting species of Sida, is
common on the lower edge of the forests in open shrubby places, at 1 500 to 3000 ft.
above the sea, and again in open places in still higher forest, and far above this to a
height of 9000 ft. At higher elevations it breeds on Cyathodes. Apparently it exhibits
no noteworthy variation in any of these stations. Nymphs in all stages, eggs, and
adults are found together on the plants named. The adults frequendy wander else-
where in their flight, and I have taken them in my garden in Honolulu. The hairy
nymphs undergo conspicuous changes in the course of their development. This is
probably the species that Blackburn supposed might be Dysdercus peruvianus. The
only other Lygaeid represented in the islands — Rhopabis hyalimis — is certainly an
introduction. Though common in Honolulu it was not obtained by Blackburn thirty
years ago. It is polyphagous, and its eggs and young are familiar objects on the plants
of Sonchus. The eggs are parasitized by two species of Proctotrupoids, Telenomus
rhopali and T. paractias.

Myodochidae. — With this family we come to an extensive and important part of
the Heteropterous fauna. The genus Metr'arga with its two sub-genera is peculiar to
the islands, so far as is known, and, moreover, forms an endemic sub-family. The
number of species is at present uncertain, as those belonging to the typical sub-genus
are apparently very closely allied. Excepting in size there does not seem to be much

F. H. I. bb

cxciv FAUNA HAWAIIENSIS

variation. In four species of the genus (sensu lat.) the variation in size is quite marked,
by the occurrence of unusually small examples. These are taken actually in company
with the larger examples. In M. contracta an interesting variety occurs in which the
hind part of the pronotum is very conspicuously pale, so that superficially it greatly
resembles typical M. nuda. It is apparently of rare occurrence, four in more than
50 examples of the normal form, all taken in company, were observed on one occasion.
Meb'arga villosa has the wings reduced to such microscopic rudiments as to be
practically apterous, though the tegmina extend to the tip of the body. The other
species are well winged.

The winged species are often notably gregarious, a dozen to scores congregating
together at the base of the leaves of a single plant of Freycinetia. The nymphs occur
in the same situation, sometimes mixed with the adults. These winged species may
also be found on the ground amongst dead leaves or fragments of fern fronds, while
the flightless M. villosa seems to have taken entirely to a terrestrial life, and perhaps
became flightless in accordance with these habits. It is remarkable that amongst large
flocks of one of the winged species (e.g. contracta) one or two examples of another
species (fiuda) are sometimes found, so that the flocks are mixed. The odour of the
species is disgusting, when a colony is disturbed, and taints the surrounding air.
While the representatives of M. nuda that are found on Hawaii, Oahu, and Maui are
very similar, it is noteworthy that the Molokai form, although of precisely similar
habits, is more distinct in appearance superficially.

The two species of Orthoea are of small interest, both having been certainly
introduced ; one of them, O. nigriceps, was already abundant more than thirty years
ago, the other, O. vincta, appeared in 1900, and is already one of the commonest of
Oahuan Hemiptera, and has now extended its range to the mountains. The latter is
attached to the common foreign grass, Cynodon dactylon, amongst which nymphs in
all stages abound amongst the adults. In the youngest nymphs the femoral armature
is little or not at all developed. Brachypterous specimens occur in company with the
macropterous. I have found nymphs of this or an allied genus, when inspecting plants
imported from Fiji.

Clerada apicicornis is a semi-domestic species, living and breeding freely in dirty
houses and cupboards, where cockroaches are allowed to multiply. It also occurs in
outhouses frequented by bed-bugs. On the other hand it can adapt itself to diverse
conditions, and I have noticed adults and nymphs in numbers in dry sandy localities,
living with various common cockroaches, especially Periplaneta, Enthyrrhapha, etc.,
beneath dead leaves. Curiously enough in the mountains it frequents the bases of the
leaves of Freycinetia, like Metrai'ga, and was once found by me in company with these.
Sephora criniger is a local but common forest insect, found on various trees, while
Nesocymus calvus lives on sedges, nymphs and adults occurring together, often in great
numbers. The latter may prove to be not endemic, though it is now widely distributed

INTRODUCTION cxcv

in the mountains, and is found on Hawaii as high as 4000 ft. above the sea, in open
places in the forest amongst low sedges. Brachypterous forms do not seem to occur.
Nesomartis psajumopkila frequents sandy places, on or near the coast, living on low
grass, or on the ground beneath, with its nymphs. In the larger of these the head is
not produced far beyond the sides of the pronotum, as in the adult, but is of ordinary
form. The youngest nymphs are remarkable for their shining black head and thorax,
with white mediodorsal line. The species will probably be found elsewhere, and prove
to be a natural immigrant.

The species of the genus Nysius form a large and important part of the Hawaiian
Heteroptera, and no doubt many remain to be discovered, the disgusting odour that
they emit rendering them unpleasant objects to collect. Some of the species occur in
vast numbers. A small tree will sometimes furnish a home for hundreds of individuals,
adult and nymphal, of A^. saundersi, and others are equally common. It is not clear to
what extent the different species are attached to particular plants. Some, which I had '
supposed to be confined to a single species of tree, I have on another occasion found
in numbers on a totally different plant, belonging to some family far removed from the
other. Some seem habitually to frequent for choice the dead or decaying branches of
the tree they inhabit, others the flowers, and many the leaves or any other part. Many
frequent low plants or ferns. No doubt there are numerous species that are very
closely allied one to another, and as there is manifestly very great variation in the
individuals of some of the species, a thorough knowledge of the genus in the islands
will require prolonged study. It is likely that the actual differences between mere
variations of some species will prove to be apparently much greater than the true
specific differences between the most nearly related, but really distinct, species. The
variable N. blackbtirni wa.?, noticed at Kilauea, Hawaii, feeding in little groups of several
together on the droppings of mynah birds. These birds at the time were feeding
on the fruit of an imported raspberry. Some species are at times met with living
gregariously at the base of the leaves of Freycinetia like the Mett-argae. The
Hawaiian series exhibit great differences in important characters in their extreme
forms. It is possible that one or two may have been imported with foreign plants.

Merragata hebroides, found on ponds near Honolulu and elsewhere, occurs also
high up in the mountains of the other islands, and is known also on the American
continent, being apodemic.

Nabidae. — Represented in the islands by a large number of species of the genus
Reduvio/us, one of which, R. innotatus^ White, I am told by Mr Kirkaldy, is apodemic
and widely distributed. The other species form two groups, each of which contains
numerous closely allied forms, but the connection between these two groups is not

' Since identified as R. capsiformis.

bb2

CXCVl

FAUNA HAWAIIENSIS

obvious. Reduviolus oscillans is typical of the first of these groups, and R. lusciosus
of the second, the latter with its allies forming the sub-genus Nesotyphlias of Kirkaldy.
R. oscillans and its near allies are all macropterous and exhibit little or no individual
variation in the development of wings and tegmina and the ocelli are perfectly formed.
In Nesotyphlias on the other hand the wings are reduced to extremely minute lobes,
the tegmina are hard and leathery, with the membrane always reduced, and the various
forms exhibit very great specific differences in the amount to which the tegmina are
shortened. The wings do not, so far as I have been able to examine the species, vary
in size in accordance with the difference in the size of the tegmina. Thus Nesotyphlias
lusciosus with its tegmina forming a perfect abdominal covering, and with much larger
membrane, has the same small, almost microscopic wings, as such a species as N. curti-
pennis, the tegmina of which fall far short of the apex of the abdomen.

There is, however, one species of Hawaiian Rediiviolus, and that one of the
' commonest and most widely distributed of all, which differs from all the others, in
having brachypterous and macropterous forms, as well as somewhat intermediate
conditions. It was described, no doubt from macropterous examples, by White, as
R. blackbiirni, there being no brachypterous specimens in Blackburn's collection.
Blackburn's specimens were such as are usually found in drier localities or at lower
elevations ; truly brachypterous forms inhabit wetter localities or higher elevations in
the mountains. I have taken some pains to observe this species at high elevations
above 4000 ft. in the mountains, where I have seen it breeding in numbers amongst
low sedges. In the most brachypterous form the membrane is much reduced in the
female, the tegmina not quite covering the abdomen, while the wings are much shorter,
though extending" somewhat beyond the middle of the abdomen. It will be seen,
therefore, that although the tegmina have suffered a reduction fully as great as in
typical Nesotyphlias lusciosus, the condition of the wings is entirely dissimilar, nor have
the ocelli suffered any apparent degradation. There is therefore a very great gap
between Nesotyphlias and the forms of R. blackburni, which form as it were a faint lead
to the condition of this always flightless sub-genus. In one other respect, in which
Nesotyphlias differs greatly from the fully- winged Hawaiian Reduvioli, R. blackburni
does make an approach to the former. Most of the winged forms have the pronotum
much widened posteriorly and this widened part, when seen in profile, is considerably
raised above the anterior portion. In Nesotyphlias this condition is exactly reversed,
the front part of the pronotum being convex and raised above the posterior part.
R. blackburni in its macropterous form is one of the few Hawaiian species, in which
the hind part of the pronotum is but little raised posteriorly, the profile of anterior and
posterior parts being about on the same level. In the brachypterous specimens the
condition of the pronotum is variable, but in many of these it is distinctly convex
anteriorly, and posteriorly is sunk to a lower level, in the same manner as in Neso-
typhlias. It should be noted that the external copulatory organs oi R. blackburni are

INTRODUCTION cxcvii

notably different from those of the other Reduvioli, whether of the fully-winged group
or of the flightless Nesotyphlias. It is quite possible that new species will be dis-
covered connecting the well-winged forms of Reduviolus more closely with the flight-
less Nesotyphlias, and such a discovery would be of considerable interest.

As in so many other Hawaiian genera containing many species, Reduviolus
presents a series of forms mostly very closely allied and sometimes more or less difficult
to discriminate ; some, indeed, without minute and careful study in the field it will
be impossible to fix as being certainly good species or only variations. Amongst these
occur a few forms, notably distinct and separable at a glance, though manifestly allied
to the others. Many of the species exhibit considerable variability not only in colour,
but in such characters as the shape of the pronotum, the thickness of the basal joint of
the antennae, etc. Such variations occur in individuals of a species taken in company.
It is noteworthy that whereas R. blackburni varies in the condition of tegmina and
wings, being apparently affected by temperature or humidity or both combined, other
species, such as R. oscillans, which are found under conditions, as diverse, seem to be
nowise affected by these conditions.

The variety of R. kei-aspkoros with flavescent tegmina on the basal part is
interesting, as nearly reproducing" the colour pattern, that is, so far as we know, fixed as
a specific character in R. sharpianus.

On Oahu I have made some attempt to study the habits of two forms of the
flightless Nesotyphlias, which are very similar, with a view to deciding on their distinct-
ness as species. On the whole their habits seemed to confirm their distinctness, seeing
that though both might be found under apparently the same conditions, the one would
also thrive in situations never occupied by the other. Thus though to some extent
alike in habits, in others they differed, and this partial difference in habits was always
accompanied by a definite difference in structure.

The habits of the Hawaiian Reduvioli are of considerable interest, for whereas
some apparently have their habitat solely on one kind of tree or plant, others are less
particular in this regard. It is noteworthy that the species, that are attached to a
single kind of plant, are invariably of very distinctive superficial appearance. In
determining the true habitat of a Reduviolus attention should be paid only to the trees
or plants affected by the nymphs, because in the fully-winged forms, which fly
sufficiently well, though weakly, individuals occur casually on plants, with which they
have no real connection. R. kahavalu attached to Sophora chrysophylla, R. tarai on
Cyathodes, and R. truculentus on Pipturus are good examples of the restricted habitat.
The Reduvioli being carnivorous, it might be supposed that the restricted habitat of
the species just mentioned (and of others to which I have not paid special attention in
the field, in order to observe them in situ on their favourite plant) was due to the fact
that these special plants furnished a special prey. This I believe not to be the case,
but the association is rather for concealment, since either in the nymph or adult or in

cxcviii FAUNA HAWAIIENSIS

all stao-es these bugs of restricted habitat most closely resemble parts of the plants
on which they are found.

Others that have not so special a habitat, yet often occur in their greatest numbers
in situations, which best serve to conceal them. I have observed scores of R. oscillans,
in all stages, on dead or dying fern fronds with which their colours harmonized very well.

The flightless species of the sub-genus Nesotyphlias, are much more terrestrial in
their habitats than the others, some in fact, so far as is known, live entirely on the
ground. They ascend ferns especially, on occasion, but are not at all arboreal as the
fully-winged group are.

The nymphs of Reduvioins are not as a rule of particular interest ; the basal
antennal joint, which usually becomes much more slender in the adult, than it was in
the nymph, in R. kcrasphoros increases in thickness in the adult, in which also the
processes of the head become much larger than in the penultimate stage. In young
nymphs these curious horns are absent.

The Hawaiian Reduvioli prey upon small and weak insects and we have never
seen them attack Coleoptera, as the introduced Zelus does. It is probable that the
comparative feebleness of their mouth parts would render this impossible. They are
commonly found on such plants, as are the home of small Delphacid leaf-hoppers, on
which they are well known to feed, while some of them eat also the honey-dew or
sweet excretion that is produced by the hoppers. They have been seen sucking the
juices of Psocids and it is probable that these form an important article of diet of
several species. The imported leaf-hopper {Perkinsiella) which did so much damage
in the cane-fields, was attacked to some extent both by R. capsiformis and R. black-
burni, both becoming common in some of the affected fields.

The eggs of R. capsifoinnis are destroyed by the Mymarid parasite, Polynema
reduvioli. In 1902 leaves of melon plants, very badly attacked by an Aphis, were sent
to me for inspection, and on these were many nymphs and adults of R. capsiformis,
preying on the plant-lice. The eggs of the Reduviolus, however, had become very
highly parasitized by the Polynema, very few young bugs appearing. Embedded
in the leaves of grasses and of the sugar-cane eggs from which parasites have escaped
are found not infrequently. Probably the eggs of species of the terrestrial, flightless
sub-genus Nesotyphlias will likewise, when discovered, be found to yield a Mymarid
parasite, for a large Polynema is constantly observed flying over the earth, in the damp
dark haunts of these insects. Further it is possible that these parasites are a strong
check on the multiplication of Hawaiian Reduvioli in general.

Gerkidae. — A family of small importance represented by two genera, each with a
single species, one of which, Halobates sericeus, is of very wide distribution, and has
been seen on the sea round various parts of the coast of several of the islands, and no
doubt occurs round all. I have seen Halobates in great numbers, when I have been

INTRODUCTION cxcix

sailing- round the coast of Hawaii near Kawaihae, but never had an opportunity of
collecting specimens.

Microvelia vagans is an abundant species and widely distributed in the islands,
from the coast to high mountain elevations. It frequents both stagnant pools and
running water, often in great numbers, and after heavy rains is sometimes seen even on
the temporary puddles in the roads round Honolulu. It flies by night and occasionally
is attracted by lights. Possibly it will be found elsewhere and is a natural immigrant,
though it may have been of early introduction in the water supply of sailing vessels.
It exhibits considerable variability in colour, but this has not been specially investigated
in reference to different localities.

Reduviidae. — This family is represented by endemic species of the Ploiiariianae
and three imported species of other groups, none of the latter being found in
Mr Blackburn's collection. One, indeed, Ze/iis renardii, was introduced about 1897,
when I observed one or two specimens, including a female by the side of its egg-mass,
at Honolulu in the Government Nursery, where plants were introduced and raised
by the Board of Agriculture for general distribution. By 1900 it had become fairly
common in Honolulu, and three years later extremely so, and had spread to all the
other islands. It preys on very different kinds of insects, and the adults will destroy
many kinds of beetles, such as Dermestids, Coccinellids and Tenebrionids, and even the
hard Hymenopterous genus Chalcis. The young feed on softer creatures, especially
Aphis, young leaf-hoppers, etc., which are also attacked by the mature bugs. Although
destroying an occasional lady-bird, when well-grown, yet the main food of Zeliis, as an
adult, consists of injurious insects or at least of such as are not beneficial, while the
young prey almost entirely on injurious species. Consequently, on the whole, Zelus
does far more good than harm.

Triatoma rubrofasciata has several times been found in houses or outhouses in-
fested with cockroaches or bed-bugs. Alloeocrantim bianmclipes has only occurred once.
The endemic genus N^esidiolestes is said to be allied to Luteva and Ploiariodes, the
other two Ploiariine genera represented. The species are terrestrial and have been
found in company with the flightless Reduviohis. Luteva and Ploiariodes prey on
Psocidae; a species of the former is occasionally found in houses in Honolulu. The
number of species of the latter is at present uncertain ; they are usually found on dead
branches of trees, to which the dry leaves are still attached, and on dead fern fronds,
whereon their prey is numerous.

Anthocoridae. — This family is represented by a small number of species scattered
in half-a-dozen genera and although these species are all, at present, known only from
the islands, it is uncertain whether several of them are not really introductions, their
small size, and unattractive appearance rendering them liable to be overlooked in

cc

FAUNA HAWAIIENSIS

tropical countries, or at least neglected by the collector. Three of the species occur
in gardens in Honolulu and two of these are widely distributed outside, but they cannot
be looked on as forest insects. All three are found in the cane-fields. These are
Triphkps persequens, Pliysopleurella nmndula, and Biuhananiella sodalis. The first-
named will I think almost certainly prove to be foreign. It is partial to flowers, e.g.
those of Laiitana camara and preys on the Thysanoptera (introduced) that are found in
these. P. mundula and B. sodalis are sometimes found in company, the former being
especially common, sometimes occurring in countless numbers, as in the cane-fields at
Paauhau in 1903, hiding amongst the dead cane-leaves, where it preyed largely on
Psocidae and small leaf-hoppers. On the leaves of growing trees or shrubs, such as
crotons, oranges, mulberries, etc., the conspicuous red nymphs and mature bugs are
often found beneath the webs made by the Psocidae, which feed on the black
fungous growth, that springs up on the excretions of various scale insects infesting these
trees. One may find at such times a small flock of Psocids resting side by side with
their enemy, beneath the covering made by the former. Both P. mimdu/a and
B. sodalis may be found in decayed stems of plants, where, I believe, they feed on
Thysanoptera, which are found in this situation. Yet another small Anthocorid, at
present undetermined, has the same habits, and this also was present in the islands at
least thirty years ago. P. mundula exhibits considerable variability or I would rather
say that, until careful examination has been made, I do not feel sure that there is not
more than one species of its genus.

Lasiochilus denigratus and its allies are true forest insects and live beneath bark or
in the cavities of dead twigs or stems, the nymphs being found in the same situations.
The specific characters appear to be feeble and uncertain.

Lilia dilecta is also a forest insect and the genus is endemic. I have not met with
it, or at least neglected to collect it. I regret that I neglected to collect specimens of
one or more forest-dwelling Anthocorids, distinct from any of these.

MiRiDAE. — The Miridae, better known to entomologists in general as Capsidae,
are represented by a greater variety of endemic forms than any other family of
Hawaiian Heteroptera. Eleven of the genera are endemic. Two recorded species
are certainly recent introductions, an undetermined species of Fitlvius (I believe the
same species as one I met with while inspecting introduced plants) and Halticus
chrysolepis, abundant in Honolulu gardens, where macropterous and brachypterous
forms occur together, the latter having mere rudiments of wings. Even so late as the
early part of 1909 single specimens representing two other genera of Capsidae, have
been found in Honolulu. These imported species are of very little interest, but their
occurrence renders it likely that one or two other Hawaiian species, not known from
elsewhere, may have been imported with plants at an earlier period. At the most
three, however, are open to suspicion. Oronomiris hawaiiensis, a very abundant species

INTRODUCTION cci

on foreign grasses, occurs everywhere in suitable places, from the coast to 5000 ft. or
more on the higher mountains. This will, I think, almost certainly be found outside
the islands, though possibly a natural immigrant. Hyalopeplus pelhicidus, so common in
the gardens in Honolulu, a doubtfully endemic species, is also ubiquitous in suitable
localities, and is chiefly attached either to foreign plants, or at least to such as are not
endemic, but it is polyphagous. In Honolulu it is mostly found on the hedges of
imported Hibiscus ; on the lower slopes it breeds, often in profusion, on the imported
guava ; in the high mountains, at four thousand feet and upwards, it is no less common
in all stages on Dodonaea viscosa, a native tree or shrub, that is apodemic. Whether in
general the species of Hyalopeplus are variable I am ignorant, but H. pelhicidus exhibits
notable variations of a melanochroic character. These appear to be mostly found in
wet localities or at high elevations, where specimens for the most part smoky black are
found, in some cases at any rate mixed with those of ordinary colour and intermediates.
Like Oronomiris, the genus Opuna was formed for a small and obscure Hawaiian insect.
It is attached to a species of Sida that is not endemic, and it will probably be found
elsewhere. Sulamita is an endemic genus, and forms an endemic division or tribe
of the Miridae, several very closely allied species being known. They frequent the
endemic forest trees (of various kinds) from 2000 — 5000 ft. The species of Tichorhinus
iyOrthotylus^ are numerous, and of universal occurrence throughout the mountain forests
of all the islands, and certainly many, and probably all the species are numerous on
occasion. They are, however, very frequently extremely unevenly distributed in some
forests, so that, while one or more trees of a certain kind may contain many, sometimes
in fact hundreds of specimens of a species, other trees of the same kind in the
neighbourhood will produce few or none.

Some of the species are polyphagous and found on very different trees, and can
thrive, moreover, at very different altitudes. Thus T. iolani may be found on an
endemic Hibiscus on the dry forehills, in some of the wettest low-lying valleys on other
native trees, as well as on an apodemic Hibiscus, or yet again above 4000 ft. on the high
mountains on other endemic trees. Such extreme cases are, however, exceptional, and
some species are, so far as we know, quite constant to a single kind of tree. Thus one
of the smallest species, of green and black colour (allied to T. kaiiakanus), is one of the
commonest insects that are attached to Pipturus albidus in the mountains round
Honolulu. Another minute red species, lives on Cyathodes on the high mountains of
Hawaii, in company with the several other Rhynchotal insects, that habitually frequent
that plant.

Some of the species exhibit much variability in colour, and as the structural
characters (unless the male genitalia should prove to be of value) appear in general to
show very slight specific distinctions, it is not always easy to define the limits of the
species. A general variability is exhibited by individuals taken in company, and
moreover there is evidently local variability as well. Though small, some of the

F. H. I. CO

ccii FAUNA HAWAIIENSIS

species are really pretty insects. The nymphs are often abundant on the under side of
the leaves of the trees, in company with the adults. Unless disturbed by shaking, very
rarely are any of the latter seen on the wing.

Koanoa, with one recognized species only, is almost universally distributed in the
forests of all the islands. It appears not so much to frequent leaves as the woody
parts of trees and is often taken on dead branches, when one is collecting beetles.
Kaniehanieha lunalilo, a species exhibiting some variability, is chiefly to be found in
damp forests, living on the mosses or creeping ferns, which clothe the trunks and
branches in such situations. Consequently it may be obtained from many kinds of
trees by indiscriminate beating of the branches.

The Cyrtopeltis {C. hatvaiiensis) was obtained from a shrub or tree, not noted at
the time, but probably Dodonaea, at a high elevation, 8000 ft. or more, on Haleakala.
An apparently allied form is very common in the mountains round Honolulu, living, in
all stages, beneath the leaves of Gonldia.

The small flightless Nesidiorchestes, in which the wings are absent, is terrestrial,
living chiefly in damp shady places, where the soil is more or less covered with decaying
leaves. Sometimes it is seen in numbers in company with the flightless Nitidulid
beetle, Apctinns cxplanatiis, and the flightless Dolichopodid fly, Eniperoptera, and
young of the flightless crickets iyParatrigonidiuni), which it slightly resembles in
appearance.

Pseudoclerada moral is a remarkable insect, exhibiting conspicuous variation.
Some of these varieties, however, may prove to be closely allied species. There is
great sexual difference in the development of the eyes, and brachypterous forms occur.
The species inhabits damp shady places in the forest and has been found beneath bark
of dead branches of trees, and also amongst the moss or creeping ferns growing on
these. Like Mdrarga, they hide at the bases of the leaves of Freycinetia, where
rubbish accumulates. They may possibly prove to be predaceous.

In the genus Sarona there are a number of forms, the extremes differing greatly
in size and colour, but apparently showing little or no distinction in superficial structure.
In most localities on Oahu they are rare, but in parts of Hawaii occur in great
numbers, frequenting the leaves of various forest trees. On one occasion I examined
a large number of specimens from Mefrosidenis, and found great variability in size and
colour, while close by on a species of Raillardia were many specimens, small, black,
and hardly at all variable either in size or in colour. On Oahu, near Honolulu, they
are to be found on Pclea, and I think these Oahuan specimens do not vary much, nor
do they visit the trees of Metrosidcriis, in the neighbourhood of the Pelea. Unless
new characters for specific distinction are discovered, the number of species that exist
will, I expect, remain very uncertain. The largely developed hooks of the male
genitalia may prove of use for distinguishing the species.

Kalania hawaiiensis is allied to the preceding and resembles it in habits, and in

INTRODUCTION cciii

fact occurs with it on the island of Lanai. Though recorded only from that island, it
may not improbably be found on Molokai or Maui or on both of these islands.

AcANTHiiDAE. — There are two distinct forms of Acanthia, and each of these
exhibits striking variation, or it may be that there are several closely allied species
related to each of these two forms. However that may be, there is certainly great
variation in individuals of a single species in superficial appearance. The diversity of
habits shown by these Hawaiian species is of considerable interest. Both frequent the
margins of mountain streams, but are found quite away from these, running on the
ground in damp shady places, in thick forest. They are also at home in damp rocky
places in open parts of the mountains. On one occasion on Hawaii, when climbing a
tree to collect certain species of beetles, I found two or three specimens of Acanthia
running on the trunks, high above the ground, a habit, as Kirkaldy informed me, quite
unique. Curiously enough two of these arboreal individuals, taken together, had no
superficial resemblance to one another, though, I think, clearly of one species, nor do
they differ from examples found running over a wet, rocky cattle trail on Molokai,
where the insect showed similar variation. It is a remarkable fact that while in some
localities a number of individuals of Acanthia may be taken together and show no
great variation, in others, individuals will occur, which differ very greatly amongst
themselves. Nymphs are often met with in the same localities as the adults, some-
times in greater numbers than these, from which they differ greatly in head and thorax,
the former with the eyes being only about as wide as the front margin of the latter and
closely adapted to this. Both A. exulans and A. oa/mensis are flightless, the wings of
the former being much smaller and shorter than the tegmina and reaching about to
the middle of the abdomen. Those of A. oa/mensis are still further reduced, and
there is evident variation in examples from different localities, which may possibly be
specific.

CoRixiDAE. — This family is represented only by Corixa blackhirni White, a
species not known from elsewhere. It is very widely distributed on the lowlands of
the islands, inhabiting salt-water pools as well as ponds of fresh water. It comes to
lieht at nisfht sometimes in considerable numbers.

NoTONECTiDAE.— Represented only by Buenoa pallipes, a foreign species. It is
equally abundant near sea-level and in ponds on the mountains at an elevation of at
least 3000 ft., being generally distributed.

cc 2

cciv FAUNA HAWAIIENSIS

Hemiptera-Homoptera.

The Hemiptera-Homoptera of the Fulgoroid and Jassoid superfamilies are no
doubt more numerous in species than the Heteroptera, owing to the fact that several
of the genera have evolved great numbers of allied species, of highly specialized habits,
in so far that they are restricted, many of them, to a single food-plant, and can only live
in those stations, where these special food-plants flourish. Moreover on different islands,
even when living on a similar food-plant, the species may be quite different. In the
present state of our knowledge we can say that the vast majority of the known species
have so far been obtained only from one kind of plant, but that a few are able to live
on quite different kinds of trees. Nearly all are attached either to trees or shrubs or to
various species of ferns, and the fauna contrasts most strongly with others, where there
is usually such a varied assembly of forms frequenting grasses, sedges, etc.

It is interesting to compare the components of these Homopterous groups with
those given already in the Heteroptera, excluding in each case such forms as are either
known to be foreign or are likely to prove so. Only Nysius, Rcduviolus (s.l.) and
Orthotylus can be compared with the more extensive genera of the Fulgoroids and
Jassoids as successful producers of species, and only a few of the Nysius and a few
species of Capsids, as equally successful producers of individuals.

PoEKiLLOPTERiDAE. — A single species representing this family, Siphanta acuta, is
of recent introduction, having appeared first about 15 years ago. It is a common
Australian insect. By 1900 it had become so extremely numerous, that in some of the
forests on Oahu it was actually destroying large numbers of certain native trees, besides
being injurious to coffee and other cultivated plants. A Proctotrupoid egg-parasite
iyAplianomcTus pusilhis), introduced by Koebele and myself in 1904, has done excellent
service in many localities in diminishing the numbers of this pest. In wet districts it
frequently is destroyed by a parasitic fungus.

FuLGORiDAE. — This family is represented by only two genera, and one of these,
lo/anta, which is endemic, contains but a single species. It is very variable in markings
and intensity of colour, and is partial to ferns, on the trunks of which it may be
frequently seen resting.

The other genus, Oliants, contains a score of species, some of which are quite
conspicuous and striking insects amongst their congeners. Many of the species are
variable in colour and markings, considerable variability being exhibited by examples
of a species taken in the same locality, and there is evidently further variation due to
different local influences. In addition to general variation, there is in many species
striking sexual dichromatism, so that the one sex of a species may sometimes bear a
greater superficial resemblance to another species than it does to its own partner.

INTRODUCTION ccv

Consequently the separation of the numerous species is attended with considerable
difficulty, very few apparently being notably distinct from their nearest congeners.

Some of the smallest and most obscure forms are strictly attached (e.g. O. kaonohi)
to tree ferns, in the cavities of the stems of which, especially when they are fallen and
more or less decayed, the nymphs are found living gregariously. Most of the finer
species, however, are attached to various forest trees, and of some of these the nymphs
live beneath the bark, sometimes in large flocks, sometimes associated with the adults.
In such situations the amount of honeydew excreted, not being exposed to sun or wind,
accumulates in extraordinary amount. Apparently several of the species are entirely
restricted to one kind of tree (e.g. O. taniehanieha on Metrosideriis) but the observations
on this point are not conclusive, since they have not been made in sufficient numbers,
nor in sufficiently numerous localities. Of these more conspicuous arboreal forms the
apparent scarcity of many is, doubtless, more apparent than real, for we have observed
some of these in considerable numbers on the trunks or stouter branches of the smaller-
sized forest trees, on which they run with considerable quickness, and with the rapid
sidling movements of the larger Fulgorids of other countries. In such circumstances
they do not readily admit of capture, and if the branches be jarred, the majority of the
individuals no doubt escape, their strong jump combined with flight carrying them
beyond the limits of any receptacle held beneath. Though of universal occurrence,
where native insects are found, they will probably be found most richly represented in
wetter forests, with very heavy rainfall. One species at least, a small and prettily
marked one, lives on a liliaceous plant (As^e/ia), growing in abundance around the
volcano house at Kilauea on Hawaii.

AsiRACiDAE. — Excluding two or three genera, the species of which are either
certainly introduced or possibly natural immigrants, the six endemic genera of Asiracid
(often known as Delphacid) leaf-hoppers form a remarkable assemblage of allied forms,
notable for the similarity of structure in the jumping spur of the tibiae. There is little
doubt, I think, that they have originated from the same ancestral immigrant, the generic
divisions of the present-day assemblage having" proceeded on lines quite similar to
those followed by other genera of Fulgoroids in other parts of the world. At the same
time the genera are very well marked indeed, as defined by Kirkaldy, though I antici-
pate that forms connecting some of these more closely, remain to be discovered. In
this connection it is interesting to note that in the mountains close to Honolulu there
occurs (at present undescribed) a form in which, though quite similar in general
characters to other Hawaiian species, the frontal keels remain separate and well defined
for half their length, in this respect being intermediate between Aloha and Nesorestias
on the one hand and the remaining endemic genera on the other.

There appears to be no material difference in habits between the representatives
of the different genera, considered collectively. After spending considerable time in

CCVl

FAUNA HAWAIIENSIS

observing Asiracid hoppers in Australia and England, as well as in the islands, one is
struck with the difference in habits between the endemic Hawaiian genera and the
others. A good many of the former are certainly attached solely to ferns, and so are
some of the latter, but so far as is known, grasses, which elsewhere usually produce
these insects in abundance, in the islands have not yielded a single species of the
endemic genera. Apart from those frequenting ferns, nearly all are attached to various
endemic trees, while one or two live on low-growing dicotyledinous flowering plants.
Aloha ipomoeae is an interesting species, in that, although it follows the plants of
Ipomoea into the forest region, it is also a true littoral species, frequenting the Ipomoea
pes-caprae on sandy beaches. I think it highly probable that this species or others
very closely allied thereto will be found on this widespread plant in other countries.

Many and probably most of the species of endemic Asiracid leaf-hoppers are
attached to a single species of plant, while others affect very different species of the
same genus of plant, as for instance Aloha ipomoeae, and Nesosydne iponioeicola on
various kinds of Ipotngea. On the other hand, even on the same island, two allied
species may frequent the same or very closely allied plants in the same or very closely
adjoining neighbourhoods, as two species of Nesodryas on Goiildia in the mountains
just behind Honolulu. One of these moreover is found on more than one species of
Goiddia. Nesosydne goiUdiae has been found not only on GoiUdia, but on a very
different endemic genus of trees, breeding thereon. It is necessary to observe that in
assigning hoppers to a particular plant one must consider only those on which they
really breed, for adults of the winged species may be found on plants with which they
have no real connection. When some nine years ago I first collected the small
Nesodryas freycinetiae, it was noticed in numbers resting on a foreign weed on the
lower edge of a forest near Honolulu and I suspected it of being a foreign insect. In
reality these specimens had been beaten down by a violent storm, that occurred in the
previous night, from plants of Freycinetia overhead, for on these alone are the nymphs
found feeding.

Although many of the species of these leaf-hoppers occur in large numbers when
found, yet they are often very irregularly distributed. In many cases scores of a
species of plant may be examined and yield no hoppers, and then one will come upon
one or several adjoining, on which there is a profusion of specimens. Some species
are no doubt particular as to the condition of the tree they affect, as is the case with
Nesosydne koae. The true leaves of Acacia koa are replaced by phyllodes and in most
cases only the latter are found on well grown trees. Some, however, will yearly
produce true leaves in abundance, and on such Nesosydne koae thrives in extraordinary
numbers year after year, when it has become established. Surrounding trees, that bear
phyllodes only, will rarely produce a few stragglers of the hoppers. Large phyllode-
bearing Koa trees, which have an occasional young shoot bearing true leaves, will
often have quite a colony of the Nesosydne confined to these shoots. One or two of

INTRODUCTION ccvii

the species are widely distributed over the islands, and at present it would be premature
to consider that the many, known only from one island, are really confined to one,
though no doubt this will prove to be the case in many instances. Nor is it probable
that the genus ^Nesodryas, consisting of small insignificant species, is really confined to
Oahu.

As in other parts of the world, these Asiracid leaf-hoppers differ much as to the
development of the wings according to the species. Nesodryas in all its species is
fully winged. In N^esosydne some species are known, in which fully winged examples
occur, but these are much rarer than the flightless individuals. I have certainly
examined many thousands of the common N. ipomoeicola in search of parasites, both
in the mountains and in the lowlands, where were colonies within a few yards of my
house for several years, but fully winged individuals were rarely met with. For several
consecutive days I examined for the same purpose great numbers of N. raillardiae,
but I never found any but flightless forms. Still they may be produced at irregular
intervals. Nesosydne koae and some others are only known as fully winged individuals,
though the species named occurs in profusion.

In the genus Aloha the conditions are very similar to those in Nesosydne. In
A. ipomoeae fully winged forms are rare as in Nesosydne ipomoeicola, though this species
also has been examined in equal numbers for parasites. A. lehuae and its allies are
always fully winged, but of Nesopleias nimbata it is unlikely that winged forms are ever
produced, since the very short tegmina have become thickened and the neuration more
reduced than in brachypterous A. ipomoeae. It would appear probable that in the
various endemic genera, species, which we know from a fair number of examples of
fully winged individuals, are not likely to yield brachypterous ones under any circum-
stances, while the normally brachypterous species sometimes produce fully winged
individuals in small numbers, but more often are entirely brachypterous. We know no
Hawaiian Asiracid, in which both winged and flightless forms are more or less equally
common, no such case in fact as is presented by the two introduced forms Perkinsiella
saccharicida and Peregrinus maidis. In the former of these winged examples are
always common, and flightless females abound in the colder months of the year. In
the latter both forms in both sexes abound at various seasons. Nesorestias contains a
single species with very short tegmina, and is not likely to yield a winged form, the
peculiar structure and texture of the tegmina being analogous with that of flightless
Hawaiian Hemerobiids in the Neuroptera.

In the Hawaiian Asiracids it should be observed that, whether fully winged or
flightless, both sexes agree in this. No species are known, which, like the introduced
Perkinsiel/a, produce brachypterous individuals in one sex only. In the flightless
Hawaiian forms the wings are reduced to microscopic rudiments, but can be seen in all
the species that I have examined. There appears to be little difference between the
' More than one species of this genus is now known from Kauai.

ccviii FAUNA HAWAIIENSIS

larcrest nymphs of some of these flightless species and the same stage of fully winged
ones, the tegminal and alar lobes being almost equally developed in each, so that in the
species which produce both winged and flightless forms it would appear that the
development continues equally in the nymphs of either to the penultimate instar, when
in the one case a fully developed wing forms within the wing pad (on which some
neuration is visible) while in the other case the wing is reduced to the rudimentary
condition of the adult. The nymphs do not appear to be particularly interesting in
general, the chief point of interest being the presence of two facial carinae in those
which produce adults with only one.

Kirkaldy tells us that the only Asiracid known outside the islands, having a tibial
spur similar to that of the Hawaiian endemic genera, is the arboreal Proterosydne of
Australia.

The genus Dictyophorodelphax, discovered by Mr O. H. Swezey, is remarkable
for the great prolongation of the head, a common feature in other groups of Homoptera,
but not known previously in Delphacids. It is clearly an offshoot from the more
normal Hawaiian forms.

Many of the species of the native genera exhibit a wide variability of colour, and
further frequently the sexes are differently coloured. The males, however, are so
easily separated by the great differences in the genitalia, that in the discrimination of
the species this is of small moment. Whether there may be different species with
similar genitalia is yet unknown, but it is not improbable that such will prove to be the
case, when species from all the islands have been more thoroughly collected. The
flightless forms are no doubt not easily spread from one locality to another, and I suspect
that in many of these a good deal of local variation may be met with. I once examined
two large series of Nesosydne pipturi from two different stations in the mountains
behind Honolulu, where the species is very common. The first lot were taken from a
number of trees, growing near together, in a rather open spot, the second lot from an
isolated tree distant not many hundreds of yards from the former. Although possibly
individuals might have been picked from each lot agreeing exactly, yet on the whole
the two series were so distinct superficially, that until I examined the genitalia I had
great doubts whether those from the isolated tree were not a really distinct species.

The eggs of some of the species are known to be destroyed by Mymarid parasites
of the genus Polynenia and nymphs and adults of very many have been found infested
by the Strepsipteron, Elenchus melanias. In the mountains of all the islands many
species are parasitized by a somewhat aberrant species oi Pseudogonatopus (Dryinidae),
this parasite attacking species of Nesosydne, Aloha and probably other genera.
On the lowlands Aloha ipomoeae is attacked by Echthrodelphax fairchildii, another
Dryinid, which likewise parasitizes the small Kelisia sporobolicola. This leaf-hopper
is common on the coasts, feeding on the foreign grass Sporobolus virginicus, and two
other species of Kelisia have also been found. Wherever these leaf-hoppers are found

INTRODUCTION ccix

in the forests, and sometimes in the open country, one or more species of the parasitic
flies of the genus Piptincidus will be found, sometimes numerously. I have bred two
species from mixed colonies of Aloha ipomoeae and Nesosydne iponioeicola and another
from A^. raillardiae. At Kilauea I observed many of these flies around a Pipturus
tree, growing in a shady place, and infested by another N'esosydne, as well as about
ferns affected by other species.

Membracidae. — Represented only by a species of Centrotypiis, of recent introduc-
tion. It was first taken in the Nuuanu valley in 1903, since which time it has occurred
occasionally and will no doubt become common.

Tetigoniidae. — This family is represented by a large number of species, closely
allied to one another, but forming two genera, one being, so far as is known, peculiar to
Kauai, and at present containing few species. Excepting that Nesophryne (the small
genus) sometimes occurs on ferns, all the endemic Hawaiian Tetigoniidae (of the exten-
sive genus Nesophrosyne) are attached to flowering dicotyledinous plants, and the vast
majority of the species frequent the various endemic forest trees. A few kinds only are
attached to low growing plants, and one of these, N. perkinsi, is of some interest, as
living on a foreign (but naturally immigrant) species of Sida, on or near the coast.
The c?i?,& oi N. pei'kinsi SiS regards habits and food-plant and its relation to its forest-
frequenting congeners is in several respects similar to that of Aloha ipomoeae in the
Asiracid series.

It is quite certain that a large number of the species oi Nesophrosyne are restricted
to a single food-plant, and more than one species may occur on the same individual
tree.

The separation of the species is at present attended with much difficulty, for many
of them are very variable in superficial appearance and there is often a considerable
difference in the colour or pattern of the sexes. It further seems to be of rather
common occurrence, in the case of such species as present these sexual differences, for
individuals of the female sex to assume more or less completely the colour of the male,
a phenomenon which is also apparent in some of the Asiracid Fulgoroids. In addition
to this, a colony of a species infesting one tree sometimes shows considerable differences
in appearance, when compared with a colony infesting another tree, even though the
distance between the two is small, and these differences are likely to be increased, when
colonies from more isolated spots are examined. I have little doubt that any number
of superficially distinct forms could be obtained by selective breeding. It is possible
that the appearance of individual colonies is often due to the nature of the original
parents that colonized the tree, for colonies, if undisturbed, persist on a single tree, as
I have experienced, for years.

Many of the species are certainly common, in fact in some localities, e.g. on the
F. H. I. dd

ccx FAUNA HAWAIIENSIS

uplands of Hawaii some of them occur in extraordinary profusion, liundreds or thousands
having been noticed on a single tree.

Although the adults present apparently very feeble characters for specific separation,
yet the nymphs by their bristles and ornamentation are often more easily distinguished.
Consequently one may breed from nymphs of the most distinctive appearance adult
hoppers that greatly resemble one another.

The superficially distinct species N. ponapona and N. piptitri are sometimes found
on the selfsame tree of Pipturus, a very remarkable case, unless they be dimorphic
forms of a single species.

The species of Nesophrosyne are subject to the attacks of a parasitic fungus, which,
on the uplands of Hawaii, we have found, at times, to amount to a severe epidemic.
On one occasion countless thousands of one or more species were to be seen sticking
on the leaves of the trees, all dead, those in which the development of the fungus had
not proceeded far, being still life-like in appearance. The eggs of these Tettigoniids
are extensively parasitized by the Mymarid genus Polynema, but neither Dryinid nor
Pipunculid' have been obtained from nymph or adult, in striking contrast with what
occurs in other countries.

The other known members of the Jassoid group are of comparatively little interest,
though Liniotettix is, I think, certainly represented by truly endemic species. A species
of Conosanus (C. hospes) extremely common in gardens in Honolulu is certainly intro-
duced and of no interest. Its introduction is quite recent.

Chermidae. — Better known as Psyllidae, these insects are represented by rather
numerous species, in fact the gall growths formed by Trioza on the predominant tree
i^Metrosidems) of the Hawaiian forests are one of the most familiar entomological sights
in the islands, while others on various species of Pelea are sufficiently common.
Although these gall-forming species are so numerous in individuals, a number of species
of Hevahcva with picturated tegmina occur much more rarely and locally, though no
doubt the species are rather numerous. If they produce gall-growths, these have not
yet been discovered.

Aphidae. — The members of this family are of little or no interest faunistically,
since probably all of them have been imported with introduced plants. In this connec-
tion however it is proper to state that formerly, 1892-1896, a species of Myzus (?) was
very abundant throughout the mountains, especially attacking the species oi Pclea, other
species of Aphids being hardly met with in the forests at the earlier date. This Pclea-
frequenting species seems to have been practically exterminated by the ladybirds
(especially Coelophora inaequalis) introduced to diminish the attacks of foreign Aphids,
on which Coelophora now maintains itself in the mountains.

' P. rotundipennis belonging to a different section of the genus from that including the other known
species, may be parasitic on Tettigoniids.

INTRODUCTION ■ ccxi

CocciDAE and Aleurodidae. — These families are of no importance in the present
connection, probably all the many species of the former and certainly all the few repre-
sentatives of the latter having been introduced with plants.

Review of Thysanoptera.

The Hawaiian Thysanoptera have so far only been collected casually, and of late
years many introduced forms have become conspicuous around Honolulu and elsewhere.

So far as I can judge, the endemic fauna is entirely restricted to the Tubulifera
and all the Terebrantia will prove to have been imported by man. Even of the former
we may suspect that Agnostochthona, Diceratothrips, and possibly Trichothrips are
represented only by foreign species, while Anthothrips iisitatus is certainly an importa-
tion. This leaves us with only four genera, all peculiar to the islands, which at present
must be considered as truly native. Three of the four genera, Derniothrips, Oedeniothrips
and Nesoih'ips, contain only a single species, while the other, Do/erotkrips, has nine,
and is evidently dominant in the islands. I believe that all the native species are
attached to dead wood, flower-frequenting species being absent. All the specimens
obtained by me were found whilst 1 was collecting beetles, and no special search for
Thysanoptera was made. Individuals of some species are quite numerous, and they
seem to occur everywhere in the mountain forests.

Review of Orthoptera.

At the present time the Hawaiian Orthoptera are represented by 83 species, 38 or
39 of which are certainly endemic, while 44 or 45 are apodemic and have mostly, no
doubt, been introduced by man's agency.

The Phasmoidea are entirely absent from the fauna, while the Mantoidea are
represented by two species of recent introduction and the Acridioidea by two foreign
species, one of quite recent importation (1900) and one established here many years
ao-o. These three great groups were therefore quite wanting in the fauna under natural
conditions, though two of them now are represented by common foreign species brought
accidentally with plants since the colonization of the islands by white men.

Hardly better represented are the Dermaptera, Forficuloidea or Earwigs and the
Blattoidea or Cockroaches. Though there are seventeen species of the latter, now
known as Hawaiian, one only has any claim to be considered endemic, a true forest
insect, Phyllodrornia obtusata. It is just possible that one or two other species are
natural immigrants, but I think this unlikely.

The Earwigs are in nearly similar case, for while a few may be natural immigrants,
we know that three or four species have become introduced within quite recent years.
One, however, listed in this work as Anisolabis pacifica, will I think prove to be a
distinct species and endemic or at least a natural immigrant.

dd2

CCXII

FAUNA HAWAIIENSIS

FoRFicuLOiDEA. — Of the genus Aniso/abes, A. annulipes is the most abundant
and ubiquitous, being found at all elevations from sea-level to four or five thousand feet
in the mountains. ^A. maritima is less abundant, but is very widely distributed and
sometimes very common beneath stones in damp localities in the forest region. It also
occurs near sea-level. ^A. littot'ea is much rarer than either of the above. We
have noticed it on the margin of salt-water ponds on the coast and it has been recorded
from a considerable elevation (2000 ft.) in the mountains. The species recorded as
"A. pacifica, but which will probably prove to be endemic, has been found only on
Kauai, where it lives beneath logs or stones in or near the forest region. It was in
company with the young of this species that Japyx sharpi was found, at an elevation
of 4000ft. A. annulipes and A. maritima are cosmopolitan species; A. liltorea is a
well-known New Zealand insect.

Labia pygidiata is a very common insect in the forests of all the islands, where it
lives beneath bark, especially that of damp and decaying trees. Other species of this
genus are of quite recent introduction and found on more than one island. Some of
these are known to inhabit Samoa and Fiji, having been found on plants imported from
those islands. L. pygidiata is reported from Java and Burma and is, no doubt, of wide
distribution.

A fine Labidura (probably iderica Serv.) is now common on Oahu, under stones
in damp places, and beneath trash in the cane-fields. Like many other foreign forms
it was probably introduced with growing plants from the Oriental region, where it is
widely distributed. It is spreading to other islands of the Hawaiian group.

Chelisochcs morio is a very common insect, especially in the Freycinetia-^roWmg
belt of forest. It generally lives at the bases of the leaves of that plant and of such
others as retain moisture, where they clasp the stem. It abounds in such situations on
Caiiiia, indica, Cordyline terminalis, and in damp localities on the sugar-cane. Though
many lie concealed during the day, others may be noticed running over the leaves of
the plants they frequent at all hours. They are largely carnivorous, but also feed on
vegetable matter, such as the red inflorescence of the Freycinetia. We have observed
them devouring caterpillars and the sugar-cane leaf-hopper. They often seize and hold
their prey in their forceps. C. morio is of very wide distribution, ranging from India
to the Philippines and through many of the Pacific islands. Most probably it was a
natural immigrant or it may have been originally introduced by the natives from other
island groups of the Pacific. It was particularly noticed by the naturalists of British
expeditions in the early part of last century. We have in recent years found it abund-
antly, in company with Sphingolabis kaivaiiensis, in consignments of plants brought
irom Fiji, so that it is easily transported by these means. The latter species,

^ Other species, A. aporonoma, eteronoma, have been described on examples, no doubt similar to those
here alluded to as foreign species.

" Since described as A. perkiiisi (Burr. Tr. Ent. Soc. Lond. 1910, p. 178).

INTRODUCTION cdxiii

6". haivaiiensis, has much the habits of Chelisoches and in fact is often found in company
with it. Both species, in wet locahties, are found nearly to sea-level.

Mantoidea. — The common Australian Mantid, Orthodera prasina, was, doubtless,
Introduced with orange trees from Australia, and was first noticed on the island of
Kauai, about the year 1896. It is thoroughly naturalized there, but apparently does
not spread rapidly and is still confined to that island. It has been noticed preying on
that most beneficial ladybird Coelopho7'a inaequa/is, as well as various other insects.

The larger Tenodera sinensis is a more recent introduction from the Orient and
was first noticed in some numbers in Hamakua district of Hawaii about the year
1900. It has spread to some extent over that island, but has not yet been reported
from other islands of the group.

Blattoidea. — The numerous introduced cockroaches are a conspicuous element in
the fauna, many of them {Periplaneta australasiae and americana, Stylopyga decorata,
Euthyrrapha pacifica, etc.) thriving both as domestic pests and out of doors in the open.
Some, e.g. Phyllodromia kospes and Loboptera exiranea, are of recent introduction,
having first become noticeable towards the end of the last century, though now exces-
sively numerous in individuals and widely spread. The females of the former are
brachypterous and flightless. The Loboptera has been found in consignments of Fijian
plants in recent years and may have been imported from that group. The common
P. germanica remains practically a household insect, and abounds on steamers which
call at Honolulu. P. hieroglyphica is one of the commonest of cockroaches at low and
medium elevations. Oniscosoina pallida, taken by Mr Blackburn 30 years ago, has not
since been met with. Leiuophaea surinarnensis is an exceedingly common species, the
young of which are often found in great numbers under stones, and are remarkable for
the appearance of the hind parts of the body, which resemble those of wood-lice, so that
when the fore parts are buried in the soil they might on superficial examination be
mistaken for those Isopods. EletUlieroda dytiscoides, another excessively numerous
species, is injurious to trees, gnawing the bark from the branches of Casuarina, Citrus,
etc. The young and adults often congregate in masses amongst the foliage, falling to
the ground when disturbed, and scuttling off with irregular gait to conceal themselves.
This species is viviparous. The pretty species of Etctliyrrapha {E. pacified) breeds in
neglected cupboards amongst rubbish in houses, and also abundantly beneath dead
leaves, etc., in the open, but only at low elevations. The nymphs are uniformly dull
and ugly creatures, very different from the really handsome adult. A second species of
this genus, or an allied form, has been more recently found in numbers on Hawaii.

Very different in habits from any of these is the endemic Phyllodroinia, P. obtusata.
It is a most abundant insect throughout most parts of the forests of all the islands,
where it lives beneath bark of trees, in clusters of dead leaves, or in living foliage.

CCXIV

FAUNA HAWAIIENSIS

where the leaves have a tendency to curl up and form a suitable place for concealment.
It exhibits much variety in the development of the wings so that in some localities all
the individuals exhibit so strong a tendency to become brachypterous, that they might
almost be considered as forming a distinct species. The varieties of this species seem
to be connected with special localities.

Both the endemic species and many of the foreign ones are subject to the attack of
parasites. The Encyrtid Solindenia picticornis is bred from the capsules not only of
Phyllodro7tiia obtnsata, but from those of other cockroaches, and parasitized oothecae
are often met with. The two Evania, of which one has not hitherto been found in
other countries, are extremely numerous on the lowlands and in the lower forest, while
these are themselves destroyed by the Tetrastichine Eulophid, Tetrastichus hagenowii.
Some of the native birds are partial to the endemic Phyllodromia, and the introduced
mongoose sometimes devours numbers of the two large Periplaneta. It is unfortunate
that the injurious Eleutheroda is, from the nature of its life-history, exempt from the
attacks of Hymenopterous parasites.

AcRiDioiDEA. — The common Oriental grasshopper Oxya veiox, confined in 1892
to Oahu and Kauai, has not yet been reported from other of the islands. It thrives in
wet or moderately wet localities, in fact particularly where one finds the introduced
Hilo grass i^Paspahun conjugatiini).

Atradornorpha crenaticeps appeared in Honolulu in 1900, and several years elapsed
before it became really common. The original examples met with were of the brown
form, but green-coloured specimens were found soon afterwards. No doubt this grass-
hopper was imported with plants from Australia, where we have found it commonly, or
from Hong Kong, whence we have seen examples collected by Mr F. Terry. It can
live in much drier localities than those frequented by Oxya.

LocusTOiDEA. — This great group is represented by five genera only, and of these
three are introduced forms. Elimaea punctifera Walk, {appendiculata Br.) was of early
introduction, being common during the period of Mr Blackburn's collecting. It is a
widely distributed Oriental species and is now thoroughly established on all the islands,
but is confined to the lowlands and lower forest regions. The flattened eggs are
inserted in the fronds of ferns and leaves of various plants causine a slieht swellino- on
the epidermis. They are much parasitized by the Encyrtid Eupelmine Anastatiis
koebelei, and a minute Trichogramma or Pentarthron, the latter issuing in large
numbers from a single egg. The former parasite, which is a common garden insect
and found in the forest also, was not met with by Mr Blackburn and was therefore
probably introduced at a later period than its host.

Holochlora venosa is no doubt a later importation from the Orient. The eggs are
laid in numbers in long slits made in young shoots of the 'Avocado pear' {Persea) and

I

INTRODUCTION ccxv

of other trees, and arranged in regular rows in these slits. They were observed
numerously as early as 1895 or perhaps earlier, but the adult insect, which is compara-
tively rarely met with, was not found till a much later period. Probably the eggs will
prove to be much parasitized by the Anastatus above mentioned. Eggs of apparently the
same cricket have been found in shoots of young plants brought from Hong Kono- and
Japan. The other imported Locustid, Xipliidium varipemie Swezey [ = X. fuscitm
huj. op. II. 14), was a very rare and local insect in 1892, and by no means numerous in
1897, but by 1900 had become one of the most abundant of insects and spread all over
the group. Probably it will prove to be an introduction from the western parts of
N. America. It is to a very large extent carnivorous, devouring Homopterous insects
and caterpillars. It is a delicate feeder on vegetable matter, preferring the stamens
and other tender parts of flowers. The eggs are laid in a row beneath the leaf-sheath
of Hilo grass, sugar-cane, Caiina, etc., and are frequently destroyed by an Aphelinine
parasite [^Paraphelinus xiphidh) of abnormal habits, of which about a dozen examples
may emerge from a single egg. For some years after its appearance no short-winged
forms of the Xiphidinin were noticed, but subsequently they became abundant. In the
driest and hottest localities the short-winged forms appear to be absent or nearly so
during the hottest months of the year, but appear numerously at other times.

Swezey has investigated the percentage of long-winged and short-winged forms in
various localities and in various months of the year. Intermediate forms are very rare,
usually about 2 per cent., where the proportion of winged and flightless examples is
about 83 per cent, and 15 per cent. ; whether the greater percentage consist of the
long-winged or short-winged forms the percentage of intermediate forms reinains much
the same.

The other Locustidae are endemic and are represented by a single Conocephaloides
(C. remotus Walk. = C. lunvaiicnsis huj. op.), while eight or nine species belong to the
endemic genus Banza {Brachyiiietopa huj. op.). The former seems now to be very
rare, but was probably once abundant, and has been destroyed by introduced predaceous
insects. It is interesting, as being a form such as one might suppose gave rise to the
more remarkable Banza. All the species of Banza (except that possibly B. niolokaiensis
and B. inauiensis may prove to be synonymous) are each one restricted to a single
island of the group, and all those species, of which a number of examples have been
collected, are dimorphic, having green and brown forms. The most remarkable case
of this dimorphism is exhibited by B. parvula W. {discolor Redt.), where the whole
appearance of the insect is changed owing to the coal-black face of the discolor var.
and the pale face of the blackbiirin form. Further reference to this species will be
found in Vol. 11. p. 689 of this work. Briefly it may be said that in the localities,
where it has been specially studied, the males of B. paii'ula are brown, black-faced
insects, with green pale-faced forms occurring rarely, while the females are pale-faced
green insects with black-faced brown coloured individuals occurring still more rarely

CCXVl

FAUNA HAWAIIENSIS

than do the green males. It is interesting to notice that whereas in this species the
common form of male is brown and the female green, in all other species collected in
numbers both sexes are usually of the green form. In B. nitida var. punae, when
brown (or at least not green) varieties occur they are, I think, always of the female sex,
while in B. parvula the discoior form is nearly always of the male sex. B. nitida,
when molested, exhibits a curious posture, threatening and protective, shown on
pi. I, fig. T,d, Vol. II., but I cannot recall having noticed this behaviour in any other
species.

The species of Banza are entirely nocturnal in their activities, resting by day on
their food-plants, and are usually very well concealed. They are not at all restricted in
their habitat, for the same species may be found on very numerous trees or plants,
e.g. B. parviila W. { — disco/or huj. op.) is common on Coi'dy/ine, various ferns,
Acacia koa, Metrosiderus, Pelea, Sti'aiissia, Freycinetia, etc. They are, however,
particularly partial to Cordy/ine, Freycinetia, and such plants as have the leaves closely
embracing the stem, thereby affording more perfect concealment, while frequently they
hide amongst masses of dead leaves, when a branch of a tree has died and the leaves
remain adherent to form a thick shelter. The young are also very numerous on soft
ferns and frequently conceal themselves beneath the leaves of Pelea, which curl up
around the edges and form a good hiding place. The eggs are found arranged in a
row at the bases of leaves of Cordylinc and Freycinetia, but they must certainly occur
also on ferns, Canna and other plants affected by the young. The latter in B. parvula
Walk, are more varied in colour than the adults, being green, testaceous, various shades
of brown, brownish crimson, etc., but the adults produced from these are extremely
uniform in comparison, being either true discolor form or true blackburni. The latter
rarely produces a variety of facial coloration, which to some extent may be looked on as
exhibiting partial characters of the discolor form. The males stridulate freely at night,
but it is difficult to locate the sound. The eggs are parasitized by a species of Enpelvius
of the Chalcids, and perhaps also by the Proctotrypids of the genus Anteris. Some of
the species of Banza seem to be extremely scarce, and I suspect that a great many
eggs are destroyed by parasites. Occasionally on Hawaii we have taken examples that
have clearly been seized by birds, but have escaped with mutilation. It is interesting
to notice that B. nitida pnnae sometimes saves its life by the loss of one or both of the
hind tibiae, which are perpendicularly elevated in its attitude of defence.

Grylloidea. — Here belong the greater part of the species which form the endemic
Orthopterous fauna, for of nearly forty described species only five have been accidentally
introduced. These introduced forms are of very little interest.

Grylhis junotabilis is one of the commonest of insects, but is not a forest insect,
being abundant on the lowlands and lower mountain elevations. We have found living
specimens in consignments of growing plants sent from other countries, showing thereby

INTRODUCTION ccxvii

that it continues to be brought here by commerce. Sometimes this cricket forms a
large part of the food of the mongoose. A second species of Gryllus appeared in the
islands in 1900 and is now at times extremely common on Oahu. Gryllodes poeyi is
abundant in many places, and is often found beneath rocks in extremely dry situations.
It also is a lowland, or at least not a forest insect. The imported mole-cricket {Giyl-
lotalpa africana) is, so far as is known, still confined to the island of Oahu and has
acquired an unpleasant notoriety, as being decidedly injurious. The injury done by this
insect is of two kinds. Burrowing in the banks of ditches etc. it allows the water, used
for irrigation purposes in cane- and rice-fields, to escape, and also, locally, seriously
injures the stems of growing sugar-cane, where they lie on the ground, by driving
large borings or tunnels through these. It is e.xcessively numerous in suitable localities,
and on hot dark nights, during the prevalence of southerly winds, is occasionally
attracted in countless numbers to the lights of lighthouses and other less powerful
lights.

The little myrmecophilous cricket is common on Oahu in the nests of various
foreign ants, such as Pleidole megacephala, Solenopsis geminata and more than one
species of Prenolepis. In migrations of some of these ants we have observed these
crickets marchingf in line with their hosts. We have also found them in nests of ants
brought in consignments of growing plants from foreign countries, when examining
such consignments on the wharf in Honolulu.

The endemic Grylloids belong to two different groups, the Trigonididae, repre-
sented only by the genus Paratrigonidium, and an endemic family or tribe Prognatho-
gryllidae, in no way related to the former, and containing several distinct genera. The
Hawaiian species of Paratrigonidijini are remarkable for the fact that while they severally
often exhibit very great distinctness in habits, in structure and appearance they often so
closely resemble one another as to be only separable with great difficulty and by very
slight characters. All are true forest insects. P. pacificum, commonest and most
ubiquitous of all the species, is chiefly terrestrial in habits. Though occasionally it
ascends ferns, bananas, etc., it is mostly found actually on the ground in damp places
and moves about actively by day in the deep shade. Many of the other species are
strictly nocturnal, living in concealment and remaining silent by day, whereas P. pacifi-
cum sings the whole day through, as well as at night. P. gj'ande and P. atte^uiatum are
commonly found beneath bark of trees, often in mixed assemblages of young and old
together. P. saltator and freycinetiae live only at the bases of the leaves oi pTeycinetia,
P. roseum, subroseum and atroferrugineum only amongst the leaves of Metrosidertis ;
the latter, indeed, has only been found on one special variety of this tree ! P. filicum
and viridesccns are found on ferns, each frequenting different kinds, and so not mixing
together. In general, the young of the species that frequent foliage are green, however
differently coloured the adults may be, whereas those that live on the ground or beneath
bark of trees, have brownish or obscurely coloured youngf. The terrestrial P. pacificum
F. H. I. ee

ccxviii FAUNA HAWAIIENSIS

is perhaps the most variable, as it is also the most numerous, and it is the most isolated
structurally. In wet places the pronotum of this species is often quite white from a
dense growth of fungus on that part, but this growth seems in no way to injure the
insect. The arboreal species are a good deal hunted by the endemic birds, which seek
them beneath the bark, as well as on the foliage. That most local of Drepanid birds,
Viridonia sagittii-ostris, was almost always found to contain abundant remains of
P. freycinetiae, which it procures from the base of the leaves of Freycinetia. The
terrestrial P. pacificiim is the least powerful in jumping, the saltatory powers of the
arboreal species, when adult, being really prodigious for their size. It may be supposed
that since these so often lose the protective colour of their nymphs, they find sufficient
protection in their powers of leaping, when they have reached maturity. At any rate
the sudden change from a green insect to a black and orange one, as seen in P. atro-
femiginmim, is quite remarkable. All the species, as adults, are quite wingless, the
tegmina alone remaining as stridulating organs. Until the last ecdysis, wings and
tegmina A.q.vAo'^ pari passu, but at that ecdysis the tegmina undergo much further
special development, while the wing-rudiments, instead of proceeding with their develop-
ment, entirely abort. It is not known whether these crickets are subject to insect
parasites, but it is possible that the eggs will be found to be attacked either by the
Mymarid, Polyiiettia, or the Proctotrypid, Anteris. Not very infrequently they are
found to be infested by a parasitic worm (^Goj'dius) which emerges from the thorax or
abdomen, and is still more frequently seen at large on fronds of ferns or on other low
plants that grow in the damp shady places most affected by these little crickets.

The rest of the endemic Grylloids form the most interesting part of the ortho-
pterous fauna. There are nearly a score of species known and they are distributed in
four genera, closely related to one another, forming together a natural group. Two of
the genera are represented by only a single species, and these are clearly offshoots from
each one of the larger genera.

Nesogryllus, once characterized as distinct, has now long been known to us as the
male of Prognathogryllus, originally founded on the female sex only. The species of
Prognathogrylhis have well developed tegmina in the ^, adapted for stridulating, but
both sexes are flightless, the wings being rudimentary.

In Leptogryllus and its offshoot 'fhaiiinatogrylhts, the wings are absent and in
some species the tegmina are so minute as to be only visible at the extreme sides of the
mesonotum, while in others they cover the whole (or almost the whole) metanotum, this
being the maximum of their development in the genus. Aphonogryllus is very imper-
fectly known and may be only an immature stage of some species of PrognatJiogryllus.
If not, it is clearly a derivative from the latter genus.

All the species of Prognathogryllidae are entirely nocturnal and we have several
times found them at night running on the trunks of trees. In the daytime some of
them conceal themselves beneath bark, or in holes in decayed wood, while others inhabit

INTRODUCTION ccxix

the pith cavities of certain forest trees. Prognathogryllus stridulans, once a difficult
insect to obtain in the mountains round Honoluki, has now become common, owing to
the unhealthy state of many of the arborescent lobelias in this locality, as elsewhere in
the islands. At the present time and in fact for the last ten years many of these trees
have lost their former healthy condition, and are now either entirely dead or have many
dead branches. These dead branches being hollow afford a most convenient home for
Prognathogryllus, and rarely is a tree found in this condition which does not harbour
the cricket in some or all stages. In former years it was most difficult to find a tree in
the dead and dry condition suited for these crickets, and they were then more often
obtained by splitting dead twigs and branches of Piptiirus, an urticaceous tree. The
males of Prognathogryllus stridulate only at night, after they have emerged from their
retreats. The species of Leptogryllus have rather varied habits which, however, are
not altogether constant in the case of a single species. Several (Z. elongatus, kajiaiensts
e.g.) have been found numerously, hiding in dead hanging fronds of tree-ferns, or
[L. fusconotatiis, elongatus, nigrolineatus) amongst dead masses of banana leaves still
adherent to the plant, beneath bark of trees (Z. siinillimus), or under moss or creeping
ferns [L. forjicularis). Another favourite hiding place for several species is at the base
of the leaves of Freycinetia, where we have found Z. nigrolineatus, L. similis, L. fus-
conotatus and other species. These crickets are sought after both by some of the
Drepanid birds and also by the Meliphagine ' Oo ' of Kauai. Adults and nymphal
forms are usually found in company. Some of the Leptogrylli feign death, lying with
the body somewhat crescentically curved. No parasites of those crickets are yet
known, but it is quite likely that the eggs may be attacked.

In concluding this brief account of the Orthoptera a few words may be said on the
endemicity in the islands of the species of the more important genera and families. In
the genus Paratrigonidium the species are so difficult and have been so little collected
in many places that not much confidence can be placed on the correctness of their
distribution, as at present known. Yet, no doubt, while some are more widely dis-
tributed, others are peculiar to a single island. Thus clearly P. saltator of Oahu
represents the P. freycinetiae of Hawaii, the two being very closely allied and having
identical habits. Probably P. subroseum, P. roseum, and P. atroferrugineum, inhabiting
Oahu, Maui and Molokai, are modified forms of one original species, for they have
peculiar and similar habits. Different in appearance as these are in the adult stage,
yet the nymphal stages of all are alike and the nymphs are quite unlike the mature
crickets.

The endemicity of the species Banza {^Brachynietopd) is no doubt great, and no
one species has been found on more than one island, though it is possible that B. molo-
kaiensis and B. matiiensis of Molokai and Maui are really one species.

In the Prognathogryllidae, Prognathogryllus has not yet been found on Hawaii,
though it occurs on Maui, while Thaumatogryllus is only known from Kauai. The

ee2

ccxx FAUNA HAWAIIENSIS

species of this group appear nearly all to be confined each to one island only, though
Leptogi-yllus nigrolineatus has been found on Oahu and Maui and L. apicalis on
Molokai, Maui and Oahu, and it is possible that these two described species are really
only forms of one. L. forfictilaris occurs on Hawaii and in the western mountains
of Maui.

Review of Thysanura and Collembola.

Very few species of these interesting insects were observed by me in the islands,
and of these a single species oi Japyx, and two each of Lcpisma and Machilis only have
any claim to be considered indigenous. Campodea was only noticed in the mountains
in the vicinity of Honolulu, in the early years of my collecting, being generally found
in decaying stumps or beneath rotting logs. As it was subsequently noticed in the soil,
in which foreign plants were imported, there is no reason to doubt that the genus is an
importation.

Japyx was only collected very rarely on Kauai, living beneath logs in company
with the earwig Anisolabis perkitisi [ = A. pacifica, huj. op. olim). Of the two species
of Machilis, M. heteropus is an abundant species in the forests and is found beneath
bark of trees, amongst dead adherent fronds of tree-ferns, and in rotten stumps. Indi-
viduals are very numerous and vary in their colour pattern. M. perkinsi was only
found on Kauai.

Lepisma hawaiiensis is also only known from that island, where it was observed in
numbers under bark of forest trees. Another Lepisma occurs on rocks near the sea-
shore both on Oahu and Kauai. At least two species of the genus have been seen in
houses in Honolulu, where one at any rate is injurious to books and other articles.
Some minute Thysanura have been imported in earth containing ants' nests and are
now found established in the islands with these ants. One box of plants that I
examined a short time after its importation contained several ants' nests in the soil, and
many Thysanura infested the nests.

It is quite uncertain whether there are any endemic Collembola in the Hawaiian
group, as they are frequently imported with plants, and many have become established
and very widely spread. In some forest localities we have noticed that they have
become much more numerous than was formerly the case, and this may be taken as
evidence in favour of their foreign origin.

The single species of the Achoreutidae, Neanura citronella, was the only form
observed that struck me as likely to be endemic, since it was found beneath the bark of
native forest trees.

INTRODUCTION ccxxi

Review of Myriopoda.

Of the few Chilopoda other than those which are probably or certainly importations
by man, it is quite possible that Lithobms and Lamyctes, of each of which one species
has been described as peculiar, may contain other allied endemic forms. A second
Lamyctes forms a new variety of a North American species. In the Diplopoda a
species of Polyxcniis (Polyxenidae) and two of Aporodesminus (Cryptodesmidae), the
latter genus described as new, are of quite uncertain status. They have been found
amongst decaying leaves, etc., and are very probably importations. The most interesting
feature of the Myriopod fauna, as at present known, is the great development of species
of the genus Dimerogonus, elsewhere known from New Zealand, Australia and Chili.
Twelve species have been distinguished by Dr Silvestri in the systematic portion of
this work, and no doubt numerous others were not collected by me. They are
apparently most numerous on the intermediate islands of the group, as only one species
was collected by me on Kauai and none on Hawaii, though I believe I have since
found specimens on the latter island.

Several new additions have been made to the Hawaiian fauna through intro-
ductions by man of late years, and we have observed these creatures in boxes of
imported plants, when making inspection of these.

Review of Arachnida.

Excluding several undetermined species of quite recent introduction, the Spiders,
as at present listed, are represented by 105 species of which 81 are at present only
known from the islands. The endemicity of the species is, according to M. Eugene
Simon, greater than that known in any other country.

Of about forty families of spiders, 32 are altogether absent from the Hawaiian
fauna or are only represented by introduced or foreign forms. These latter are the
Sicanidae, Pholcidae, Clubionidae and Agelaenidae, and to these should probably be
added the Dysderidae.

The endemic fauna is therefore probably confined to the families Theridiidae,
Argiopidae, Thomisidae, Lycosidae and Attidae, or five families only, so far as present
information is concerned.

The Theridiidae are represented by five genera, none of them endemic, and one,
Teutana, is no doubt an introduction, while I suspect that Argyrodes comes under the
same category, one of its species being known to be foreign and the other probably is
so. The single species of Ulesanis is also subject to the same suspicion. Excluding
these we are left with a single remarkable species oi Ariamnes, and nine unquestionably
endemic species of Theridion, of which genus two introduced forms are present.

ccxxii FAUNA HAWAIIENSIS

The Aro-iopidae have lo genera, one of which, Erigone, contains only a single
foreign species, while two Microneta and Cnephalocotes also contain a single species,
each of which may prove to be foreign. Argiope contains a widely distributed species,
A. avara, with a peculiar endemic variety on Kauai, and is probably a comparatively
recent, natural immigrant. One species of Tetragnatka, T. mandibulata, which often
abounds in the sugar-cane fields, is introduced, the other species being endemic, as are
all the species of Cyclosa, excepting C. oculata and turbinaia, both foreign, and those of
Araneus excepting A. nauticus. The genera Priperia and Doryonychus are only
known from the islands.

The Thomisidae are probably the most interesting and important group in the
Hawaiian spiders. Three of the genera, Proernus, Pagiopalus and Adrastidia, form
an endemic group ' Proerneae,' and the genus Mecaphesa, with three species known, is
also endemic. Of the other three genera, Misinnena, Diaea and Synaeuia, all the
species are peculiar to the islands and no foreign forms have been recognized in the
family, though I believe I have noticed an introduced Thomisid in recent years.

The Lycosidae are represented by three genera, one of which, Syrolorna, is endemic,
as are all the species in the others.

The Attidae are represented by a number of endemic species of Sanda/odes, a
genus pertaining to the Australian region, and several imported species of other genera,
which of recent years have been added to by fresh introductions not yet determined.

The 8 1 species at present known only from the islands, represent 24 genera, seven
of these being themselves endemic, and it is worthy of note that the endemic species
contained in apodemic genera are generally highly peculiar forms, and that the endemic
genera are sometimes osculant forms, e.g. Syro/oma, which is a link between the Lyco-
sidae and certain Clubionidae, and the ' Proernus ' group of Thomisidae which forms a
link between these and the Clubionidae.

How far the species are restricted in their range in the islands is at present
uncertain, owing to the imperfect way in which the spiders have been collected. All
those obtained by me were collected while in search of various kinds of insects.
Extreme variability is exhibited by Araneus emmae, some species of Misumena, and
Diaea msulana. The habits of the Hawaiian spiders have been very little studied,
though some of the species are very numerous in individuals. Those of the genus
Theridion are as abundant as any, spinning their webs usually low down in the vegeta-
tion (e.g. across the narrow overgrown tracks made by man or beast through fern), in
the cavities of hollow trees, or in hollows in cliffs, etc. Argiope avara is one of the most
abundant spiders, its strong webs being often conspicuous on the telephone wires, wire
fences, etc., as well as amongst vegetation. Its peculiar variety is restricted to and
abundant on Kauai. The endemic species of Tetragnatka are not usually common and
are mosdy obtained from branches of trees, being much sought after by the native
Passerine birds. The species of Synaema, Misumena and Pagiopalus sometimes

INTRODUCTION ccxxiii

greatly resemble the surfaces on which they rest, viz. the lichen-covered boughs of
trees, and I suspect many of them are rare, since they are by their habits most subject
to the attacks of the many birds that hunt for food along the limbs of large trees.
Some species of Pagiopahis and Proernus are abundant, living at the base of leaves,
where these clasp the stem closely, or amongst dead leaves on growing trees.
P. atomarius has its eggs destroyed both by Dipterous [Lencopis) parasites, and by
those of an Ichneumonid, and the former are themselves destroyed by the Hymeno-
pterous Chalcid genus Eupelmns and by an Eulophid. The Thomisid spiders are,
doubtless, e.vtremely ancient inhabitants of the islands. As another Hymenopterous
genus, Baeus, containing excessively minute insects, parasitic in spider-eggs, also occurs
far in the native forests, some spiders are destroyed by these, though the particular
hosts have not been ascertained.

Of the Lycosidae species of Lycosa and Syrolonia are found beneath the bark of
trees, forming tubes of silk for their retreats. Possibly certain burrows formed in the
soil, the occupants of which are not known, belong to others of this group, of which
some species have been found amongst dead leaves on the ground. The native species
of the Attidae are often noticed hunting on the trunks or limbs of forest trees, and hide
themselves and nest beneath the bark. They are an important source of food-supply
for the native birds. Generally speaking it would appear that the native spiders, which
live on low vegetation near the ground, or in places not much investigated by the
endemic birds, are by far the most numerous in individuals.

Review of Mollusca.

The Mollusca', as listed in Vol. ii. p. 271 et seq. are 476 in number. These
represent 15 families, but of these, five (Philomycidae, Limacidae, Helicidae, Steno-
gyridae and Paludestrinidae) are unimportant, containing only species that are introduced
or possibly in a few cases immigrant.

The chief interest is attached to the endemic family Achatinellidae, of which there
are eight genera containing in all 311 species.

The Tornatellinidae contain 14 species of Tornatellina and 20 of Aur-iculella.
Twenty-seven species of Succinea (Succineidae) have been described, and the Endo-
dontidae are represented by 24, and the Zonitidae by 25 species. It will be seen
therefore that the great majority of species of land molluscs are contained in compara-
tively few genera.

' I was only able to devote very little time to the collecting of Mollusca, and a great deal of my
time was spent in localities, where these are very poorly represented. Only a very brief account of
these animals is here given, since they have been so much more studied by Dr Montague Cooke,
Curator of Mollusca in the Bishop Museum, and others than by myself, and many new species have
been described since Mr Sykes published his paper in Vol. 11. of this work.

CCXXIV

FAUNA HAWAIIENSIS

The earliest record of the existence of slugs in the islands, that I have been able
to find, is contained in the MSS. of one of the old bird collectors (Bloxam) who found
' slugs in the maw ' of Oreomyza, shot on Oahu near Honolulu. I suspect, however,
that this remark really applied to Siucinea, which is very rarely eaten by some birds.
We have never found Limacidae to be eaten by them, and the Philomycidae are
certainly of quite recent introduction. The species of Agriolimax and Amalia, though
some have been described as peculiar to the islands, have not the appearance (from
their distribution, etc.) of being native, but are probably all introductions by man.

The Zonitidae (with seven genera) were little collected by me. Godwinia tenella
was found at a higher elevation (9000 ft.) than any mollusc that I met with. The
Endodontidae are, no doubt, numerously represented by endemic species. Some of the
species are common beneath the bark of trees, and are particularly fond of Cheirodendroii.
Others occur beneath large decayed logs, or on the ground amongst decayed leaves.

Of the Helicidae the introduced Eulota is now widely spread and extremely
common in many places. It has been observed high up the mountains on Hawaii.
Papuina barnaclei is in the list probably on account of the specimens having been
wrongly labelled as to locality.

The very minute shells of the genus Ptipa of the Pupidae were not collected by
me. The species are numerous and often found in a sub-fossil condition.

Of the Achatinellidae, the sub-genus Achatinella, s. str., is found only on Oahu, as
also is Bulimella, both with numerous species or at least local forms. Parhihna is
entirely confined to the three adjacent middle islands, Maui, Molokai and Lanai,
excepting that the aberrant species A. (P.) dubia is found on Oahu, and two or three
aberrant forms, for which a distinct sub-genus {Ba/diuinia) has been proposed, are
peculiar to Hawaii. Acliatinellastruvi is chiefly developed on Oahu, but also occurs on
Maui, and is barely represented on Molokai. The distribution of these sub-genera is
of great interest.

• The beautiful shells of Achatinella (s.l.) have been so much studied and collected by
others that it is not necessary for me here to make any lengthy remarks. Practically
all the species, except on rare and probably accidental occasions, are of arboreal habits.
They are found on leaves, branches or trunks of the forest trees, and individuals of a
species are frequently not at all particular as to what part of the tree they frequent, nor
as to the species of tree. They are often found numerously on quite dead trees, and in
many places are abundant on those imported by man, especially the guava, and even
on Lantana camara. The Myrtaceous 'Ohia' being the dominant forest tree probably
contains more of these shells than any one other species of plant. It is doubtless due
to the fact that the Achatinellas do not feed on the trees themselves, but on the small
organisms that grow on these, that they are found on so many native and foreign plants.
Great diversity of opinion exists as to the limits of the species of Achatinella (s.l.) and
a very great deal of special breeding will probably be necessary before these limits can

INTRODUCTION ccxxv

be fixed. It is quite certain that a very large number of the forms, that have been
described as distinct, are not true species in the same sense that the majority of the
species of insects are. On the whole the phenomena of variation in Achatinella are
rather different from those exhibited by the variable forms of insects, but these are
probably explicable by the very stationary habits of the Mollusca, and the difference
between the two groups is rather of degree than of kind. On the other hand, I think
it probable that a good many of the forms of Achatinella, which differ very little in
appearance or structure, are absolutely distinct species. In this they are quite paralleled
by many insects, for we know that in these, perfectly distinct species are sometimes
separated by characters apparently much smaller than those exhibited by the extreme
varieties of other species. There are numerous cases in insects where one particular
variety of a very variable species has its peculiarities exactly reproduced as a constant
specific character of an allied species, and I have found, as I interpret the species,
exactly similar cases in Achatinella. But in the insects the complexity of structure
allows us to be certain of the real specific distinctness of such forms, owing to structural
differences that exist to confirm it, whereas the Mollusca (at least as studied from the
shells) are very poorly endowed with structural characters, on which to base specific
distinctions, as compared with even the most simple form of insect, and one is obliged
to place more or less faith in colours and patterns of colour. In many groups of
Hawaiian insects such characters, if relied on for discriminating species, would lead to
hopeless confusion.

It has always been a tradition with the natives that the Achatinellas are able to
sing or produce musical sounds, but I know of no confirmation of this excepting the often-
quoted observation by Barnacle. Though I have lived for weeks in spots where shells
were to be found on the trees immediately surrounding my camp, I have never heard
any such sounds. So confirmed were the natives in their opinion, that the song of the
land-shells was even put to words. An old native, whom I once had with me in the
mountains of Oahu, one night called my attention to the song of a land-shell, but I
actually found the creature, a species of small cricket {Paratrigonidium) that was
making the sounds. Though the motions of the elytra in producing its song were
quite visible, he utterly declined to believe that it was caused by the cricket, and
persisted that it was due to a land-shell. I would suggest that what Mr Barnacle
heard (making allowance for an exaggeration in description) was the stridulation of
crickets beneath the bark of a tree, where they often congregate, and what he saw was
a group of Achatinella on the bark. Several natives have informed me that the real
singing shells were found especially on the ' Ki' plant [Cordyline), and it is certainly
curious that this same plant is a favourite home of the larger green crickets of the
genus Banza.

The bright coloration of the Achatinellas, especially of many of the banded forms,
is of some interest, because it reminds one so strongly of many other animals, in which
a somewhat similar strong contrast of colours is supposed to produce the effect of
F. H. I. ff

ccxxvi FAUNA HAWAIIENSIS

rendering the creatures less visible, and to be of value for protective purposes. Utterly
conspicuous as the shells appear when removed from their surroundings, it is quite
certain that, in spite of their bright colours, they are by no means so when resting on the
leaves or branches of trees, except for occasional specimens in incongruous positions.
This is quite evident from the fact that a skilled collector, with very practised eye in
discovering these shells, will go over the very same trees that have just been well
searched by one less accomplished and gather an astonishing number of shells from
these. The remarkable fact is that though these colour patterns must have been
developed on the spot, the Achatinellas would not appear to have had any need for
concealment. Not even once were these shells ever found within birds, nor seen to be
eaten by them, and it is astonishing that the thrush genus Phaeornis should not have
availed itself of such an abundant source of food. It is true that the introduced rats,
imported by man, feed eagerly on these Molluscs, so much so that I have gathered a
hatful of empty shells of Achatinella tesselata at the foot of a single hollow tree, into
which the rodents had carried them. But these cannot be supposed to have been a
factor in determining the colour patterns. Similarly we find the terrestrial Achati-
nellidae of the genus Atnastra all of dull colours and in strict harmony with their
environment, these being equally neglected by birds, but devoured by imported rats.
Either, therefore, from some unknown cause these land Mollusca become adapted m
colour to their environment, or if these colours have been modified and controlled by
causes elsewhere supposed to be efficient, this must have taken place in past ages and
under different faunistic conditions. In the latter case it would be natural to consider
the coloration, as having been determined by the ancestors of the existing species of the
thrushes [Phaeornis) from the Kauai form of which, on one occasion, a minute Helicine
shell was obtained by dissection. Further observations on Lanai and Molokai may yet
prove that these birds do still on occasion feed on Achatinellas ; but the numerous
young and old birds that I examined at various seasons gave no evidence of this, and
further we are perplexed by the entire absence of Phaeornis from Maui, unless we
suppose the genus to have once existed there and now become extinct, as we know to
be the case with the Phaeornis oahuensis on Oahu.

The other genera of Achatinellidae (i.e. the true genera as distinguished from the
sub-genera of Achatinella itself, above mentioned) are of no less interest.

Perdicella is a comparatively small genus of prettily marked arboreal shells.
P. helena is an abundant and variable species widely distributed on Molokai, but most
of the known forms appear to be rare or very local. It is found on the leaves of Ki,
Ohia and various other plants. P. niinuscula, recorded on my specimens as being found
on Molokai, must, I think, have been wrongly labelled, since 1 observed a species of
Perdicella in numbers on Urticaceous plants in the lao valley, Maui, on one occasion,
and collected specimens. The genus is restricted to Molokai and Maui.

The elongate shells of the genus Newcombia are also restricted to these two
islands and almost to Molokai. A^. cinnamomea and allied species are found on the

INTRODUCTION ccxxvii

trunks and branches of 'Pua' trees [Olea sandwichensis) and are very well concealed
and not very likely to be noticed unless specially sought for.

Atnastra with loi and Lepfachatwa with 76 species are the genera most widely
distributed, species occurring on all the islands, though Kauai and Hawaii at either end
of the group are comparatively poor in species. The species of Amastra {s. s.) are
essentially terrestrial and found beneath and in cavities of rotten logs and tree-ferns,
under stones, in decayed stumps, in the hollows and crevices of hard logs, and amongst
decaying vegetable debris, in damp places in the forest. On Kauai (though not peculiar
to it) the smaller sub-genus Aviastrella is dominant. Here too are the two most re-
markable forms of the small sub-genus Kauaia. The species of the sub-genus Laviinella
are of great interest from their habits, being transitional in these between Achatinella
and Amastra (^s. s.'). They are largely of arboreal habits, many of them being found
especially on the trunks and dead branches of trees even at a considerable height; they
have the habit of smearing themselves with mucus, to which fragments of debris
become attached, so that they closely resemble the surface on which they rest. Some
of the species are particularly fond of Urticaceous plants and may be found on the
leaves of these as well as on the trunks. L. gravida is sometimes found in great
colonies on the fronds of soft-leaved ferns. L. depicta is abundant in the highest
boggy forests of IMolokai on the leaves of Astelia, above the range of other Achati-
nellas, and there is an allied species in similar localities on the \V. Maui mountains.
The small shells of the genus Leptachatina resemble those of Amastra {s. s.) in their
habits and are often found in company with the latter. L. arborea is common on trees
on Hawaii and of wide distribution, and even occurs on the leaves of JMyoporum in the
higher forests, above the rain-belt.

Thaamwiia omphalodes is a remarkable development o^ Leptachatina, and apparently
very rare. I have never met with it.

Carelia, containing the largest Hawaiian shells, is peculiar to Kauai, though it
formerly existed also on Niihau. Living specimens are now scarce, but in some parts
of the lower forests of Kauai many dead ones (mostly broken) were noticed, in witness
of their former abundance. In some of these localities they were accompanied by many
dead shells of Kauaia and the remains of the large weevils of the genus Rhyncogonus,
all species still existing, but rare.

Of the Tornatellinidae the very minute shells of the genus Tornatellina are very
numerous and occur on all the islands. They were only casually collected by me and
are doubtless very numerous in species. Some species occur quite outside the forest,
at low elevations.

Auriculella is very abundant on Oahu, species and individuals being numerous.
They are variable not only in colour, but in the fact that some of the species have either
dextral or sinistrorsal shells. Colonies of a species differ greatly in this respect, even
when found at no great distance from one another. Of one species a large number
of examples taken together had about 50 per cent, dextral and the same number

ccxxviii FAUNA HAWAIIENSIS

sinistrorsal, while a near-by colony had only two per cent, of the one form. They
are arboreal in their habits and, making allowance for their small size, they appeared to
me much more conspicuous than the Achatinellas.

The Succineidae are found throughout the group, but are dominant on the large
island of Hawaii. Twenty-seven species of Succinea were enumerated by Sykes, but
the limits of the species appear to be even less definite than in the Achatinellas. The
Succineae are able to thrive under the most diverse conditions of climate, though
probably best developed in the true forest-belt. Some species are common in the open
country at elevations of about 5000 ft., where there is little permanent moisture, and
some even abound on the hottest and driest coasts. In many parts of Hawaii both the
surface of the ground is covered with their empty shells and the humus filled with
these, while on other of the islands, where now they are less numerous, there are great
deposits, mixed with the shells oi Amastra, Leptachatina, and various other living genera.

The other families of Mollusca are comparatively of little importance, but it may
be mentioned that Limnaetis pereger is the species of fresh-water snail, in which Dr Lutz
found the Redia of the Liver Fluke.

Remarks on Vermes.

xA.lthough a considerable number of species of earthworms was collected by me at
various stations, often very remote from settlements, throughout the islands, I believe
that all these are importations by man. On several occasions boxes of earth containing
growing plants were examined, when they were landed from steamers arriving in
Honolulu from China and Japan, and were found to contain great numbers of very
lively and healthy earthworms. Some of these were preserved and found to be identical
specifically with species that now are found far from settlements in the mountain forests.
Some earthworms were specially collected in the most out-of-the-way forests in boggy
places, where nearly every animal was endemic, but these proved to be only well-known
foreign forms, such as AUolobophora foetida, etc. As plants have been imported
continually into the islands both from America and the Oriental region for the course
of a century, there has been ample time for foreign worms to become very widely
distributed. Of late years it has been illegal to introduce plants in earth, for economic
reasons, in order to keep out insect pests, so that the number of species that now occur
(and doubtless some have been introduced since I made my collections) may not be so
quickly added to.

The Entozoa recorded from the islands are of no interest faunistically, excepting
the remarkable Apororhynchus heviignathi, taken from the Drepanid bird Hemignathus
procerus on Kauai, and forming the endemic family Apororhynchidae of the Acantho-
cephala, and Drepanidotaenia he)nignathi, belonging to an apodemic Cestode genus,
with the same host. Another tapeworm was found in another Drepanid bird, Loxops
caeruleirostris. It is curious that no Entozoa were noticed in birds excepting on Kauai.

NOV 2i, 192,

H. S. Battler,
0. S. NationtJ Museum,
Wuhington, 0. C.

FAUNA HAWAIIENSIS

VOL. I. PART I.

HYMENOPTERA A CUEEA TA

R. C. L. Perkins.
Prof. Aug. Forel.

Price Sixteen Shillings.
To Subscribers Eight Shillings.

The Fauna Hawaiiensis will be published in parts at irregular inter-
vals, and will it is hoped be completed in about two years.

Contributions have been made or promised by the following, viz.

F. E. Beddard, F.R.S.

Prof. AUGUSTE FOREL

Dr L. O. Howard and W. H. Ashmead

G. W. Kirkaldy, F.E.S.
Sir John Lubbock, F.R.S.
E. Meyrick, F.Z.S.

R. C. L. Perkins, B.A.

R. I. POCOCK

D. Sharp, F.R.S. ...
A. E. Shipley, M.A.
M. EuG. Simon

E. R. Sykes, F.Z.S.
The Lord Walsingham, F.R.S.
Mynheer F. M. van der Wulp

Earthworms.

Formicidae.

Hymenoptera Parasitica.

Heiniptera.

Thysanura and Collembola.

Macrolepidoptera.

[Hymenoptera Aculeata, Orthoptera,
\ Neuroptera, and part of Coleoptera.

Myriapoda.

Part of Coleoptera.

Parasitic Worms.

Arachnida.

Mollusca.

Microlepidoptera .

Diptera.

It is also intended to give a list of the Vertebrates, with their distribution,
in the Islands.

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FAUNA HAWAIIENSIS

OR THE

ZOOLOGY OF THE SANDWICH (HAWAHAN) ISLES

Being Results of the Explorations instituted by the Joint Committee

appointed by

THE ROYAL SOCIETY OF LONDON FOR PROMOTING NATURAL KNOWLEDGE
AND THE BRITISH ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE

And carried on with the assistance of those Bodies and of the Trustees of

THE BERNICE PAUAHI BISHOP MUSEUM AT HONOLULU.

EDITED BY

DAVID SHARP, M.B., M.A., F.R.S.

SECRETARY OF THE COMMITTEE.

VOLUME I. PART I.

HYMENOPTERA ACULEATA
By R. C. L. PERKINS, B.A., and Professor AUGUSTE FOREL.

Pages I — 122, Plates I, II and Map.

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INSCRIBITUR.

I. HYMENOPTERA ACULEATA\ *'"'•' a"-

§ 1. General considerations on the Aculeata.

The Aculeate Hymenoptera of the Hawaiian Islands form an important part of
the fauna, nearly 200 species being at present known. Each of the large divisions
of the group, excepting the Heterogyna or Ants, is represented by many endemic
species. The Fossores include 34 species, divided between four sub-families ; the
Diploptera are well represented by 88 species in two sub-families, the Anthophila or
bees by 56 species in three sub-families. The total number of species in these
groups as represented in the islands, is therefore 1 78, but of these some are known
to have been introduced in recent times from other countries, while others from
various kinds of evidence we can be tolerably certain are also to be regarded as
having been imported by man. To arrive at a true understanding of the peculiarities
of the fauna, it is necessary to consider each family in detail.

i. In the Fossores the Sphegidae are represented by a single species of Pelopceiis,
an American insect, known to have been introduced.

The Trypoxylonidae have two species of the genus Pison. Although both of
these were described from the islands yet one of them is also known to inhabit
Fiji. It is an abundant species, generally being found about houses, and nests in
the woodwork of which these are built, and is never found at any great distance
from towns or settlements. The second species was found only in Honolulu some
twenty years since. There is little doubt that both these species are importations,
and I suspect that P. iridipennis after arrival has failed to establish itself.

The Mimesidae have 10 species divided equally between two genera, both of
which are endemic. The two genera are certainly allied, and have probably arisen
by divergence from a common ancestor, and evolved species side by side, the one
not being a direct off-shoot of the other.

The Crabronidae are represented by 21 species in two genera, of which one
containing 6 species is endemic, as also are all of the 21 species. It is probable
however that the 15 endemic species now referred to the sub-genus Solenius of

' By R. C. L. Perkins; except Heterogyna (or Ants): this is by Prof. Aug. Forel of Ziiricli.
Hymenoptera Parasitica has been undertaken by Dr L. O. Howard and Mr Ashmead, of Washington.
There are no Hymenoptera Sessiliventres in this Fauna.

P. F. H. I

2 FAUNA HAWAIIENSIS

Crabro, will themselves ultimately form one or more peculiar genera, the species
being closely related to one another, and also to the endemic genus Nesocrabro.

Putting together the results of this analysis it will be seen that the foreign element
includes 3 species of two genera, representing two sub-families, two of the species
and both genera being known from elsewhere, while the third species has only been
taken in the city of Honolulu, a fact which alone would mark it as foreign. This
gives an average of i '5 species to the genus. The endemic species also represent
two sub-families, with four genera, and 31 species. Three of the genera are endemic
and all of the species, and there is an average of 775 species to a genus.

ii. In the true Wasps, or Diploptera, the Vespidae have two species of Polistes,
both foreign forms, and known to have arrived since the settlement of white men
on the islands. There is no doubt that both were introduced by man, and it is
remarkable that a parasitic Stylops should have been brought with them.

The Eumenidae are represented by the single genus Odyneriis, which is extremely
rich in species, no less than 86 distinct species having occurred. All the species are
endemic and form a most remarkable assemblage, exhibiting a great variety of form,
although all belong to one section of the genus. Some of the species might readily be
separated as distinct genera, were this course advisable, so great are their peculiarities,
but as this would still leave the bulk of the species in Odynertis, and dissociate what
appears to be really a natural series, it seems better to leave them intact, until they can
be separated as a whole.

iii. In the Anthophik, or Bees, the Obtusilingues have 52 species all belonging
to one genus, which, so far as is known, is endemic. These again form a remarkable
series, and some of the species at first sight would hardly be recognized as belonging
to the section to which they are assigned. Nevertheless when studied as a whole
they are seen to be intimately related to one another, widely different as the extreme
forms of the series may appear.

The Acutilingues are very poorly represented by a single Xylocopa, known to
have been imported, and three species of Megachile, two of which are recent introduc-
tions, although not identified from elsewhere. They have greatly increased in numbers,
and extended their range over the islands during the last few years. The third species
is very possibly endemic, and is probably becoming scarcer, being now a rare insect,
or at least excessively local.

Thus of the Fossores, Bees, and Wasps together, there are 170 endemic species
in 7 genera, four of the latter being also endemic, with an average of over 24 species
to a genus, while there are 8 introduced species representing 5 genera, giving an
average of less than two species per genus.

The arrival of Megachile in the islands, presuming that M. diligens is really an
endemic species, was no doubt very recent, compared with the remote periods at
which the first representatives of the Fossores, Odyneri and the blunt-tongued Bees

HYMENOPTERA 3

reached them. Yet both Dipterous insects and Lepidoptera must have been well
established before the arrival of the predatory wasps. The Megachile amongst the
endemic aculeates occupies a position similar to that of the solitary species of Coi~uus,
and Buteo amongst the endemic land-birds.

iv. The Heterogyna, or Ants, form a striking contrast to the other groups of the
Aculeata. Twenty species are at present known, and these are distributed amongst
twelve genera. Nearly all of these are to be found most numerously in the
neighbourhood of houses, although some have now spread very widely over the
country, and still are spreading. The only one that has any claim to be considered
endemic is a species of Pone?-a, {P. perkinsi), which is found only in the mountain
forests under logs, and beneath the stones on the margins of the mountain streams.
Two other species are not at present known from elsewhere, but of these one, (a
Prenolcpis), is known to have been introduced in boxes of earth containing plants,
and the other {Poncra kalakanae) has been only taken near settlements, where endemic
insects were absent, and it also occurs in the middle of the city of Honolulu. Of
the rest, several species form races now described for the first time, but as the e.xact
locality whence they have been imported is unknown, it is quite uncertain whether
these races have been formed since the time of their importation. We have known a
single box of imported plants to contain the winged sexes of three different species
of ants. It is not unlikely, however, that the Lcptogeiiys is a natural immigrant,
and has arrived in drift-wood, for it frequently nests in the interior of tree-trunks,
or beneath tightly-fitting bark. The Ponera, which is alluded to above as being
probably endemic, may be classed with the endemic Megachile, as a recent form
compared with the rest of the native Aculeates.

Insular endeniicity. The species of Megachile that is probably endemic has been
found on several of the islands, and the endemic Ponera is also distributed over the
whole group. Excluding the non-endemic species (amounting to about 27), the two
species just mentioned and five Odynerus the localities of which are unknown, there is
still left a total of 164 species of endemic Aculeata.

The proportion of peculiar species to the total number found varies greatly in
the case of the different islands, as shown in the followinor table.

Pecul

iar species

Total

of species

Percentage

of peculiar species

Kauai

30

33

90-9

Oahu

22

33

66-6

Molokai

10

38

26-3

Maui

17

49

34'6

Lanai

2

26

7-6

Hawaii

44

54

8 1 '4

Thus Kauai stands easily first in the peculiarity of its species, and it may further

I — 2

4 FAUNA HAWAIIENSIS

be remarked, that in the case of two of its three species which are found also on other
islands, the Kauai form is by no means identical with that occurring elsewhere, but
exhibits well-marked variation. Hawaii with far the largest area of any of the islands,
has the greatest number of species, and ranks next to Kauai in the proportion of those
peculiar to it. Maui with the second highest total of species has a much smaller
proportion of peculiar ones than Oahu. In general the more remote is a given island
from its neighbours the greater is the peculiarity of its fauna. The fact that Hawaii
and Kauai are placed at either end of the chain of islands would tend to increase the
endemic at the expense of the total number of their species, since they give and receive
emigrants in one direction only. It is true that the island of Niihau lies to the west
of Kauai, but it is a small and unimportant island with no considerable mountains, which
can never have possessed more than a scanty fauna, and being now a pasturage for
sheep was not visited by me. The Aculeata of the three adjacent islands Maui,
Molokai and Lanai are much more nearly related, and a large number of species are
common either to two, or to all of them. The mountains of West Maui yield some of
the species which otherwise are quite peculiar to Molokai. That Maui surpasses
Molokai in the number and in the peculiarity of its species is due to the much greater
size and much more varied conditions of the former island. Its two widely separated
mountain masses each yielding peculiar species, the great elevation of Haleakala, of
which the region above the forest-belt has a special fauna, and the extensive low
sandhills, dividing its eastern and western mountains, and favourable for Hymenoptera,
give it a great advantage. Hawaii, as might be expected from the extreme difference
in climate between the leeward and windward sides, and the very great height of its
mountains, is very rich in species, and its position is favourable for a high percentage
of forms peculiar to it. Oahu has the advantage of two separate mountain-ranges,
each with some peculiar species, but the mountains are only of moderate height.
Only two of its species are the same as those of Kauai, but it has seven identical
with those of the less distant island of Molokai. Apparently not a single one of
the species tabulated above extends its range over the whole group, although two
or three are found on all the islands from Oahu to Hawaii.

With regard to the affinities of the endemic Hawaiian species, with those of other
countries I think, in the present state of our knowledge, that there is little to be
said. F. Smith expressed the opinion that they were most nearly related to the North
American aculeates. Probably he based this opinion partly on the occurrence of certain
well-known American species (of Xylocopa, Polistes, Pelopceus), and partly on the state-
ment of de Saussure that certain of the Odynerus belonged to groups found in
N. America. As I have mentioned above those American species that are known
to occur also in the islands, have certainly been introduced by man, and therefore
cannot be taken into account in deciding the affinities of the fauna. De Saussure's
opinion on the Odyneri is open to suspicion, because he assigns the Hawaiian species

HYMENOPTERA 5

that he examined to several of his groups of American Odynej'us, whereas after an
examination of the complete series of species described in this work, it appears that these
are in reality intimately related to one another. As a matter of fact the Aculeata are a
group but ill-adapted for throwing any light on the derivation of the Hawaiian fauna.
Odynerus, the most numerous in species of this group, is a genus almost ubiquitous over
the world, with vast numbers of species described, and no doubt vast numbers still
uncollected. Although these display an extraordinary diversity of form and appearance,
they have so far defied any satisfactory classification. The Crabronidae are almost as
unsatisfactory, and have been certainly still less completely collected. Nevertheless the
fact that the Hawaiian species all belong to one of the sections, in which the males are
remarkable for their 12-jointed antennae, will no doubt greatly aid ultimately in deciding
their affinities. The Mimesidae likewise are a widely distributed groujs of obscure
insects, but little collected. The bees of the genus Prosopis, from which I have now
dissociated the Hawaiian species under a new generic name, are of world-wide distribu-
tion, and are peculiarly difficult to study, and certainly great numbers of existing species
are still unknown. The structure of the terminal (concealed) abdominal segments of
the male is of paramount importance in this group, yet they have been entirely ignored
in the majority of species described. These structures in the Hawaiian species are very
distinctive, and differ greatly from such American and European Prosopis as I have been
able to dissect, and I suspect that the affinities of Nesoprosopis will prove to be rather
with the species of Prosopis found in New Zealand or Australia than with the others.

So far as one can judge from a study of the relationship of the endemic species to
one another, all the Mimesidae, Crabronidae, Eumenidae, and the Bees of the genus
Nesoprosopis could have been evolved from four species which reached the islands at
some very remote period, one of the four species of course representing each group.
The total absence of any representative of so many groups of the Aculeata, certainly not
less fitted to pass over the great distances between the islands and other lands, and for
which the country is admirably adapted, is a point greatly in favour of the view that the
numerous species of each of the families represented arose from a single immigrant
species, and the examination of the structures of the species themselves greatly supports
this view. How rarely an immigrant can have arrived from without, can be judged
from the great number of species which fail to cross the short distances between the
islands themselves.

In the fragmentary condition of their Hymenopterous fauna the Hawaiian islands
considerably resemble New Zealand, but in the case of the latter country it is less
extreme. At the present time the Aculeata of New Zealand have been too much
neglected to make any detailed comparison of value, but few species of this group
having been collected there.

An important fact in connection with the Hawaiian species is their variability.
This is most noticeable in the Bees, Crabronidae, and Mimesidae, a great many of the

6 FAUNA HAWAIIENSIS

species in these groups being in a very unstable condition. The variation is not
confined to differences in size, colour, &c., but affects important structures, in which
it is unusual to find any noticeable variability, and to this is due the extreme difficulty
of determining and describing the numerous species, the specific characters frequently
having to be taken from structures which are obviously variable.

In striking contrast with the groups above mentioned are the species of Odynerus.
Very few of the 86 species exhibit any variation of note, and this when it occurs is nearly
always of an unimportant character (e.g. colour). From this one would infer that the
Odyneri have now reached the maximum of species that the islands can support, in the
present condition of the Lepidopterous fauna, on which, as they prey on caterpillars,
they are dependent. The Bees on the other hand are not similarly restricted, for
with flowers abundant at all seasons, the islands so far as one can see, are capable of
supporting much greater numbers of these than of Wasps. The Fossores, which
like the wasps are predatory, living on Dipterous insects, are very variable, but the
total number of species of these is insignificant compared with that of the Odyneri.

The coloration of the Aculeata of the islands is very remarkable. No one
examining an extensive collection of these could fail to remark the general blackness of
these insects. In the majority of the endemic species the wings are dark, with blue,
violet, or purple iridescence, and such species are found in each division of the group,
and in every genus. For this reason many of the Fossores, Bees, and Wasps, when
on the wing, greatly resemble one another and can hardly be distinguished except by
differences in their flight. It is not probable that this similarity of appearance has any
protective significance, for some of the species which are clear-winged and of ordinary
appearance are amongst the most abundant, and birds which alone could be their
enemies, neglect both alike.

In the case of the genus Odynerus the coloration of the species presents some
remarkable features. Thus excepting one coast species, all the Kauai forms are
similarly coloured, having two white or yellow abdominal bands. On all the other
islands only a very few species are found with these markings, and in general the
bands, when they occur, are much less conspicuous. In spite of the identity in
general appearance of the Kauai insects they are often structurally very remote from
one another. Thus O. nigripennis, a black-bodied Wasp of large size, found on all the
islands from Oahu to Hawaii, is represented on Kauai by O. radida, with the yellow
bands characteristic of the species inhabiting that island. Again O. keterochrojims, a
black species found on Hawaii and very remote structurally from O. nigripennis, is
also represented on Kauai by a species with two yellow bands, and so on in other
instances. On Molokai a very large number of species have red markings. Two
species found in company on Oahu, O. oa/mensis, and O. psendochromtis, are excessively
alike in superficial appearance, and unlike any other species, being both remarkable for
their hyaline wings, and peculiar red markings ; yet structurally they are not allied to

HYMENOPTERA 7

one another. It might be supposed that the local peculiarities of coloration have
a protective value, but as I have pointed out in the Proceedings of the Cambridge
Philosophical Society all the .evidence is opposed to this view.

Another noteworthy point about the endemic aculeates is the general feebleness
of their sculpture. Of the large number "of species of Odynei-iis there are certainly
a good many in which the puncturation is strong and even coarse, but in many it is
very feeble or nearly entirely effaced. The bees are nearly all remarkable for their
fine and shallow puncturation, as also are the Mimesidae, while in the Crabronidae
the general tendency is to effacement of the sculpture.

The literature relating to the Hawaiian aculeata is as follows: —

Fabricius, Eiit. Syst. 11. p. 269.

De Saussure, Etud. fani. Vesp. iii. Mon. Masar. et Suppl. p. 289.

Smith, Cat. Hym. Ins. i. p. 23. Id. op. cit. iv. p. 421.

Holmgren, Eugenies Resa, Zool. vi. p. 441.

Smith, J. Linn. Soc. xiv. pp. 674 — 6S5.

Blackburn and Kirby, Ent. Mo. Mag. xvii. pp. 85 — 89.

Cameron, Trans. Ent. Soc. 1881, p. 562.

Blackburn and Cameron, P. Manchester Soc. xxv. (Session 1885 — 86), pp.
134—176.

Dalla Torre, Wien. Ent. Zeitg. viii. {1889), p. 124 et seq. (also Cat. Hym.
Ins. passim).

Perkins, Pj'oc. Phil. Soc. Cambridge, Vol. ix. Part vii. (1897), p. 378.

Altken, Ent. Nachr. xxiv. (1898), p. 340.

§ 2. Systematic account of the Hymenoptera Aculeata,

FOSSORES.

The Fossorial Hymenoptera of the islands are represented by only six genera,
and of these probably two have no place in the autochthonous fauna. All the
genera belong to that section, which comprises the insects with short prothoraces, and
they represent four distinct sub-families. The truly endemic species however belong
entirely to the Mimesidae and Crabronidae, and all prey on Dipterous insects; the
members of the former family, so far as I have observed, provisioning their cells
invariably with species of Tipulidae, while those of the latter prey not only on
these, but also on other Flies. In some cases at any rate a species of Crabro will
take Flies of very different species, by no means confining its attention to the
capture of one particular kind. Some of the species of this genus are very
abundant, and may sometimes be seen in great numbers around a dead animal, to
which they are attracted by the abundance of their prey.

8 FAUNA HAWAIIENSIS

Sphegidae.

(i) Pclopceus cae7ftentarms.

Sphex caementaria, Drury, Exot. Ins. i. p. 105.

Pelopcejis caemetttarius, Blackburn and Cameron, P. Manch. Soc. xxv. p. 173.

Hab. Very abundant all over the islands, but not extending to great altitudes
on the mountains. An introduced species, common in North America. Preys on
Spiders.

MiMKSIDAE.

The Hawaiian Mimesidae form two distinct genera, the females of which are
very unlike one another, but the males in some cases can only be distinguished by
slight characters. In the genus Nesoviimesa the males of the several species are
excessively difficult to separate, but the females afford better characters. All the
species are remarkable for the feebleness of their thoracic sculpture. The genal
spines of the ?, although subject to excessive variation in most species, nevertheless
afford useful characters, as also does the condition of the surface of the anterior area
of the propodeum, and the colour of the spines of the anterior tarsi. In the genus
Deinomiinesa also the females afford the better characters. These are chiefly found
in the form of the clypeus, but the carinated pedicel of the basal abdominal segment,
although variable in structure in some species, is of considerable assistance in the
determination of the species. The Hawaiian species of the family, so far as they
have been observed, prey entirely on Tipulidae. They usually burrow in the ground,
but have occasionally been seen entering burrows in dead trees.

Nesominiesa, gen. nov.

Forma gracili, elongata, capite a fronte transverso. Palpi maxillares longi, pilosi,
articulo 2° et 3° fortioribus, 4° elongate lateribus parallelis, 5° forma praecedentis sed
longiore, 6° perlongo et gracillimo. Palpi labiales articulo apicali perlongo. Antennae
longae, cT evidenter, ? subfortiter clavatae. Tibiae posticae spinis brevibus armatae.
Tarsorum articulus apicalis ? in basali parte spinis utrinque fortioribus armatus, ad
apicem spinis longis, gracillimis. Abdominis segmenti primi pars petiolata parte apicali
evidenter longior. Armatura genitalis </ duabus appendicibus angustis et elongatis
apice instructa. Caput ? utrinque spinis genalibus armatum ; area pygidialis triangu-
laris, punctata, setis decumbentibus vestita.

Allied to Miviesa, having a similar neuration. Both sexes have long clavate
antennae, but the thickening of the apical joints is more pronounced in the ?.
The third joint is much longer than the fourth, which is about equal in length

HYMENOPTERA 9

to the scape. In the % the cheeks beneath are prolonged into a large spine,
which differs in form in the different species, and is very variable in examples
of the same species. This sex is also remarkable in having the last joint of the
tarsi armed on either side towards the base with somewhat stout spines ; at the
apex there are longer and very fine ones. The pygidial area is flat, punctured,
and carinated at the sides, and bears appressed setae of a spinose character, which
give it an appearance of being strigose. The stipites of the </" genital armature
are rounded at the apex, and there bent inwards, and fringed with hairs ; a little
before the apex they each give off a long thin process, set with short hairs, and
the one crossing the other. The spine of the apical ventral segment is long,
strong, and slightly curved upwards.

(i) Nesomimesa kauaiensis, sp. nov.

Nigra, elongata, antennarum articulis apicalibus subtus, tarsisque d" anterioribus
plus minusve pallidis ; clypei cT margine antico plus minusve distincte tridentato ;
genis ? post oculos in spinam validam productis. Alae subinfuscatae. cf ? . Long.
8'5 — 13 mm. (Plate I. figs, i — i c.)

Male black, the front tarsi testaceous, the apical joints of the antennae pale
beneath. Clypeus with dense silvery pilosity, its apical margin more or less distinctly
tridentate. Antennae long, subclavate, extending back as far as the apex of the
basal segment of the abdomen, the third joint considerably longer than the scape.
The front and vertex of the head are dull, without evident puncturation. Mesothorax
less dull than the head, with very feeble scattered punctures, the surface with an
exceedingly fine reticulation of raised lines ; wings more or less infuscate. Anterior
area of the propodeum smooth except for the minute surface sculpture (which is like
that of the mesothorax), not defined by a raised line, but rendered distinct by the
absence of the pubescence which covers the rest of the propodeum. Spines of the
front tarsi pale. Abdomen impunctate or nearly so, the petiole long and narrow,
much longer than the apical part of the segment, usually rounded above at least
on its basal portion, but somewhat compressed in some examples.

Female generally larger and more robust than the t/, but with similar sculpture.
The apical joints of the antennae more or less fulvous beneath. Head large and
wide, mandibles very long, the anterior margin of the clypeus angulately produced
in the middle, the cheeks behind the eyes produced into a strong spine, which
continues their outline, the antennae more strongly clavate than those of the </, their
third joint very long and slender. Anterior tarsi with much longer pale spines, and
the posterior and intermediate tibiae and tarsi with the spines much more strongly
p. F. H. 2

lo FAUNA HAWAIIENSIS

developed. Apical dorsal segment of the abdomen carinated at the sides, punctured,
clothed with appressed hairs, which give it a strigose appearance.

Hab. Kauai (2500 — 4000 ft.); common, burrowing in the hard ground in bare
spots in the forest.

(2) Nesominiesa sciopteryx, sp. nov.

Praecedentis forma ; alis totis piceis, clypeo subtiliter griseo-pubescente distinc-
tissima. ?. Long. 1 1 mm.

Female very like that of the preceding in form. The wings are entirely of a
pitchy colour, and have a slight violet iridescence. The face below the antennae
is clothed with a fine greyish pubescence, instead of the appressed silvery pilosity
of all the other Hawaiian species. The posterior calcaria are testaceous, and the
petiole of the abdomen is stouter, and its dorsal surface more strongly curved.

Hab. Halemanu, Kauai (4000 ft.) ; very rare, i ? only taken.

(3) Nesomintesa antennata.

Miniesa antennata, Smith, Cat. Hym. Ins. iv. p. 431.

N. kauaiensi simillima ; % spina genali ad basim contorta, </ clypei margine
apicali haud evidenter tridentato distinguendus. cT tarsis anticis testaceis, ? propodei
area antica haud nitida, tarsorum spinis anticorum pallidis. d*?- 7 — ^3 rn^n-

Very like N. kauaiensis, but generally the ? is less robust and has the head
smaller. It may be at once distinguished by the form of the spine on the cheek,
which, instead of continuing the outline of the face behind the eyes, is raised at
the base, and somewhat twisted, so that, in a lateral view of the head, the spine
presents a sharp edge. The apical margin of the clypeus is produced into a small
median tooth. In well-developed examples the facial spines are very long, more or
less pointed at the apex, and their margins sinuate. The mesothorax is somewhat
shining, the scutellum distinctly so, the anterior area of the propodeum very dull, as
compared with the scutellum. The wings are sometimes more or less clouded, often
almost entirely clear. The spines of the anterior tarsi are pale.

The cT differs from that of N. katiaietisis only in the shape of the anterior
margin of the clypeus, which is not evidently tridentate, although somewhat produced
in the middle.

Hab. Mountains of Oahu (2000 ft. and upwards).

HYMENOPTERA ii

(4) Nesoinimesa nitida, sp. nov.

Praecedenti simillima ; ? area propodei antica nitida, </ tarsis anterioribus
infuscatis distinguendus. cT?- Long. 7 — 12 mm. (Plate I. figs, i and \ a.)

Extremely like the preceding species. The ? is distinguished readily by the form
of the spine on the cheeks, when this is well developed. In such examples, when the
head is viewed from in front the spines are widely, and more or less obliquely, truncate
at the apex, and the margin is there reflexed. When the spines become reduced
in size this distinction is lost, in which case the smoother anterior area of the
propodeum, which is but little less shining than the scutellum, will separate the two
species. The wings are entirely, but not very deeply, infuscate, and often have
a blue iridescence. The spines of the tarsi are for the most part pale.

The /, which varies greatly in size, can only be distinguished, so far as I can
see, by the darker anterior tarsi.

Var. a. Abdomen red. (?.)

Hab. Molokai, Lanai, and Maui (2000 — 5000 ft.). It is possible that the
examples from Maui, of which I have seen only one or two, may be distinct.

(5) Nesoinimesa hawaiiensis, sp. nov.

Duabus spp. praecedentibus simillima ; ? spinis genalibus plerumque brevioribus,
acutis; area propodei antica opaca; tarsorum spinis piceis vel nigricantibus distinguenda.
Tarsi c/" anteriores obscurati ; area propodei antica haud nitida. i ?. Long. 6-5 — 13 mm.

Female similar to those of the two preceding in general appearance. The spines
on the cheeks apparently do not ever attain to so great a length as in well developed
examples of those species. In front view they are acute at the apex, and divergent,
but sometimes are so short as to be invisible in this aspect. The thorax is altogether
duller than in the allied species, the anterior area of the propodeum being quite dull.
The spines of the tarsi are dark.

The cf is extremely similar to that of N. nitida, but the duller surface of the
anterior area of the propodeum will usually distinguish them.

Hab. Mountains of Hawaii (4000 ft.); widely distributed.

Deinominusa, gen. nov.

Genus Nesoinimesae cognatum. Genae % inermes ; clypeus fortiter elevatus, labro
patente ; antennae fortiter clavatae. Abdominis segmenti primi (c/* ?) pars petiolata
distinctissime carinata.

2 — 2

12 FAUNA HAWAIIENSIS

The species for which this genus is formed are evidently allied to those of the
genus Nesomimesa, but the females present peculiar and striking characters, and the
males are not difficult to distinguish. In the former sex the antennae are more
strongly clavate, the cheeks are not armed with spines, the clypeus is greatly raised,
and exposes the whole or a great part of the large labrum, and the posterior tibiae
and tarsi are much more densely spinose. In both sexes the petiole of the abdomen
is very distinctly carinated, and in some of the species is extraordinarily developed.
The males may further be known by the greater development of the raised lines
on the propodeum.

(i) Deinomimesa ferox, sp. nov.

Nigra, sparsim minus distincte punctata, antennarum articulis apicalibus subtus
fulvescentibus, alls subinfuscatis. Mesopleurae subopacae. Abdominis segmentum
primum fortiter et acute carinatum. Clypeus % in medio margine fortiter emar-
ginato. (/?. Long. 8— 13 "5 mm. (Plate I. figs. 3 — 3^5.)

Male black, the face below the antennae, and the base of the mandibles, with
appressed silvery pubescence ; above, with longer pale hairs, the surface dull, without
definite puncturation. Antennae long, clavate. Mesothorax with some very feeble
indefinite punctures, scutellum somewhat shining, the mesopleurae dull. Wings more
or less clouded, the marginal cell and apical portion more deeply. Propodeum rugose.
Abdomen with the petiole flattened above at the sides, and with a sharp median
carina from base to apex, its surface dull, finely rugulose. The rest of the abdomen
shining, and impunctate.

Female more robust than the <} , the clypeus strongly raised, and exposing the
large rugose labrum. The apex of the clypeus is deeply emarginate in the middle,
the mandibles are strongly curved. Antennae with the club more definite than that
of the cf, the apical joints very wide in proportion to their length, the third joint
slender, and very long. Mesothorax with feeble indistinct punctures, the mesopleurae
dull. Propodeum more or less rugose, but the raised lines are not numerous, the
posterior concavity is large and deep and bounded by strongly raised lines. Inter-
mediate and posterior tibiae with dark spines, the posterior metatarsi spinose above,
beneath, and outwardly. Abdomen with the petiole very wide, dull and rugulose,
raised in the middle into a great carina, which (at least towards the base), is not
very sharp above as is that of the d", and is gradually raised from the base to the
apex. Behind the petiole the segment is generally longitudinally grooved, but not
in all examples, and its surface is very smooth, shining and impunctate. Pygidial
area as in the genus Nesomimesa.

Hab. Mountains of Kauai (3000 — 4000 ft.).

HYMENOPTERA 13

(2) Deinoniirnesa cognata, sp. nov.

Praecedenti cognata ; ^ mesopleuris laevioribus et nitidis ; % clypeo (desuper
aspecto) levissime lateque emarginato, distincta. c/' ?. Long. 9 — 12 mm. (Plate I.
figs. \—\b.)

Female of more slender form than the preceding species. The anterior margin
of the clypeus, as seen from above, is not deeply and dentately emarginate, but only
very lightly and widely so. The petiole of the abdomen is differently formed, its
dorsal surface being very narrow, with the margins parallel and straight, but the
sides beneath are extended outwardly, and so are visible from above, and form the
outline of the segment in a dorsal view. The carina itself is much less elevated
and almost of even height throughout its length. On the ventral side the basal
segment lies in two planes, the basal part being sub-horizontal, the apical inclined. The
latter occupies more than half the segment. In the preceding species the formation
of the basal ventral segment is on a similar plan, but the inclined posterior portion
is relatively much smaller.

The male is much more difficult to distinguish, but the petiole is narrower
in proportion to its length, and the mesopleurae are smoother and more shining.

Hab. Kauai (4000 ft.). Local and rare.

(3) Deinomimesa hawaiiensis, sp. nov.

Praecedentibus minor, abdominis segmenti primi parte pedicellata carinam mediam
linearem ferente : ? clypei margine antico (desuper viso) fortissime rotundato, haud
emarginato. i%. Long. 7 — 8mm. (Plate L fig. 5.)

Allied to the preceding species, but not very closely. It is of considerably smaller
size. The petiole is very slender in both sexes and the carina appears as a median
raised line.

In the (/■ the anterior area of the propodeum is traversed longitudinally by
numerous distinct but very fine raised lines. In the ? the clypeus is raised, its
front margin seen from above is very strongly rounded, and not at all emarginate ; the
basal segment of the abdomen beneath is simple, not formed as in D. cognata.

Hab. Kona and Kau districts on Hawaii (4000 ft.); several examples taken,
but only one ?.

(4) Deinomimesa punae, sp. nov.

Praecedenti simillima ; ? scutello minus opaco, clypeo magis abrupte elevato,
margine desuper viso antice subangulato, distinguenda. ?. Long. 9 mm.

14 FAUNA HAWAIIENSIS

This species resembles D. hawaiiensis in general appearance, and in the form
of the petiole of the abdomen. The clypeus is very abruptly raised, and in a front
view of the face nearly the whole surface of the labrum is exposed, which for the
most part can only be seen in an apical view in the preceding species. Seen from
above the apical margin of the clypeus is angulate in the middle. The scutellum
has a median depression and the surface is in that region somewhat shining.

Hab. Olaa, Hawaii (2000 ft.) ; i ? taken in June, 1895.

(5) Deinomimesa haleakalae, sp. nov.

D. konae simillima ; cT parte abdominis segmenti primi pedicellata supra compressa,
et carinata. cT. Long. 8 — 9 mm.

Male very similar to that of D. hawaiiensis, but a larger insect. It may be
easily distinguished by the form of the petiole of the abdomen which is compressed
above from the sides into a median carina, whereas in D. haivaiiensis this part is
flattened above and has a raised line down the middle. The front tarsi outwardly
are more or less infuscate.

Hab. Haleakala, Maui (4000 ft.); a few ^ (S taken in May, 1896.

This species in the c/" approaches most nearly to the genus Nesomimesa, but the
distinct carination of the abdominal petiole, and the much more rugose propodeum,
assign to it the allied one ; and the % will no doubt be found to have the characteristic
form of clypeus, when that sex is discovered.

Trypoxylonidae.

( I ) Pison iridipennis.

Pison iridipennis, Smith, J. Linn. Soc. xiv. p. 676.

Hab. Honolulu (Blackburn). I have never met with this species. I suspect
it of being an introduced species, which apparently has failed to establish itself.

(2) Pison hospes.

Pison hospes. Smith, /. c. p. 676.

Hab. Abundant all over the islands, especially about houses. No doubt an
introduced species. I have received examples from Fiji.

HYMENOPTERA 15

Crauronidae.

Crabro {Solenius).

The fifteen species which I have referred to the sub-genus Solenms of Crabro
fall naturally into three groups, which are readily distinguished by structural characters
in the (f, but the females present no special distinctions in the two groups, in which
this sex is known. In the first group the sixth joint of the i antennae is produced
into a rather long prominent tooth at its apex ; in the second it is emarginate, but only
slightly produced. The third group contains only two species (one of which I have
never seen), the </ only being known, remarkable for the form of the ventral abdominal
segments. Possibly, however, Blackburn's C. abnormis does not really belong to this
group, and C. curtipes is the only representative. Although I have referred these
Hawaiian species to the sub-genus Solenms, I have no doubt they will ultimately form
one or more peculiar genera. The pygidial area of the ? is flatter, less elongate
and excavated than in typical Solenms, and there are other differences. The punctu-
ration is very similar in most of the species, and is generally feeble and shallow, often
subobsolete. The chief characters for specific distinction are found in the antennae
of the (/■, differences in sculpture of the thorax, the colour of the pilosity of the clypeus,
of the antennae, mandibles, &c., and in the form and sculpture of the second ventral
segment of the abdomen.

(i) Crabro {Solenuis) monticola, sp. nov.

Niger, clypeo argenteo-piloso, abdomine flavo-notato, alis subhyalinis. cf an-
tennarum articulo sexto fortiter dentato. <^i. Long. 5-5 — 9-5 mm. (Plate I. figs. 6
and 6 a.)

Male black, second segment of the abdomen with a yellowish-white fascia at the
base, sometimes reduced to a round spot on either side. Third segment black, or
with a spot on each side ; fourth sometimes with an entire fascia, more often an
interrupted one, sometimes only a spot on each side, or entirely black ; fifth with
an entire fascia, often very broad, as also the sixth segment. Head and mandibles
black, the clypeus with appressed silvery pubescence ; antennae with the fifth joint of
the flagellum emarginate beneath and strongly produced at the apex into a projecting
tooth ; vertex dull, the surface rugulose with very shallow and obscure subobsolete
puncturation. Mesothorax dull, clothed with thin pale pubescence, the surface
densely rugulose, with very feebly impressed punctures. Propodeum longitudinally
rugose in front, the surface dull, clothed with pale hairs. Abdomen subovate shining,
with very fine indistinct punctures ; second ventral segment very finely, but not
closely punctured, except on a round area on either side, where the punctures are

1 6 FAUNA HAWAIIENSIS

fine and dense ; third segment beneath slightly, fourth more distinctly, fifth and sixth
strongly depressed.

Female with the mandibles in front (except at the apex), the front of the scape
of the antennae, a fascia at the base of the second segment of the abdomen (often
widely interrupted, or reduced to two round lateral spots), sometimes a spot on
either side of the third and fourth segments, and a complete band on the fifth,
yellowish-white. In one example a small round spot on either side of the second
segment is the only abdominal marking. Sculpture very much as in the c/', the
puncturation of the thorax generally rather more distinct, the mesothorax posteriorly
and the front of the scutellum more or less shining, but variable in this respect.
Abdomen generally rather stouter than that of the </ ; sixth dorsal segment distinctly
punctured, the surface shining ; second segment beneath hardly shining, finely and
remotely punctured, except on the circular lateral pubescent spots, where the punctura-
tion is fine and very dense ; the following segments with an apical row of punctures,
otherwise impunctate ; apical ventral segment subcarinated, and closely punctured on
either side. Posterior tibiae with pale spines. Wings subhyaline in both sexes.

Hab. Mountains of Kauai (3000 — 4000 ft). Mountains of Oahu, both ranges.

Obs. The Oahuan examples agree with those from Kauai in structure, but
show a stronger tendency to a decrease in size or obliteration of the pale markings
on the abdomen.

(2) Crabro (Solenius) molokaiensis, sp. nov.

Niger, ^ antennarum articulo sexto fortiter dentato, ? articulo primo antice
cum mandibulis flavis. Clypeus argenteo-pilosus. Abdomen nigrum. </ ? . Long.
6"5 — 10 mm.

Allied to the preceding species, the i entirely black, except the front tibiae which
are testaceous inwardly, the ? with the mandibles (except at the apex) and the scape of
the antennae in front yellowish-white. Clypeus with silvery pubescence in both sexes.
Male with the fifth joint of the flagellum of the antennae strongly produced at the apex
into a prominent tooth. Vertex of head in the mesothorax with obscure subobsolete
puncturation, the scutellum, more or less, slightly shining. Abdomen beneath dull, the
second segment with fine punctures, the lateral pubescent spots very finely and densely
punctured ; fourth and following segments deeply concave. Female with the meso-
thorax much more distinctly punctured than that of the d", dull in front but more or
less polished behind, where the puncturation is less shallow and more distinct; scutellum
entirely shining, not depressed in the middle, distinctly punctured : propodeum dull,
rugulose, with very short longitudinal rugosity in front. Abdomen with the pygidial
area of the sixth segment shining, distinctly punctured, its sides raised ; second

HYMEN OP TERA 1 7

segment beneath hardly shining, remotely and finely punctured, except on the lateral
pubescent spots, where there is the usual very fine and close puncturation.

Wings in cf with distinct blue iridescence, which is generally less evident, and
sometimes wanting in those of the ? .

Hab. Mountains of IVIolokai {3000 ft.), 1S93. Haleakala, Maui (5000 ft.), i i.

(3) Crabro {Soleniiis) mmiiensis.

Crabro mauiensis, Blackburn and Cameron, P, Manch. Soc. Vol. .\xv. p. 165.
(1885—86).

Resembles C. affinis in the golden pubescence on the clypeus, but the more
deeply canaliculated front of the head, and the coarser facets of the eyes, would
(the i being unknown) rather associate it with C. monticola. That species, however,
has the clypeus clothed with bright silvery pubescence.

Hab. "A single female occurred on Maui, near Wailuku, flying over flowers."
(Blackburn.)

(4) Crabro {Solenius) lialeakalae, sp. nov.

Niger, clypeo aureo-piloso, mandibulis nigris, antennarum articulo primo antice
albido. Mesonotum postice cum parte scutelli anteriore laeve ac nitidum. Abdominis
segmentum 2 ventrale nitidissimum, et circa medium parcissime punctatum. ?.
Long. 10 mm.

Female greatly resembling C. violokaicnsis in general appearance but with the
mandibles entirely black and the clypeus clothed with golden pubescence. Posterior
part of the mesothorax and the scutellum in front with the surface smooth shining
and distinctly punctured, the latter dull posteriorly. Abdomen with the second ventral
segment highly polished all over the middle portion, with a very few scattered
punctures, at the sides with the usual circular pubescent spots and dense fine punctura-
tion. Spines of posterior tibiae dark, and stronger than those of the preceding species.
Wings almost clear.

Hab. a single ? taken on Haleakala, Maui, at an elevation of 4000 ft.
May, 1896.

(5) Crabro {Solenius) hawaiiensis, sp. nov.

Niger, clypeo argenteo-piloso, alls infuscatis, subcaeruleo-iridescentibus, mandi-
bulis articuloque antennarum primo nigris. i antennarum articulo sexto fortiter
dentato. i%. Long. 6 — 10 mm.

p. F. H. 3

1 8 FAUNA HAWAIIENSIS

Both sexes entirely black, the wings infuscate, and in the d" with a distinct blue
iridescence; clypeus with silvery pubescence.

Male with a prominent tooth at the apex of the fifth joint of the flagellum of
the antennae, as in the preceding species.

Head and thorax entirely dull with very shallow subobsolete puncturation, hardly
visible in some examples. Female with the thoracic puncturation, and especially that
of the scutellum, much more distinct than that of the ^ , the mesothorax posteriorly and
the scutellum more or less shining, but variable in this respect. Second ventral segment
of the abdomen with the surface exceedingly finely rugulose, not highly polished, in the
(/ with very fine indefinite punctures about the middle, in the ? with remote but
larger ones.

Hab. Hawaii, various localities ; common at an elevation of about 4000 feet.

Obs. This species is variable in size and sculpture ; the % is at once distinguished
from C. molokaiensis by the black scape and mandibles, the <^ is very similar but the
scutellum and the mesothorax posteriorly appear to be always quite dull.

(6) Crabro (Solenhts) tumidoventris, sp. nov.

Praecedenti simillimus, sed abdominis segmento secundo ventrali fortiter convexo,
mandibulis ? ex majore parte pallidis distinguendus. <} antennarum articulo sexto
fortiter dentato. d"?. Long. 7 — 9"5 mm. (Plate I. fig. 7.)

Very like the preceding in general appearance ; </ with the scape and mandibles
black ; % with the scape of the antennae black, the mandibles white ; </ rarely with
some indication of a pale spot on the mandibles.

Fifth joint of the flagellum of the antennae produced into a prominent tooth at
the apex in the </■, the front of the head and the mesothorax with very shallow
rugose puncturation ; propodeum more or less longitudinally rugose in front, and in
this sex usually with a few fine transverse raised lines above the insertion of the
abdomen. Second ventral segment of the abdomen very convex longitudinally and
transversely, the surface shining, finely and rather remotely punctured about the
middle, more closely towards the sides, and very densely and minutely on the circular
pubescent spots ; fourth and fifth segments generally strongly depressed, sometimes
the fourth less strongly, and the fifth and sixth more so. Basal joint of the front
tarsi unusually wide, about twice as long as its greatest width.

Female very like the cT, except for the white mandibles and sexual differences.
Mesothorax and scutellum quite dull ; second ventral segment shaped as in the d",
finely and distincdy punctured in the middle, densely and very finely on the pubescent
spots. Apical dorsal segment very narrow between the lateral carinae, more or less

HYMENOPTERA

19

largely and rugosely punctured. Wings of the </, and often of the ? with blue
iridescence.

Hab. Both mountain ranges of Oahu ; Molokai, Lanai and Maui. Examples
(at least of the ?) from Oahu appear to have a less distinct blue iridescence on
the wings than those from Molokai &c.

Crabro (Solenius) tumidoventris var. leucognathus.

Forma praecedentis, i mandibulis, ? mandibulis, antennarumque articulo basali
antice albis ; abdomine nonnunquam albo-notato.

This form on Hawaii corresponds to C. tumidoventris on the four islands named
above. A single % from Oahu appears to hardly differ from the Hawaii form, and a
few a from Maui are somewhat intermediate. For the most part, (and I have
examined many of both forms) the two are readily distinguished. The variation of
the var. leruognathus appears to be very different to that of the typical form, since
in the d" the abdomen not infrequently is spotted at the sides of the 5th and 6th
abdominal segments, (or on one of these), and rarely also on the 2nd segment ;
one ? has small lateral whitish spots on this segment, and on the 4th, and an
interrupted band on the 5th.

Hab. Island of Hawaii ; Kona (2000 — 3000 ft.) ; Kilauea (4000 ft.) ; Olaa
(2000 ft.).

(7) Crabro {Solenius) affinis.

Crabro affinis, Smith, J. Linn. Soc. xiv. p. 677 ; Blackburn and Cameron, P.
Manch. Soc. Vol. xxv. (1885—86), p. 165.

Niger, alis subhyalinis, abdomine plus minusve flavo-notato. </ clypeo argenteo-
piloso, antennarum articulo sexto baud fortiter dentato ; ? clypeo aureo-piloso,
antennarum articulo basali antice, mandibulisque plus minusve flavescentibus. c/?-
Long. 6'5 — II mm. (Plate L fig. 8.)

Male with the scape of the antennae and mandibles dark, in the ? they are
more or less yellowish. Abdomen in the ,?, with the 2nd, 4th, and 5th, rarely the
3rd, with pale markings. Sometimes these markings form entire bands, or they
may be reduced to lateral spots. Female with a band on the 2nd, 4th, and 5th
segments, often similarly reduced in size, those on the 2nd and 5th sometimes wanting,
so that probably an entirely black variety may be found.

Male, clypeus clothed with silvery hairs ; antennae with the 5th joint of the
flagellum emarginate beneath, very little produced at the apex, beyond the base of

3—2

20 FAUNA HAWAIIENSIS

the following joint, so that it does not form a conspicuous prominent tooth, as in
all the preceding species. Front of the head with rough, shallow puncturation, smoother
on the vertex behind the ocelli. Mesothorax and scutellum dull, with shallow obsolete
puncturation, but the punctures are more distinct in some examples than in others.
Mesopectus at the sides posteriorly with the carinae strongly elevated, forming a stout
prominent tooth when viewed from in front. Abdomen above somewhat shining ;
second ventral segment shining, remotely and distinctly punctured about the middle ;
4th and following segments flattened and depressed.

Female with the clypeus clothed with golden hairs. Puncturation much as in the
</, but generally more definite, the mesothorax posteriorly and the front of the scutellum
being often more or less polished and shining. Abdomen with the second segment
above hardly shining, very finely, but rather distinctly punctured ; beneath it is very
highly polished, and has only a few scattered punctures on the middle portion, and a very
dense and minute puncturation on the lateral pubescent spots. Apical dorsal segment
nearly flat above, its margins very slightly raised, the surface more or less rough,
and punctured. Posterior tibiae with the spines well developed, and dark. Wings
subhyaline in both sexes.

Hab. Kauai, abundant from the coast to 4000 ft.

(8) Crabro [Solenius) notostictus, sp. nov.

Niger, clypeo argenteo-piloso, pronoto cum postscutello abdominisque segmento
secundo flavo-notato, antennarum articulo sexto haud fortiter dentato. </. Long.
6"5 — 8 "5 mm.

Van Abdominis segmento secundo nigro.

Male allied to the preceding, having the antennae similarly formed. Mandibles
and scape of the antennae black, clypeus with silvery pubescence. Prothorax with
yellow spots, the postscutellum with a transverse one. The second segment of the
abdomen has a yellow band, sometimes broken into two spots or altogether absent ;
the other segments always black. The front of the head has the puncturation nearly
obsolete and shows, in certain positions, distinct but very fine strigosity. The meso-
thorax is dull and rugulose with hardly visible puncturation. The second ventral
segment of the abdomen with the surface evidently but very finely rugulose, and
a few scattered, rather large, subobsolete punctures about the middle, the sides with
the usual dense and minute puncturation. The following segments with their surface
quite dull.

Female unknown.

Hab. Mountains of Oahu, taken on several occasions.

HYMENOP TERA 2 1

(9) Crabro {Solenitis) viandibjilaris, Smith.

Crabro matidibtilaris, Smith, Proc. Linn. Soc. xiv. p. 677 %.

Crabro deniicornis, Smith, (c/) I.e. p. 678.

Crabro vtandibiilaris, Blackburn and Cameron, P. Manch. Soc. Vol. xxv.
(1885—86), p. 167.

Niger, ^ clj'peo argenteo-piloso, postscutello (nonnunquam etiam pronoto, tuberculis,
abdominisque segmento secundo) flavo-notato, antennarum articulo sexto baud fortiter
dentato ; % antennarum articulo basali, mandibulis plus minusve, pronoto, tuberculis, et
postscutello flavo-notatis, clypeo aureo-piloso. ^%. Long. 7 — 10 mm.

Black, the ? with the front of the scape of the antennae, the mandibles more or
less, a spot on each side of the prothorax, its tubercles, and a transverse spot on
the postscutellum, yellowish ; the </ generally has only the spot on the postscutellum,
rarely also the tubercles and prothorax and the sides of the second abdominal segment
with yellow markings.

Male with the sixth joint of the antennae formed much as in the preceding species,
being but little produced at the apex. Clypeus clothed with silvery hairs, the head
above the antennae generally distinctly strigose and feebly punctured, but in small
examples the strigosity is sometimes obsolete, or nearly so. In the region of the
ocelli the puncturation is generally distinct though shallow ; the surface of the meso-
thorax is smoother than that of the preceding species, the puncturation very feeble.
Surface of the abdomen very finely rugulose, and with hardly visible puncturation ;
second ventral segment with the surface finely rugulose, and not highly polished,
with sparse scattered punctures.

Female, clypeus with golden hairs ; head in front strigose and punctured, smoother
on the vertex posteriorly, with shallow but distinct punctures between and at the sides
of the ocelli. Mesothorax with shallow punctures, the surface somewhat smooth,
especially posteriorly, where it is even slightly shining (or at least less dull than in
front), as also the scutellum. Abdomen with grey pubescence ; second segment not
shining, rugulose, without distinct puncturation, beneath the surface is distinctly rugulose
and very sparsely punctured, except at the sides. Apical dorsal segment flat, its
margins but little raised, dull towards the apex, punctured, and more or less smooth
between the punctures towards the base. Wings quite infuscate in the (/, less so
in the ?.

Hab. Molokai, Lanai, and Maui, on the coast and in the mountains at an
elevation of 3000 ft.

This species is very closely allied to C. notostictiis /, but the puncturation of
the vertex of the head is more distinct, and the mesothorax smoother. The normal

22

FAUNA HAWAIIENSIS

coloration of the two is different, the Oahuan species having, in typical examples,
the prothorax and also the second abdominal segment spotted, whereas in C. mandibu-
laris individuals so marked are found only as very unusual varieties.

(lo) Crabro [So/enius) fulvicrus, sp. nov.

Niger, clypeo aureo-piloso, tibiis anticis femoribusque (plus minusve) intus fulvo-
testaceis ; c/' articulo antennarum sexto baud fortiter dentato, abdominis segmento 4° et
5° (vel uno ex his) nonnunquam albo-notatis ; ? mandibulis et antennarum articulo
primo plus minusve albo-flavescentibus. </?• Long. 8 — 12 mm.

Black, (/ with the anterior femora almost entirely, and the anterior tibiae inwardly,
bright fulvotestaceous ; ? with the colour of the femora often much obscured. Abdomen
black in the ?, in the <? sometimes with a whitish spot on the sides of the 4th and 5th
segments, or on the 5th only, and sometimes an entire band on the latter. Scape of
the antennae in front and the basal part of the mandibles yellowish in the ? . Clypeus
of both sexes with golden pubescence, of a very pale tint in the </'.

Scape of the antennae in the </ often more or less fulvous, the fifth joint of the
flagellum very little produced at the apex, hardly dentate. Head in front very shallowly,
rugosely punctured, mesothorax with feebly impressed puncturation. Abdomen with
the second segment above rather shining, very finely, but evidently punctured ; beneath,
with the surface shining, and finely and remotely punctured about the middle.

Female with the head above the antennae finely and densely punctured, the meso-
thorax posteriorly more or less smooth, and generally (as also part of the scutellum)
somewhat shining. On this smoother portion there is a shallow but evident puncturation.
Abdomen with the second segment above as in the (/ ; beneath about the middle
very smooth and shining with sparse and rather large puncturation. Sixth dorsal
segment flat, its margins slightly raised, the surface rough and punctured.

Wings of c/ infuscate generally with more or less blue iridescence, the wings
of the ? clearer.

Hab. Kona, Hawaii (4000 ft.) ; Olaa (2000 ft.).

(11) Crabro {Soleiiius) polynesialis.

Crabro polynesialis, Cameron, Trans. Ent. Soc. 1881, p. 562. Blackburn and

Cameron, P. Manch. Soc. xxv. (1885—86), p. 168.
Praecedenti simillimus, niger, clypeo aureo-piloso, cT antennarum articulo sexto
haud fortiter dentato, ? mandibulis, antennarumque articulo basali, plus minusve

HYMENOPTERA 23

flavescentibus. Tibiis anticis femoribusque haud fulvo-testaceis, mesonoto (?) postice
haud distincte punctato, abdominisque segmento 2 ventrali ruguloso, minus nitido
distinguendus. i%. Long. 7 — 12 mm.

Very like the preceding in most respects, but the c/, so far as I know, never
has the abdomen spotted with white.

Both sexes may easily be distinguished by their dark front femora and tibiae,
and the ? by the mesothorax being duller posteriorly, and without the distinct punctu-
ration of the preceding on that part. The second ventral segment also is evidently less
highly polished, its surface being evidently rugulose.

Hab. Mountains of Hawaii (4000 ft.). Common generally.

(12) Crabi'o {Solenius) iinicolor.

Crabro unicolor, Smith, Cat. Hym. Ins. iv. p. 421. Blackburn and Cameron,
P. Manch. Soc. Vol. xxv. p. 169 (1885—86).

Niger, alis infuscatis, et caeruleo-iridescentibus, mandibulis utriusque sexus cum
articulo basali antennarum nigris, clypeo argenteo-piloso. </ articulo antennarum sexto
haud fortiter dentato. cT?. Long. 7-5 — 13 mm.

Black, the wings infuscate and with a steely-blue iridescence. Mandibles and
scape of the antennae black in both sexes, and the clypeus clothed with silvery
pubescence. Calcaria of the posterior tibiae bright testaceous in the $.

Male with the sixth joint of the antennae very little produced at its apex beyond
the base of the following joint ; head in front with shallow, close and rugose puncturation.
Mesothorax with very shallow punctures, the surface somewhat smooth about the middle.
Propodeum longitudinally rugose in front. Abdomen with the second ventral segment
finely and not very closely punctured about the middle on its basal portion, towards
the hind margin densely and very minutely ; third segment somewhat depressed except
at the base ; the following segments deeply depressed.

Female like the cf in most respects. The mesothorax posteriorly towards the
middle is smoother and more or less shining. Propodeum very finely longitudinally
rugose to the brow, at its anterior margin the rugosity is not so fine. Abdomen
with the second segment very finely but densely and quite distinctly punctured ;
beneath very highly polished on its middle portion and sparsely and clearly punctured,
very finely and densely on the lateral pubescent spots. Apical dorsal segment nearly
flat, its margins slightly raised, the surface somewhat rough, and punctured.

Hab. Oahu, Molokai, Lanai and Maui; abundant on the coast and in the
mountains to an elevation of 4000 ft. or more. Preys on Tachinids &c.

24 FAUNA HAWAIIENSIS

(13) Crabro {Solenius) atripennis, sp. nov.

Praecedenti forma facieque simillimus, mandibulis antennarumque articulo basali
albescentibus facile distinguendus. d"?. Long. 8 — 13 mm.

Very like the preceding in form and sculpture, but in neither sex is the mesothorax
posteriorly as smooth, nor is the surface in that region at all shining. The calcaria of
the posterior tibiae are darker, and the front of the scape of the antennae and the
mandibles are yellowish-white. Wings deeply infuscate and with a steely iridescence,
and the sixth joint of the antennae but little produced at the apex, as in the preceding
species.

Hab. Common generally on Hawaii from the lowlands to an elevation of 5000 ft.
Preys on Tachinids, and also sometimes enters houses and carries off the introduced
house-fly.

(14) Crabro {Soleniics) curtipes, sp. nov.

Niger, alls infuscatis, antennarum articulo sexto baud fortiter dentato, clypeo
argenteo- vel pallidissime aureo-piloso, abdominis segmento primo pubescentia longa
nigraque vestito, segmento 2 ventrali subdepresso, dense punctato, segmentis caeteris
peropacis et depressis. ^. Long. 6 — 11 mm. (Plate L fig. 9.)

Male black, the wings infuscate and with little iridescence. Head, thorax, and
basal segment of the abdomen with erect dark pubescence, clypeus with silvery, or
faintly golden, appressed hairs. Antennae with the fifth joint of the flagellum of the
antennae emarginate beneath, but little produced at its apex. Head very densely
rugosely punctured in front, less so on the vertex posteriorly. Mesothorax dull,
rugosely punctured. Propodeum with excessively short wrinkles at its anterior margin,
behind these with shallow subobsolete punctures. Abdomen with the basal segment
extremely finely punctured, and clothed with long dark hairs ; second and following
finely closely and evenly punctured. Beneath, the second segment is flattened, closely
punctured, and inclined, the third flattened or slightly depressed and inclined in the
opposite direction to the second, so that the two meet at an obtuse angle. The
surface of the third and of all the following (which are depressed) is very dull, having
an appearance of granulation or dense puncturation, which is due to a dense meshwork of
raised lines. Posterior tarsi very short in proportion to the tibiae, all the joints taken
together hardly being equal to the latter in length.

Hab. Kona, Hawaii, about 4000 ft. ; i c/, Aug. 1892. Olaa (2000 ft.), and
Kilauea (4000 ft.), several i^ in 1896. I do not know the ? of this remarkable
species, which might well form a distinct genus, should the other sex present any
striking characters.

H\ 'ME NOP TERA 2 5

(15) Crabro {So/eiiius) abnorniis.

Crabro abiiormis, Blackburn and Cameron, P. Manch. Soc. Vol. xxv. p. 168
(1885-86).

This remarkable species is perhaps allied to S. curtipes, and probably might
well be separated generically from the other Hawaiian species. It differs from all
these in the abruptly incrassate fifth joint of the antennae, and the extremely long
tooth on the sixth. Although I repeatedly searched for it in the locality specified,
I never had the good fortune to meet with a specimen.

Hab. Konahuanui, Oahu (2500 ft.) ; i c/ taken by Mr Blackburn. The ? which
he suggests as belonging to this i is more probably that of C. himidoveniris.

Nesocrabro, gen. no v.

Caput inter oculos latum, baud fortiter concavum. Fossae antennales ab oculorum
marginibus spatio distincto disjunctae. Clypeus pilis suberectis (baud metallicis)
vestitus. Antennarum <} articulus sextus subtus emarginatus, apice haud fortiter
producto. Alarum cellula submarginalis longe post medium, apicem versus, venam
recurrentem accipiens. Area propodei antica haud definita. Tibiae posticae spinosae,
tarsorum articulus ultimus fortissimus. Area pygidialis ? elongata, angustissima,
utrinque fimbriata.

The species for which this genus is proposed appear to be allied to those which
are provisionally placed under the subgenus Solenius of Crabro. The face is unusually
wide between the eyes, and but little concave. The antennal fossae are separated
from the latter by a considerable space. The facets of the eyes in front are
comparatively fine. The clypeus is clothed with a fine suberect pubescence, instead
of the appressed silvery or golden hairs, so usual in Crabronidae. In the <^ the 6th
joint of the antennae is emarginate beneath, and slightly produced at the apex. The
ocelli form a trianMe, much widest at the base. In the winpfs the recurrent nervure
is received far beyond the middle (towards the apex) of the submarginal cell. The
anterior area of the propodeum is not defined. The front tarsi are simple, the posterior
tibiae spinose, the claw joint of the tarsi very large. Pygidial area of the ? elongate
and very narrow, fringed on each side with long hairs, its sides carinated.

( I ) Nesocrabro co^npactus, sp. nov.

Niger, thorace et abdomine albido-notatis, alls subhyalinis, abdominis segmentis
apicalibus haud rufo-pubescentibus. i antennarum articulo sexto subtus emarginato,
apice vix dentato. d"?. Long. 7-5 — 9mm. (Plate I. fig. 10.)

p. F. H. 4

26 FAUNA HAWAIIENSIS

Male black, the prothorax often with two spots on the hind-margin and a
small one on the tubercles, a transverse spot on the postscutellum, a band usually
broad and entire on the second abdominal segment, a spot or line on each side
of the third or fourth, a wide band on the fifth, and one on the sixth, yellowish-
white. Basal segment also sometimes with an apical spot.

Female with a line on the scape of the antennae, the basal part of the mandibles,
two spots or a band on the prothorax, a transverse spot on the scutellum and
postscutellum, a broad band on the second abdominal segment, a narrower one on
the third and fourth, sometimes also a line on the posterior and intermediate tibiae
beneath, a spot at the apex of the front tibiae, on each of the posterior coxae and
trochanters, and a small one on each side of the second ventral segment of the
abdomen, yellowish-white.

These markings are very variable.

Male, with the fifth joint of the flagellum of the antennae emarginate beneath,
hardly produced at the apex. Head in front, and the mesothorax with dense and
rugose but shallow puncturation. Propodeum more or less longitudinally rugose.
Abdomen with the second segment extremely finely punctured ; beneath, somewhat
strongly convex, and finely punctured ; fourth ventral segment flattened or slightly
depressed, fifth and sixth depressed. Apical dorsal segments with inconspicuous
pale pubescence, and the puncturation almost obsolete.

Female very like the <^ in general sculpture, but the puncturation usually slightly
weaker. Posterior tibiae roughened, the asperities with short pale spines. Apical
dorsal segment elongate and very narrow, coarsely punctured at the base, and sparsely
fringed with pale hairs. Second ventral segment sparsely punctured about the middle,
very minutely and densely on the lateral pubescent spots. Wings subhyaline in
both sexes.

Nesocrabro covipactus var., lanaiensis var. n.

Male with a large spot on the scutellum, as well as the postscutellum, yellowish-
white ; the band on the second abdominal segment narrow and interrupted. In
the ? this band is less wide than in the typical specimens. The surface of the head
on the vertex is smoother and less dull in both sexes, and the surface of the meso-
thorax posteriorly in the ? somewhat smooth and shining between the punctures.

Hab. Mountains of Kauai (2500 — 4000 ft.), preying upon Diptera of moderate
size, and forming burrows in trodden pathways and bare banks in the forest. Var.
lanaiensis. Mountains of Lanai (above 2000 ft.). Not common. In the </ the
tendency seems to be to an increase of thoracic, and decrease of abdominal marking,
as compared with the Kauai series.

HYMENOPTERA 27

(2) Nesocrabro bidecoratiis, sp. no v.

Niger, mandibulis, antennarum articulo basali, thorace, et tibiis flavo-notatis^
abdomine fasciis flavis ornato ; segmento quinto cupreo, dense punctate, pubescentia
aureo-rufa vestito, sexto pilis ejusdem colons fimbriate. ?. Long. 10 mm.

Female black, with the basal half of the mandibles, a line on the scape of the
antennae, an interrupted band on the prothorax, a transverse spot on the scutellum
and postscutellum, a spot at the base of all the tibiae beneath, and a band on each
of the first four segments of the abdomen, yellow. Fifth segment of a somewhat
metallic copper colour, densely punctured, and clothed with dark golden-red pubescence,
the elongate sixth segment fringed with similar hairs, its surface somewhat smooth,
and strongly, but not densely, punctured. Head in front with shallow dense punctures,
the vertex with dark pubescence. Mesothorax clothed with black pubescence, the
surface dull, the puncturation shallow, and by no means coarse. Propodeum with
grey pubescence, and with short longitudinal rugosity at the extreme front ; behind
this dull, the surface roughened. Abdomen with the second segment densely and
finely punctured ; beneath, about the middle, it is impunctate ; towards the sides
distinctly punctured, very densely and minutely on the lateral pubescent spots. This
segment and the basal have a pale yellow spot on their ventral surface. Posterior
tibiae with pale reddish spines, the calcaria bright fulvo-testaceous. Wings sub-
hyaline, somewhat clouded towards the base.

Hab. a single ? taken at Kilauea, Hawaii, in September 1895. I'"" spite of
its extremely distinct appearance I suspect it may prove to be a variety of the following-
species.

(3) Nesocrabro rubrocaudatiis.

Crabro rubrocaudatus, Blackburn and Cameron, P. Manch. Soc. Vol. xxv.
p. 172 (1885-86).

Niger, abdomine nigro, segmentis apicalibus rufo-pubescentibus ; c/ thorace opaco,
haud flavo-notato, alis infuscatis, caeruleo-iridescentibus, % thorace (antice saltern)
opaco, alis subhyalinis minus fortiter infuscatis. 1% . Long. 7-5 — 10 mm. (Plate L
fig. 1 1 and I i«.)

Male black, the wings deeply infuscate and with bright blue iridescence ; the
5th, 6th, and 7th abdominal segments densely clothed with red pubescence. Female
with the 5th segment so clothed and the sixth with a fringe of the same colour,
the prothorax and postscutellum sometimes spotted with yellow, wings much less dark
than those of the (/, subhyaline or lightly in.fuscate, sometimes with more or less
blue iridescence.

Antennae of the ^ with the 6th joint but little produced at the apex ; front
of the head dull and subobsoletely punctured, clothed with dark hairs and in some

4—2

28 FAUNA HAWAIIENSIS

examples distinctly longitudinally strigose amongst the punctures. Mesothorax dull,
with dense surface rugulosity and shallow puncturation. Propodeum more or less
rugose, more strongly in some examples than others. Second segment of the abdomen
very finely punctured above ; beneath very finely and densely punctured towards the
apex, less so towards the base, the punctures distinct ; the apical ventral segments
lightly depressed, and fringed with golden-red hairs.

Female, except for the differences given above, very like the c/. The mesothorax
posteriorly is slightly smoother, and less dull, the longitudinal rugosity of the pro-
podeum extremely short. The second ventral segment of the abdomen, about the
middle, has at the most a few somewhat large and very shallow punctures, its surface
is excessively finely rugulose, and not very shining ; the apical dorsal segment is very
narrow, and coarsely punctured. There is a rather conspicuous pale pubescence on
the segments preceding the two apical ones.

Hab. Various localities on Hawaii (from 2000 — 4000 ft.). Not very abundant.

(4) Nesocrabro daciiionius, sp. nov.

Niger, alis infuscatis, haud evidenter caeruleo-iridescentibus, mesonoto minus
opaco, plus minusve flavo-maculato, abdominis segmentis apicalibus pubescentia rufa
ornatis, segmento ? 2 ventrali nitido, laevissimo, in medio fere impunctato ; fronte
pilis nigricantibus, tibiis anticis pubescentia brevi et obscura vestitis. c/ ? . Long.
8 — 12 mm.

Black, the wings infuscate (less so in the $ ), but with little or no blue
iridescence. The prothorax and postscutellum usually both bear yellow spots in
the c/, but they are variable in this respect ; in the ? these spots are much larger,
and the scutellum also has a large transverse one, as well as the first and second
ventral segments of the abdomen. The latter may also be present in the (/, as also
spots on the scutellum. The apical segments are clothed with golden-red hairs as
in N. riLbrocatidatus, and the preceding segments in the ? with dense and fine
whitish pubescence. From that species the much less dull surface of the whole
insect will readily separate the present one, as well as the much more distinct
puncturation of the front of the head and the mesothorax ; the surface of the latter
in the ? being altogether smooth and shining between the punctures. In the d"
the second ventral segment of the abdomen is densely and distinctly punctured all
over, in the ? its surface about the middle is nearly or quite impunctate, smooth,
and shining.

The fifth dorsal segment of the $ is aeneous and very densely punctured. Front
of the head, and the front tibiae with dark pubescence, very short on the latter.

Hab. Mountains of Molokai (3000 — 4000 ft.). lao Valley, Maui.

HYMENOPTERA 29

(5} Nesocrabro adspectans.

Crabro adspectans, Blackburn and Cameron, P. Manch. Soc. Vol. xxv. p. 171
(1885-86).

I have not seen this species. It is very closely allied to N. dacmonius, but
differs from that species in having the front of the head clothed with golden-red
pubescence, and long hairs of the same colour on the front tibiae.

Hab. Haleakala, Maui (5000 /t.). A pair were taken by Mr Blackburn 15

(6) Nesoc7-abro stygius.

Crabro stygius, Kirby, Ent. Mo. Mag. xvii. p. 88. Blackburn and Cameron,
P. Manch. Soc. Vol. xxv. p. 170 (1885-86).

Niger, alls subhyalinis, vix infu.scatis, pronoto % nonnunquam llavo-notato,
segmentis </ apicalibus pubescentia pallida $ pubescentia rufa vestitis. i. Long.
8 mm.

This species is very closely allied to A^. rubi'ocaudatus, but the </ may be at
once distinguished by the subhyaline and very faintly infuscated wings, the pubescence
of the apical abdominal segments, which is of a pale golden colour, the more distinctly
subrugosely punctate front of the head, and the shining surface of its vertex.

From N. daenwnius, the dull and less smooth surface of the mesothorax and
scutellum, the unspotted thorax and the clearer wings, from N. adspectans, the
obscurely coloured pubescence of the head and front legs (as well as the characters
which distinguish it from A^. daemonius), will readily separate it.

I have not seen an example of the ?.

Hab. Mountains of Oahu (Blackburn). Head of Pauoa Valley (March 1895).

DIPLOPTERA.

Vespidae.

(i) Polistes aurifer.

Polistes aurifer, Saussure, Mon. Guepes Soc. p. 78.

Hab. Very abundant all over the islands. Stylopized examples taken on
Lanai and Hawaii.

FAUNA HAWAIIENSIS

(2) Polistes hebraeus.

Polistes hebraeus, Fab. Mant. Ins. i. p. 292.
Polistes macaensis, Fab. Syst. Piez. p. 272.

Hab. Oahu and Kauai ; on the plains. Olaa, Hawaii (2000 ft.).

EUMENIDAE.

This group is represented by a large number of species of the genus Odyneriis,
no less than 86 species being known to me. These Odynerus are of great interest and
importance, and exhibit a great diversity of structure in the various species, and
will no doubt, at some future period, themselves form several distinct genera. In
striking contrast to other Hawaiian aculeates (the Mimesidae, Crabronidae, and Neso-
pi'osopis) the specific structural characters, (and even the coloration if a few species
are excepted), are remarkably constant. These characters are chiefly found in the
general sculpture of the insect, the form of the clypeus, the shape of the dorsum
of the second segment of the abdomen, but especially in the structure of the ventral
plate of this segment. This ventral segment normally consists of three distinct parts,
(i) a smaller basal portion, (2) a transverse sulcature traversed by longitudinal costae,
(3) a larger apical portion, with a more or less distinct depression. Each of these
parts may furnish useful characters ; the basal portion in some species is large and
tumid, the costae may be of great length, moderate, or entirely obsolete, the apical
portion may be flattened to the level of the costae or greatly and perpendicularly
raised above them, and the depression may be wide, narrow, deep, or obsolete. The
habits of the species are of interest. All those that I have been able to observe prey
on the larvae of moths (Pyralidae, Noctuidae, and Micro-Lepidoptera), so that the
number of caterpillars destroyed must be immense, especially as the wasps appear
to be on the wing at all seasons of the year. Their cells are sometimes formed
in the ground, often in the wood of dead trees, and in the case of many species in
the cavities of the porous blocks of lava. A few build solitary cells of mud, attached to
leaves of trees, but these I have only found when the leaf has been rolled up by
a spider, the nest of the latter and the cell of the wasp being fixed side by side.
That very abundant species O. nigripcnnis is very partial to houses, forming its
cells in cavities in woodwork, or unused locks. It also frequently occupies the
empty cells of Pelopceiis.

All the Hawaiian species of the genus belong to the section formerly known
as Leionotus. As in the Fossores and Anthophila I have described afresh all the
species previously known, whenever I have had specimens for examination, the large

HYMENOP TERA

.^1

number of new forms rendering the old descriptions of little use. The measurements
of Odynei'HS are taken from the front of the vertex of the head to the apical margin of
the first abdominal segment, instead of to the apical extremity of the abdomen.

(i) Odynerus venator, sp. nov.

Niger, minus robustus, fronte inter antennas flavo-maculata, segmenti primi
abdominis margine apicali saepe pallido, alis infuscatis et violaceo-iridescentibus.
Clypeus leviter dentato-emarginatus. Mesonotum minus fortiter densissime rugoso-
punctatum. Segmentum abdominis secundum a basi fortiter elevatum. Long, (a
fronte usque ad apicem segmenti 2' abdominis) c/ 7 — 9, ? 9 — 12 mm.

Black with a small yellow spot between and just behind the points of insertion
of the antennae, and another behind each eye near the vertex ; the apical margin of
the basal segment of the abdomen often narrowly yellow, or testaceous. Clypeus
with the apex dentately emarginate very feebly in the ?, more strongly so in the cT ;
head above the antennae with shallow rugose puncturation. Mesothorax dull, somewhat
finely and very closely rugosely punctured ; wings infuscate, with violet iridescence.
Propodeum quite dull, impunctate or nearly so. Abdomen with the basal segment
shallowly punctured, rather more deeply and closely in the </ than the ? ; second
much raised from the base, the highest point being about one-third the length of the
whole segment from the basal margin, finely, evenly and remotely punctured to near
the apical margin, where the puncturation becomes close, coarse and shallow, as on
the following segments ; beneath, with its depression triangular and somewhat deep,
meeting the apices of the costae ; at the sides the segment is raised from their
apices to about the height of its basal portion.

H.\B. Hawaii, Kona and Kau districts (2000 to 4000 ft.).

(2) Odynerus erro, sp. nov.

Praecedenti forma et puncturatione simillimus,' sed thorace toto nitido distinctis-
simus. ?. Long. 11 mm. (Plate I. fig. 12.)

Black and shining with a median spot just behind the antennae, another behind
each eye near the base, and the sides of the apical margin of the basal .segment of
the abdomen, pale. Clypeus with the apex dentately emarginate ; head above the
antennae dull with shallow, close and rugose puncturation. Mesothorax shining;
densely, subrugosely punctured, the puncturation consisting of scattered larger punctures
(which are not coarse), and a system of smaller punctures which in this species is
extremely strongly developed, so that the difference between the two systems is much

32 FAUNA HAWAIIENSIS

less than usual ; wings with violet iridescence. Propodeum with feeble subobsolete
punctures, sometimes hardly visible. Second segment of the abdomen strongly raised
from the base, the depression beneath not so deep as in the preceding species. ?.

Hab. Oahu, Waianae Mts. and coast. Haleakala, Maui (5000 ft.) } A single ?
only taken in each case. I think it probable that the latter locality is erroneous.

(3) Odynerus naiadum, sp. nov.

Niger, alis infuscatis, caeruleo-iridescentibus, fronte, mesopleuris, postscutello
(maris etiam pronoto) rubro-notatis ; segmento primo abdominis postice rubro-
marginato. (/ clypeus fortiter, ? minus fortiter sed distincte dentato-emarginatus.
Mesonotum haud nitidum, subtilius subrugoso-punctatum. Abdominis segmentum
secundum elevatum ; subtus, depressione sat lata et alta. </ ?. Long, g — 10 mm.

Black, the wings infuscate and with blue iridescence. The front of the head
behind the antennae, the mesopleurae, the postscutellum, and in the cf the prothorax
also, have red markings. The apical margin of the basal segment of the abdomen
has a red band, dilated at the sides. Clypeus deeply dentately-emarginate in the
t/, less deeply, but distinctly so in the ?. Head closely and rugosely punctured.
Mesothorax dull, with two systems of puncturation. The larger punctures are not
coarse and on the posterior half of the thorax somewhat irregular, the minute
interstitial punctures are unusually strong, especially in the ?, and both kinds have
a tendency to run into each other, giving the thorax a subrugose appearance.
Propodeum with subobsolete shallow puncturation, the posterior concavity subrugose.
Basal segment of the abdomen shallowly punctured ; second strongly raised from the
base in the </, somewhat less so in the ? ; beneath, with the depression distinct
and deep.

Hab. Molokai mountains {3000ft.); local and scarce. lao Valley, Maui, i?.

(4) Odynerus erythrognatlms, sp. nov.

Niger, minus robustus, mandibulis rufis, alis caeruleo-iridescentibus. Clypeus
ad apicem depressus, vix emarginatus. Mesonotum opacum sparsim subtilissime
punctatum, puncturatione fere obsoleta. Abdominis segmentum secundum elevatum,
subtus depressione lata. </?. Long. 8 — 10 mm.

Black, the mandibles red, the wings with blue iridescence. Apex of clypeus
(as in nearly all the Hawaiian species) depressed from the sides, giving it a dentate
appearance, very slightly emarginate, or truncate ; head above the antennae very dull,
with fine feebly impressed punctures. Mesothorax dull, very finely and obscurely

HYMENOPTERA 33

punctured, scutellum impunctate or nearly so ; wings infuscate with blue iridescence.
Propodeum dull, impunctate, or with faint traces of almost obsolete punctures. Basal
segment of the abdomen dull, with shallow punctures, second raised from the base
but not very strongly, more so in the ^ than the ? ; beneath, with the depression
wide and deep ; the segment at the sides, raised up abruptly and rather strongly
from the apices of the costae, prominent on either side of the depression at its base.

Hab. Kilauea, Hawaii (4000 ft.).

(5) Odynerus melanognathus, sp. nov.

Niger, minus robustus, alis caeruleo-iridescentibus. Clypeus cf fortiter, ?
evidenter dentato-emarginatus. Mesonotum opacum, sparsim subtiliter punctatum.
Propodeum puncturatione levissime impressa, fere obsoleta. Abdominis segmentum
secundum subtus depressione lata. ^%. Long. 9— 11 mm.

In general appearance very like the preceding, but easily known by the following
characters. Mandibles dark, apex of clypeus of d" deeply, of ? distinctly, though
less strongly, dentately-emarginate. Mesothorax rather more distinctly punctured, the
propodeum in front with very shallow but evident punctures. Second abdominal
segment beneath rather less prominent on either side of the depression in front.

Hab. Kona, Hawaii (1500 ft. and above). Rare, ic/' 2? taken.

(6) Odynerus cyphotes, sp. nov.

Niger, alis caeruleo-iridescentibus. Mesonotum opacum subtilissime sparsim
punctatum. Segmentum abdominis secundum fortiter subitoque tuberculato-elevatum,
subtus depressione minus lata. </?. Long. 8 — 10 mm. (Plate L fig. 16.)

Mandibles dark, apex of clypeus hardly emarginate, head above the antennae dull,
evenly and very shallowly punctured. Mesothorax dull, with fine sparse punctures,
sometimes nearly obsolete, and an exceedingly minute and close puncturation between
these. Wings infuscate, with blue iridescence. Propodeum sometimes with a very
feeble indication of shallow punctures. Abdomen with the basal segment slightly
depressed along its apical margin, and shallowly punctured; second very strongly
and abruptly raised from the base into a tuberculate form above ; beneath, with
the depression rather narrow, the segment at the sides rising abruptly from the
costae to a height as great or rather greater than that of its basal portion.

Hab. Kona and Kau districts of Hawaii (4000 ft.).

p. F. H. 5

34 FAUNA HAWAIIENSIS

(7) Odynerits vulcanus.

Odynertis vtilcamis, Blackburn, P. Manch. Soc. Vol. xxv. (1885-86), p. 152.

Niger, alis caeruleo-iridescentibus. Clypeus leviter emarginatus vel subtruncatus.
Mesonotum cum scutello peropacum, subaequaliter distincte punctatum. Propodeum
(plerumque reticulatim) rugosum. Abdominis segmentum secundum (praecipue maris)
fortiter elevatum. c/?. Long. 8 — 10 mm.

Black, the mandibles dark, the wings with blue iridescence. Clypeus with
the apex depressed and slightly emarginate, sometimes truncate. Front of the head
densely and distinctly punctured. Mesothorax with the surface quite dull, somewhat
closely and evenly punctured, posteriorly about the middle the punctures generally
are sparser. Scutellum dull and distinctly punctured. Propodeum with rugose
sculpture generally reticulate. Abdomen with the basal segment closely and largely
punctured ; second segment strongly and abruptly raised from the base, especially
in the (/ ; beneath, the depression wide but not deep, so that even at the sides
the segment rises not at all strongly from the level of the apices of the costae.

Hab. Hawaii, widely distributed and not rare.

(8) Odynenis Iiiloeiisis, sp. nov.

Praecedenti simillimus, sed mesonoto minus opaco, densius ac grossius punctato,
abdominis segmento secundo subtus minus late depresso distinguendus. cT?. Long.
7|- — io-| mm.

Extremely like O. vulcanus but may be known at once by the almost or quite
shining surface of the thorax between the punctures. The mesothoracic puncturation
is also closer and coarser, and the depression of the second ventral segment evidently
less wide.

Hab. Hawaii, not rare on the windward side of the island, in the forests
above Hilo (2000 ft.) and at Olaa.

(9) Odynerus konanus, sp. nov.

Niger, alis caeruleo-iridescentibus. Clypeus levissime emarginatus vel truncatus.
Mesonotum nitidum, distincte aequaliter punctatum. Propodeum rugosum. Segmentum
abdominis secundum elevatum, subtus depressione lata, late costarum apices antice
attingente. cf?. Long. 9 — 1 1 mm.

Black, the wings with blue iridescence. Clypeus depressed at the apex, slightly

HYMENOP TERA

35

emarginate or truncate. Head in front densely and distinctly punctured, shining
between the punctures. Thora.x shining, mesothorax strongly and evenly punctured,
rather more largely and closely in the <? than the ?. Propodeum rugose in front.
Abdomen with the second segment raised from the base (more strongly in the i) ;
beneath, the depression wide but not deep, meeting the apices of the costae widely at
its base.

Hab. Hawaii, Kona district (600 to 2000ft.). A single e.xample (?) taken
in the mountains of Molokai (3000 ft.) nearly agrees with the Hawaii specimens,
as also one from the mountains of West Maui.

(10) Odynerus orbits, sp. nov.

Niger, mandibulis rufis, alis caeruleo-iridescentibus. Capitis vertex incrassatus.
Clypeus ad apicem depressus, levissime emarginatus. Mesonotum haud nitidum,
distincte (nee grosse) punctatum. Propodeum obscure punctatum. Abdominis seg-
mentum 2 a basi elevatum, subtus depressione lata at alta, lateribusque suis post
costas subfortiter elevatis. ?. Long. 10 — 1 1 mm. (Plate I. fig. 17 and 17a.)

Black, the mandibles red, the wings with blue iridescence. Clypeus with a
depression at the apex, which is very slightly emarginate. Head above the antennae
distinctly and closely punctured, the vertex somewhat strongly incrassate. Meso-
thorax dull, distinctly but not coarsely punctured ; scutellum with fine and feeble
puncturation. Propodeum with some evident but very feebly impressed coarse
punctures. Abdomen with the second segment, raised from the base but not at all
abruptly, beneath with the depression wide and deep, the segment at the sides
rising abruptly and rather strongly above the apices of the costae.

Hah. Hawaii, Kona (2000ft. and upwards). Rare. Kilauea (4000ft.). i?.

(11) Odyncriis caenosits, sp. nov.

Niger, alis infuscatis caeruleo-iridescentibus, abdominis segmenti primi et secundi
margine apicali flavo-albido. Frons capitis densissime rugoso-punctata. Mesonotum
cum scutello fortiter denseque punctatum, subnitidum. Propodeum rugosum. Abdo-
minis segmentum secundum a basi elevatum, subtus depressione haud lata, lateribusque
suis abrupte supra costarum apices subfortiter elevatis. Long. 8 — 9J mm.

Black, the two basal segments of the abdomen with an apical creamy-white band,
the second being the wider of the two. The front of the head is very densely
rugosely punctured, the mesothorax coarsely and closely punctured, the surface shining.
The propodeum is rugosely sculptured. Basal segment of the abdomen shining, coarsely

5—2

36 FAUNA HAWAIIENSIS

and closely punctured ; the second raised from the base above ; beneath, the depression
is narrow and hardly meets the apices of the costae, the segment at the sides being
abruptly raised from these to about the height of its basal portion.

Hab. Mountains of Kauai. Halemanu and elsewhere on the high plateau.

(12) Ody nevus Iencozo7iias, sp. nov.

Praecedenti simillimus, et eodem colore, sed mesonoto magis nitido, propodeo
laevi (punctato), et abdominis segmento secundo fortius et abruptius elevato, bene
distinctus. <}%. Long. 8 — 10 mm.

Very similar to the preceding in form and colour.

The surface of the head in front, the mesothorax and scutellum, are very smooth
and shining between the punctures, the system of minute punctures between the larger
ones on the mesothorax being hardly observable, instead of very distinct. The pro-
podeum is much smoother, with shallow but distinct punctures, and the second segment
of the abdomen is more strongly and abruptly raised from the base.

Hab. Kauai (2000 — 3000ft.). Found also on the high plateau.

(13) Odynerus eludens, sp. nov.

Praecedenti simillimus, margine apicali segmenti abdominis primi angustissime
pallido. Mesonotum nitidum fortiter punctatum, interstitiis evidenter minutissime
punctatis. Propodeum laeve, antice sparsim subobsolete punctatum, concavitate fere
impunctata. Abdominis segmentum primum (a latere visum) a basi usque ad marginem
apicalem aequaliter curvatum. ?. Long. 9*5 mm.

Allied to the two preceding species but with the basal segment of the abdomen
(viewed laterally) more evenly and gradually curved from the petiole — not abrupt in
front. The mesothorax is smooth and shining between the punctures as in O. leitco-
zonias, but the interstices have the minute system of punctures very evident. The
propodeum in front is somewhat shining, with some very feebly impressed punctures ;
the concavity is smooth and almost impunctate. The pale apical band of the basal
segment of the abdomen is unusually narrow ; the second segment is considerably,
but by no means abruptly, raised from the base, the highest point attained (as seen in
lateral view) being rather more than one-third of the whole length of the segment from
the base. Beneath, the depression somewhat narrow, deeper than in the two preceding
species.

Hab. Halemanu, Kauai (4000ft.). i?.

I

HYMENOPTERA 2,7

(14) Odynerus homochromus, sp. nov.

Niger, abdomine fasciis duabus albidis, secunda latiore. Mesonotum fortiter punc-
tatum, interstitiis nitidis, distincte punctulatis. Propodeum opacum subobsolete punctatum,
concavitate rugulosa, baud evidenter punctata. Segmentum secundum abdominis fere ad
medium subfortiter elevatum, subtus depressione distincta. ^ ?. Long. 8|— 12-| mm.

Black, with two pale bands on the abdomen. Thorax strongly punctured, meso-
thorax shining between the punctures, the minute system between these quite distinct.
Propodeum dull with shallow puncturation in front, the concavity almost or quite
impunctate with finely rugulose surface. Abdomen with the basal segment evenly
punctured, subvertical in front ; second segment raised from the base but not abruptly,
the highest point being nearly at its middle ; beneath with a distinct and neither very
narrow nor deep depression.

Hab. Mountains of Kauai (3000 ft.). Not common.

(15) Odynerus kirbyi.

Odynerus kirbyi, Dalla Torre, Wien. Ent. Zeitg. viii. (1889), p. 125.
Odynerus exfraneus, Kirby, Ent. Mo. Mag. xvii. p. 86 (nee de Saussure).
Blackburn and Cameron, P. Manch. Soc. Vol. xxv. (1885-86), p. 151.

Niger, abdomine fasciis duabus albidis ornato, secundo latiore. </ clypeo albido,
apice emarginato, mandibulis albido-notatis. Mesonotum fortiter denseque punctatum.
Propodeum rugosum. Abdominis segmentum primum dense punctatum, secundum
subtus costis fortibus et longis, depressione nulla. cT ?. Long. 9 — 12 mm. (Plate L
fig. 18— 18 (5.)

Black, with two whitish abdominal bands. The (/ has also the clypeus and more or
less of the mandibles of the same colour. The head in front is exceedingly densely
punctured, the mesothorax and scutellum are also densely and coarsely punctured,
and the surface between the punctures is shining. The entire propodeum is rugose.
Abdomen with the basal segment closely punctured, more coarsely in the ^ than
the $ ; second raised from the base rather strongly in the c/ ; beneath, the costae
are strong and very long and there is no depression beyond their apices.

Hab. Kauai, in the mountains. Not rare.

(16) Odynerus dilatatipcs, sp. nov.

Praecedenti simillimus, eodem modo ornatus, mesonoto fere opaco minus dense et
grosse punctato ; propodei concavitate laeviori, tantum rugulosa ; tibiis posticis (/ ad

.S FAUNA HAWAIIENSIS

o

apices fortiter dilatatis, et externe fortiter depressis, bene distinctus. </?. Long.
9f— II mm. (Plate I. fig. 19.)

Extremely like the preceding in general appearance. Male with the head, above
the antennae, more finely and shallowly punctured, as likewise the mesothorax and
scutellum. The propodeum is much less rugose ; its concavity almost smooth, except
for the surface rugulosity. Basal segment of the abdomen with the dorsal and
anterior faces meeting less sharply, and less coarsely and closely punctured. Female
with the head and thorax evidently more finely punctured, and the surface of the
latter dull, or almost dull, between the punctures. The posterior concavity of the
propodeum is smoother, and the basal segment of the abdomen more finely punctured.
The </ is further distinct from any other species by the strongly and suddenly dilated
apex of the hind tibiae, the dilated portion outwardly being deeply concave.

Hab. Mountains of Kauai (3000 ft.). Not a common species.

(17) Odyneriis conifer, sp. nov.

Niger, abdomine fasciis duabus albidis ornato. Mesonotum nitidum sparsim subtilius
punctatum. Propodeum rugoso-punctatum. Abdominis segmentum primum supra
fortiter transversum, antice truncatum, parte antica parti dorsali acute occurrente ;
segmentum secundum acute conicum, subtus costis longis, depressione nulla. ?.
Long. 9 mm.

Head closely punctured. Mesothorax smooth and shining, somewhat finely punc-
tured, remotely and irregularly on the posterior half. Between these punctures the
minute system of puncturation is very distinct. Propodeum with shallow and somewhat
rugose puncturation. Abdomen with the basal segment strongly transverse above,
depressed, and distinctly punctured, sharply truncate in front ; second segment strongly
raised into a sharp cone, beneath the middle costae very long, and no depression beyond
their apices.

Hab. Kauai, on the high plateau. A very remarkable and rare species, of
which only i ? was taken.

(18) Odynerus kauaiensis, sp. nov.

Niger, fasciis duabus albidis ornatus. Mesonotum densissime grosse punctatum.
Propodeum fortiter rugoso-punctatum. Abdominis segmentum primum ad basim
puncturatione grossissima rugosum ; secundum haud elevatum ; subtus, costis longis ;
post has triangulariter deplanatum, vix depressum. c/?. Long. 8 — 10 mm.

Apex of clypeus very slightly emarginate or truncate. Mesothorax and scutellum
coarsely and closely punctured, the surface between the punctures shining. Propodeum

HYMENOPTERA 39

with a coarse rugose puncturation. Basal segment of the abdomen very coarsely
punctured towards the brow, less so near the apical margin ; second segment simple
above, not raised from the base, but with only the ordinary longitudinal convexity ;
beneath with the costae long, followed by no distinct depression, but usually somewhat
flattened triangularly in its place.

Hab. Mountains of Kauai. Not common.

(19) Ody Iter Its peles, sp. nov.

Niger, peropacus. Rlandibulae fere totae nigrae. Clypeus levissime emarginatus
vel truncatus. Capitis et mesonoti puncturatio fere obsoleta. Propodeum rugosum
vel rugoso-punctatum. Abdominis segmentum secundum baud elevatum, tantum longi-
tudinaliter convexum ; subtus, depressione distincta, minus alta. d"?. Long. 6 — 9 mm.

Male black, the abdomen never with yellow bands. Mandibles dark, the extreme
apex sometimes reddish or piceous. Apex of clypeus slightly emarginate or truncate.

Head and thorax very dull, with shallow subobsolete puncturation, sometimes almost
invisible. Mesothorax not clothed with a silky pile, but with a very short erect
pubescence, easily seen in lateral view. Propodeum rugose, generally more or less
reticulately so, the rugosities being apparently the interstices between large shallow
punctures, hardly now to be recognized as such. Abdomen dull, the basal segment
with very shallow punctures ; the second simply convex above, not raised from the base,
beneath with the depression somewhat wide at its base but not deep.

Female very like the d", with obscure puncturation, the interstices between the
punctures of the mesothorax very dull, and the minute punctures thereon not very
distinct and somewhat scattered and remote from each other.

Hab. Kona and Kau districts (2000 — 4000 ft.) of Hawaii. Not a rare species.

Obs. This species greatly resembles the following, but the d" is abundantly
distinct by the form of the clypeus and the different form of the mesothoracic
pubescence. The ? may be known by the very slightly emarginate or truncate apex
of the clypeus and the different sculpture of the surface of the mesothorax, which in the
following has the minute system of punctures very dense and distinct.

(20) Odynems sociabilis, sp. nov.

Niger, d" sericeo-pubescens. Margo segmenti primi et secundi (vel unius ex his)
apicalis saepe anguste flavus. Mandibulae ex majore parte rufae. Clypeus fortiter
dentato-emarginatus. Mesonotum puncturatione obsoleta vel fere obsoleta. Propodeum
puncturatione subobsoleta rugosum. Abdominis segmentum secundum subtus depres-

40 FAUNA HAWAIIENSIS

sionc lata, minus alta. ? minus sericeo-pubescens. Clypeus minus fortiter sed distincte
emarginatus. Mesonotum subtiliter remote punctatum (puncturatione nonnunquam fere
obsoleta), interstitiis distincte densissime punctulatis. Mandibulae plerumque rufae.
cf?. Long. 6| — 10^ mm. (Plate I. fig. 20.)

Male black, dull, with an appressed sericeous pubescence, often with the apical
margin of the first and second abdominal segments narrowly yellow, or with one or
other of them so coloured. Mandibles for the most part red. Clypeus very deeply
emarginate, the emargination forming rather more than a semicircle. Head above
the antennae dull, finely and feebly subobsoletely punctured. Mesothorax and scutellum
with an appressed pubescence concealing the surface which is hardly visibly punctured.
Propodeum with feeble subobsolete punctures, giving it generally a reticulately rugose
appearance in front. Abdomen dull, with sericeous pubescence, and very feebly
punctured. Second segment simple above, not raised from the base ; beneath with
the depression shallow, meeting the apices of the costae widely, the surface dull,
somewhat evenly punctured beyond the depression.

Female rather unlike the d", much less densely clothed with sericeous pubescence.
Mandibles entirely red, or more or less dark. The clypeus, although distinctly dentately-
emarginate, is much less deeply so than that of the rf". Mesothorax dull, with fine
sparse punctures, nearly obsolete in some examples, in others more distinct ; between
these there is an exceedingly close and distinct minute puncturation. Propodeum
rugosely punctate as in the ^. Abdomen less dull, owing to the pubescence being
much less dense.

Hab. Mountains of Maui and Hawaii in open localities from 4000 — 10,000 ft.
Common.

(21) Odynej-iis scoriaceus, sp. nov.

Praecedenti cognatissimus. </ margine apicali segmentorum 2 basalium flavo,
nonnunquam etiam pronoto postscutello, tegulisque flavo-notatis. Mandibulae rufae.
Frons dense subgrosse (nee fortiter) punctata. c/ mesonoto distinctius punctato,
? fronte dense distincteque, scutello evidenter subtiliter punctato, discernenda. ^ ? .
Long. 7 — II mm.

Very like the preceding which it exactly resembles in form, c/' with two
basal segments apparendy always pale along their apical margins. The prothorax,
postscutellum and tegulae are also sometimes spotted with yellow ; the mandibles
are red. The head above the antennae is more largely and closely and less
obsoletely punctured, than that of the preceding, the sericeous pubescence of the
thorax is less dense and the puncturation larger and more distinct. In the ? the

H YMENOP TERA

41

mandibles are also red, the head above the antennae is closely and distinctly punctured,
the mesothorax is less dull, and more strongly punctured, the minute interstitial
puncturation less extremely dense, and the scutellum is sparsely and finely but evi-
dently punctured.

Hab. Kona, Hawaii, on the coast and in the mountains (4000 ft.).

(22) Odynerns niolokaiensis, sp. nov.

Praecedenti simillimus. Fasciae abdominis i 2 pallidae plerumque plus minusve
obsoletae. Pronotum cum tuberculis, tegulae, scutellum, postscutellum, et clypeus
nonnunquam flavo-notata, vel haec omnia nigra, t^ ? fronte fortius punctata ; $ meso-
noto nitido, distinctissime punctate, distinguenda. c/?. Long. 7 — 10 mm.

Extremely like the preceding, of similar form and the mandibles red in both
sexes. (/ with the head in front evidendy less shallowly punctured. The abdominal
bands are generally more or less obsolete, and in a series of specimens much less
evident, than in the preceding species. On the other hand sometimes not only the
prothorax, tegulae and postscutellum are marked with yellow, but also the clypeus,
the tubercles of the prothorax, and the scutellum. The ? is quite distinct by the
closely and deeply punctured head in front, and the entirely shining surface of the
thorax, with its very distinct puncturation.

Hab. Molokai mountains (3000 ft).

(23) Odynerus smitkii.

Odynerus agilis, Smith, J. Linn. Soc. xiv. p. 681 (nee Smith, op. cit. iii, p. 164).

Blackburn and Cameron, P. Manch. Soc. xxv. p. 162.
Odynerus smithii, Dalla Torre, Wien. Ent. Zeitg. viii. (1889), p. 124.

Niger, alis minus infuscatis, hand evidenter caeruleo-iridescentibus. Mandibulae
nigrae. Frons post antennas flavo-notata. cf fasciis duabus abdominis pallidis dis-
tinctis, clypeo fortiter emarginato, mesonoto dense aequaliter punctato. ? mesonoto
opaco, (antice saltem) dense aequaliter punctato ; segmento abdominis 2 ventrali post
costas levissime (late tamen) depresso. cT ? . Long. b\ — 9^ mm.

Allied to the several preceding species, but of smaller average size. Black,
with a small median yellow spot just behind the antennae. The mandibles are
dark. The d" has the two basal segments of the abdomen distinctly bordered with
yellow along their apical margins, and they are obscurely and very narrowly pale
in the single ? , which I have examined.

(/ clypeus deeply emarginate, head above the antennae dull, closely punctured.
Thorax black, entirely dull ; mesothorax without sericeous appressed pubescence,

p. F. H. 6

42 FAUNA HAWAIIENSIS

closely, evenly, and distinctly punctured, the interstices with a dense minute
puncturation. Scutellum with a very similar puncturation. Propodeum rugose from
large subobsolete punctures.

? with the head above the antennae closely punctured, the interstices with very
distinct minute puncturation. Mesothorax dull, closely and evenly punctured at least
on the front half, the minute system of punctures between the larger ones, very
dense and distinct. Scutellum more finely, but distinctly punctured. Propodeum as
in the (/. Basal segment of the abdomen with shallow even puncturation, second
simple above, beneath, with the depression wide at the base but very faint.

Hab. Lanai, on the coast, and Wailuku, Maui.

The specific name ' agilis ' given to this species by Smith had already been
used by him for a species of the same genus found in the Aru Islands.

(24) Odynerus nubicola, sp. nov.

Niger, opacus, alis subhyalinis, vix iridescentibus ; frons cum pronoto plerumque
flavo-notata. Abdominis segmentum primum et secundum margine apicali flavo.
Clypeus leviter emarginatus. Mesonotum opacum, antice subaequaliter, post medium
sparsim, obscure punctatum. Abdominis segmentum secundum baud elevatum, subtus
depressione levissima, nonnunquam fere obsoleta. (/?. Long. 7 — 9 mm. (Plate I.
fig. 21 and 21 rt.)

Black, a median spot behind the antennae, two on the prothorax (rarely absent),
and the apical margin of the two basal abdominal segments, yellow. Mandibles dark.
Clypeus in both sexes emarginate at the apex, but not deeply, very convex longi-
tudinally. Head above the antennae dull, especially in the (/, with both systems of
puncturation evident. Mesothorax very densely and finely punctured between the
larger punctures, which are very shallow and subobsolete, and still further obscured in
the c/' by the appressed fuscous pubescence. The larger punctures themselves are
sparse and irregular on the posterior half of the mesothorax, but more regular in
front. Abdomen with the basal segment coarsely and shallowly subrugosely punctured ;
second simply convex above, beneath, with the depression very feeble, often hardly
evident except for a median longitudinal impressed line, the segment rising from the
apices of the costae only with the slight convexity of its surface. The wings in
both sexes are subhyaline with hardly any iridescence.

Hab. Haleakala, Maui. Common above the forest belt up to the summit, and
also within the crater.

(25) Odynerus ecostatus, sp. nov.

Niger et nitidus, alis caeruleo-iridescentibus. Mandibulae ex majore parte rufae.
Clypeus vix emarginatus. Mesonotum antice aequaliter, postice circa medium sparsim,

HYMENOPTERA

43

distincte punctatum. Abdominis segmentum primum minus dense punctatum ; secun-
dum a basi elevatum, subtus, costis obsoletis, (vel fere obsoletis), sulco nitido. i%.
Long. 8 — lo mm. (Plate I. fig. 22 and 22«.)

Black and shining, the wings dark with bright blue iridescence. Mandibles for
the most part red. Clypeus very slightly emarginate in the c/", the head above the
antennae densely punctured. Mesothorax shining, with distinct regular punctures in
front, which posteriorly towards the middle become scanty. Scutellum punctured,
more largely in the <} than the % ; propodeum smooth and punctured. Abdomen
shining, basal segment very distinctly, but not densely punctured ; the second raised
from the base but not abruptly ; beneath with the costae obsolete or nearly so, the
sulcature very shining, the depression meeting it rather widely, and the sides of the
segment rather abruptly raised from it, though not strongly, hardly attaining the
height of its basal portion.

Hab. Molokai, Lanai and Maui, in the mountain forests (2000 — 4000 ft.).

(26) Odynerus moiitamis.

Odynerus montamcs. Smith, J. Linn. Soc. xiv. p. 680. Blackburn and Cameron,
P. Manch. Soc. xxv. p. 158.

Niger, subnitidus, alis caeruleo-iridescentibus. Clypeus vix emarginatus. Meso-
notum subnitidum, distincte minus dense punctatum. Propodeum opacum et rugo-
sum. Abdominis segmentum secundum plus minusve (cf subfortiter) elevatum; subtus,
depressione lata, minus alta. c/?. Long. 7 — 11 mm.

Black, somewhat shining, wings dark and brightly iridescent. Clypeus hardly
emarginate at the apex. Head above the antennae deeply, closely and distinctly
punctured (rather more largely in the </). Mesothorax rather shining, distinctly but
not coarsely punctured, somewhat remotely in the ?, more closely and rather more
largely in the c/'. The minute interstitial puncturation is shallow and not dense, but
very evident. Propodeum dull or nearly so, and rugose. Abdomen with the basal
segment distinctly and evenly punctured ; second raised from the base, more strongly
but not very abruptly in the c/ ; beneath, with the depression shallow, but rather wide ;
the costae well developed.

Hab. Oahu, on the coast and in the mountains.

(27) Odynerus unictis, sp. nov.

c/ niger, nitidus, alis caeruleo-iridescentibus. Clypeus levissime emarginatus.
Frons minus fortiter punctata. Mesonotum subnitidum, sparsim subtiliter punctatum.
Propodeum laeve, antice (ad latera) impunctatum, concavitate sparsim minus fortiter

6—2

44 FAUNA HAWAIIENSIS

punctata. Abdominis segmentum secundum elevatum ; subtus, costis subobsoletis, a
sulco fortiter elevatum, depressione angustula, minus alta. i. Long. 7 mm.

Black, shining, wings dark with blue iridescence. Clypeus very slightly emar-
ginate at its apex ; head above the antennae rather finely and shallowly punctured.
Mesothorax with fine sparse and irregular punctures, between which the minute
system is evident, but not dense. Propodeum smooth, impunctate in front, the
posterior concavity with some very shallow punctures. Basal segment of the abdomen,
viewed laterally, forming an almost even curve from the petiole to the hind margin,
above somewhat irregularly and shallowly punctured. Second segment raised from
the base ; beneath, the depression neither very wide nor deep, the costae subobsolete,
and the segment rising at the side from their apices to a height rather greater
than that of its basal portion. <? .

Hab. Mountains near Honolulu, i cT, March 1897.

(28) Odynerus camelinns, sp. nov.

Niger, fronte post antennas rubro-notata, tegulis rubris ; (/ clypei apice, mandi-
bulis, pronoto et postscutello nonnunquam rubro-notatis ; alis caeruleo-iridescentibus.
(/ clypeus fortiter, ? levissime emarginatus. Caput post antennas opacum, distincte
punctatum. Mesonotum vix nitidum, sparsim subtiliter obscurius punctatum, densissime
etiam et minutissime punctulatum. Abdominis segmentum primum fere impunctatum,
secundum fortiter elevatum, coniforme ; subtus depressione lata, leviter impressa.
</?. Long. 7 — 10 mm. (Plate L fig. 23 and 22, a.)

Black, a median spot behind the antennae and the tegulae red. In the <^ some
or all of the following parts are also of this colour ; the mandibles, the apex of the
clypeus, the apex of the anterior and intermediate femora, the prothorax in front and
part of the postscutellum.

Clypeus of cT deeply, of ? slightly emarginate at the apex. Head above the
antennae distinctly punctured, the interstices with very distinct minute puncturation.
Mesothorax scarcely shining, very feebly and sparsely punctured, with a very minute
and close puncturation between the larger punctures. Propodeum almost dull, smooth
and scarcely punctured. Abdomen with the basal segment strongly transverse, with
very feeble, ill-defined, and sparse punctures ; second segment strongly raised from
the base into a conical form ; beneath, with the depression wide and very shallow,
in the middle the surface depressed even a little below the level of the apices of the
costae.

Hab. Molokai Mts. (2000 — 4000 ft.). Maui, lao Valley, above Lahaina, and
on Haleakala.

HYMENOPTERA 45

(29) Odynerus dromedarms.

Odynerus dromedarms, Blackburn, P. Manch. Soc. xxv. (1885-86), p. 151.

Praecedenti cognatissimus, sed tegulis atris : mesonoto magis opaco. ^ apice
tibiarum et clypei, mandibulis pronoto et postscutello nunquam rufo-notatis. c/'?-
Long. 8 — 9 mm.

Differs very little from the preceding except in colour. The c/ has no red
markings except the small median .spot behind the antennae and those behind the
eyes. In the ? the former is sometimes absent and in both sexes the tegulae are
always dark.

The surface of the thorax is rather more dull, the minute system of punctura-
tion being rather more dense, and generally the puncturation, especially of the scu-
tellum, is slightly better defined.

Hab. Kona, Hawaii (3000 — 4000 ft.). Kilauea (4000 ft.).

(30) Odynerus oaJiuensis, Dalla Torre.

Odynerus diversus, Blackburn, P. Manch. Soc. xxv. p. 161 (nee Walker).
Odynerus oahensis (sic), Dalla Torre, Wien. Ent. Zeitg. viii. (1889), p. 124.

Niger, alis ex majore parte subhyalinis, haud caeruleo-iridescentibus. Frons,
pronotum, tegulae, mesopleurae, scutellum, et postscutellum rubro-notata. Abdominis
segmentum primum et secundum postice rubro-marginata, hujus etiam lateribus rubro-
maculatis. Segmenta caetera etiam saepe plus minusve rubro-marginata.

c/' clypeo fortiter, ? vix emarginato. Mesonotum subnitidum, fortiter punctatum.
Propodeum laeve, parce subobsolete punctatum. Abdominis segmentum primum for-
titer transversum : secundum convexum, haud a basi elevatum, lateribus fortiter
rotundatis ; subtus post costas late triangulariter deplanatum, vix depressum, costis
distinctis. cT ? . Long. 8 — 10 mm.

Black, with a red median spot behind the antennae and another behind each
eye. The prothorax, tegulae, mesopleurae, scutellum and postscutellum are spotted
with red. The apical margin of the first and second abdominal segments as well as
the sides of the latter are of the same colour, and some of the following segments
are more or less red along their apical margins.

Clypeus of i strongly, of ? hardly emarginate. Head above the antennae
coarsely and very closely punctured. Mesothorax rather more largely but not quite
so closely. Scutellum sparsely punctured. Propodeum with the surface smooth,
bearing some very shallow punctures. Abdomen with the basal segment strongly

46 FAUNA HAWAIIENSIS

transverse above ; second strongly convex longitudinally, but not raised, its sides
strongly rounded ; beneath, widely flattened beyond the costae, hardly depressed, not
raised up from their apices even at its sides, the costae themselves well developed.
Wings subhyaline, the front pair infuscate along the anterior margin, but without any
blue iridescence.

Hab. Oahu, both mountain ranges. Not common.

(31) Odynerus rudolphi.

Odynerus cardinalis, Blackburn, P. Manch. Soc. xxv. p. 158 (nee Morawitz).
Odynerus imdolphi, Dalla Torre, Wien. Ent. Zeitg. viii. (1889), p. 124.

Niger, nitidus, alis purpureo-iridescentibus. Clypeus vix emarginatus. Meso-
notum sparsim subtiliter sed distincte punctatum. Propodeum laevissimum. Abdo-
minis segmentum secundum ventrale baud supra costarum apices ad latera elevatum,
costis fortibus, depressione nulla, cf ? • Long. 7 — 9 mm. (Plate I. fig. 24 and 24 a.)

Deep black and shining, generally with a minute yellow spot behind the antennae
and another behind each eye near the vertex. Wings infuscate with extremely bright
iridescence.

Clypeus hardly emarginate at the apex ; head above the antennae distinctly but
not so very closely punctured. Mesothora.x finely remotely and distinctly punctured,
the surface very highly polished, and the minute system of punctures extremely
feeble and almost obsolete. Propodeum very smooth, shining, and with at the most
a few very fine punctures. Abdomen with the basal segment, seen from the side,
evenly curved from the petiole to the hind margin ; second segment strongly convex
longitudinally ; beneath flat, with no distinct depression, the costae strong, and the
segment at the sides not rising up from their apices.

Hab. Mountains and coast of Oahu. Not rare.

(32) Odyneriis brevicostatus, sp. nov.

(/ niger, mandibulis rufis, alis nitide fuscis, margine antico tantum purpureo-
iridescente. Clypeus vix emarginatus. Mesonotum subnitidum, inaequaliter sub-
tiliter punctatum. Propodeum nitidum fere impunctatum. Abdominis segmentum
secundum fortiter convexum (baud elevatum) ; subtus, depressione definita nulla,
costis brevissimis, parte sua basali permagna et tumida. c/. Long. 6| mm.

(/ black, with the mandibles red, wings infuscate with a purple iridescence.
Clypeus truncate at the apex. Mesothorax shining, irregularly, sparsely, and finely

HYMENOPTERA 47

punctured, with the minute system of punctures between these larger ones very
distinct. Propodeum smooth and shining, hardly punctured. Abdomen shining,
basal segment remotely punctured ; second not raised from the base except by its
longitudinal convexity, which is strong ; beneath, with extremely short costae, the
basal portion of the segment in front of these very greatly developed, tumid and
shining ; beyond the costae the segment is nearly flat, not at all raised from their
apices, and without any definite depression.

Hab. Molokai mountains (3000 ft.), i </ taken.

^2)'^ Odynerus eupteryx, sp. nov.

(/ praecedenti simillimus, niger, mandibulis atque clypei apice rufis, alls caeruleo-
iridescentibus. Clypeus levissime emarginatus. Frons opaca, puncturatione fere
obsoleta. Mesonotum opacum subobsolete punctatum. Propodeum dense minutissime
rugulosum, opacum, fere impunctatum. (/. Long. 7^ mm.

Closely allied to the preceding, having the second ventral segment of the abdomen
very similarly formed, but with the costae rather longer and the tumid basal portion
of the segment less shining. Otherwise it may easily be distinguished by the following
characters. The extreme apex of the clypeus is red, as well as the mandibles, the
head above the antennae is very obscurely punctured, the thorax quite dull, the larger
system of punctures very feebly impressed, and the minute system much less distinct.
The propodeum dull, with a very minute and dense surface rugulosity. The wings
are darker with a bright blue iridescence.

Hab. Molokai mountains (3000 ft.), i i taken.

(34) Odynerus purpurifer, sp. nov.

Niger, nitidus, mandibulis clypeique apice rufis; alls fuscis, purpureo-iridescentibus.
Clypeus dentato-emarginatus. Mesonotum nitidum, subtilius minus dense punctatum.
Propodeum nitidum, sparsim subobsolete punctatum. Abdominis segmentum secundum
(praecipue </) subelevatum ; subtus, post sulcum transversum fortissime elevatum, costis
subobsoletis. c/'?. Long. 7— 11 mm. (Plate I. fig. 25 and 25a.)

Black and shining, the mandibles and apex of clypeus red, wings shining fuscous
with purple iridescence. Head above the antennae closely and distinctly punctured,
the vertex in the ? somewhat incrassate. Mesothorax with scattered punctures, the
surface between them with the minute system very distinct, but not dense. Propodeum
in front shining, with a few feebly impressed punctures. Abdomen with the basal
segment not densely punctured ; second raised from the base in the c/, but not strongly

48 FAUNA HAWAIIENSIS

or abruptly, and still less so in the ? ; beneath, the costae obsolete or nearly so, the
sulcature shining, and the part of the segment beyond it strongly and abruptly raised
to a height greater than that of its basal portion, its depression narrow but deep in
front.

Hab. Molokai mountains (3000 — 4000 ft.). Mountains of West Maui in the lao
Valley, and above Lahaina (3000 ft.). Lanai (2000 ft.).

(35) Odynerus instabilis, sp. nov.

Niger, mandibulis rufis, alis infuscatis caeruleo-iridescentibus. Caput densissime
punctatum. Mesonotum subfortiter punctatum, % postice irregulariter, interstitiis
crebre minutissime punctulatis. Propodei concavitas punctata. Abdominis segmentum
secundum basi subfortiter elevatum ; subtus, post sulcum fortiter elevatum, depressione
angusta sat distincta.

Var. Tegulis rufis vel piceis. </?. Long. 7 — 9'5 mm.

This species is very variable but quite distinct from any other. The surface in
some examples is quite dull, (especially in examples from Molokai), while in others
it is very shining. The mandibles are red, the head above the antennae densely,
but not very deeply punctured. The mesothorax is distinctly punctured, rather more
coarsely in the (/, and somewhat sparsely and irregularly on the posterior portion in
the ?. The propodeum is not rugose, but the posterior concavity is punctured. The
second segment of the abdomen is distinctly raised from the base ; beneath, it rises
up very strongly from the sulcature to an elevation much greater than its basal portion,
and there is a narrow but very distinct median depression. The wings are dark,
and have a blue iridescence. In examples from Maui the tegulae are generally red,
but in a few examples they are dark, as in the Lanai and Molokai specimens.

Hab. Molokai, Lanai, and Maui, in the mountain forests (2000 — 5000 ft.).

(36) Odynerus deinogaster, sp. nov.

Niger, subnitidus, fronte, pronoto, et nonnunquam postscutello rubro-notatis, alis
infuscatis, caeruleo-iridescentibus. Caput, mesonotum, concavitasque propodei dense
fortiter punctata. Abdominis segmentum primum dense punctatum ; secundum supra
convexum, haud a basi elevatum ; subtus, sulco transverso nitidissimo, post sulcum
fortissime abrupte elevatum, costis et depressione obsoletis. c/ ? • Long. 7 — 8 mm.
(Plate L fig. 26 and 26 a.)

Black, with a spot behind the antennae, the prothorax in front and sometimes the
postscutellum, red. Abdomen entirely black. Wings infuscate and with a blue iri-
descence. Clypeus hardly emarginate at the apex ; head above the antennae densely

HYMENOPTERA 49

punctured. Mesothorax with a somewhat coarse and close puncturation, the surface
somewhat shining and the system of minute punctures evident. Abdomen with the
basal segment closely and distinctly punctured ; second simply convex longitudinally
above ; beneath, the sulcature shining, without any costae, and the part of the segment
behind it very strongly and abruptly raised, subprominent in the middle in front, the
depression wanting.

Hab. Molokai mountains (3000 ft.). Rare. 2 d" 2 ? taken.

(37) Odyiierns homceogaster, sp. nov.

Praecedenti forma similis, sed antennarum articulo basali antice, et margine seg-
menti primi abdominis postice, rubris. </ ? . Long. 8 — 9 mm.

Perhaps only a subspecies of the preceding, but readily distinguished by the red
line on the scape of the antennae in front, and the red apical margin of the basal
abdominal segment. In the ? the abdominal band is interrupted, and less conspicuous
than that of the i.

Hab. lao Valley, Maui. 4 </ i ?.

{^%) Odyiierus hcierochromus, sp. nov.

Niger, opacus, alis caeruleo-iridescentibus. Abdominis segmentum secundum ut
in O. homoeogasteri fere formatum. Thorace opaco et colore bene distinguendus.

Var. (/. Segmentum abdominis basale postice flavo-marginatum. (/?. Long.
6^ — 8^ mm.

Black, c/" very rarely with the apical margin of the basal segment of the abdomen
pale, and sometimes with a small pale median spot just behind the antennae.

Apex of the clypeus slightly dentately-emarginate ; head above the antennae dull
with shallow and very close puncturation. Mesothorax dull, rather coarsely punctured
in the (/, in the ? the punctures are finer, sparser and less distinct. Scutellum in the
(/ closely punctured, less closely and much more finely in the ?. Propodeum towards
the sides in front rough with large shallow feebly-impressed punctures. Abdomen with
the basal segment closely, but not deeply, punctured ; second segment above not raised
from the base ; beneath, exceedingly strongly raised from the sulcature, the costae
subobsolete, and the depression wanting, or represented only by a faint longitudinal
impressed line.

Hab. Kilauea, Hawaii (4000 ft.). Common ; burrows in dead tree trunks. I did
not meet with it on the leeward side of the island.

p. F. H. 7

50 FAUNA HAWAIIENSIS

(39) Odynerus minius, sp. nov.

Forma fere praecedentis, niger, abdominis segmentis duobus basalibus postice
albido-mareinatis, alis infuscatis caeruleo-iridescentibus. Mesonotum nitidum, dense
fortiter punctatum. Abdominis segmentum secundum supra baud elevatum, leviter
convexum ; subtus, post sulcum fortissime elevatum, costis subobsoletis, depressione
nulla. (/ ? . Long. 7^ — 9 mm.

Not a large species, agreeing for the most part in form with the preceding.
Black, with the apical margins of the first and second abdominal segments yellowish-
white. The first band narrow, the second much wider.

Head and mesothorax densely and coarsely punctured, the surface of the latter
shining between the punctures. Propodeum with the surface smooth and shallowly
punctured. Basal segment of the abdomen evenly punctured ; second simple above,
slightly convex longitudinally ; beneath, extremely strongly and abruptly raised from
the sulcature (the greatest height attained being at the middle), the costae more or
less obsolete, the depression wanting, or represented only by an impressed line.

Hab. Mountains of Kauai (3000 ft.).

(40) Odynerus pseudochrotnus, sp. nov.

Niger, capitis fronte, pronoto, mesopleuris, tegulis (saepe), scutello, et postscutello
rubro-notatis. Abdominis segmentorum margines apicales, (duorum basalium dis-
tinctissime), rubri. Alae fere hyalinae, marginibus anticis et apicalibus infuscatis.
Mesonotum cum scutello dense fortiter punctatum. Abdominis segmentum secundum
minus elevatum, fortiter convexum ; subtus, fortissime post sulcum elevatum, depres-
sione distincta, minus lata. (/?. Long. 6 — 8^ mm. (Plate L fig. 27 and 27a.)

Black, with a median spot behind the antennae, another behind each eye, the
prothorax in front, a spot on the mesopleurae, a small one on the mesothorax near
the tegulae, one or more spots on the latter, part of the scutellum and postscutellum,
the hind margins of most of the abdominal segments (the first and second most widely),
and a line on the scape of the antennae of the c/, red. These markings vary a little
but are for the most part constant. Wings nearly clear, except along the margin, and
with no trace of blue iridescence.

Apex of clypeus with a depression, but hardly emarginate. Mesothorax coarsely
and densely punctured, the scutellum closely but rather less coarsely. Propodeum with
shallow puncturation. Basal segment of the abdomen densely punctured ; second

HYMENOPTERA 51

somewhat strongly convex, especially in the <^ ; beneath very strongly and abruptly
raised behind the sulcature, the costae ill defined, subobsolete, the depression very
distinct, deep in front, the segment prominent on either side of it.

Hab. Mountains of Oahu, both ranges.

Obs. This species has a most remarkable resemblance superficially to O. oahuensis.
It is less robust and lacks the red spot on the sides of the second segment of the
abdomen. The second ventral segment is as different as it well can be, and there
are other important structural differences, so that I believe the two species are not
really at all closely related ; yet their general appearance is extremely similar, and
unlike other Hawaiian species.

(41) Odynenis leiodemas, sp. nov.

Praecedenti simillimus, eodem modo rubro-notatus, sed angustior. Mesonotum
minus dense punctatum, scutello sparsius ac subtilius. Abdominis segmentum secun-
dum subtus minus fortiter post costas elevatum. ? . Long. 7^ mm.

This species is exactly like the preceding in its markings and the colour of the
wings, but is evidently narrower in form. The mesothorax is more finely and less
regularly punctured and more shining, the scutellum more finely and sparsely. The
second segment of the abdomen more strongly convex at the base longitudinally (when
seen from the side), while beneath it is evidently less strongly raised from the sulcature.

Hab. Waianae mountains, Oahu. A single % taken.

(42) Odynenis laevisiilcatns, sp. nov.

Niger, nitidus, alis infuscatis caeruleo-iridescentibus, forma gracili. Clypeus vix
emarginatus. Capitis vertex subincrassatus ; frons densissime punctata. Mesonotum
nitidum, antice aequaliter, postice ad medium subsparsim, fortiter punctatum. Pro-
podeum laeve, concavitate sua dense punctata. Abdominis segmentum secundum
subelevatum vel fortiter convexum ; subtus, post sulcum transversum, ad altitudinem
partis suae basalis (vel magis alte) elevatum, depressione angusta distinctissima, sulco
ipso nitido, costis fere obsoletis. %. Long. 7 — 8 mm.

Female black, wings infuscate, with blue iridescence. Apex of clypeus hardly
emarginate. Head above the antennae very closely punctured, the vertex incrassate.
Mesothorax strongly punctured, evenly in front, posteriorly, at least about the middle,
somewhat sparsely. The puncturation of the scutellum is also very distinct, but finer
than that of the mesothorax. Propodeum with the surface smooth and shining,
distinctly but not deeply punctured, densely so in the posterior concavity. Abdomen

52 FAUNA HAWAIIENSIS

shining, basal segment with distinct nearly even puncturation ; second somewhat
raised from the base, or at least very strongly convex ; beneath, raised above the
sulcature to a height rather greater than that of its basal portion, the sulcature itself
shining, with indistinct, nearly obsolete costae, the depression narrow but ver\'
distinct.

Hab. Haleakala, Maui (5000 ft.). Two ? taken in the early part of 1894;
probably rare, as it was not met with again on several subsequent visits.

(43) Odynerus xanthorhoes, sp. nov.

Niger, nitidus, alis fuscis, nitidissimis. Abdomen fasciis duabus ferrugineo-flavis.
Frons, pronotum, mesopleurae, tegulae plerumque, postscutellum, tibiaeque omnes
(plus minusve), eodem colore decorata. Mesonotum ( ? praecipue) remote puncta-
tum, minutissime etiam et dense punctulatum. Propodeum fortiter rugosum. Abdo-
minis segmentum primum ad basim grossissime punctatum ; secundum in formam
conicam fortiter elevatum. </ ? . Long. 8 — 9 mm.

Black, with a median spot behind the antennae, another behind each eye, part
of the prothorax, a spot on the mesopleurae, the tegulae more or less, the post-
scutellum in front, the hind margin of the two basal abdominal segments, all the
tibiae more or less, of an orange-yellow colour. Mesonotum shining, the system of
larger punctures distinct but not coarse, and on the posterior half the puncturation
is sparse and irregular. In the % these punctures are finer than in the cf and much
more sparing, the system of minute punctures occupying the greater part of the
surface. Propodeum with coarse rugose sculpture. Abdomen shining, basal segment
very coarsely punctured towards the base ; second raised near the base into a conical
form ; beneath beyond the sulcature also raised to a height equal to, or slightly
greater than, that of its basal portion, the depression short and narrow, but distinct.

Hab, Mountains of Kauai (2500 — 3000 ft.). Local.

(44) Odyneriis nivicola, sp. nov.

Niger, alis infuscatis, caeruleo-iridescentibus, abdominis segmentis duobus basa-
libus flavo-marginatis. Clypeus distincte emarginatus. Mesonotum plus minusve
nitidum, irregulariter punctatum, interstitiis dense subtilissime punctulatis. Propodeum
opacum et rugosum. Abdominis segmentum secundum (praecipue maris) abrupte
elevatum; subtus, post sulcum fortiter elevatum, depressione angustula. cf?. Long.
6 — 9 mm.

HYMENOPTERA 53

Black, the wings with blue iridescence, the apical margins of the two basal
segments of the abdomen pale yellow.

Clypeus distinctly emarginate at the apex ; the head above the antennae closely
and distinctly punctured. Mesothorax more or less shining, sparsely irregularly and
not coarsely punctured (in the % generally more finely and sparsely than in the (/) ;
between these punctures with a fine and close puncturation, which is generally clearer
in the ? than in the cf. Propodeum dull, and more or less rugose towards the
sides. Basal segment of the abdomen with shallow punctures ; second abruptly and
rather strongly raised from the base ; beneath, finely punctured, and abruptly raised
from the apices of the costae, the depression narrow.

Hab. Haleakala, Maui. In the higher forest, and above it to an elevation of
8000 ft., and also in the summit crater.

(45) Odyncrus dryas, sp. nov.

Niger, alis infuscatis, caeruleo-iridescentibus, capite, thorace et abdomine rufo-
notatis. Pronotum rufo-maculatum. Abdominis segmentorum 2 basalium apices
rufo-marginati. Mesonotum nitidum, sparsim irregulariter punctatum. Abdominis
segmentum secundum elevatum ; subtus depressione sat lata. c/?. 7 — 8 mm.

Black, the wings infuscate and with blue iridescence. A median spot on the
head behind the antennae, two large ones on the prothorax, one below each of the
tubercles, sometimes one on each of the tegulae, the postscutellum, two spots some-
times on the scutellum, the propodeum more or less at the sides, of a bright red
colour. Basal segment of the abdomen with an apical red band strongly dilated at
the sides, and the apical margin of the second of the same colour.

Mandibles black. Clypeus very slightly dentately-emarginate ; head above the
antennae closely punctured. Mesothorax smooth and shining, somewhat finely ir-
regularly punctured, the surface between these punctures with very minute but quite
evident puncturation ; scutellum sparsely punctured ; propodeum with the posterior
concavity closely punctured. Abdomen with the basal segment coarsely and evenly
punctured ; second raised from the base but not very strongly ; beneath, at the sides,
raised from the apices of the costae to about the height of the basal portion of the
segment, the depression wide but not deep.

Hab. Haleakala, Maui, 5000 ft. 3 J' 1 ?.

(46) Odynerus erythrostactes, sp. nov.

Niger, alis infuscatis, caeruleo-iridescentibus, fronte, pronoto, tegulis, mesopleuris
et postscutello rubro-notatis. </ tibiis anticis saepe, intermediis posticisque rarius,
articuloque basali antennarum plus minusve, rubro-lineatis. Abdominis segmentum

54 FAUNA HAWAIIENSIS

primum postice rubro-marginatum. cT-is clypeus leviter, ?-ae vix emarginatus.
Mesonotum subnitidum, distincte punctatum. Propodeum rugosum. Abdominis seg-
mentum secundum fortiter elevatum, lateribus subcompressis ; subtus, depressione post
costas distincta, minus alta. </?. Long. 7 — 10-5 mm.

Black, the wings infuscate and with blue iridescence. A median spot behind
the antennae, one on either side of the prothorax, nearly united, one or more on the
tegulae, one on the mesopleurae, the postscutellum in front, and the hind margin of
the basal segment of the abdomen, red. In the ^ the front tibiae usually, sometimes
the intermediate, and rarely the posterior are more or less red, as also a longer or
shorter line on the scape of the antennae.

Clypeus of cT dentately-emarginate but not deeply. Head above the antennae
closely and rugosely punctured. Mesothorax distinctly punctured, less closely and
regularly behind than in front, between these punctures with a distinct minute
puncturation, the surface more or less smooth and shining. Propodeum rugose.
Abdomen with the basal segment largely punctured ; second very finely and
remotely, except towards the apical margin, strongly raised from the base in both
sexes, its sides somewhat compressed ; beneath, with the depression distinct, but
shallow, rather deeper in the ? than in the j", the segment at the sides not at all
strongly raised from the apices of the costae.

Hab. Molokai mountains (3000 ft.). lao Valley, Maui, 2 ^ not quite typical,
having the apical margin of the second abdominal segment red at the sides, and
below the average size of the species.

{47) Odynerits luontivagui, sp. nov.

Niger, alis infuscatis, caeruleo-iridescentibus. Caput nigrum, mandibulis rufis.
Pronotum rubro-notatum. Abdominis segmentum primum margine apicali late rubro ;
secundum utrinque rubro-maculatum. Mesonotum subnitidum, distincte punctatum.
Propodeum laeve, fere impunctatum. Abdominis segmentum 2 ventrale depressione
angustula. cT?. Long. 6 — 7 mm.

Black, the mandibles red. Prothorax with red markings, the rest of the thorax
black. Apical margin of the basal segment of the abdomen with a wide red band,
second segment with a red spot on either side.

Clypeus distincdy dentately-emarginate at the apex (but not deeply) in the c/,
less distincdy so in the ?. Head above the antennae more or less shining, very
closely and distinctly punctured. Mesothorax and scutellum not coarsely, but some-
what deeply and remotely punctured ; propodeum almost smooth, slightly shining, and
nearly impunctate. Basal segment of the abdomen hardly shining, with irregular
shallow puncturation ; second segment rather abruptly, but not very strongly, raised

HYMENOPTERA 55

from the base ; on its ventral surface it rises strongly and abruptly from the apices
of the costae, its depression short and narrow and rather deep in front.

Hab. Molokai mountains (3000 — 4000 ft.). \ ^ \ %. lao Valley, Maui, i %.

(48) Odyneriis microdetnas, sp. nov.

Niger, alis infuscatis, caeruleo-iridescentibus, fronte, pronoto, mesopleuris, post-
scutello, lateribusque propodei rubro-notatis. Abdominis segmentum primum ex majore
parte rubrum ; secundum ad latera nonnunquam rubro-maculatum.

Caput supra antennas nitidum, dense punctatum. Mesonotum laeve, grosse
fortiterque punctatum. Abdominis segmentum secundum minus elevatum, subtus
depressione angustula. </$. Long. 5 — 7 mm.

Black, the wings dark, with blue iridescence. The front of the head, the
prothorax, the mesopleurae, postscutellum and sides of the propodeum have red
markings. The basal segment of the abdomen is red over the greater part of its
surface, and the second is sometimes spotted at the sides.

Head above the antennae closely coarsely and shallowly punctured, the apex of
the clypeus hardly emarginate. Mesothorax coarsely punctured, the surface smooth
between these punctures and almost (or quite) without the minute interstitial punctu-
ration. Abdomen with the second segment not much raised from the base, shining
and shallowly punctured ; seen from beneath, its ventral surface is somewhat strongly
raised from the costae at the sides, and even in the middle the depressed portion,
where it meets these, rises up convexly from their apices ; the depression itself not
very wide.

Hab. Molokai mountains (3000 ft.).

(49) Odyneriis monobius, sp. nov.

Niger, alis infuscatis, caeruleo-iridescentibus, fronte, pronoto, mesopleurisque
rubro-maculatis ; abdominis segmento primo postice interrupte rubro-marginato. Clypeus
levissime dentato-emarginatus. Caput supra antennas laeve, distincte punctatum.
Mesonotum subfortiter et irregulariter, propodeum in concavitate sua dense punctatum.
Abdominis segmentum primum dense et grosse punctatum ; secundum evidenter
elevatum ; subtus, ad latera minus fortiter sed abrupte supra costarum apices eleva-
tum, depressione costis oblique occurrente. </. Long. 6 mm.

Male black, wings infuscate, with blue iridescence. A median spot behind the
antennae, the prothorax in front, a spot on the mesopleurae, and the apical margin
of the basal abdominal segment narrowly, red. Head above the antennae smooth,

56

FAUNA HAWAIIENSIS

and somewhat largely punctured. Mesothorax irregularly punctured, the punctures
closer in front and much sparser posteriorly, the surface smooth with minute inter-
stitial puncturation visible, but by no means distinct. Propodeum with the concavity
densely punctured. Basal segment of the abdomen coarsely, closely, and rugosely
punctured ; second evidently, but not very strongly, raised from the base ; beneath,
the depression shallow, the segment at the sides abruptly raised above the apices of
the costae, to a height about equal to that of its basal portion.

Hab. Mountains of Molokai (3000 ft.), i i.

(50) Odynerns rubritiiictus.

Odynerus rtibritinchis, Smith, J. Linn. Soc. xiv. p. 679. Blackburn and Cameron,

P. Manch. Soc. Vol. xxv. p. 155.
Odynerus sandwichensis, Dalla Torre, Cat. Hym. Fam. Vesp. (nee Saussure).

Niger, pronoto nigro, fronte, tegulis, mesopleuris, scutello saepe, postscutello
et propodeo rubro-notatis ; abdominis segmento primo fere toto rubro, secundi margine
apicali lateribusque rubris. Caput supra antennas cum mesonoto nitidum, et grosse
punctatum. Abdominis segmentum secundum convexum, vix elevatum. c/ ? • Long.
5 — 8 mm.

Black, the wings infuscate, with a blue or violaceous iridescence. The head in
front, the tegulae, mesopleurae, the scutellum often, the postscutellum, and propodeum
have red markings. The prothorax is black. Basal segment of the abdomen entirely
or almost entirely, the apical margin of the second segment, and its sides, red.
Head and thorax shining, coarsely punctured. Basal segment of the abdomen with
close shallow punctures ; second segment rather strongly convex longitudinally ; be-
neath, at the sides, raised from the apices of the costae, the depression which is
moderately wide meeting them obliquely.

Hab. Lanai, on the coast. Haleakala, Maui (4000 ft. or more). Not a rare
species. Referred by Dalla Torre in his catalogue to O. sandzvichensis, but probably
distinct.

(51) Odynerus potamophibis, sp. nov.

Niger, fronte, pronoto, mesopleuris, tegulis, scutello, postscutello, et propodeo
rubro-notatis. Abdominis segmentum primum fere totum rubrum ; secundum margine
apicali lateribusque suis rubris. Caput supra antennas cum mesonoto nitidum et
fortiter punctatum. Abdominis segmentum secundum vix elevatum ; subtus, depres-
sione costarum apicibus oblique occurrente. ?. Long. 7 — 8-5 mm.

HYMENOPTERA . 57

Very closely allied to the preceding but readily distinguished by the red mark-
ings of the prothorax. The mesothorax in front is rather less coarsely punctured,
the punctures are deeper and more distinct, being more distant. The structure of
the second ventral segment of the abdomen is very similar in the two species.

Hab. Haleakala, Maui (4000 — 5000ft.). Rare. 3?.

(52) Odyneriis petrobiiis, sp. nov.

Niger, subnitidus, alls infuscatis, caeruleo-iridescentibus. F" route, mesopleuris,
tegulis, nonnunquam scutello, postscutello, et propodeo, rubro-notatis. Segmentum
abdominis primum late rubrum ; secundum lateribus nonnunquam rubro-maculatis.
Caput cum mesonoto grosse denseque punctatum. Segmentum abdominis secundum
vix elevatum ; subtus, depressione lata, c/ ? . Long. 5 — 8 mm.

Black, the wings with blue iridescence. The front of the head, the tegulae,
mesopleurae, sometimes the scutellum, the postscutellum, the propodeum at the
sides, the basal segment of the abdomen over a large part of its surface, and some-
times the sides of the second, have red markings. The prothorax and apical margin
of the second abdominal segment are black. Clypeus truncate or very slightly
emarginate at the apex ; head coarsely and very closely punctured, especially in the
c(*. Mesothorax with close and large puncturation, less regular posteriorly in the ? ;
scutellum punctured, generally more finely in the ? than in the <} . Propodeum with
shallow, large punctures. Basal segment of the abdomen with coarse punctures,
especially towards the base ; second segment convex, hardly raised ; beneath with
the depression wide and rather deep, the segment at the sides being raised from
the apices of the costae to a height equal to, or rather greater than, that of its
basal portion.

Hab. Molokai coast, and in the mountains as high as 3000 ft.

(53) Odynenis rubropustulatus.

Odyneriis rubropustulatus, Blackburn, P. Manch. Soc. Vol. xxv.. Session 1885 —

1886, p. 159.
Niger, rubro-notatus, alis infuscatis caeruleo-iridescentibus, praecedenti simillimus,
mesonoto minus dense punctato, thorace toto cum propodeo nigro bene distin-
guendus. i % . Long. 6 — 8 mm.

Very closely allied to the preceding, the wings with a similar bright blue
iridescence. The thorax is rather less shining between the punctures, which are
r. F. H. 8

58 FAUNA HAWAIIENSIS

less strong; and the propodeum as well as the rest of the thorax is entirely black,
without red markings. The depression beyond the costae of the second ventral
segment is also of a somewhat different character, and less deep.

Hab. Mountains of Hawaii (4000 ft.), Kona and Kau districts.

(54) Odynerus blackburni.

Odynej'tis blackburni, Kirby, Ent. Month. Mag. xvii. p. 87. Blackburn, P.
Manch. Soc. Vol. xxv. No. 8, Session 1885 — 1886, p. 156.

Odynerus rubritinctus, Smith ^ nee ?. J. Linn. Soc. Vol. xiv. p. 674.

Niger, alis fuscis, subaeneo- vel violaceo-micantibus, fronte, tegulis, mesopleuris,
scutello plus minusve, postscutello, et propodeo rubro-notatis. Abdominis segmentum
primum ex majore parte rubrum ; secundum maculis lateralibus rubris. Coxis femori-
busque saepe plus minusve rufis. (/?. Long. 6 — 9 mm.

Form and sculpture much as in the two preceding species, with which it agrees
also in having the prothorax and apical margin of the second abdominal segment
black. The scutellum is always spotted with red, sometimes almost entirely of that
colour, and the second segment of the abdomen has large lateral red spots. The
propodeum is largely red. The head, thorax, and basal segment of the abdomen
are covered with large and close punctures ; the second segment longitudinally convex,
but not evidently raised from the base. The wings are dark with somewhat of a
brassy glitter, and in some specimens with more or less violaceous iridescence, but
not blue.

Hab. Kauai coast and lower slopes of the mountains. Abundant.

(55) Odynerus soror, sp. nov.

0. blackburni simillimus, sed pronoto anguste rufo-lineato, mesonoto magis nitido,
postice magis profunde punctato, abdominis segmento secundo fortius convexo dis-
tinguendus. ?. Long. 8 mm.

Very like O. blackburni, the wings of the same colour, without any bright blue
iridescence. The prothorax in front has a narrow red line on each side, the whole
thorax is more shining, the puncturation of the mesothorax is deeper and clearer
posteriorly ; the second segment of the abdomen is rather more strongly convex
longitudinally, and beneath, its depression is rather deeper.

Hab. Mountains of Kauai in the forest (3000ft.); 2? taken.

HYMENOPTERA 59

(56) Odynerus /rater, D. T.

Odynerns f rater, Dalla Torre, Cat. Hym. Fam. Vespidae.

Odynerus pacific us, Blackburn, P. Manch. Soc. Vol. xxv. (1885 — 1886), p. 159;
(nee Kirsch).

Niger, opacus, alis obscure caeruleo-iridescentibus, abdominis segmento prime
et secundo totis, vel fere totis, rufis. Clypeus emarginatus. Caput cum mesonoto
peropacum, subobsolete punctatum. Abdominis segmentum secundum haud quaquam
elevatum ; subtus, depressione lata. Thorax cum propodeo totus niger, tegulis non-
nunquam rufis. c/?. Long. 5-5 — 8 mm.

Black, the wings infuscate and with slight blue iridescence. Two basal seg-
ments of the abdomen nearly entirely red. Clypeus distinctly emarginate, head and
thorax with the surface very dull, and the punctures feebly impressed, more nearly
obsolete in some examples than in others. Abdomen with the basal segment dull,
closely, but very shallowly, punctured ; second slightly shining, simply convex longi-
tudinally ; beneath, with the depression well-defined, meeting the apices of the costae
widely at its base.

Hab. Hawaii, on the coast. Molokai and Maui coast, and lower slopes of the
mountains. On the latter two islands this species has the tegulae red ; those from
Hawaii have these parts black.

{57) Odynerus obscure-punctatus.

Odynerus obsciire-punctatus, Blackburn, 1. c. p. 160.

Niger, alis infuscatis, laete caeruleo-iridescentibus, thorace cum propodeo nigro,
abdominis segmentis 2 basalibus maculis rubris lateralibus ornatis. Caput supra
antennas subobsolete punctatum. Mesonotum peropacum, plus minusve obscure et
subobsolete punctatum, propodei puncturatione fere obsoleta. Abdominis segmentum
primum aequaliter punctatum, segmenti 2 ventralis depressione lata, costarum apicibus
late occurrente. Long, c/ 6 — 8, ? 8 — 9 mm. (Plate L fig. 13.)

Black, wings infuscate, and with bright blue iridescence. Mandibles more or
less red. Thorax and propodeum without red markings. Two basal segments of
the abdomen w^ith red lateral spots. Clypeus very slightly emarginate or truncate ;
head above the antennae with very feebly impressed puncturation. Thorax very dull,
with very shallow more or less obsolete punctures. Propodeum with indications of
large, shallow puncturation. Abdomen shining, basal segment evenly punctured ;

8—2

6o FAUNA HAWAIIENSIS

second more finely so, somewhat strongly convex at the base in the i, less strongly
in the ? ; beneath with a well-marked deep depression, meeting the apices of the
costae widely at its base.

Hab. Kona district of Hawaii, on the coast, and in the mountains up to an
elevation of 3000 ft. or more. Oahu } Beechey e.xpedition. In the British Museum.

(58) Odynerus dyserythrias, sp. nov.

Niger, alis infuscatis, caeruleo-iridescentibus, abdominis segmento secundo
subtus rubro, nonnunquam lateribus ejus rubro-maculatis ; mandibulis rufis. Clypeus
distincte dentato-emarginatus. Caput supra antennas confertissime, mesonotum dense
fortiterque punctatum. Propodeum rugosum. Abdominis segmentum 2 ventrale
depressione angustula, minus alta. </. Long. 8 mm.

Male black, the abdomen entirely black above, or with a red spot at the sides
of the second segment, which beneath is nearly entirely red. Mandibles red, the
clypeus distinctly dentately-emarginate ; head above the antennae very densely
punctured ; mesothorax deeply and closely (more densely in some examples than in
others), the interstices between these punctures somewhat shining and minutely
punctured ; scutellum very distinctly punctured, but more finely than the mesothorax ;
propodeum rugose. Abdomen with the basal segment closely and evenly punctured ;
second segment beneath raised at the sides above the apices of the costae to about
the height of its basal portion, the depression feeble, with a more deeply impressed
median line.

Hab. Kilauea, Hawaii (4000 ft.). Eight or nine cf taken, but no ?.

(59) Odynerus cyanopteryx, sp. nov.

Niger, alis infuscatis, caeruleo-iridescentibus, mandibulis cum apice clypei rufis,
abdominis segmenti secundi lateribus rubro-maculatis. Mesonotum opacum, subtilius,
sat distincte punctatum. Abdominis segmentum secundum juxta basim subelevatum ;
subtus, costis brevissimis, depressione levissima et angustissima. c/ ? • Long. 7 — 9 mm.
(Plate L fig. 28 and 28«.)

Black, the wings with bright blue iridescence, the thorax entirely black, as also
the basal segment of the abdomen. Mandibles and apex of clypeus red. Second
segment of the abdomen with a red spot at the sides in front, and more or less red
on its ventral surface. In one example these markings are very obscure, but they
can be seen in a favourable light. Apex of clypeus very slightly dentately-emarginate ;
the head above the antennae dull, and shallowly punctured. Mesonotum not coarsely.

HYMENOPTERA 6i

but quite distinctly punctured, the surface dull. Abdomen with the surface shining,
the basal segment depressed along its apical margin, with shallow puncturation ;
second segment evidently raised from its base, especially in the i ; beneath with the
costae very short, the depression narrow and very light, sometimes hardly evident.
Hab. Kona and Kau districts of Hawaii (4000 ft.).

(60) Odyneriis egens, sp. nov.

Niger, alls infuscatis, caeruleo-iridescentibus, mandibulis et apice clypei rubris,
abdomine toto nigro. Caput cum mesonoto peropacum, vix evidenter punctatum.
Abdominis segmentum 2 ventrale costis fortibus et brevissimis, post has subplanum,
depressione nulla. Long. cT 8 mm.

Black, the wings with blue iridescence, the apex of the clypeus and the man-
dibles red. Thorax and abdomen black. On the second ventral segment of the
latter a faint reddish tint can be seen in a strong light. Head and thorax with the
surface finely roughened, dull, the puncturation almost obsolete. With a very strong
lens both systems of the thoracic punctures can be seen to be present, but very
feebly impressed ; the minute ones are rather less nearly obsolete, and form the chief
part of the puncturation. The mesothorax in front has a smooth median line, ex-
tending back about one-third of its whole length. The second segment of the
abdomen is very little raised from the base ; beneath, the costae are short but strong,
not so long as the basal part of the segment, which is shining ; beyond the costae
there is no evident depression, but the surface is nearly flat.

Hab. Kona, Hawaii (4000 ft.), Aug. 19, 1892, 1 ^.

(6 1 ) Odyneriis nesiotes, sp. nov.

Niger, alis infuscatis, caeruleo-iridescentibus, abdominis segmentorum 2 basalium
marginibus postice albo-marginatis. Mesonotum subnitidum grosse, fortiter, denseque
punctatum. Abdominis segmentum 2 ventrale sulco nitido, costis fere obsoletis, de-
pressione lineari, minus distincta. t/?. Long. 7 '5 — 9 mm.

Black, the wings with blue iridescence. Basal segment of the abdomen with
a narrow, and the second with a wide, cream-coloured apical band. Head above the
antennae, and the mesothorax, very densely, coarsely and rugosely punctured, the
surface between the punctures shining. Propodeum with evident but shallow punc-
turation. Abdomen with the basal segment densely punctured ; second segment be-
neath, with the sulcature for the most part smooth, with only traces of the costae at
its base, the depression represented by a faintly impressed line.

Hab. Mountains of Kauai, near Makaweli (2000 — 3000 ft.).

62 FAUNA HAWAIIENSIS

(62) Odyneriis dubiosus.

Odynerus dubiosus. Smith, Proc. Linn. Soc. xiv. p. 681. Blackburn and Came-
ron, 1. c. p. 155.

Niger, alis fuscis, liaud caeruleo-iridescentibus. Mesonotum vix nitidum, </ sub-
grosse, ? sLibtilius punctatum. Abdominis segmentum primum juxta basim grosse
punctatum ; secundum longitudinaliter convexum, vix elevatum ; subtus, depressione
distincta, sat lata. i%. Long. 6 — 8 mm.

Black, the wings shining fuscous, without blue iridescence. Apex of clypeus
depressed, hardly emarginate, head above the antennae with close and very shallow
punctures. Mesothorax with the surface very slightly shining, somewhat coarsely
punctured, but not deeply. Propodeum with very shallow punctures, giving it a more
or less rugose appearance. Basal segment of the abdomen coarsely punctured at the
base, the punctures becoming finer towards the apex ; second segment hardly raised
from the base, but longitudinally convex ; beneath, with a very distinct depression,
which is wide in front.

Hab. Honolulu, Waianae, &c., Oahu ; on the plains. Very abundant round walls
built of lava, in the holes of which it forms its cells.

(63) Odynerus threnodes, sp. nov.

Niger, opacus, alis fuscis, subaeneo-micantibus. Clypeus vix emarginatus. Meso-
notum opacum, crebre, aequaliter, nee grosse, punctatum. Abdominis segmentum
secundum minus elevatum ; subtus, depressione lata, sat alta, costis oblique occurrente.
?. Long. 6"5 — 8 mm.

Female black, with the wings shining fuscous and with a slight bronzy tint in
certain aspects. Mandibles black, reddish at the tips ; clypeus depressed at the apex,
hardly emarginate ; head above the antennae dull, with close but shallow punctures.
Mesothorax dull, for the most part evenly and rather finely punctured ; propodeum
with the surface finely rugulose, the puncturation nearly obsolete. Basal segment of
the abdomen in dorsal view about as long as wide, closely and shallowly punctured,
the punctures coarser than those of the mesothorax ; second segment scarcely raised
from the base, hardly more than ordinarily convex ; its sides beneath rather strongly
raised from the apices of the costae, attaining a height evidently greater than that of
the basal portion of the segment, the depression somewhat wide and deep, meeting
the apices of the costae obliquely.

Hab. Waianae Mountains, Oahu (2000 ft. or more). 2 ?.

HYMENOPTERA 63

This species is very closely allied to the preceding, but may be distinguished by
the more shining mandibles, the duller surface of the mesothorax, which is more
finely and rather more deeply punctured, and by the deeper depression of the second
ventral segment of the abdomen.

(64) Odynenis pteropkaennes, sp. nov.

Niger, nitidus, alls fuscis, micantibus, clypei apice truncato. Mesonotum nitidum
sparsim irregulariter punctatum ; propodeum laeve, haud dense punctatum. Abdominis
segmentum secundum subfortiter elevatum, nitidum, puncturatione fere obsoleta ;
subtus, depressione minus lata. ?. Long. 7-5 mm.

Female black, shining ; wings fuscous, darker along the costal margin. Clypeus
truncate at the ape.x, head above the antennae smooth and shining, with shallow
punctures. Mesothorax shining, with fine sparse and irregular puncturation, propo-
deum smooth, but less shining than the rest of the thorax, with evident, but shallow,
punctures. Abdomen shining, nearly vertical in front, coarsely punctured at the base,
the punctures decreasing in size towards the apex ; second segment rather abruptly
raised from the base, with very fine indistinct punctures, even to the apical margin ;
beneath, with the depression narrow and not deep.

Hab. Oahu, a single ? taken in March, 1893, on the coast at Waialua, and a
second in the Waianae Mountains (2000 ft.) in February, 1896.

(65) Odynerus iopteryx, sp. nov.

Niger, alis infuscatis, caeruleo-iridescentibus. Clypeus apice truncato ; meso-
notum subnitidum, sparsim subtiliter punctatum ; propodeum opacum et rugosum.
Abdominis segmentum primum juxta basim grosse, secundum vel ad apicem vix
punctatum. ?. Long. 7 mm.

Female black, the wings infuscate and with blue iridescence. Clypeus truncate
at the apex ; head above the antennae shining, with close and very shallow punc-
tures. Mesothorax not very shining, finely and sparsely punctured, and with a distinct,
but extremely fine, interstitial puncturation ; scutellum with a few very feeble fine
punctures ; propodeum dull and rugose. Basal segment of the abdomen with very
coarse shallow punctures at the base, less coarse towards the apex; second segment
very strongly convex longitudinally from the base, its surface shining and without a
definite puncturation, although in certain aspects traces of nearly obsolete punctures
can be discerned ; beneath, at the sides, it is raised from the apices of the costae to
about the height of its basal portion, the depression shallow.

Hab. A single ? taken in the Waianae Mountains, Oahu, in April, 1892, at an
elevation of over 2000 ft.

64 FAUNA HAWAIIENSIS

(66) Odynerus ivaianaeanus, sp. nov.

Ni'o-er, alis nitide fuscis, baud caeruleo-iridescentibus, abdominis segmento primo
postice flavo-marginato. Clypeus leviter dentato-emarginatus. Mesonotum minus ni-
tidum, subfortiter punctatum. Abdominis segmentum 2 ventrale depressione angus-
tissima, haud alta. (/. Long. 7 mm.

Male black, the wings fuscous, iridescent, but not blue ; basal segment of the
abdomen narrowly pale along its posterior margin. Clypeus slightly dentately-emar-
ginate at the apex, head above the antennae closely punctured. Mesothorax slightly
shining, somewhat coarsely and closely punctured. Propodeum with the surface some-
what smooth and bearing some large and very shallow punctures. Basal segment
of the abdomen as long as wide in dorsal aspect, depressed along the apical margin,
with shallow irregular punctures. Second evidently raised from the base ; beneath
with the depression very shallow and narrow.

Hab. Waianae, Oahu, on the coast. 1 (/ taken.

(67) Odynerus floscuhis, sp. nov.

Praecedenti simillimus, abdominis segmentis duobus basalibus postice albo-margi-
natis. i. Long. 7 mm.

Very like the preceding, of which it may possibly be a variety. It differs in
having a rather wide yellowish-white apical band on the second segment of the
abdomen, which is continued on the ventral surface. The mesothorax posteriorly
is rather more rugosely punctate, and the depression of the second ventral segment
is more definite, with a well-marked impressed median line.

Hab. Waianae, Oahu, on the coast ; i i taken.

(68) Odynerus cooki, sp. nov.

Niger, alis fuscis, nitentibus, iridescentibus, haud caeruleis ; abdominis segmentis
duobus basalibus postice flavo-marginatis. Mesonotum opacum, subtilius punctatum.
Abdominis segmentum secundum longitudinaliter convexum ; subtus, costis validis>
depressione nulla, t/. Long. 5 — 6 mm.

Male black, the wings shining, fuscous, iridescent, but not blue. Apical margin
of each of the two basal abdominal segments narrowly yellowish-white. A minute
median spot behind the insertion of the antennae, and one behind each eye of the
same colour. Clypeus slightly dentately-emarginate. Head above the antennae with

HYMENOPTERA 65

obscure, ill-defined punctures. Mesothorax dull, somewhat finely and not closely
punctured, the punctures shallow. Propodeum dull, with the posterior concavity ru-
gose. Basal segment of the abdomen transverse in dorsal aspect, with shallow punc-
tures ; second simply convex longitudinally above ; beneath with the costae strong,
followed by a smooth space in the part usually occupied by a depression, which in
this species is wanting, the segment being nearly flat beyond the costae and not
elevated even at the sides.

Hab. Kealakeakua bay, Hawaii ; cT only taken, close to the monument erected
to Captain Cook.

(69) Odynerits accelogasier, sp. nov.

Niger, alls infuscatis, subcaeruleo-iridescentibus, clypeo, fronte, tegulis, post-
scutello, tibiisque flavo-notatis, abdominis segmentis duobus basalibus postice flavo-
marginatis. Clypeus apice truncato. Mesonotum vix nitidum, distincte, sed postice
minus aequaliter, punctatum. Abdominis segmentum 2 ventrale costis parte sua basali
brevioribus, post has subplanum, depressione obsoleta. </. Long. 7'5 mm.

Male black, the clypeus, a median spot behind the antennae, one on the tegulae,
the postscutellum, the tibiae more or less above, and the hind margin of the two
basal abdominal segments, pale yellow. Wings infuscate and with a blue irides-
cence. Apex of clypeus truncate. Mesothorax slightly shining, distinctly and rather
finely punctured, more sparsely posteriorly than in front. Propodeum dull, somewhat
finely rugose. Basal segment of the abdomen with shallow punctures ; second some-
what raised from the base ; beneath, with the costae short, shorter than the basal
portion of the segment, which is tumid ; beyond the costae the segment is nearly
flat, and without any definite depression.

Hab. Waianae, near sea-level ; i c/ taken. The markings would probably vary
in a series, but the species is very distinct structurally.

(70) Odynerus vittativentiHs, sp. nov.

Niger, alis infuscatis caeruleo-iridescentibus, abdominis segmentis duobus basa-
libus postice albo-marginatis. Mesonotum dense distincteque nee grosse punctatum.
Propodeum sublaeve, vix evidenter punctatum. Abdominis segmentum 2 ventrale
costis brevissimis, sat fortibus, parte sua basali tumida, post costas depressione nulla.
</?. Long. 8 — 10 mm. (Plate L fig. 29 and 29^.)

Black, the wings infuscate, and with blue iridescence, the two basal segments
of the abdomen with yellowish-white apical bands, that on the second the wider.
Clypeus slightly dentately-emarginate in the (/, truncate or nearly so in the ?.
p. F. H. 9

66 FAUNA HAWAIIENSIS

Mesothorax dull in the c/, generally somewhat shining in the ?, distinctly and
closely, but not coarsely, punctured. Propodeum somewhat smooth, with very
obscure traces of puncturation. Basal segment of the abdomen finely and not very
closely punctured ; second hardly raised from the base ; beneath, with the costae very
short, although rather strong, much shorter than the tumid and strongly developed
basal portion of the segment, beyond the costae somewhat flat, and with no evident
depression.

Hab. Mountains of Kauai ; not rare.

(7 I ) Odynerus cephalostictus, sp. nov.

Niger, alis infuscatis, caeruleo-iridescentibus, fronte flavo-notata, abdominis seg-
mento primo rufescente, secundi lateribus rufo-maculatis. Clypeus fortiter emarginatus.
Mesonotum minus nitidum, inaequaliter subtiliterque punctatum. Propodeum opacum
subobsolete rugoso-punctatum. Abdominis segmentum 2 ventrale depressione levis-
sima, male definita. ?. Long. 9 — 9-5 mm.

Female black, with a small median flavous spot behind the antennae, the basal
segment of the abdomen mostly red, the second red at the sides near the base.
Wings infuscate and with blue iridescence. Apex of clypeus deeply emarginate ;
head above the antennae not very densely punctured. Mesothorax somewhat shining,
with fine shallow and irregular puncturation ; between these punctures the surface is
very densely and minutely punctured. Propodeum dull, with rugose and almost
obsolete puncturation. Basal segment of the abdomen vertical in front, and shallowly
punctured ; second slightly raised from the base ; beneath, with the depression very
shallow and more or less vague, the segment even at the sides hardly raised from
the apices of the costae.

Hab. Mountains of Molokai ; rare, 3 ? taken between June and September,
1893, at an elevation of 3000 ft.

(72) Odynerns axestes, sp. nov.

Niger, fronte flavo-notata, mandibulis plus minusve rufis, abdominis segmento
primo et secundo lateribus obscure rufescentibus, alis infuscatis, caeruleo-irides-
centibus. Clypeus fortiter emarginatus. Mesonotum peropacum, inaequaliter leviter
punctatum, propodei concavitate rugosa. Abdominis segmentum secundum longi-
tudinaliter convexum, subtus depressione levissima. </. Long. 9 mm.

Black, with a median flavous spot behind the antennae, the mandibles more or
less red, and the two basal segments of the abdomen obscurely reddish at the sides,
the second for the most part red also beneath. Wings infuscate, with a blue

HYMENOPTERA 67

iridescence. Clypeus deeply emarginate, the head above the antennae dull, and with
very shallow punctures. Mesothorax with the surface very dull, the puncturation
irregular, very feebly impressed, and somewhat fine, the interstices with minute
puncturation which is also very feebly impressed. Propodeum dull, the surface finely
roughened, the concavity somewhat rugose. Abdomen with the second segment
longitudinally convex, not otherwise raised from the base ; beneath, with the depres-
sion evident, but very shallow.

Hab. Kona district, Hawaii, 4000 ft. Rare, 2 ^ taken; June and September,
1892. Closely allied to the preceding but easily known by the very dull mesothorax,
the less raised (or tuberculate) second dorsal segment of the abdomen, &c.

{73) Odynerus insulicola.

Odynerus insulicola, Blackburn, P. Manch. Soc. Vol. x.w. (1885-86), p. 163.
Odynerus nautartim, Dalla Torre, Cat. Hym. Fam. Vesp., nee de Saussure.

Niger; baud nitidus, alis infuscatis, plus minusve caeruleo-iridescentibus. d"
clypeo, antennarum articulo basali, tegulis, postscutello, nonnunquam pronoto, tibiisque,
fiavo-notatis ; abdominis segmentis 2 basalibus postice flavo-marginatis. Colore varia-
bilis, sed clypeo semper plus minusve flavo-notato ; ? nigra, abdominis segmento primo
nonnunquam postice pallido-marginato. Clypeus fortius emarginatus. Frons capitis
remote, mesonotum inaequaliter, subtiliter punctatum. Abdominis segmentum secun-
dum haud elevatum ; subtus, depressione distincta, minus alta. </?. Long. 7 — 9 mm.

Male with the clypeus almost entirely, or only a small spot on it, yellow. The
scape of the antennae, the tegulae, the apical margins of the first two abdominal
segments, the tibiae, and sometimes the prothorax and postscutellum have yellow
markings. Excepting that the clypeus has always (as it appears) at least a yellow
spot, all these markings may be wanting, and some of them at least, generally are.
Female black, with a minute spot behind the eyes, and sometimes the apical margin
of the basal segment of the abdomen pale.

Clypeus distinctly, and usually somewhat angulately emarginate in both sexes ;
head above the antennae finely and remotely punctured. Mesothorax dull, finely and
irregularly punctured, the puncturation finer in the ? than in the (/. Propodeum
subobsoletely and somewhat rugosely punctured. Basal segment of the abdomen with
shallow, more or less even punctures ; second not raised from the base, covered in
fresh examples with fine sericeous pubescence ; beneath with the depression rather
wide, but shallow, meeting the apices of the costae obliquely.

Hab. Molokai, Lanai, and Maui, on the coast, and in open country up to an
elevation of 3000 ft., but not in the forest. Dalla Torre in his catalogue refers this
species to O. nautarum, Sauss., but that species has ' le metathorax seul ponctue.'

9—2

68 FAUNA HAWAIIENSIS

(74) Odynerus nesotrephes, sp. nov.

Niger, alis infuscatis, subcaeruleo-iridescentibus, tegulis cum postscutello flavo-
notatis, abdominis duobus segmentis basalibus postice flavo-marginatis. Clypeus
distincte emarginatus. Mesonotum opacum, subtiliter et inaequaliter punctatum,
interstitiis densissime et minutissime ruguloso-punctatis. Propodeum subobsolete
punctatum, concavitate rugosa. Abdominis segmentum 2 ventrale depressione lata,
minus alta. ?. Long. 8 mm.

Female black, with the tegulae and postscutellum spotted with yellow, and the
hind margin of the two basal abdominal segments of the same colour. Wings infus-
cate with very little blue iridescence. Clypeus distinctly emarginate, head above
the antennae dull with somewhat remote and fine puncturation. Mesothorax dull,
finely and irregularly punctured, more sparsely behind than on the anterior part.
Propodeum with some large shallow punctures in front, the concavity rugose.
Abdomen dull, covered with sericeous pubescence, the second segment not raised,
ordinarily convex longitudinally ; beneath with a well-marked, wide, but shallow
depression, costae longer than the basal part of the segment, strong, but not very
closely set.

Hab. Waialua, Oahu, a single example on the coast.

(75) Odynerus lanaiensis, sp. nov.

Niger, alis plus minusve infuscatis et caeruleo-iridescentibus. Clypeus vix
emarginatus. Mesonotum dense fortiter punctatum. Propodeum opacum rugoso-
punctatum. Abdominis segmentum secundum vix elevatum ; subtus, depressione
distincta nulla, c/'?. Long. 6"5 — 10 mm.

Black, the wings infuscate, but not deeply, except along the costal margin of
the anterior pair, their iridescence blue.

Apex of the clypeus hardly emarginate, head above the antennae densely punc-
tured. Mesothorax strongly and closely punctured, the punctures rather larger in
the d", and the surface of the thorax more dull. Propodeum rugose. Basal segment
of the abdomen somewhat evenly punctured ; second slighdy raised from the base ;
beneath, somewhat flat beyond the costae, with no depression, or at the most with
only a vague indication of one.

Hab. Lanai, on the coast at Manele.

HYMENOPTERA 69

(76) Odynenis pterocheiloides, sp. no v.

Niger, alls infuscatis, caeruleo-iridescentibus, fronte ^ flavo-notata, mandibulis
rufis. Caput cum mesonoto ^ opacum, % vi\ nitidum ; mesonotum <^ minus dense,
? sparsim subtiliter punctatum. Propodeum puncturatione fere obsoleta subrugosum.
Abdominis segmentum secundum baud elevatum, subtus depressione fere obsoleta.
? palpi labiales pilis longis utrinque ciliati. Long. </ 5 — 7 '5, ? 9 mm.

Black, the wings infuscate, and with blue iridescence, the cT with a median
flavous spot behind the antennae.

Head and mesothorax dull in the d", and hardly shining in the ?. Mesothorax
finely, feebly, and sparsely punctured in the %, rather more largely and closely in
the d", but very shallowly. Minute puncturation between these punctures distinct.
Propodeum somewhat rugose, with nearly obsolete punctures. Abdomen with the
second segment convex but not raised from the base ; beneath, with the depression
nearly obsolete. Labial palpi of the ? extremely long, and beautifully ciliated with
long hairs. Mandibles more or less red or reddish.

Hab. Kona district of Hawaii (4000 ft.). Hawaii (loc. ?), Blackburn. Mr
Blackburn has sent over a ? of this species, as representing his O. hawaiiensis, but
it does not at all agree with his description of that species.

kn) Odyneriis congrinis.

Odynerus congruus, Smith, J. Linn. Soc. xiv. p. 680. Blackburn and Cameron,
P. Manch. Soc. xxv. p. 155.

Praecedenti forma et magnitudine similis, capite et mesonoto magis nitidis et
laevioribus distinguendus. c/?. Long. 6 — 10 mm. (Plate \. fig. 30.)

Very closely allied to the preceding, but easily distinguished by the more shining
surface of the front of the head and the mesothorax. In the ? the second ventral
segment has no depression beyond the costae, and behind the antennae there is a
median flavous spot as in the i.

Hab. Molokai, Lanai, and Maui, on the coast, and in the mountains, up to an
elevation of 3000 ft., but not in the forest. This and the closely allied preceding
species are, as far as the ? is concerned, very different to any other Hawaiian
species. The type of the ^ has four yellow spots on the clypeus, which is abnormal,
the clypeus usually being entirely black. It is remarkable that the extraordinary
appearance of the palpi has been passed over unnoticed. The locality 'Honolulu'
is given in Lit. and Phil. Soc. Manch. Vol. xxv. (1885-86), p. 155, but this is no
doubt an error, as in Ent. Mo. Mag. Vol. xvii. p. 87, the species is said to have
been taken with Prosopis blackburni, an insect peculiar to Maui, and 1 have myself
taken them together on that island.

j,o FAUNA HAWAIIENSIS

(78) Odynerus c he lifer, sp. nov.

Nio-er alis infuscatis caeruleo-iridescentibus, mandibulis plus minusve rufescent-
ibus vel piceis. Mesonotum opacum, distincte subtilius punctatum. Abdominis seg-
mentum secundum baud elevatum ; subtus, depressione fere obsoleta. Uterque sexus
genis inter oculos mandibulasque distinctis (?-ae longioribus) insignis. Mandi-
bulae (?) perlongae et angustae, dentibus fere obsoletis. i%. Long. 5 — 7 mm.

(Plate I. fig. 3I-)

Black, the wings infuscate, and with blue iridescence. Mandibles more or less
red or piceous on their apical portion. The cheeks between the base of the man-
dibles and eyes are distinct in both sexes, but longer in the ?, in which sex the
mandibles are extremely long and narrow, with the teeth obsolete or nearly so.
The length of the part of the mandible, which projects beyond the apex of the
clypeus, is about equal to the length of the clypeus itself. Interantennal carina
very distinct and sharp, no flavous spot at its base. Mesothorax dull, distinctly but
finely punctured ; propodeum roughened by the subobsolete punctures. Abdomen
with the second segment simple above, not raised from the base ; beneath, with the
depression extremely feeble and indefinite.

Hab. Kona, Hawaii (4000 ft.); Molokai and Lanai (coast to 3000 ft.). Rare.
The examples from Hawaii do not altogether agree with the others, but the material
is insufficient to separate them specifically.

(79) Odynerus nigripennis.

RJiygchittm nigripennis, Holmgren, Eugenies Resa, Zool. vi. p. 441.

Odynerus viaurus. Smith, J. Linn. Soc. .kiv. p. 679.

Odynerus nigripennis, Blackburn and Cameron, P. Manch. Soc. Vol. xxv.
(1885—86), p. 151.

Niger, robustus, alis infuscatis, caeruleo-iridescentibus, fronte flavo-notata. Cly-
peus leviter dentato-emarginatus. Mesonotum cum scutello densissime, subtilius,
rugoso-punctatum. Postscutellum ad truncationem linea elevata (plerumque serrulata)
munitum. Abdominis segmentum secundum baud elevatum ; subtus, depressione
lata, minus alta, costis subobsoletis. Long. (/ 7 — io'5 mm. % 8 — 14 mm.

Black, the wings infuscate, and with a blue (but not bright) iridescence. A
small median spot behind the antennae, and another behind each eye, often flavous.
Apex of clypeus depressed, and lightly emarginate. Mesothorax finely, but very
densely rugosely-punctate, the punctures generally rather larger in the ^. Post-

H J 'MENOP TERA 7 1

scutellum with a very distinct raised line (usually serrulate or spinulose) at the trun-
cation. Propodeum rough with large, feebly impressed, punctures. Abdomen with
the second segment not raised from the base ; beneath, with a wide depression, but
shallow, meeting the apices of the costae obliquely, the costae themselves more or
less obsolete or indistinct.

Hab. All over the islands from Oahu to Hawaii on the coast and as high as
4000 ft. in the mountains.

(80) Odynerus radula.

Odynerus raduia. Fab. Ent. Syst. 11. p. 269. Blackburn and Cameron, I.e.

p. 150.
Odynerus localis. Smith, J. Linn. Soc. xiv. p. 678. {^ nee ? .)

Praecedenti cognatus, niger, robustus, alis infuscatis, caeruleo-iridescentibus,
abdominis segmentis 2 basalibus postice flavo-marginatis. Mesonotum dense rugoso-
punctatum ; propodeum rugosum. Abdominis segmentum secundum haud elevatum ;
subtus, depressione latissima, oblique costis occurrente. Long. ,} 6'5 — 11, ? 9 — 14 mm.
(Plate L fig. 14.)

Black, the wings infuscate and with blue iridescence, the apical margins of
the two basal abdominal segments yellow. Of the same robust form as the pre-
ceding, and like that species with transverse basal segment of the abdomen, and a
raised line at the truncation of the postscutellum. On the mesothorax two forms
of puncturation can be made out in the c/, consisting of larger and smaller punc-
tures, the whole forming a dense and subrugose puncturation. In the ? the meso-
thoracic puncturation is almost identical with that of the preceding. The depression
of the second ventral segment is wide and shallow, the costae are less obsolete than
those of O. nigripeiinis .

H.\B. Kauai, common on the coast and in the mountains, occupying the place
which O. iiigripennis holds on the other islands. It is evidently a directly modified
form of that species.

(81) Odynerus localis, Smith.

Odynerus localis, Smith, J. Linn. Soc. xiv. p. 678. (? nee (/.)

Niger, alis infuscatis, caeruleo-iridescentibus, abdominis segmentis 2 basalibus
postice albo-marginatis. Mesonotum </ dense rugoso-punctatum, ? creberrime sub-
tilius punctatum. Postscutellum linea elevata munitum. Abdominis segmentum
primum subdepressum, parte anteriore dorsali parti subacute occurrente ; secundum

72 FAUNA HAWAIIENSIS

haud elevatum; subtus depressione minus lata. d"?. Long. 8 — 17 mm. (Plate I.

fig- I5-)

Allied to the preceding species, but with the abdominal bands wider. The

scutellum is more rugosely punctured, and the basal segment of the abdomen is

differently formed, being somewhat depressed from the base to the apex, and where

the anterior and dorsal surfaces meet a comparatively sharp edge is formed, instead

of this part being evenly rounded off. The depression of the second ventral segment

is much less wide at its base, occupying only about the middle third of the segment,

and the middle costa of the series is conspicuously long. The abdomen is altogether

more shining, as also the surface of the mesothorax of the ? .

Hab. Mountains of Kauai. Not rare.

The following five species of the genus Odynerus were brought back by the
Beechey expedition many years ago. Probably all were collected at or near Honolulu,
and most if not all of them are in that case now extinct. Neither the Rev. T.
Blackburn nor myself have met with any of these species. The descriptions of the
first two are copied from de Saussure's Etud. Fam. Vesp. (Pt. iii.). The types
were originally in the British Museum, but apparently no longer exist. A single
insect in that collection was assigned to O. nautarum, de Sauss. but does not agree
with the description. Under the name O. sandwichensis, de Sauss. (or rather sand-
ivithii !), were placed several insects of three quite distinct species, none of which
could possibly have been the subject of de Saussure's description,

"Etud. d. Fam. Vesp. (Pt. in.). Mon. Masar. et Suppl. p. 289. Div. Anto-
dynerusy

(82) " O. nautarum, n. sp."
" Niger signaturis flavis : abdo^ninis fasciis djiabus fiavisT
"Long. 9 mm.; env. 18 mm."

"Male. Formes allongees de XO. punctnm. Metathorax arrondi, lisse au milieu.
Chaperon bitubercule au bout. Insecte noir, lisse ; le metathorax seul ponctue.
Chaperon, un point au haut des mandibules, devant du premier article des antennes,
jaunes. Deux taches sur le prothorax, ecaille, un tache sur I'aile, postecusson et
une bande interrompue sur lecusson, jaunes. Les deux premiers segments de
I'abdomen orn(^s d'un large bordure jaune. Pattes noires ; les tibias seuls, jaunes
d'un cote ; tarses noirs. Ailes hyalines, la cote enfumee, et le bout un peu violet.

Var. Ecailles, (icusson, et antennes noires.

Habite: Les iles Sandwich. (Musee de Londres.)"

HYMENOPTERA 77,

(83) " O. sandwichensis, n. sp."

" Paitmlus, niger, perdepressus ; postscutello, metathorace, abdominis primo seg-
menio, secundi margine et lateribus, rubris ; alis caerulescetiiibus ."

"Long. 7 mm.; env. 15 mm."

" Male. Petit, grele, ires ddprim^. Metathorax depassant de beaucoup le post-
ecusson, arrondi. Abdomen tres plat ; le premier segment en cloche, moins large
que le deuxieme. Insecte noir, ponctud, mais lisse et luisant. Entre les antennes
un point rouge ; un autre sous I'aile ; deux autres sur chaque ecaille ; post^cusson
et metathorax d'un rouge sombre ; le premier segment de I'abdomen, le bord du
deuxieme et ses cot^s, de la meme couleur, ainsi qu'un fin lisere le long des autres
segments. Pattes noires. Ailes assez brunes, avec un reflet violet ; deuxieme cubi-
tale subtriangulaire.

Distinct par sa forme tres aplatie.

Habite. Les iles Sandwich. (Musde de Londres.)"

Obs. This species is evidently closely allied to O. rubriti^ictus, Sm.

The three following species are in the collection of the British Museum, and
each is represented by only a single example. They appear to be distinct from
any of the species collected by me.

(84) Odynerus infaushis, sp. nov.

Niger, mandibulis clypeique parte apicali rubris. Caput cum mesonoto obsolete
punctatum. Abdominis segmentum secundum ventrale baud post costas depressum,
parte basali permagna, costis multo longiore. ?.

Black, mandibles and apical half of the clypeus red, the latter faintly emarginate
at the apex. Head and whole thorax dull, the puncturation obsolete. Abdomen
with the punctures of the basal segment very feebly impressed. Second ventral
segment beneath with the basal portion very large, several times as long as the
short costae, beyond which there is no depression. Wings dark, with violet irides-
cence.

Hab. Brought back by the Beechey expedition, probably from Oahu. The
species appears to be very closely allied to O. egens, next to which it may be
placed.

p. F. H. 10

74 FAUNA HAWAIIENSIS

(85) . Odynerus oblitus, sp. nov.

Niger, alls fuscis, abdominis segmentum basale postice testaceo-marginatum.
Mesonotum opacum subtiliter sparsim punctatum, necnon etiam interstitiis subtilis-
sime distincte punctulatis. Abdominis segmentum secundum ventrale post costas
haud depressum, costis fortibus. i.

Black, the wings fuscous without blue iridescence, the apical margin of the
basal segment of the abdomen testaceous, perhaps yellow in fresh examples. Cly-
peus faintly emarginate at the apex. Head dull, finely, feebly, and irregularly punc-
tured. Mesothorax dull, very finely and sparsely punctured, and with a distinct and
very minute puncturation between the larger punctures. Propodeum dull impunc-
tate. Basal segment of the abdomen obsoletely punctured ; second, beneath, with
strong costae and beyond their apices flat, with no depression.

Hab. Brought back by the Beechey expedition, probably from Oahu. A single
much mutilated </" example in the British Museum.

(86) Odynerus rclicfus, sp. nov.

Niger, capite cum thorace flavo-notato. Abdominis segmenta duo basalia postice
flavo-marginata. Mesonotum opacum, sat evidenter, subirregulariter, punctatum. Ab-
dominis segmentum primum leviter punctatum ; secundum ventrale post costas haud
depressum, costis distinctis, parte sua basali sat brevi. ^.

Male black, the mandibles with a small yellow spot at the base. The clypeus,
a small spot on the scape of the antennae, one behind their insertion, two on the
prothorax, others on the tegulae, and the postscutellum, yellow, as well as the apical
margin of the two basal abdominal segments. No doubt these yellow markings
would be variable in a series of examples. Head dull, subobsoletely punctured ;
thorax dull, evidently, but somewhat irregularly, punctate, and with the system of
interstitial minute puncturation distinct ; scutellum irregularly punctured, the pro-
podeum dull, with the surface somewhat roughened by large subobsolete punctures.
Abdomen with the basal segment feebly punctured ; second convex, distinctly punc-
tured on its yellow apical margin ; beneath, its basal portion is short, the costae are
distinct, and there is no depression beyond them. All the tibiae have a yellow
line above. The wings are infuscate, and have a slight blue iridescence.

Hab. Probably from Oahu (Beechey expedition). A single <? example in the
British Museum under the name of O. nautarum, de Sauss. The description of that
species says "le metathorax seul ponctue," which will not at all agree with the insect
above described. This species might be placed near O. insulicola, Blk.

HYMENOPTERA 75

Two species described by the Rev. T. Blackburn, O. haivaiiensis and O. halea-
kalae, I have not been able to identify with any certainty, not having seen the
original specimens. Mr Blackburn very kindly sent me an example under the former
name, but it was quite clearly not the subject of his description. This example
belongs to the species I have called O. pterocheiloides, and is excessively closely
allied to O. congrtms. Smith. There is no trace of tuberculation on the second
segment of the abdomen, and this alone is sufficient to distinguish it from O. hazaaii-
ensis as described, but it is certain from the remarks made at the end of the de-
scription of O. hawaiiensis, that several species were included under that name. As
regards O. haleakalae I cannot refer it for certain to any particular one of the species
found on Maui. There is no doubt, however, that both these species will prove
referable to two of the species which I have described under new names. Possibly
O. hawaiiensis, Blk. is the same as my O. erythrognathus, and O. haleakalae, Blk.
as O. ecostahis.

ANTHOPHILA.

Obtusilingues.

Nesoprosopis, gen. nov.

Under this generic name I propose to separate certain bees which have hitherto
been referred to the genus Prosopis, although at present it is necessary to rely on ^
characters for the separation. In all the species examined (and these comprise most
of the 52 species known to me) the 8th ventral segment is highly peculiar, and although
exhibiting great variety in detail, yet always maintains the same general form. Its
apex is always produced into an extremely long process, which on the ventral side
rises erect or suberect from the body of the segment. In its simplest form the
process is a delicate curved rod, expanded at the apex, or more usually bifurcated,
the bifurcations being more or less recurved. On its apical portion at least it is
clothed with long hairs. In many of the species the process is greatly expanded
dorso-ventrally, so that in extreme cases it may be nearly as wide as long, and the
apical bifurcations are also sometimes greatly expanded. All intermediate conditions
between this and the simple form may be seen in the various species known from
the islands.

The extreme apex of the process is always exposed in life, showing beyond
the sixth segment, which is more or less compressed or carinate, and emarginate at

10 — 2

76 FAUNA HAWAIIENSIS

the apex, the ventral surface of a part of the process resting within the carina.
The seventh segment is entirely concealed, and in strong contrast with the eighth
shows little specific modification. It is produced at the apex into two processes,
one on either side, which are more or less bent downwards. These processes are
longer in some species than others, and are not hairy as is the apical process of
the eighth segment.

The genital armature itself is also remarkably similar, even in the most widely
separated species. The stipites are thin, somewhat concave inwardly, and simple,
there being no trace of a lacinia. On the apical portion they are always clothed
with long hairs. The sagittae do not extend as far as the apex of the stipites,
being strongly curved downwards a little before that point is reached, or in one
or two species (owing to the length of the stipites) considerably before.

The sculpture of the various species is remarkable for its feebleness. The
puncturation is always fine and shallow, and excepting a group of species, which
are relatively of very great size, there is in no case any definite abdominal puncturation.
This extraordinary similarity of sculpture adds greatly to the difficulty of differentiating
the species. The anterior area of the propodeum is but ill-defined, and its posterior
face always bears a longish erect pubescence.

The habits of the bees of this genus exhibit considerable variety. On the
coast and dry mountain slopes they form their burrows in the ground, but in thick
forests and wet districts their cells are made in dead wood, generally of standing
trees. The larval food contains comparatively little pollen, as these bees have no
special poUinigerous apparatus, and in cells that I have opened the larva was floating
on the liquid food. Such pollen as is collected is swept towards the mouth by the
curved hairs on the anterior tarsi, an d regurgitated with the honey. Some species are
quite peculiar to the coast region, others to the forests, and a few to the region above
the forest line. A few are found in dense and gloomy woods, which bees would
hardly be e.xpected to inhabit, and may be seen flying round some bush, where
a little sunlight is able to penetrate.

In the following descriptions I have used the term 'anterior area' for that part
of the propodeum called by Smith ' the enclosed space of the metathorax,' the ' basal
area' of many other hymenopterists. In the Hawaiian species it is not enclosed, and
should, I think, rather be called the apical than basal area. In any case the term used
avoids any possible confusion. All the known species, where possible, have been
redescribed, the old descriptions being insufficient for their determination.

The species of Nesoprosopis form several more or less definite groups. One of
these is easily distinguished by the evidently punctate abdomen of both sexes, and
the large, robust form, at least of the females. N. fuscipennis is typical of this
group, to which also must be referred N. andrenoides, a most remarkable species,
resembling at first sight a medium-sized or rather small Andrena. It differs from

HYMENOPTERA 77

all the other large species in its nearly impunctate metallic abdomen, which bears
fasciae of white pubescence. A second group is defined by its parasitic habits, and
the clothing of the front tarsi of the ? , the hairs of which have not the regular curved
form of the industrial species. The females of all the parasitic species but one have the
abdomen ferruginous at least at the base, but in two species the males are black or
nearly so. Very closely allied to this group is another, the females of which are
industrial, and provided with well-developed curved sweeping hairs on the front
tarsi. The face is always long, and the pubescence of the front of the head is very
short and inconspicuous. The remaining species form several ill-defined groups,
none of which are parasitic, and in all the abdomen is impunctate or nearly so.
The front of the head is clothed with more or less long hairs, at least in those
which have the face elongate. Several species are distinguished by their small
size, narrow form, and the more than usually long dorsal surface of the propodeum.
N. crabrotioides is the most striking species of this group. Others are remarkable
for the great width of the face across the eyes, e.g. N. laticeps and its allies.
Finally there are a number of species closely allied to N. facilis, which comprise the
least remarkable species of the genus. The face is not extremely short and wide, nor
is the form very narrow ; the dorsal surface of the propodeum is short. These three
last-mentioned groups, however, seem to be connected by intermediate forms.

The specific characters of the (/ are chiefly to be found in the amount of
dilatation of the scape of the antennae, the markings of the face (which, however,
vary a good deal in some species), and the relative length and width of the head.
The eighth ventral segment, which it is necessary to extract for examination, also
furnishes very useful characters. If the scape of the antennae be viewed from the
front, so that the front edge instead of the flattened surface be examined, it will be
seen to be more or less concave beneath. The height and form of the arch so
formed often furnishes useful specific distinctions. The females are much more
difficult to separate, and in a few cases I see no specific distinction between two
species, although the males are quite distinct. The shape of the head and its
puncturation in front, the sculpture of the anterior area of the propodeum, the colour of
the wings, and of the hairs on the apical segment of the abdomen, as well as the
facial and prothoracic markings when present, furnish the most useful characters.

(i) Nesoprosopis facilis.

Prosopis facilis, Smith, J. Linn. Soc. xiv. p. 683.

Prosopis facilis, Blackburn and Cameron, P. Manch. Soc. Vol. xxv. (1885 —

86), p. 142. (Plate II. fig. i, and fig. 8— 8/^.)
Male black, with the clypeus, the plate above it, and an elongate spot on either
side adjoining it, flavous ; front tibiae and more or less of the front femora testaceous

78 FAUNA HAWAIIENSIS

inwardly, intermediate and posterior legs black or nearly so. The sides of the face
are widely and deeply depressed along the inner margins of the eyes ; the antennae
black with the scape dilated, about twice as long as wide, and strongly arched beneath ;
head above the antennae with the surface rough, shallowly punctured, clothed with
rather long pubescence ; mesothorax dull, with fine and shallow puncturation, that
of the scutellum rather more distinct ; wings more or less infuscate ; propodeum
longitudinally rugose to the brow, the rugosities more regular in some individuals
than others ; abdomen with the surface rugulose, with hardly definite or visible
puncturation ; beneath, with the sixth segment emarginate at the apex and carinated
behind the emargination ; process of the eighth sublinear, rising erect from the body
of the segment and curved, bifurcate at its apex, very densely clothed with hairs on its
apical half, the bifurcations with a long and regular fringe ; genitalia with the stipites
much produced at their apex, with long hairs on their outer margins, which do not
extend to the extreme apex, being almost absent on the submembranous apical
portion.

Female black, without any yellow markings on the face ; head above the antennae
pubescent as in the cT, the antennae simple, and the face much wider between the eyes :
mesothorax with very similar puncturation, but generally more clearly defined, as also
is the anterior area of the propodeum, and more regularly longitudinally rugose ;
abdomen without definite puncturation, the terminal segments with dark pubescence
above and beneath. Length, 6 — 9 mm.

Hab. Common generally on Oahu, Maui, Lanai, and Molokai, in dry or
moderately dry localities, from the coast to an elevation of 4000 ft. in the
mountains.

Obs. This is not a very variable species so far as the facial markings of the
d" are concerned. The elongate spots adjoining the clypeus and that on the plate
behind it are sometimes diminished in size or rarely absent. The latter part, although
its sides are always longer than the apical margin, is variable, the length of the sides
being considerably greater (in proportion to the length of the anterior margin), in some
examples than in others. Those from Maui, Lanai and Molokai have this plate
extremely long and narrow, but not more so than in some Oahuan specimens. The
latter often have the wings clearer, and with a less distinct blue iridescence than those
from the other islands, they are also on the average of smaller size, and the
pubescence of the mesothorax is often paler in colour.

(2) Nesoprosopis clilorosticta, sp. nov.

Praecedenti colore ac puncturatione simillima, sed </ tibiis tarsisque posticis basi
flavo-maculatis, capite latiore distinguendus. ^%. Long. 6— 7-5 mm.

HYMENOPTERA yg

This species is very closely allied to the preceding, but the </ is easily distinguished
by the yellow base of the posterior tibiae and tarsi, and apparently is not variable in
this respect, as I have examined a fine series. It also has the face evidently wider
across the eyes than facilis. The female is much more difficult to separate, but the
face appears to be slightly wider, and the average size of the insect considerably less.

Hab. Mountains of Kauai (2000 — 4000 ft.). It is also found on the coast.

(3) Nesoprosopis simplex, sp. nov.

Praecedentibus simillima ; c/" tibiis posticis haud flavo-notatis ; genitalium stipitibus
minus productis, et usque ad apices longe ciliatis, distinctus. (/?. Long. 6 — 9 mm.
(Plate II. fig. 9.)

In general appearance and puncturation very like the two preceding species ; the
<r may be known at once from N. chlorosticta by the entirely dark posterior tibiae,
and from either by the genital armature, the stipites of which are less produced, and
fringed right up to the apex with long hairs. The plate above the clypeus is very variable
in its proportions, the length of its lateral margin being sometimes longer, sometimes
equal to, or even shorter than its anterior margin. I see no character to separate the
? from that of facilis ; the wings are strongly and entirely infuscate with evident blue
iridescence, wherein they especially resemble examples of that insect, from Maui and
Molokai, although their average size is less.

Hab. Island of Hawaii, generally distributed from 1500 — ■4000 ft. elevation,
and abundant.

(4) Nesoprosopis hirsuiula, sp. nov.

Praecedentibus cognata, sed capite latissimo, latiore quam longiore ; (/ tibiis basi
longe flavescentibus, tarsis haud maculatis ; segmento ventrali 8° apice haud longe
bifurcate, bene distinctus. c/?. Long. 6 — 9mm. (Plate II. fig. 10 — 10^.)

Male with the face very broad, transverse, the scape of the antennae slightly
dilated, not quite so much as in N. facilis, &c., nor quite so strongly arched beneath :
the clypeus, a small spot on either side of it, and the plate above it, pale yellowish-
white. The latter two markings are variable, sometimes absent. The plate above
the clypeus is very wide ; cheek between the eye and mandible extremely short ;
clypeus clothed with rather long erect hairs, generally of an obscure colour ; head
above the antennae with long, dark pubescence, and roughly punctured. Thorax
with rather long obscure pubescence ; puncturation very like that oi facilis, sometimes
perhaps rather stronger ; posterior tibiae white at the base, but the tarsi dark ; eighth
ventral segment of the abdomen with the process without long apical bifurcations.

go FAUNA HAWAIIENSIS

Female very like the </, the face very wide with obscurely-coloured pubescence :
cheek extremely short ; the scutellum more or less shining ; apical segments of the
abdomen above and beneath with the hairs black or of an obscure colour.

Hab. Mountains of Kauai, 3000 ft., and on the high plateau.

(5) Nesoprosopis difficilis, sp. nov.

Nigra, mesonoto griseo-pubescente, subtiliter nee dense punctato, propodeo antice
rugoso, alls plus minusve hyalinis, baud caeruleo-iridescentibus ; d" articulo 1° anten-
narum dilatato, subtus fortiter arcuato, bis longiore quam latiore ; capite prae antennis,
necnon saepe tibiis tarsisque plus minusve flavescentibus ; genitalium stipitibus apice
rotundatis ac fimbriatis, baud productis ; % pedibus, segmentisque abdominis apicalibus
pallide pubescentibus. (/?. Long. 5 — 8-5 mm. (Plate II. fig. ir — iic.)

^ Black, with the clypeus, the plate above it, and a spot on each side adjoining it,
yellow ; anterior tibiae pale in front ; antennae with the flagellum often more or less
pale beneath ; the posterior legs often have the tibiae and basal joint of the tarsi more
or less yellow, sometimes also the intermediate legs are similarly coloured. All these
markino-s are variable, the posterior and intermediate legs are often entirely dark.
The general appearance is that of N. facilis, &c., the head being of similar form and
in typical specimens similarly marked.

Antennae with the scape dilated as in A^. facilis, about twice as long as wide,
and strongly arched beneath ; plate above the clypeus generally short, the length of
each of its sides to the antennal fossa subequal to or less than the length of its anterior
margin ; cheeks between the eye and base of the mandibles short ; head above the
antennae dull, with roughened surface, closely and shallowly punctured, clothed with
long grey hairs. Mesothorax and scutellum clothed with somewhat long, erect, grey
pubescence, puncturation much as in N, facilis, &c., the punctures fine and very
shallow, but not very close, the fine rugosity of the surface and the pubescence
generally giving them an indistinct appearance ; anterior area of the propodeum
longitudinally rugose, wings subhyaline, or quite clear in fresh examples. Abdomen
as in N, facilis ; genital armature with the stipites rounded at the apex, not at all
produced, evenly fringed with long hairs ; eighth ventral segment apparently rather
variable, its process towards the apex clothed with hairs, but with a less dense
covering than that of N. facilis, its apex not bifurcated into long branches, but usually
only slightly dilated at the extremity, rarely with the angles of the dilatation more or
less produced.

Female in general appearance very like that sex of A^. facilis. Head above the
antennae dull, with roughened surface, closely and shallowly punctured, clothed with
long pubescence. Mesothorax very finely punctured ; propodeum with the anterior

HYMENOPTERA 8i

area more or less regularly longitudinally rugose ; wings hyaline or subhyaline without
blue iridescence ; abdomen without definite puncturation, calcaria testaceous ; legs and
the apical segments of the abdomen above and beneath with pale pubescence.

Hab. Molokai, Lanai, Maui and Hawaii ; abundant in the mountains. This is
a most perplexing species on account of its variability. In general appearance and
sculpture it greatly resembles N. facilis and the allied forms. The yellow markings
of the face in the </ are variable, being sometimes reduced in size, or altogether
absent except that of the clypeus, which is always yellow over at least the greater
part of its surface. Structurally the </ is quite distinct from the three species first
described, by the simply rounded apex of the genital armature, which is not at all
produced, and by the differences in the process of the 8th ventral segment. The
female may be known by the clearer wings which are without blue iridescence and
by the pale pubescence of the legs, and terminal segments of the abdomen. Some-
times the abdomen is of an immature reddish colour, as is also the case in other
of the Hawaiian species which are normally black, the paler forms being apparently
produced when the individuals arrive at maturity after an unusually short period
has been occupied in the earlier stages.

(6) Nesoprosopis laeta, sp. nov.

Nigra, subnitida, praecedenti simillima, sed mesonoto et scutello subtilissime
punctatis et laevioribus ; metanoto minus rugoso ; cT tuberculis pedibusque fere
semper flavo-notatis ; antennarum articulo primo fortiter arcuato ; ? tuberculis saepe
flavo-notatis, genis brevissimis. c/ ? . Long. 5 — 7 mm.

Closely allied to the preceding, the yellow markings variable. In the most
brightly coloured males the following parts are yellow ; the front tibiae in front and
within, the intermediate tibiae inwardly, and the base and apex also outwardly ; the
posterior, except for a black spot towards the apex inwardly, and a more or less
distinct fuscous stain outwardly ; the basal joint of all the tarsi and sometimes also
the apical ones, as well as the extreme apex of all the femora ; the clypeus, the
plate above it, an elongate spot on either side, and the tubercles of the prothorax
are also yellow. In general the basal joint of all the tarsi, and the base of the
posterior tibiae widely, are yellow. Of forty or fifty specimens of the ^ one only
has the legs entirely of an obscure colour, and this also has the tubercles black ;
while of about a score of the other sex, three or four have the tubercles black, and
some of them have the posterior tibiae widely yellow at the base.

Male with the antennae formed much as in the preceding, the scape being strongly
arched beneath, the lower surface of the flagellum pale ; the plate above the clypeus
as long to the antennal fossa, as the length of its apical margin, or rather longer ; the

p. F. H. II

82 FAUNA HAWAIIENSIS

cheeks between the mandible and eye very short. Mesothorax slightly shining, evenly
clothed with pale hairs, very finely and shallowly punctured ; the scutellum more
shining, and also very finely punctured ; propodeum finely longitudinally rugose in
front. Abdomen without definite puncturation, the apex with pale hairs ; process of
the 8th ventral segment bifurcate at the apex.

Female generally with a spot on the tubercles of the prothorax, and sometimes
the base of the tibiae and tarsi pale ; wings subhyaline, cheeks very short as in the ^ ;
mesothorax slightly shining, and clothed with very short pale erect pubescence ;
scutellum smooth and shining, finely and sparsely punctured ; propodeum finely longi-
tudinally rugose in front ; apex of the abdomen above and beneath with pale hairs.

Hab. Oahu both mountain ranges (2000 — 3000 ft.) and also on the coast at
Waianae. Kauai, Makaweli (3000 ft.) and Halemanu (4000 ft).

Examples taken on the coast of Molokai and Maui, which are of larger size, appear
referable to this species, as also others (from the mountains of the former island),
having the abdomen red. It is not improbable that both this species, and the pre-
ceding, as characterized above, in reality include several distinct forms.

(7) Nesoprosopis kona.

Prosopis kona, Blackburn, P. Manch. Soc. xxv. (1885 — 86), p. 144.

Female, black, with a narrow line bordering the eyes, two spots on the prothorax,
the tubercles, a spot at the base of the anterior and intermediate tibiae, and the basal
half of the posterior, yellow. Face somewhat long, the clypeus lightly emarginate
at the apex, the head above the antennae clothed with long pale hairs, and shallowly
punctured. Mesothorax and scutellum dull, with exceedingly minute and remote
punctures. Anterior area of the propodeum with the longitudinal rugosities extremely
short. Wings clear. Apical segment of the abdomen with dark hairs. All the tarsi
dark.

Male, black, the whole face below the antennae yellow, and this colour is extended
backwards along the margin of the eyes above the insertion of the antennae, as in
N. blackburni. A line on the prothorax, the tubercles, all the tibiae, and the basal
joints of the tarsi, yellow. The tibiae are spotted with black. Basal joint of the
antennae dilated, not so wide as long, the sides strongly rounded. Thorax, dull with
very fine and remote puncturation, propodeum more shining, and with some oblique
wrinkles. Length 5 — 7 mm.

Hab. Kona, Hawaii (4000 — 6000 ft.). I have only seen the ? of this species,
and the description of the d" is condensed from that given by Blackburn (/.r. supra).
Although the coloration of the face is like that of several species of the N. blackhirni
group, I believe this species is more closely related to N. facilis and its allies.

HYMENOPTERA 83

(8) A^esoprosopis volcanica, sp. nov.

N. difficili simillima, d" antennarum articulo primo subtus levius arcuato,
lamina supraclypeari angustiore, genis longioribus, segment! 8' apice longe bifurcato ;
? genis longioribus, scutello magis opaco distinguenda. ^ % . Long. 6 — 8 mm.
(Plate II. figs. 12 — 12(5.)

This species has the form and general appearance of A^. difficilis, and the facial
markings of the </ are similar to those of that species, and similarly variable. The
legs are nearly always entirely dark, without yellow markings.

Male, with the scape of the antennae rounded on its posterior margin, about twice
as long as wide, as in most of the foregoing species, but very distinctly less strongly
arched beneath ; cheeks between the mandible and eye longer, and the plate above the
clypeus narrower in proportion to its height, than in A^. difficilis. Mesothorax and
scutellum dull from the surface rugulosity, clothed with long grey hairs, as also is the
front of the head behind the antennae ; wings clear in fresh examples. Process of
the 8th ventral segment with long delicate bifurcations at its apex.

Female, very like the </" apart from sexual differences, the head and thorax being
similarly clothed, the cheeks unusually long, the scutellum quite dull, the wings hyaline
or subhyaline.

Hab. Hawaii, near the active crater Kilauea, where it is abundant. I have
also taken it in the Kona district at a similar elevation {4000 ft.), and at the bottom
of the crater of Haleakala, Maui (7000 ft.).

(9) Nesoprosopis nivalis, sp. no\'.

Nigra, opaca, genis longissimis, capite et mesonoto pubescentia longa vestitis ;
c/ capite, ut praecedentis, flavo-decorato, utrinque juxta oculos fortiter depresso ;
antennarum articulo primo fortiter dilatato, lateribus rotundatis, longiore quam latiore;
? scutello opaco, aequaliter distincteque punctato. c/?. Long. 6 — 8 mm. (Plate II.
figs. 13 and 13a.)

Male, with the face very long and narrow between the eyes, the cheeks between
the mandibles and eyes extremely long ; the clypeus, the plate above it and a spot
on each side of it, yellow ; these markings are variable, the spots varying in size,
and those outside the clypeus may be entirely wanting ; antennae with the scape
much more strongly dilated than in the preceding species, having both its anterior
and posterior margins rounded, but its length is evidently greater than its width.
The face is very deeply depressed at the sides, then strongly raised round the

II — 2

84 FAUNA HAWAIIENSIS

antennal fossae, forming a ridge which partly encircles them. Mesothorax dull,
clothed with long grey hairs, the surface finely roughened, with very shallow, obscure
and rather close puncturation ; scutellum with close shallow punctures ; the anterior
area of the propodeum longitudinally rugose ; the base of the posterior tibiae, and
the basal joint of the posterior tarsi, pale. Abdomen with the 6th ventral segment
emarginate at the apex, and carinated behind the emargination, its sides also emar-
ginate ; process of the 8th shortly bifurcated at the apex, or apparently sometimes
truncate.

Female, very like the </ apart from sexual differences ; entirely black, with the
face very long between the eyes, and the cheeks extremely long ; head and thorax
clothed as in the ^ . Mesothorax dull, finely, closely and shallowly punctured ;
scutellum with very distinct, close, and even, but shallow puncturation ; apex of the
abdomen with pale hairs.

Hab. Haleakala, Maui, above the forest nearly to the summit of the mountain
(loooo ft.). Frequents the flowers of Cyathodes etc. and is very abundant, but I took
only a small series.

(lo) Nesoprosopis riigulosa, sp. nov.

? nigra, griseopubescens, haud nitida, mandibulis truncatis, baud distincte dentatis ;
genis brevissimis ; mesonoto densissime ruguloso, subtiliter punctato ; propodei area
antica irregulariter rugosa ; abdominis segmentis ventralibus distinctius ciliatis ; alls
subhyalinis. ?. Long. 6 mm.

Female, black, antennae with the flagellum sometimes pale beneath ; head with
grey pubescence, mandibles somewhat obliquely truncate at the apex, and not toothed ;
cheeks extremely short, so that towards the clypeus the base of the mandible nearly
touches the eye ; the clypeus is closely and very shallowly punctured, the punctures
ill-defined ; the suture of its lateral margins with the sides of the face somewhat
deeply impressed ; head above the antennae closely and rather largely, though shallowly
punctured. Mesothorax with grey pubescence, its surface dull, densely and excessively
finely rugulose, the puncturation fine, shallow and indistinct ; scutellum more largely
punctured ; propodeum irregularly rugose in front. Abdomen with the basal segment
hardly shining ; intermediate ventral segments pale at their apices, and rather dis-
tinctly ciliated along them with white decumbent hairs.

Hab. Kilauea, Hawaii (4000 ft.), 2 ?. I do not know the d".

(11) Nesoprosopis vicina, sp. nov.

? nigra, genis brevibus, capite supra antennas levissime rugoso, haud dense
punctato ; mesonoto aequaliter subtiliter punctato ; propodeo antice longitudinaliter

HYMENOPTERA 85

rugoso ; abdominis segmento primo pernigro, nitido, subtilissime ruguloso ; alis sub-
hyalinis. ?. Long. 6 mm.

This species is extremely like several of the preceding, but without doubt distinct.
The mesothora.x and scutellum are quite dull, smooth except for the very fine rugulosity
of their surface, clothed with short pubescence, and finely and evenly punctured ; the
mesopleurae are not at all strigose or rough but are finely punctured. The basal
segment of the abdomen is deep, black and shining ; the apical segments clothed
with dark pubescence.

Hab. Olaa, Hawaii (2000 ft.); a rare species. I took only two or three
specimens, and have not seen the </.

(12) Nesoprosopis koat\ sp. nov.

? nigra, praecedenti simillima, capite supra antennas minus opaco, et distinctius
punctato ; thorace minus opaco ; alis infuscatis, ad apices subcaeruleo-iridescentibus,
facile distinguenda. ?. Long, circa 6 mm.

This is a very distinct species ; the thoracic puncturation appears to be identical
with that of the preceding, but the head above the antennae is less dull, and more
distinctly punctured ; the mesothorax less dull, and the scutellum somewhat shining.

The wings are entirely infuscate, with distinct bluish iridescence on their apical
portion in certain lights. The longitudinal rugosity of the propodeum is unusually
short. The basal segment of the abdomen deep black, and shining, as in the pre-
ceding, and the apical segments clothed with black hairs.

Hab. Mountains near Honolulu, Oahu (above 2000 ft.). A single specimen was
taken in 1892. In March, 1897, three more females were taken from the blossoms of
Acacia koa.

(13) Nesoprosopis connectens, sp. nov.

i niger, clypeo macula flava magna ornato, capite brevi, trans oculos lato, lamina
supraclypeari latiore quam longiore ; antennarum articulo primo haud fortiter dilatato ;
alis infuscatis ; segment! 8' ventralis parte producta minus fortiter dilatata, apice
bifurcato et ciliato. i. Long. 6 mm.

Male, black, the clypeus with a large yellow spot, the front tibiae yellow inwardly.
Face short and wide across the eyes, the apical margin of the plate above the clypeus
much longer than its side to the antennal fossa. Antennae with the scape about
twice as long as wide, and strongly arched beneath. Head above the antennae
finely rugulose, dull, and very shallowly punctured. Mesothorax and scutellum finely

86 FAUNA HAIVAIIENSIS

punctured, dull, the pubescence of the former short. Propodeum longitudinally rugose
in front. Wings rather strongly infuscate, and with a slight blue iridescence. The
process of the 8th ventral segment of the abdomen is evidently but not at all strongly
dilated, its apical bifurcation more strongly so, and ciliated with long hairs.

Hab. a single d" was taken in the lao valley, Maui. A female captured with it
is evidently of the same species, and is very closely allied to A^. koae, but this example
is much mutilated. A single ? taken on Lanai is also extremely close to, if not
identical with, one of these species.

(14) N^esopi'osopis melanotJirix, sp. nov.

Nigra, capite, thorace et abdominis segmentis apicalibus densius nigro-pubes-
centibus ; propodei rugis longitudinalibus antice brevissimis, vel absentibus ; mesonoto
et scutello subaequaliter punctatis ; alls infuscatis caeruleo-iridescentibus ; c/" capite
prae antennis toto nigro, aut maculis tribus flavis ornato ; antennarum articulo 1°
fortissime arcuato, scutello opaco ; ? scutello nitido, clypei apice distincte angulatim
emarginato. c/?. Long. 6 — 8 mm. (Plate II. figs. 14 — 14^.)

Male, entirely black, except the testaceous front of the fore tibiae, or with the
clypeus, and a spot on each side bordering the eyes, yellow, or with the latter markings
only present ; the clypeus is more or less emarginate at the apex, clothed with dark,
and rather long, erect hairs, somewhat largely but shallowly punctured, the plate
above it is similarly punctured, generally much wider than long, but variable in this
respect ; head above the antennae, and the vertex, with very long dark hairs, densely
and rugosely punctured, and dull ; antennae with the scape dilated, its posterior
margin rounded but not strongly, the dilated surface evidently not twice as long as
wide ; beneath exceedingly strongly arched, so that when the anterior margin is
viewed from in front the apex appears to be strongly produced, both base and apex
being much thickened owing to the deep concavity of the part between. Mesothorax
with long erect black hairs, shallowly and rather closely punctured, its surface dull
and rugulose between the punctures ; scutellum similarly clothed and dull, the punctures
rather larger than those of the mesothorax ; propodeum with very short ill-defined
longitudinal rugosity in front, sometimes obsolete : behind this the surface finely
rugulose, its sides clothed with pubescence of an obscure colour ; wings infuscate,
with blue iridescence ; thorax beneath, and the legs with dark pubescence. Abdomen
very finely rugulose, and hardly shining ; beneath, shallowly punctured ; 6th segment
with the apex emarginate, and carinated behind the emargination ; 8th with the
process strongly dilated dorso-ventrally, the ventral edge densely hairy, its apex
bifurcate, the bifurcations expanded, fringed with long hairs along their ventral
margins.

HYMENOPTERA 87

Female, very like the cf in general sculpture, &c., clothed with similar dark
pubescence ; clypeus with its apical margin smooth and shining, and angulately
emarginate ; scutellum shining between the punctures which are distinct and even ;
propodeum often with a few very sliort wrinkles from its front margin, beyond these
the surface smooth (except for the fine rugulosity of the surface), and slightly
shining ; wings quite dark, with very distinct blue iridescence ; fifth and sixth ventral
segments of the abdomen with long black hairs.

Hab. Haleakala, Maui (5000 ft.). In 1894 a small colony of this species was
found burrowing in the hard dry trunk of a dead, but still standing, Ohia tree
{Metrosideros). From this a short series of females was obtained, as they returned
to their burrows. In October 1896 an enormous colony was found high up in a
dead and decayed tree of Strmissia, and most of the specimens examined (about 50
in number) were obtained as they flew wildly over the ferns in the immediate vicinity
of the colony.

(15) Nesoprosopis haleakalae, sp. nov.

Nigra, capite trans oculos lato ; mesonoto et scutello aequaliter punctatis ; area
propodei antica fortiter clathrate rugosa ; alis fuscis ; </ maculis tribus prae antennis
flavis ; antennarum articulo 1° dilatato, multo longiore quam latiore, margine antico
subtus vix arcuato ; segmenti ventralis 8' productione fortius dilatata ; metatarsis
posticis saepe plus minusve pallidis. </ ? . Long. 6 — 7 mm.

Male, with a spot on the clypeus, and one on each side of the face without it,
yellow ; front of the front tibiae, and sometimes all the tarsi testaceous ; base of the
posterior metatarsi generally more or less pale, sometimes only obscurely so ; the
facial markings are more distinct in some examples than others, but I have seen
none in which they are wanting.

Face wide across the eyes, and strongly convex from the ocelli to the apex
of the clypeus ; the latter distinctly but shallowly punctured, clothed with long hairs,
the plate above it wide and punctured ; the scape of the antennae dilated, but much
longer than wide, its anterior margin when viewed from in front almost straight
beneath, not concave or arched ; if, however, the under surface be examined, it will
be seen to be deeply concave as in other species, only the concavity in this species
does not extend quite so far as the anterior margin ; head above the antennae with
long dark hairs, exceedingly densely punctured towards the middle, where the close
sculpture forms a distinct deep black area ; thorax and scutellum dull, with erect
dark pubescence, and closely and evenly punctured ; the whole of the anterior area
of the propodeum is somewhat coarsely clathrately rugose ; abdomen with the apical
process of the 8th ventral segment dorso-ventrally expanded, its bifurcate apex also
dilated, and beautifully fringed with long hairs.

88 FAUNA HAWAIIENSIS

Female, apart from sexual characters very like the male ; in some examples there
is a very narrow yellow line along the inner margin of the eyes, or the head may be
entirely black ; face very wide, and very strongly convex longitudinally, with long dark
pubescence ; propodeum coarsely clathrately rugose to the brow, as in the cT ; apical
segments of the abdomen beneath with dark hairs ; wings in both sexes fuscous,
often with slight blue iridescence towards the tips.

Hab. Haleakala, Maui (4000 — 5000ft.). Not a common species; found flying
round ferns in the forest. It is very distinct by the structure of the scape of the cT,
and the clathrate area of the propodeum in both sexes.

(16) h esoprosopis unica, sp. no v.

c/ capite latissimo, fortius transverse, longitudinaliter fortiter convexo, clypei apice,
et magnis duabus maculis extra clypeum, flavo ; pronoto interrupte flavo-Iineato :
metatarsis pallidis ; alls subfuscis ; antennarum articulo primo dilatato, longiore quam
latiore, subtus fortiter arcuato ; area propodei antica breviter subreticulatim-rugosa.
d". Long, circa 6 mm.

Male, head very wide, across the eyes decidedly transverse ; face with a spot
near the apex of the clypeus, and two large triangular ones bordering the eyes, and
also a widely interrupted line on the hind margin of the prothorax, yellow ; clypeus
with its posterior margin extremely wide, the sides very little divergent thence as
far as the apex of the eyes, evenly punctured, and clothed with rather long pale
hairs ; plate above the clypeus very wide, its anterior margin about equal to the
combined length of its sides ; face very convex longitudinally ; the scape of the
antennae dilated, subtriangular, its posterior margin rounded, longer than wide,
beneath somewhat strongly arched ; head above the antennae with the surface finely
roughened, and somewhat closely punctured. Mesothorax and scutellum with dark
erect pubescence, finely, regularly and closely punctured, the scutellum rather the
more largely, and its surface slightly less dull than that of the mesothorax ; anterior
area of the propodeum subreticulately rugose along its front margin, behind this
smooth except for the surface rugulosity ; wings fuscous ; the front of the front
tibiae, and all the metatarsi, pale.

Hab. a single male taken in the mountains near Honolulu at an elevation of
about 2500 ft. (1897).

(17) Nesoprosopis laticeps, sp. nov.

Praecedenti affinis, capite transverso, fortiter convexo, alis fuscis ; </ antennarum
articulo primo dilatato, longiore quam latiore, subtus fortiter arcuato ; capite prae
antennis ad latera flavo-maculato, vel toto nigro ; % propodei area antica brevissime

HYMENOPTERA 89

antice rugosa ; capite supra antennas in media parte sublrregulariter punctato. </ ? .
Long. 6 — 8 mm. (Plate II. figs. 15 — 15 (5.)

Male, face entirely black, or with two yellow spots, one on each side between
the eye and clypeus ; face transverse, the plate above the clypeus very broad, twice
as wide as high ; head above the antennae punctured, and clothed with obscure
pubescence, as also the thorax ; mesothorax dull, very finely punctured, scutellum
somewhat more largely but not very closely ; anterior area of the propodeum
generally with some short rather strong longitudinal wrinkles at the extreme front.
In some examples these are longer than in others and less regular, but they do not
reach the posterior margin of the area, which has only the usual rugulose sculpture
of the surface. Front legs pale in front, tarsi generally more or less testaceous ;
wings entirely fuscous with more or less blue iridescence ; 8th ventral segment of
the abdomen with the process dilated, as also its apical bifurcations.

Female, very like the male apart from sexual characters ; head very wide and
strongly convex, above the antennae very finely strigose and finely punctured, the
punctures rather remote towards the middle ; mesothorax and scutellum dull, clothed
and punctured, as in the </ ; propodeum with the anterior area smooth, except
for the rugulosity of its surface, and some extremely short wrinkles at the front
margin, sometimes obsolete ; wings as in the t/, legs dark, apical segments with
black hairs.

Hab. Dense wet forests high up on the mountains of Molokai, (above 4000 ft.).
Not common, flying rapidly over ferns in places where the sunlight can penetrate the
brush. On Lanai (2000 — 3000 ft.) the species is found of considerably smaller average
size but (so far as I can see) inseparable from the Molokai examples by any constant
character. The localities where it is found on Lanai are much less wet, and less
heavily timbered, than those on Molokai, but appear to have been of much the same
character before the forest had been so much thinned out and destroyed.

(18) Nesoprosopis neglecta, sp. no v.

Forma facieque praecedentis, capite supra antennas circa medium densissime
rugoso-punctato, propodei area antica irregulariter fere tota rugosa, bene distincta.
? . Long. 7 mm.

Of the same general form and appearance as the preceding but no doubt distinct.
The head above the antennae is very densely subrugosely punctured, and the pro-
podeum rather finely and irregularly rugose right up to the brow, whereas in N.
laticeps the rugosity is extremely short, and the brow itself slightly shining.

Hab. Mountains of Molokai in the high boggy forest. Sept. 21st, 1893. i ? taken.

p. F. H. 12

90 FAUNA HAWAIIENSIS

(19) Nesoprosopis kauaiensis, sp. nov.

Forma fere praecedentium, N. unicae cognatissima ; alis subhyalinis ; t/ clypeo, et
duabus extra clypeum maculis, pallide flavis ; pronoto postice interrupte flavo-lineato ;
? lineis duabus juxta oculos flavis, margine postico pronoti ad latera flavo-lineato.
</?. Long. 6 — 7 mm.

Male, with the scape of the antennae and the form of the head much as in the
preceding species ; clypeus almost entirely, a spot on each side of the face outside
the clypeus, and the hind margin of the prothorax at the sides, very pale yellow ;
the posterior edge of the clypeus strongly rounded ; head with long dark pubescence.
Mesothorax dull, and closely punctured, densely clothed with black pubescence ;
scutellum closely and evenly punctured ; propodeum with the anterior area longitu-
dinally rugose in front, the rugosities short, not reaching the brow ; posterior tibiae
and tarsi normally dark, sometimes, when the abdomen is of a more or less reddish
immature colour, they are more or less pale ; 8th ventral segment of the abdomen
much as in the allied species.

Female, in general sculpture and form like the cT ; two spots on the prothorax,
and a line on each side of the face near the eyes, pale yellow ; mesothorax and
scutellum quite dull, evenly and closely punctured ; propodeum with a few longitudinal
wrinkles of moderate length, not reaching the brow ; basal segment of the abdomen
shining and very smooth ; apical segments with dark hairs.

Hab. Mountains of Kauai (3000 — 4000 ft.) ; taken on several occasions, but
scarce. The large pale markings of the face in the </, and the spotted collar and
clear wings in both sexes, give this little species a very distinct appearance.

(20) Nesoprosopis comes, sp. nov.

Nigra, capite longitudinaliter minus fortiter convexo ; mesonoto opaco, subtiliter
minus dense punctato, pilis fuscis longioribus vestito ; scutello haud nitido, minus
dense subirregulariter punctato ; propodei area antica subtiliter irregulariter rugosa ;
alis plus minusve infuscatis ; </ clypei apice flavo-maculato ; antennarum articulo primo
dilatato, longiore quam latiore, subtus modice arcuato; segmenti 8' ventralis produc-
tione fortiter dilatata. cT ? . Long. 6 mm.

Black, the d" with a spot of variable size (which would probably be sometimes
absent) on the clypeus near its apex ; front of the front tibiae pale, as is usual in
this sex of most species. Male with the face short, but not of the great width
of the several preceding species, nor nearly so convex longitudinally ; plate above

HYMENOPTERA 91

the clypeus short, the length of its side to the antennal fossa less than that of its
anterior margin ; head above the antennae with long fuscous hairs, with very dense
sculpture about the middle, forming an area of a more deeply black colour than that
of the general surface ; scape of the antennae dilated, but very evidently longer than
wide, its posterior margin rounded, the anterior nearly straight ; the front margin
seen from in front moderately arched beneath, much less deeply concave than in
N. katiaiensis, laticcps, &c., in which species the arch is highest near the apex, while
in this species it is highest about the middle of the length of the scape. Mesothorax
with long fuscous hairs, quite dull, very finely and not very closely punctured about
the centre ; scutellum very slightly less dull, and with rather larger puncturation, the
punctures somewhat sparse and irregular, not close and even as in N. kauaiensis, &c. ;
propodeum quite finely irregularly rugose in front, the rugosity becoming less evident
posteriorly, the actual brow somewhat less dull than the part in front. Apex of
abdomen with dark hairs ; 8th ventral segment strongly dilated dorso-ventrally, and
the apical bifurcations also expanded ; wings somewhat infuscate.

Female, very like the d", but the face entirely black, clothed with similar dark
pubescence ; head much less convex longitudinally than that of N. kauaiensis. &c. ;
above the antennae the surface rather shining, distinctly punctured, the punctures
slightly decreasing in size inwardly ; along the middle line the sculpture is very dense,
forming a quite opaque area. Mesothorax very finely and rather remotely punctured,
quite dull from the fine rugulosity of the surface between the punctures ; scutellum
very slightly shining at the sides, less dull than that of the ^, somewhat sparsely
and irregularly punctured ; propodeum as in that sex ; basal segment of the abdomen
rather dull, impunctate, the surface distinctly finel)- rugulose ; apical segments with
dark hairs.

Hab. Haleakala, Maui (4000 — 5000 ft.) ; rare, three males and one female taken
in company with A^. haleakalae and A^. melmiothrix.

(21) Nesoprosopis coniceps.

N. coniceps, Blackburn, P. Manch. Soc. Vol. xxv. (1885 — 86), p. 145.

A species taken on Hawaii, and very closely allied to the preceding, is I believe
referable to the above. In sculpture &c. it seems hardly to differ from N. comes.
The clypeus has the basal part, the lateral margins and the extreme apex black, all
the rest flavous, as well as two large triangular spots between it and the inner margins
of the eyes ; the base of the posterior tibiae and of the basal joint of the hind
tarsi (and sometimes of the intermediate tarsi), are sometimes yellow ; the process
of the eighth ventral segment appears to be slightly less dilated than that of N.

12 — 2

92 FAUNA HAWAIIENSIS

comes. The female is somewhat variable, and I see no definite character to separate
it from the single individual of that sex of the preceding.

Hab. Kilauea, Hawaii (4000 ft.), 1895 and 1896. Not common. Mauna Kea
(6000 ft.), Rev. T. Blackburn.

(22) Nesoprosopis dumetorum, sp. nov.

Parvula, nigra, opaca, mesonoto subtilissime nee dense punctato, pilis nigris bre-
vissimis vestito, propodeo antice brevissime rugoso, postice nitidulo ; cT fronte tribus
maculis flavis ornata ; maculis quam praecedentis minoribus ; pronoto utrinque, cum
tuberculis et tibiarum basi, nonnunquam flavo-notato, nonnunquam his omnibus nigris ;
articuli antennarum primi margine antico subtus vix arcuato ; ? duabus juxta oculos
lineis flavis ; pronoto postice ad latera, tuberculis, tegulis plerumque, cum basi tibi-
arum flavo-notatis ; capite longitudinaliter fortissime (maris minus fortiter), convexo.
Long. 4'5- — 6 mm.

In the male a spot near the apex of the clypeus, and one on each side of the
face bordering the eyes, are yellow. These spots are generally much smaller than in
N. coniceps though sometimes nearly as large ; prothorax on each side, the tubercles,
and the base of the tibiae, sometimes spotted with yellow, but more often all these
are black. The head is shaped very like that of the two preceding species, but the
front margin of the scape of the antennae is nearly straight, hardly arched, beneath ;
face above the antennae dull, and very densely and finely punctured about the middle,
with a large deep-black area in contrast with the rest of the surface and on which
the sculpture is exceedingly dense. Mesothorax very finely punctured, clothed with
very short dark pubescence ; scutellum with slightly larger punctures, but fine and
not very close ; propodeum rugose at the extreme front, behind this part the surface
only rugulose, the brow sometimes, at least in certain aspects, slightly shining. Ab-
domen with the basal segment dull, with distinct surface rugulosity ; eighth ventral
segment with the process dilated, much as in N. coniceps ; wings sometimes somewhat
infuscate, but often hyaline.

Female, small, and very like the c/" in most respects ; face with only a narrow
line along the eyes yellow ; posterior margin of the prothorax at the sides, a spot on
the tegulae (sometimes wanting), one on the tubercles, the whole front of the an-
terior tibiae, the extreme base of the intermediate, and the base of the posterior
tibiae more widely, yellow ; face strongly convex longitudinally, above the antennae
hardly shining, but not so dull as in the </, and without the deep-black dull area of
that sex, finely and closely punctured ; mesothorax clothed, as in the ^ , with ex-
ceedingly fine puncturation, its surface quite dull ; scutellum dull, very finely punc-
tured, but quite evidently more strongly so than the mesothorax, the punctures not

HYMENOPTERA 93

very close ; propodeum with very short rugosities at its anterior margin, behind these
the surface finely rugulose, and about the brow in certain aspects quite brightly
shining, as also beyond it ; apical segments of the abdomen with blackish hairs.

Hab. Hawaii from 2000 — 4000 ft. Taken in the heart of dense damp forests
in places where a little sunlight penetrates, and may also be found at the edges of
such forests. I have examined many examples. It is quite a distinct species, though
the cT is very variable in colour.

(23) Nesoprosopis niutata, sp. nov.

Praecedenti magnitudine forma et colore simillima, ^ capite supra antennas
minus distincte punctato, et plaga pernigra carente, scutello vix opaco, segment! 8'
ventralis parte producta haud dilatata, antennarum articuli basalis margine antico
subtus distincte arcuato ; ? scutello laeviore et nitido, tibiis posticis haud flavo-
notatis bene distincta. Long. 5-5 mm.

This species represents on Kauai the A'^. dumeforum of Hawaii but is quite
distinct. The head is similarly formed, but above the antennae the surface is rougher
and the puncturation less distinct, and the c/ lacks entirely the deep-black mark so
conspicuous in the preceding ; the scutellum of the </ is decidedly less dull, of the ?
even shining ; the eighth ventral segment has the process of a quite different form,
not being dilated dorso-ventrally, nor evidently bifurcate at its apex.

The two males taken have the facial markings as in N. diimetoruni, the tubercles,
prothorax and legs black, as in some varieties of that species ; the single ? has the
tegulae unspotted as in some examples of diimetoruni, and the base of both posterior
and intermediate tibiae also dark.

Hab. Kauai (3000 ft.) ; 2 c/, i ? in a dense forest, flying over ferns in a sunny
spot.

(24) Nesoprosopis specular is, sp. nov.

? nigra, praecedentibus simillima ; capite supra antennas minus subtiliter punc-
tato ; spatio verticis, inter ocellum exteriorem et oculum sito, laevissimo nitidoque, ne
minime quidem ruguloso ; clypei apice flavo-lineata, distinguenda. Long. 5'25 mm.

Female, like the preceding in size and general appearance, but the following
characters will readily distinguish it. The head above the antennae is exceedingly
closely and, for the size of the insect, rather strongly punctured : the surface between
the punctures is smooth and shining ; the spaces connecting the exterior ocelli with
the impressed longitudinal lines bordering the eyes are extremely smooth and shining.

94 FAUNA HAWAIIENSIS

and the apical margin of the clypeus is yellow. The scutellum is perhaps hardly so
dull as in N, dwnetorum, but more so than that of N. mutata. Besides the line on
the clypeus there is a long and rather broad yellow line along the inner margin of
the eyes ; the posterior margin of the prothorax at the sides, the tubercles, and the
base of the posterior and intermediate tibiae are also marked with yellow ; the clypeus
is less convex longitudinally than that of N'. diimdoriun.

Hab. Hawaii ; very rare, a single specimen only taken at Kilauea.

(25) Nesoprosopis crabronoides, sp. nov.

% nigra, angustula, capite supra antennas subnitido, dense distincteque punctato,
vertice fortissime incrassato ; mesonoto et scutello opacis, subtilissime punctatis. Caput
prae antennis maculis duabus flavis lateralibus ornatum, pronoti margine postico ad
latera, tuberculis, basique tibiarum, flavo-notatis. Long. 4-5 — 5 mm. (Plate II. fig.
2 and 2 a.)

Female, narrow and elongate, the face with two yellow lateral spots, and some-
times an obscure one near the apex of the clypeus ; an interrupted line on the
prothorax posteriorly, the tubercles, and the base of the tibiae, also yellow ; head
with the vertex extraordinarily incrassate, the face exceedingly strongly convex lon-
gitudinally, distinctly punctured behind the antennae, the surface between the punc-
tures shining, as also the smooth spaces adjoining the exterior ocelli. Mesothorax
very dull and finely punctured, clothed with short pubescence, scutellum with fine
sparse puncturation ; propodeum shortly rugose at the extreme front of its anterior
area, which otherwise is very finely rugulose and shining : abdomen narrow and sub-
elongate.

Hab. Kilauea, Hawaii (4000 ft.) : rare.

This minute and remarkable species cannot be confounded with any other of the
Hawaiian bees known to me. Its resemblance, when on the wing, to a minute
species of Crabro is very great. A few burrows were found in the hard trunk of
a large dead tree, which was still standing. Though I visited this tree on many
occasions I took but few specimens — all females — the males neither coming to the
burrows, nor visiting the flowers in the immediate vicinity.

(26) Nesoprosopis matiiensis, sp. nov.

N. nmtatae simillima ; </ clypeo nigro ; extra hunc flavis duabus maculis ; pro-
noto, tuberculis, tibiisque posticis haud flavo-notatis ; capite supra antennas subrugose
punctato ; antennarum articulo primo fortius dilatato, margine antico subtus distincte
arcuato ; ? capite juxta oculos et margine postico pronoti ad latera, flavo-lineatis ;
tuberculis, tibiisque posticis haud flavo-notatis; scutello opaco. Long. 575 mm.

HYMENOPTERA

95

Male, with only a line bordering the inner margins of the eyes yellow, the
clypeus, prothorax, tubercles and hind tibiae black ; antennae with the scape rather
more dilated than the other small and narrow species, its anterior apical angle
somewhat prominent, and bent downwards, the front margin distinctly arched be-
neath ; head above the antennae clothed with long sparse pubescence, and having an
area about the middle of a deeper black than the general surface, but less distinctly
marked than that of A^. dumetorum ; in front of this are two smooth spaces corre-
sponding in shape to the dilated scape. Mesothorax and scutellum dull, with very
minute punctures ; propodeum at its anterior margin with extremely short rugosity,
behind which the anterior area is smooth except for the fine surface rugulosity, and
slightly shining ; 8th ventral segment of the abdomen with the process and its
apical bifurcations dilated.

Female, with a narrow yellow line along the margins of the eyes, and one on
each side of the hind margin of the prothorax yellow ; head above the antennae
with the surface shining (except narrowly in the middle), finely and closely punc-
tured ; mesothorax dull, and very finely punctured ; scutellum also dull, finely and
somewhat remotely punctured ; anterior area of the propodeum with only the fine
general surface rugulosity and shining in certain aspects ; wings clear and iridescent.

This species may be known from its ally on Kauai by the more dilated scape
of the antennae, the entirely black clypeus, and different sculpture above the antennae
of the </ ; the ? by the dull scutellum, and the more shining and more distinctly
punctured head above the antennae ; from N. dumetorum the distinctly arched an-
terior margin of the scape of the antennae beneath will distinguish the <^ , the black
legs and tubercles the % .

Hab. Haleakala, Maui {5000 ft). A pair (cf and ?) were dug out of a burrow,
which was made in a very hard tree trunk, in April 1894. Subsequent visits in
1895 ^'^^ 1896 failed to produce further specimens.

(27) Nesoprosopis angustula, sp. nov.

Nigra, N. dumetoru^n cognatissima, antennis ejusdem formae ; c/* frontis plaga
pernigra vix distincta ; ? capite tibiisque posticis nigris, baud flavo-notatis, illo
supra antennas subnitido, distingue nda. Long. 5 — 6 mm.

Very close to N'. diimetornjii, the c/ with the scape of the antennae similarly
formed. Male with a yellow spot at the apex of the clypeus, and a well-marked
triangular one along the inner margin of each eye ; tubercles, posterior and inter-
mediate tibiae and tarsi, black ; head above the antennae very densely punctured about
the middle, where there is no very distinct deep-black area, differing greatly from the
surrounding sculpture. In A^. dumetorum on close examination that area is found to

96 FAUNA HAWAIIENSIS

be formed of a patch of extremely short and close-set black pubescence. Female
with the face entirely black, the prothorax with small lateral yellow spots, and the
tubercles are also marked with yellow ; intermediate and posterior tibiae and tarsi
black ; head above the antennae especially towards the vertex distinctly shining
between the closely-set punctures.

Hab. Lanai (2500 ft); January 1894, very rare; 2 t/, i ? only taken.

(28) Nesoprosopis dimidiata, sp. nov.

cT capite prae antennis fere toto flavo, tibiis tarsisque flavis, illis nigro-maculatis,
horum articulis apicalibus plus minusve infuscatis, tuberculis pronoti flavo-notatis ;
capite supra antennas dense ruguloso, minus distincte sparsim punctato ; antennarum
articulo primo multo longiore quam latiore, subtus modice arcuato ; ? nigra, angus-
tula, tibiis intermediis et posticis ad basim breviter pallidis ; mesonoto cum scutello
opaco, subtilissime punctato. Long. 5 mm.

Male, with the whole of the face below the antennae, except the upper part of
the plate above the clypeus, yellow ; antennae with the scape dilated, but consider-
ably longer than wide, its anterior margin moderately arched beneath ; head above
the antennae dull, with the surface very finely roughened, and very shallowly, some-
what remotely punctured. Mesothorax dull and finely punctured ; scutellum dull with
shallow and not very close puncturation ; propodeum with the anterior area rugose
at the extreme front, otherwise only finely rugulose and dull, hardly shining even at
the brow ; tubercles of the prothorax with a yellow spot, all the tibiae and tarsi
bright flavous, the front tibiae with a black spot behind, the intermediate and pos-
terior with a black ring ; apical joints of the tarsi more or less obscured in colour ;
pubescence of head, thorax and legs pale : the process of the eighth ventral segment
dilated.

Female, entirely black, except the front of the anterior tibiae, which are yellow,
the flagellum of the antennae, which is testaceous beneath, and the extreme base
of the middle and posterior tibiae, which have a yellow spot. Face not at all
strongly convex longitudinally, above the antennae rather shining, and finely punc-
tured ; mesothorax and scutellum quite dull, with exceedingly feebly impressed
punctures ; scutellum with very sparse, almost obsolete puncturation ; propodeum
with hardly any distinct rugosity at its anterior margin, the whole anterior area being
very densely rugulose and dull, the brow shining in certain aspects, dull in others ;
basal segment of the abdomen hardly shining, the apical segments with pale hairs.

Hab. a single d' taken in Kona, Hawaii, at an elevation of 4000 ft. (Aug.
1892). The $ I have here described came, I believe, from the same locality, but
unfortunately the locality label was lost.

HYMENOPTERA 97

(29) Nesoprosopis blackburni.

Prosopis b/ackbui'ni. Smith, J. Linn. Soc. xiv. p. 682. Blackburn and
Cameron, P. Manch. Soc. xxv. (1885-S6), p. 143.

(Plate II. fig. 16—16^.)

Male, with the whole face below the antennae bright yellow, which colouring
is continued upwards behind them rather broadly along the margins of the eyes ;
labrum, the mandibles more or less, the tubercles and all the tibiae and tarsi are
yellow, the tibiae generally with a testaceous stain or a black spot behind ; the scape
of the antennae has the front half of its upper surface yellow, and the flagellum
fulvous or even yellow beneath. Face subrotundate, the cheeks between the eyes
and mandibles very short ; scape of the antennae hardly dilated, twice or more than
twice as long as wide, the anterior margin widely but not deeply arched beneath ;
the plate above the clypeus is rather short but not wide : head above the antennae
hardly shining, shallowly punctured, very densely in the middle immediately behind
the antennae, with only a very short inconspicuous pale pubescence. Mesothorax
rather smooth, the surface rugulosity being exceedingly fine, very finely and evenly
punctured, and clothed with short pubescence ; scutellum slightly shining ; propodeum
with its anterior area more or less longitudinally rugose ; eighth ventral segment with
the process dilated, and bifurcate at the apex, the bifurcations fringed with long hairs.

Female, with only the front of the anterior tibiae, and the under side of the
flagellum of the antennae pale. Head very little convex longitudinally, above the
antennae with only very short scanty pale pubescence, distinctly punctured, the surface
between the punctures somewhat shining, at least in certain aspects ; cheeks very
short ; mesothorax with very short pubescence, rather smooth but not shining, very
finely and evenly punctured ; scutellum shining, very finely but not very closely
punctured ; propodeum with the anterior area more or less longitudinally rugose in
front and subopaque ; legs and apex of the abdomen with pale hairs ; wings clear.
Length 5 — 675 mm.

Hab. Maui, but only on the coast and lowlands ; common on the sandhills at
Wailuku and near the coast at Lahaina.

The c/ is very distinct from any other species, the ? is very like some of the
following. This is the species described by Smith in his paper in J. Linn. Soc.
(xiv. pp. 674 — 685), the types being in the British Museum. Mr Blackburn clearly
had several quite distinct species before him, when he subsequently made some
remarks on what he supposed to be A", blackburni. (P. Manch. Soc. loc. cit.)

V. F. H. '3

98

FAUNA HAWAIIENSIS

(30) Nesoprosopis longiceps, sp. nov.

Praecedenti affinis, capite elongate, supra antennas densissime punctato,
mesonoto opaco dense aequaliter punctato, propodei area antica rugosa, abdomine
baud nitido, alis baud infuscatis ; c/' colore fere praecedentis sed niandibulis, pronoti
tuberculis, antennarum articulo basali, tibiis posticis et intermediis (basi extrema
excepta) nigris ; tarsis omnibus plerumque flavis vel pallidis, rarius piceis. Long.
575— 8-5 mm. (Plate II. fig. 3.)

Male, with facial markings like those of A^. blackbur^ii, but with the mandibles,
the scape of the antennae, and generally the labrum, black ; face extremely narrow
between the eyes and longer than its greatest width across them ; plate above the
clypeus very narrow and elongate ; head above the antennae very densely punctured,
especially over the middle portion, the surface dull with short inconspicuous pale
pubescence ; the cheeks between the mandibles and eyes short ; scape of the antennae
twice or more than twice as long as wide, its anterior margin widely and shallowly
arched beneath, the flagellum beneath fulvous. Mesothorax and scutellum hardly
shining (often quite dull), closely and evenly punctured, clothed with grey pubescence ;
propodeum with the anterior area irregularly rugose to the brow — more strongly so
in some examples than in others ; wings in fresh specimens very clear, with dark
neuration. Abdomen dull, without definite puncturation ; eighth ventral segment with
its process somewhat dilated, bifurcate at the apex, the bifurcations somewhat narrow
and fringed with long hairs. The legs are variable in colour, but all the tarsi are
generally yellow or at least pale ; the posterior and intermediate tibiae are black with a
yellow spot at the base and sometimes at the extreme apex ; tarsi rarely entirely piceous.

Female, without yellow facial markings ; the anterior tibiae pale in front ; antennae
with the flagellum fulvous beneath ; face very long and narrow for this sex, the apex
of the clypeus slightly emarginate ; head above the antennae finely and very densely
punctured (at least except at the extreme sides), dull, with short inconspicuous pale
pubescence, the whole front hardly at all convex longitudinally. Mesothorax and
scutellum closely and evenly punctured, not shining ; anterior area of the propodeum
rugose, more strongly so in some examples than in others, sometimes irregularly,
sometimes more or less longitudinally. Abdomen dull, impunctate, the apical segments
with pale hairs ; legs black with silvery pubescence ; wings in fresh examples almost or
quite clear.

Hab. Coast and lowlands of Molokai, Lanai, and Maui.

Obs. Sometimes examples are taken which have the abdomen more or less of an
immature-looking red colour — the so-called ' highly-coloured ' varieties of Smith and
others. Such individuals are liable to differ also in sculpture and other respects from
typical specimens, not only in this, but also in other species.

HYMENOPTERA 99

(31) A^csoprosopis obscurata, sp. nov.

Praecedenti simillima, sed i colore flavo tantum anguste supra antennas pro-
ducto, lamina supraclypeari tota, vel ex parte, nigra, minus elongata, tibiis posticis
et intermediis nigris ; ? capite supra antennas minus dense punctato, inter puncta
laeviori, scutello subnitido et laeviori, alis infuscatis, distinguenda. Long. 6 — 8'5 mm.

Very closely allied to N. longiceps, but the ^ with the head rather less
elongate, the plate above the clypeus decidedly wider, and entirely or partly black,
the yellow markings of the face only very narrowly produced behind the antennae ;
the posterior and intermediate tibiae are not pale at the base, the posterior
tarsi black or piceo-testaceous ; wings more or less distinctly infuscate.

Female, with the head rather less densely punctured above the antennae, than
in the preceding, the surface between the punctures smoother and less dull, the
scutellum somewhat shining, the wings quite infuscate, and the face somewhat wider.

H.\B. Coast or lower slopes of the mountains of Molokai and Lanai ; coast of
Hawaii (Kealakeakua Bay). Rare.

Ob.s. I have taken the specimens from Hawaii as types. It is uncertain whether
they will prove specifically identical with those from the other islands, but the material
taken is insufficient to settle this point.

(32) A^esoprosopis flavipes.

Prosopis flavipes. Smith, Cat. Hym. Ins. pt. i. p. 23; Blackburn and Cameron,
P. Manch. Soc. xxv. (1885-86), p. 149.

" Male. Length 2^ lines. Black ; the face yellow, the colouring is continued
upwards on each side nearly to the vertex of the eye ; the scape cylindrical, black, the
rest of the antennae orange, yellow beneath. Thorax, the metathorax has no distinctly
enclosed space, and is subrugose ; the wings hyaline, the nervures dark fuscous, all the
tibiae and tarsi bright yellow, the former have a ferruginous stain behind. Abdomen
smooth and shining, the margins of the segments narrowly rufotestaceous,"

" Hab. Sandwich Islands."

The above description is taken from Smith's work (/. c. supra). The species is
represented by a single example brought home by the Beechey expedition. Probably
it represents on Oahu the N. Jinitima of Kauai, and A'^. longiceps of Molokai, &c.
Although very closely allied I believe it to be distinct from either of these species.

13—2

loo FAUNA HAWAIIENSIS

{ii) Nesoprosopis finithmx, sp. nov.

N. longicipiti cognata, eodem colore et magnitudine sed mesonoto et scutello
subtilius punctatis ; ? capite etiam minus elongato, et pro longitudine latiore dis-
tinguenda. Long. 7 mm.

(/ with the face shaped and coloured as in N. longiceps, but with the puncturation
of the mesothorax and scutellum distinctly finer ; the ? is more distinct, the difference
between the puncturation of its mesothorax and scutellum and that of longiceps being
more evident, and its head is evidently shorter and wider.

Hab. Kauai, on the coast at Makaweli in 1894; a single pair only taken. It
must be a very scarce species in this and other localities where I searched for it,
as I was never able to take another specimen.

(34) Nesoprosopis anthracina.

Prosopis anthracina, Smith, Cat. Hym. Ins. i. p. 23.

Prosopis rugiventris, Blackburn and Cameron, P. Manch. Soc. xxv. (1885-86).
p. 146.

(Plate II. fig. 17 — 17 d.)

Male, with the clypeus, the plate above it and a spot on each side of it yellow, the
greater part of the face in front of the antennae being of this colour ; front of the
anterior tibiae more or less flavous ; legs black, with the tarsi sometimes piceous or
testaceous. Head elongate, longer than its width across the eyes, above the antennae
dull, rugulose, and shallowly punctured, without any excessively finely and densely
punctured area, clothed with short inconspicuous pubescence ; scape of the antennae
dilated, strongly rounded on its posterior margin, little or not at all on the anterior,
evidently but not greatly longer than its greatest width, the front margin viewed
from in front deeply arcuate beneath. Thorax and scutellum dull, evenly and closely
punctured ; propodeum with its anterior area rugose, sometimes rather regularly
longitudinally, sometimes quite irregularly, the rugosities much stronger in some
individuals than others ; seen from in front the rugosities extend to the brow, which is
not at all smooth or shining. Abdomen dull, the intermediate ventral segments often
raised transversely across the middle ; when strongly raised, then generally the surface
is smoother and more shining, but extremely variable in this respect ; process of the
eighth ventral segment not much dilated dorso-ventrally, the apex bifurcate and
fringed with long hairs.

Female, black, with only the flagellum of the antennae beneath, and the front of
the anterior tibiae pale. It closely resembles the c/ in form and sculpture; the clypeus

HYMENOPTERA loi

is slightly emarginate at its apex ; the head above the antennae quite dull and rugulose,
shallowly punctured as in the d". Scutellum dull, rugulose between the punctures,
which are close and even. Abdomen dull, the apical segments with dark hairs.
Wings in both sexes clear, or clouded across the middle. Length 55 — 7*5 mm.

Hai!. Coast and lowlands of Molokai, Lanai, and Maui ; abundant. Oahu
(Honolulu and Waianae) ; Kealakeakua Bay, Hawaii.

Obs. Most of the examples (</) from the intermediate islands have the ventral
segments transversely ridged more or less strongly, but in some the ridges are
obsolete, and then the surface is generally duller and more or less evidently punctured ;
Oahuan specimens are generally of the latter form, but sometimes the ridges are quite
strongly developed. The cT is quite distinct from any other except the slightly modified
form next described, although its general appearance is extremely similar to that of
N. facilis and others. The ? is very like that of N. longiceps and blackburni, to which
it is really closely allied, but the much less densely punctured head behind the antennae
will easily separate it from the former ; the longer face, and the duller and more closely
punctured scutellum, from the latter.

(35) Nesoprosopis flavifrons.

Prosopis flavifrons, Kirby, Ent. Mo. Mag. xvii. p. 85. Blackburn and
Cameron, P. Manch. Soc. xxv. (1885-86), p. 144.

(Plate II. fig. 18— 18^)

Male, like the preceding in general form and colour ; scape of the antennae often
with the anterior margin more or less pale, and evidendy more strongly dilated than
that of N. anthracina, subcordiform in shape, the anterior margin distinctly rounded
as well as the posterior : the face is also rather wider, and the eighth ventral segment
has the process rather strongly dilated. I see no character whereby the females of the
two forms can be separated. Length 5 '5 — 7 -5 mm.

Hab. Coast of Kauai, not rare; many males were taken in January, 1897, but
only two or three females. I have seen cells of this species formed in dead twigs.

(36) Nesoprosopis assinmlans, sp. nov.

A^. obscuratae cognata, et colore simillima ; </ antennarum articulo primo magis
dilatato, margine posteriore fortius rotundato ; ? mesonoto subtilius punctato bene
distincta. Long. 675 — 9-5 mm.

(Plate n. fig. 19 — 19b.)

Male, with the greater part (often nearly the whole) of the clypeus, and a large
subtriangular mark on either side of it which reaches as high, or a little higher than the

lo:'

FA UNA HA IVAIIENSIS

line of insertion of the antennae, yellow ; the lateral triangles are always divided from
the yellow of the clypeus by more or less narrow black lines ; the plate above the
clypeus is entirely black. In form the species is very like N. obscurata, but the
following characters will easily distinguish it. Male with the scape of the antennae
evidently more strongly dilated, its posterior margin more strongly rounded ; punctura-
tion of the mesothorax and scutellum rather finer, these parts being very dull, with
very close and shallow punctures. The % may be known at once by the exceedingly
minute shallow puncturation of the mesothorax, that of the scutellum being only slightly
more distinct, and the surface of both quite dull. Wings more or less distinctly
clouded, especially across the middle portion.

Hab. Mountains of Lanai (2000 ft.) and on the coast at Awalua. Wailuku,
Maui on the sandhills, and at Lahaina. Not common.

Nesoprosopis assimulans var. oahue'nsis, var. nov.

(/ maculis flavis minoribus, ? alis fortiter infuscatis distinguenda.

Agrees with the former in structure, but the </ has the yellow markings of the
face often much reduced in size, and the wings generally darker ; ? with the wings
entirely infuscate, and in certain lights with a distinct steely iridescence.

Hab. Waialua and Waianae (Oahu), on the coast, or a few hundred feet above
sea-level.

(37) Nesoprosopis inquilina, sp. nov.

Nigra, opaca, griseo-pubescens, alis hyalinis ; </ clypeo fere toto, maculisque duabus
triangularibus extra clypeum, late supra antennas productis, flavis ; lamina supra-
clypeari tota, vel ex majore parte, nigra ; antennarum articulo primo fortius dilatato,
apice antice producto ; ? capite nigro, trans oculos lato, mesonoto opaco, levissime
punctato ; tarsis anterioribus pilis brevioribus, vix curvatis, vestitis. Long. 7 mm.

Male, with the clypeus almost entirely, and the sides of the face between it and
the eyes, yellow ; the latter markings produced rather widely above the antennae along
the margin of the eyes ; plate above the clypeus entirely or almost entirely black ;
anterior tibiae and tarsi pale in front ; tibiae of the intermediate and posterior legs
sometimes with a yellow spot at the extreme base, and slightly pale at the apex, their
tarsi black or piceous.

Face much shorter and wider than that of A^. longiceps. the scape of the
antennae somewhat strongly dilated, and of peculiar form, as its anterior apical angle is
somewhat produced ; head above the antennae closely, subrugosely and very shallowly

HYMENOPTERA 103

punctured. Mesothorax dull, with grey pubescence, and very shallow ill-defined
puncturation ; the scutellum with very similar sculpture ; propodeum with the anterior
area entirely dull, rugose to the brow. Abdomen dull, with rugulose surface ; the
first, second, and third segments with a short fringe of pale decumbent hairs, at least at
the sides, but these bands are very easily abraded; process of the eighth ventral
segment dilated, and densely clothed with long hairs on the ventral side, and the apical
bifurcation fringed. Wings clear in fresh specimens.

Female, black, with the anterior tibiae testaceous in front. The face is wide across
the eyes, in certain positions appearing even transverse ; the apex of the clypeus
slightly emarginate ; head above the antennae quite dull, and shallowly punctured.
Mesothorax dull, with fine, indefinite punctures, these being very shallow, and the
general surface rugulose ; scutellum also dull and similarly punctured ; propodeum as
in the </. Abdomen dull, the apical margins of the segments widely pale, apical
segments with pale hairs ; front legs with the intermediate joints of the tarsi with
somewhat short hairs, quite different from the long, curved, and regularly disposed ones
of all the preceding species.

Hab. Kilauea, Hawaii (4000 ft). Very rare. 1 took a c/' and ? in company in
December, 1896, and a single </ on each of two previous visits to the same locality.
The ? is somewhat abraded and shows no trace of lateral pubescent streaks, but I
suspect they would be present in a fresh example.

Obs. This and the four following species are parasitic on certain of the species
already described. The females are easily known from those of the industrial forms by
the degeneration of the sweeping hairs on the front tarsi. The males however seem to
show no important points of distinction.

(38) Nesoprosopis hilaris, Sm.

Prosopis hilaris, Smith, J. Linn. Soc. xiv. p. 683. Blackburn and Cameron,
P. Manch. Soc. xxv. (1885-86), p. 147.

Male, with the whole face below the antennae bright yellow, and this colouring
is produced above the line of insertion of the antennae broadly along the border of
the eyes ; mandibles ferruginous with a yellow line ; scape of the antennae yellow on
the anterior half of its dilated surface, fulvous on the posterior ; abdomen with the
basal segments ferruginous. Antennae with the scape dilated, evidently longer than
wide, but not nearly twice as long ; head above the antennae dull, somewhat rugosely
punctured. Mesothorax with grey pubescence, dull, and evenly punctured ; scutellum

jo^ FAUNA HAWAIIENSIS

with similar sculpture ; propodeum rugose to the brow ; apical segments of the abdomen
with narrow fasciae of white pubescence along their apical margins ; all the tibiae and

tarsi fulvous.

Female, like the c/ in sculpture, cheeks, clypeus and the face at the sides, as well
as the antennae, more or less red ; the clypeus distinctly emarginate at its apex ; the
face wide across the eyes ; intermediate tibiae almost entirely pale, their apex only
narrowly fuscous, the posterior widely pale at the base, their apical half generally more
or less fuscous ; the intermediate and posterior trochanters both red or pale ; wings
in both sexes clear. Length, 5 — 8 mm.

Hab. The sandy Isthmus between Ea.st and West Maui ; also found on the
coast of Lanai at Manele. In both cases the closely allied species N. volatilis Sm.
is found with it, but apparently that species alone frequents the neighbouring island
of Molokai, as the present species was not found there. N. volatilis extends its range
far up the mountains— as high as eight or nine thousand feet — but N. hilaris is confined
to sandy localities near the coast. Individuals vary greatly in size ; on Maui the small
examples breed in the cells of A", blackburni and probably of N. antkracina, the large
ones in the cells of N. assimulans. The delicate fringe of white pubescence on the
apical margins of the apical segments is very easily destroyed, but the present species
could easily be distinguished from N'. volatilis by this character, as they flew together
over the sand.

(39) Nesoprosopis hostilis, sp. nov.

Praecedenti forma et colore simillima ; segmentis abdominis apicalibus pubescentia
haud fasciatis ; </ articulo primo antennarum antice pallido, postice nigro ; tibiis posteri-
oribus et intermediis basi anguste pallidis ; ? capite flavis duabus maculis juxta oculos
ornato, tibiis posterioribus basi anguste flavis distinguenda. Long. 5 — 6 mm. (Plate
II. fig. 4, also fig. 20 — 20b.)

Very closely allied to the preceding species, from which it seems hardly to differ
in sculpture, although it is a rather more shining insect than any of the other parasitic
species.

Male, with the face coloured as in A\ hilaris, the yellow markings being produced
behind the antennae rather broadly along the borders of the eyes; mandibles without
a yellow line ; scape of the antennae with the upper surface pale only on its anterior
part, the posterior being black or nearly so ; intermediate and posterior tibiae dark,
pale at the base outwardly for only a short distance.

Female, with a yellow (generally triangular) spot on each side of the face, surrounded
by reddish colour, with which they gradually become blended ; the legs coloured much
as in the </. The range of colour in the ? is quite different from that of the allied

HYMENOPTERA 105

species, the prothorax, the mesothorax at the sides and the propodeum wholly or
in part being generally red or reddish.

Hab. Mountains of Kauai (3000 — 4000 ft.) in various localities. Parasitic on
N. laeta, and probably other species.

(40) Nesoprosopis volatilis.

Prosopis volatilis, Smith, J. Linn. Soc. xiv. p. 683. Blackburn and Cameron,
P. Manch. Soc. xxv. (1885-86), p. 148.

Closely allied to N. hostilis but duller. In the </ the yellow colour is less widely
produced along the eyes behind the antennae ; the scape of the antennae is coloured
like that of N. hostilis, but the pale colour is often much diminished, and sometimes
absent in Oahuan specimens, which are in general duller, and have the yellow markings
more clouded, or reduced in size, than examples from Molokai and Lanai. The ?
has the face below the antennae red without yellow markings ; the intermediate and
posterior trochanters are of an obscure colour, or quite black. The wings in both
sexes are less clear than those of A', hilaris, and the margins of the abdominal segments
are without a fringe of pubescence. Length 5 — 8*5 mm.

Hab. Oahu, Lanai. Molokai and Maui, both on the coast and in the mountains
— as high up as 8000 ft. on Haleakala. I have taken remarkably large specimens at
Waianae, Oahu, in company with N. assiviulans var. oalmensis — a large species— on
which no doubt they were parasitic. It also attacks N. facilis, N'. difficilis, and other
species.

(41) Nesoprosopis sphecodoides, sp. nov.

Praecedentibus afifinis, </ abdomine toto nigro, vel nonnunquam segmento basali
plus minusve obscure rufo vel piceo, antennarum articulo primo nigro ; ? capite prae
antennis toto nigro distinguenda. Long. 5 — 7 mm.

Male, with the abdomen entirely black, or with the basal segment sometimes
more or less obscurely reddish ; clypeus with a yellow spot extending from its base
to about three-fourths of its whole length, and outside it there is a triangular
spot on each side of the face ; these spots are separated by more or less black
between them, and they are variable themselves, being much reduced in size in
some examples; scape of the antennae entirely black. Superficially the d" bears a
close resemblance to some of the non-parasitic species, but the inconspicuous pubescence
of the front of the head above the antennae, the closely punctured scutellum, and the
p. F. H. 14

io6 FAUNA HAWAIIENSIS

propodeum, which is rugose right up to the brow, will generally distinguish it. The
% is black with the basal and more or less of the second segment of the abdomen
ferruginous ; the face is entirely black, the clypeus at the most showing a slight tinge
of obscure red; posterior and intermediate tibiae black or of an obscure colour.

Hab. Hawaii, both sides of the island, at an elevation of 4000 ft. Parasitic on
N. difficilis and probably other species.

Obs. The five parasitic species above described are extremely closely allied to
one another, but I believe them to be sufficiently distinct. They all agree in having
the vertex of the head somewhat incrassate, the scutellum closely and evenly punctured,
the propodeum rugose to the brow, and the head between the antennae and the vertex
with only an inconspicuous pubescence, the latter character being characteristic of the
blackbicrni group of non-parasitic species, to which I believe these are closely allied.
The males (except N. inqitiliiia) all have the scape similarly formed ; the females
have the apex of the clypeus distinctly emarginate, and the sweeping hairs of the
anterior tarsi in an evidently degraded condition.

(42) Nesoprosopis fuscipennis.

Prosopis /uscipennis. Smith, J. Linn. Soc. xiv. p. 682. Blackburn and Cameron,
P. Manch. Soc. xxv. (1885-86), p. 140.

A very large species, the </ with the face black, deeply depressed along the eyes,
the depressions dull ; clypeus with shallow punctures, and a few hairs along the apical
margin. Scape of the antennae strongly dilated, closely and finely punctured, both
front and hind margins rounded, the latter much the more strongly, the former with
a white line, seen from in front the front margin is very strongly arcuate beneath ;
head above the antennae with shallow punctures. Prothorax with a whitish band
posteriorly ; mesothorax dull and punctured, the punctures slightly wider apart and
larger posteriorly ; scutellum with larger and less shallow punctures, depressed from
the sides to the middle line ; propodeum with the anterior area more or less strongly
irregularly rugose. Legs with the apical joints of the tarsi usually clear testaceous,
sometimes however entirely obscure ; posterior tibiae with a white line beneath at the
base, the posterior metatarsi also generally with a short basal streak, but this is
sometimes absent. Basal segment of the abdomen with scattered punctures, second
and following with very distinct though shallow puncturation ; beneath shining, rather
largely and shallowly punctured.

Female, very like the d", apart from sexual differences. The prothorax is similarly
banded, and the posterior legs are marked in the same way ; the tarsi are often without

HYMENOPTERA 107

the white streak, their apical joints are generally pale, but sometimes dark. Apical
segments of the abdomen generally with bright brown hairs, but sometimes these are
of an obscure colour. Length, 8 — 1 1 mm.

Nesoprosopis fuscipentiis, var. obsciiripes, var. nov.

Tarsi all dark, and the wings, especially beneath, with a violet iridescence ; pubescence
of the apical segments of the abdomen of the % usually darker than in typical examples.

Hab. Mountains of Oahu, both ranges. Mountains of West Maui, var. obscuripes.

Obs. This and most of the following species are remarkable for their great
size, and the very evident puncturation of the abdomen. The examples taken on
Maui appear to be always of the var. obscuripes ; some of the Oahuan specimens
are hardly separable from these, while others with shining fuscous wings without
iridescence, and pale tarsi, have a distinct appearance.

(43) Nesoprosopis caeruleipennis, sp. nov.

Praecedenti simillima, pronoto postice albo-marginato, tarsis infuscatis, alis laete
caeruleo-iridescentibus. Long. 8 — 1 1 mm.

Hardly differs in structure, so far as I can see, from the preceding, but the
dark wings with light blue iridescence on both surfaces, give it a very distinct
appearance. The pale markings are like those of A^. fuscipennis, those on the legs
are variable. The apical segments are clothed above and beneath with more or less
obscurely-coloured pubescence, and the tarsi are dark.

Hab. Mountains of Molokai and Lanai, from two to four thousand feet. Many
examples taken, and a variety of both cT and ? on Molokai with the abdomen more
or less reddish.

(44) Nesoprosopis pubescens, sp. no\'.

Praecedentibus simillima, abdomine magis pubescente, pronoto postice nigro, rarius
albo-marginato, segmento secundo ventrali a basi magis elevato, saepe subtuberculato ;
alis fuscis; ? abdominis segmentis apicalibus pallide pubescentibus. Long. 8 — 11 mm.
(Plate II. fig. 21 — 21 c.)

Prothorax generally black, sometimes with a much broken white band on the
posterior margin or faint indications of such, very rarely the cT has an entire band. The
legs are variable in colour, in some examples almost the whole of the posterior metatarsi
are white. The wings in the ? are shining fuscous, generally also in the c/", but in
one of these they show a distinct blue iridescence. The prothorax in the ? appears

14 — 2

io8 FAUNA HAWAIIENSIS

never to have an entire pale band, its abdomen is decidedly more pubescent and
rather more punctured than in the allied species, and the second ventral segment is
more strongly raised from the base, having in some specimens a tuberculate form.

Hab. Mountains of Hawaii from 2000 — 4000 ft. in various localities (Kona,
Puna, and Kau). Not rare.

(45) Nesoprosopis setosifrons, sp. nov.

Nigra, alis fuscis caeruleo-iridescentibus ; clypeo breviter nigro-setoso ; scutello
vix depresso, aequaliter punctato ; ^ pronoto nigro, nonnunquam postice albo-lineato,
antennarum articulo primo nigro atque dilatato, evidenter longiore quam latiore ; capite
prae antennis utrinque, nonnunquam etiam clypeo, albo-maculato ; tibiis posticis albo-
lineatis; ? segmentis abdominis apicalibus pilis nigricantibus vestitis. Long. 7 '5 —
10-5 mm. (Plate II. fig. 22 — 22 c.)

Male, with a large white spot on each side of the face below the antennae, and
sometimes one near the apex of the clypeus ; the hind margin of the prothorax rarely
with a white band ; posterior and intermediate tibiae with a pale line from the base,
of variable length, sometimes reaching to their apex ; basal joint of the tarsi with a
spot at their base ; sometimes however the legs are entirely dark, except the front
of the anterior tibiae. Scape of the antennae black, without a white line on its front
margin, dilated, its hind margin strongly rounded, its front one very slightly so,
considerably longer than wide ; clypeus with short erect black hairs (easily seen in
lateral view); the face not deeply grooved at the sides along the eyes, above the
antennae clothed with black hairs. Mesothorax and scutellum with dark pubescence,
and shallowly punctured, the latter not depressed from the sides to the middle line ;
anterior area of the propodeum rugose, more strongly so in some examples than in
others. Abdomen subelongate, evidently, but very shallowly, punctured ; apical
segments with dark pubescence ; eighth ventral segment with the process dilated for
about half its length, the dilatation of triangular shape, fringed on the ventral edge
with long hairs, as also the terminal bifurcation.

Female, like the c/' in general sculpture, but more robust. Face rather strongly
convex longitudinally ; clypeus with black bristly hairs. Prothorax always with a white
margin ; all the tibiae above white, or with a white line, beneath dark, except at
the base; basal joint of the posterior tarsi with a white line. Abdomen shining
with shallow and by no means close puncturation ; second and third segments at the
sides without indications of pale pubescence ; apical segments with black hairs. Wings
in both sexes entirely dusky, with steely-blue iridescence.

Hab. Mountains of Hawaii (4000 ft.). Kona district and at Kilauea. The ^
is easily known from any of the preceding large species by the form of the scape

HYMENOPTERA 109

of the antennae, which is less strongly arched beneath, and the less strongly dilated
process of the eighth ventral segment, while the black-haired clypeus, the steely
iridescence of the wings, and the less pubescent and less punctured abdomen, will
distinguish either sex. Generally taken from flowers of Metrosiderus, Rubus, and
sandal trees, and from burrows in the trunks of the latter. The single </ taken in
Kona is the only one with the white-bordered prothorax, and it also has a large
white spot on the clypeus. The ? ? taken there do not differ from the Kilauea
specimens. The latter sex appears to be much more constant in colour than the
former.

(46) Nesoprosopis perspicua, sp. nov.

Praecedenti affinis, pronoto latissime albo-fasciato, tibiis posticis (macula nigra
apicali excepta) albidis ; alis peropacis, nigricantibus ; clypeo minus pubescente ; d"
capite toto nigro, antennarum articulo basali antice albo-marginato, bene distinguenda.
Long. 8 — 9-5 mm. (Plate II. fig. 5.)

Closely allied to the preceding, but easily distinguished by the very wide creamy-
white collar, and the posterior tibiae almost entirely of the same colour, being black
only at the apex within. The wings are very dark, with steely iridescence. The
posterior metatarsi are black, sometimes with a small white spot at the base. The
</■ has the face entirely black, but the anterior margin of the scape of the antennae
is white. The eighth ventral segment is dilated much as in the preceding species. In
both sexes the thorax is clothed with short inconspicuous pale pubescence, while in
A^. setosifrons it is longer and black.

H.AB. Mountains of Kauai about 3000 ft. (January, 1S97). A nice series were
taken all from the flowers of a single tree (a species of Straussia), but only one of
these was a d".

(47) Nesoprosopis satelles

Prosopis satelles, Blackburn, P. Manch. Soc. xxv. (1885-86), p. 141.

(Plate II. fig. 23 — ^^d.)

Male, with the face entirely black, or with the clypeus tinged with red, or
brightly red, as also sometimes the plate above it ; scape of the antennae entirely
black or with the anterior margin red. The face is wide across the eyes, and its
sides along their borders deeply depressed, the depressions extending behind the line
of insertion of the antennae. Scape of the antennae greatly dilated, not longer than
wide, distinctly and very closely and finely punctured, both front and hind margins

no FAUNA HAWAIIENSIS

strongly rounded, beneath deeply arcuate. Mesothorax and scutellum with dark
pubescence, distinctly and evenly punctured ; propodeum with the anterior area more
or less rugose in front, behind these rugosities its surface merely rugulose, sometimes
the whole area rugulose. Abdomen subelongate, with a fine and shallow, but quite
distinct puncturation, even on the basal segment ; eighth ventral segment with its pro-
cess exceedingly strongly dilated, the dilated part with a pale membranous appear-
ance, its ventral crest densely clothed with generally sooty-black hairs, the extremit)-
bifurcate and greatly dilated, fringed with long pubescence. Posterior tarsi some-
times testaceous, sometimes dark.

Female very like the (/, but more robust, the clypeus and sometimes the plate
above it and the scape of the antennae (more or less) red. Face strongly convex
longitudinally, above the antennae generally finely strigose and punctured, clothed
with dark pubescence. Prothorax black, as in the cT, and the mesothorax and scu-
tellum similarly punctured ; propodeum with the rugosity of its anterior area extremely
short, sometimes almost absent, the surface finely rugulose. Abdomen with the basal
segments shining, the first distinctly, though finely and shallowly punctured, some-
what closely towards the apex ; second segment very finely punctured on the basal
half ; the following segments with rather larger, but very shallow puncturation ; apical
segments with black hairs. Wings entirely dark in both sexes, and with blue iri-
descence. Length, 8 — lo mm.

Hab. Mountains of Molokai and Lanai, and on Haleakala, Maui (5000 ft.).
The males from Molokai generally have the face entirely black, or with the clypeus
only obscurely reddish towards the apex. On Lanai they apparently always have
the clypeus and anterior margin of the scape of the antennae pale. Two examples
from Molokai resemble those from Lanai. Specimens from the latter island are of
smaller average size than those from the former. On Maui I have only taken the %.

(48) Nesoprosopis insignis, sp. no\".

Praecedenti finitima, d" articulo primo antennarum fortiter transverso marginibus
ambobus fortissime rotundatis ; ? clypeo nigro distinguenda. Long. 8 — 9-5 mm.
(Plate IL fig. 24.)

Like the preceding in general form and sculpture, but the ,} with the scape still
more strongly dilated, it being strongly transverse, both front and hind margin ex-
ceedingly strongly rounded. The facial markings are evidently variable, one of the
two examples taken having the face entirely black, the other with a broad longi-
tudinal yellow band, expanded at the apex, down the middle of the clypeus. In
one the sides of the face are very deeply grooved, in the other much less so. Thorax
and abdomen much as in N. satelles.

HYMENOPTERA 1 1 1

Female, face entirely black. Scutellum very dull, and very shallowly punctured ;
anterior area of the propodeum more rugose than that of satelles. Apical segments
of the abdomen with a very faint aeneous tint in some lights, and clothed with dark
pubescence. Wings dark, with blue iridescence.

H.\B. Kilauea, Hawaii (4000 ft.). Two pair were taken, but neither in very
good condition. When fresh, the ? probably has fairly distinct apical pubescent
bands on the basal segments.

(49) Nesoprosopis andrenoides, sp. nov.

? praecedentis forma ; propodei area antica clathrate-rugosa ; abdomine laevis-
simo, subtilissime sparsim punctato, aeneo-micante, segmentis tribus basalibus postice
pulchre albido-fasciatis (fascia prima interrupta), bene distincta. Long. 9*5 — 10 mm.
(Plate II. fig. 6.)

Female, black, very like the preceding in shape. Mesothorax and scutellum quite
dull, and distinctly punctured ; anterior area of the propodeum entirely clathrately-
rugose. Abdomen with the surface very smooth, sparsely and very finely punctured,
black with a distinct aeneous or bluish tint ; the first, second and third segments
with beautiful fasciae of pale decumbent hairs on their apical margins, the first widely
interrupted, apical segments with black hairs, beneath finely but distinctly punctured.
Legs black (except that the anterior tibiae in front are sometimes more or less pale),
with black pubescence. Wings dark, with blue iridescence.

Hab. Mountains of Kauai (2000 — 3000 ft.). Four females of this beautiful
species were taken from the flowers of Metrosidcrus.

(50) Nesoprosopis paradoxica, sp. nov.

Grandis et robusta, nigra, griseo-pubescens, propodeo antice rugoso, abdomine
rufo (? rufo-nigro), distincte punctato: alis fuscis, supra aeneo-micantibus, subtus
caeruleo-iridescentibus ; (/ antennarum articulo primo fortiter dilatato, sed haud latiore
quam longiore, margine antico saepe plus minusve pallido, subtus fortiter arcuato ;
clypeo depresso ; abdomine supra nigro-pubescente. Long. 9'5 — ii'5 mm. (Plate II.
fig. 7, also fig. 25 and 25 a.)

Male, with the face entirely black, scape of the antennae sometimes with a pale
line in front. The face is not deeply depressed at the sides, but the depression ex-
tends over the greater part of the clypeus ; the scape of the antennae dilated, not
much less wide than long, clothed with long pale hairs, its front and hind margins
both rounded, beneath deeply arched. Thorax and scutellum with grey pubescence.

112 FAUNA HAWAIIENSIS

and distinctly punctured, the latter depressed from the sides to the middle line ; pro-
podeum rugose in front. Abdomen red, with the basal segments shining, distinctly
punctured, and clothed rather densely, especially on the third and following segments,
with short black hairs ; eighth ventral segment with the apical portion of its process
hardly dilated, the terminal bifurcation fringed with dense long hairs.

Female, like the d", but more robust ; face not very strongly convex longitudinally ;
scutellum dull, closely and evenly punctured ; anterior area of the propodeum irregularly
rugose. Abdomen shining, distinctly punctured, the basal segment red, more or less
obscured, the rest reddish-black ; second ventral segment simple, somewhat .strongly
and evenly punctured, the following segments more closely, the apical ones clothed
with black hairs.

Wings in both sexes fuscous with blue iridescence beneath, and a bronzy glitter
above.

Hab. Kona, Hawaii (4000 ft.). Not common. Taken while entering burrows
in dead trunks of Sophora. It is an industrial species, though the ferruginous abdomen
reminds one of most of the parasitic forms. This colour and the great size distin-
guish it at a glance from all but the following species.

(51) Nesoprosopis erythrodemas, sp. nov.

? praecedenti simillima, nigra, abdomine toto rufo ; capite longitudinaliter
magis convexo ; propodeo, a fronte viso, acutius postice rotundato, sparsim longitudi-
naliter rugoso ; abdominis segmento secundo ventrali minus nitido, subtilius punctato,
et a basi fortiter elevato, distinguenda. Long. 10 mm.

Female, very like the preceding, but somewhat less robust ; the face strongly
convex longitudinally ; the propodeum seen from in front sharply rounded behind,
bearing a few longitudinal wrinkles. Abdomen entirely red, with the second segment
more sparsely punctured above, beneath very strongly raised from the base to near
the apex, and less shining and more finely punctured than that of paradoxica.

Hab. Kilauea, Hawaii (4000 ft.). Very rare, a single % only taken, but had I
supposed it to be distinct from the preceding at the time of capture, others probably
might have been found.

(52) Nesoprosopis anotiiala, sp. nov.

? minor, capite, oculis exceptis, rubro ; pronoto postice albido-marginato ;
mesonoto densissime punctato, pubescentia pallida vestito ; propodei area antica glabra,
subnitida, clathrate-rugosa, lateribus et parte posteriore dense pubescentibus ; abdomine
ad basim rubro, postice rufo-nigro, distincte punctato : tibiis rufis, supra albo-lineatis.
Long. 7*5 mm.

HYMEN OP TERA 1 1 3

Female robust, but not very large ; head entirely red except the eyes, closely
and rugosely punctured above the antennae, the pubescence pale. Thorax black,
prothorax with a whitish posterior margin ; tegulae testaceous with a yellow spot ;
mesothorax excessively densely and shallowly punctured, the disc glabrous, but all
the margins clothed with pale fulvous pubescence, as also the whole of the scutellum,
postscutellum, and propodeum, except the anterior area of the latter, which is quile
hairless, and rather strongly clathrately-rugose and shining. Abdomen shining, the
base red, the rest blackish, but more or less tinged with red ; second and following
segments distinctly punctured, apical segments with black hairs. All the legs red,
the tibiae with a yellow line above : wings fuscous with very little iridescence.

Hab. Mountains near Honolulu. A single % taken on the blossoms of Acacia
koa. Allied to N. setosifrons and perspicua, this remarkable species in general
appearance is quite unlike any other.

acutilingues.
Apidae.

(i) Xylocopa aeneipennis.

Xylocopa aeneipennis, de Geer, Memoires, in. p. 573, tab. 28, fig. 8. Smith,

J. Linn. Soc. xiv. p. 684.
Hab. Abundant on the lowlands, but not found far up the mountains.

(i) Megachile diligens.

Megachile diligens. Smith, 1. c. supra.

Hab. Oahu, Molokai, Kona district of Hawaii ; not in the mountains. Rare.
Blackburn says ' not uncommon,' and I suspect the species is rarer now than it was
twenty years ago. It may be an endemic species, while the two following are
certainly introduced, and are now abundant on most of the islands. Had they
occurred in the islands formerly, Mr Blackburn would certainly have met with them,
as they are common around the houses in Honolulu. I have not identified either
from elsewhere, and do not know whence they were imported.

p. F. H. '5

114 FAUNA HAWAIIENSIS

(2) Megachile schauinslandi.

Megachile schmiinslandi, Alfken, Ent. Nachr. xxiv. (1898), p. 340.

• Niger, thorace abdominisque segmento primo pubescentia fulva breviter denseque
vestitis, segmentis caeteris utrinque macula pubescente albida ornatis, alls Infuscatis,
caeruleo-iridescentibus, scopa ? pallida. Long. 9 — 11 '5 mm.

Black, the thorax and basal segment of the abdomen densely clothed with short
fulvous pubescence.

Male : clypeus fringed with long pale hairs in front, otherwise shining, coarsely
and closely punctured, and sparsely clothed with erect black hairs. Head above the
clypeus with pale hairs, becoming fulvous about the insertion of the antennae. Thorax
with short dense fulvous hairs, becoming longer at the sides of the propodeum.
Anterior tarsi simple, the basal joint three or four times as long as wide. Wings
and nervures fulvescent at the base, deeply infuscate over more than the apical half,
and with a blue iridescence. Abdomen somewhat shining, coarsely punctured, the
puncturation becoming less distinct on the apical segments, basal segment densely
clothed with fulvous hairs, the following with inconspicuous black ones, and each
with a small spot of white pubescence on either side along the apical margin, the
second and third deeply impressed at the base, sixth with its apical crest slightly
emarginate, and deeply foveolated before the crest. Ventral segments very densely
punctured, clothed with appressed white pubescence, and each of the four visible
ones with an entire apical fascia of longer and denser appressed hairs.

Female like the c/ in general appearance but larger, the clypeus without the
pale fringe and its puncturation excessively dense. Mandibles dull, rugose and
punctured, flattened in front. Ventral scopa of silvery hairs, those on the apical
segment black.

Hab. Several and probably all of the islands in and around settlements, often
making its nidtis in holes in woodwork, keyholes, &c. Very abundant in Honolulu.

Obs. I have had this species described for some years under the name of
M. domesticuni in MSS. awaiting publication, and have given it away under this
name.

(3) Megachile pahnarum, sp. nov.

Niger, cinereo-pubescens, abdomine </ 4, ? 5, fasciis pubescentiae pallidae ornato,
alis subhyalinis, segmento sexto ^ profunde emarginato, scopa ventrali ? pallida.
Long. 9 — 10 mm.

HYMENOPTERA 1 1 5

Male : face densely clothed with pale fulvous pubescence to above the insertion
of the antennae, the vertex almost bare and very densely punctured. Thorax finely
and very densely punctured, sparsely clothed with pale pubescence. Wings subhyaline.
Front tarsi simple. Abdomen densely punctured, the first four segments with a
narrow entire apical band of pale pubescence, sixth with the apical crest deeply
emarginate, and having a spot of appressed pubescence before the crest ; beneath
with four segments exposed, the second and third with an entire apical band of pale
pubescence, the apical margin of the fourth sinuate ; 5th submembranous, with a
semilunar impressed area, which is notched in the middle of its apical margin, and
appears to be densely covered with minute asperities (under the microscope these
apparent asperities are seen to consist in reality of peculiar short thick hairs with
knobbed apices) ; 6th band-like and fragile, with a transverse line of remarkable
hairs, which are flattened and curved, with their apices bent and acuminate ; 8th
very delicate, tongue-like, obtuse at the apex ; genital armature with the stipites
and sagitiae of equal length, the latter connected by membrane to their apex, the
former flattened, widening towards the apex, and there pointed, bent outwards, and
set with a few extremely short hairs. Calcaria pale.

Female very like the <} in general appearance. The pubescence is cinereous
with little or no fulvous tinge, that on the clypeus is sparse, so that the puncturation
is exposed. The first five abdominal segments have a band of pale pubescence,
beneath the scopa is formed of silvery hairs, those on the apical segment black.

H.\B. Several and probably all the islands, especially about towns or settle-
ments. Nests frequently in the leaves of coconut and other palms when they have
been rolled up by the larva of a Pyralid.

(i) Apis mellifica.

Apis mellifica, Linn. Syst. Nat. ed. x. i. p. 576.

Hab. The hive bee is common throughout the islands, and is now found wild
in many of the mountain forests, forming its nests in hollow trees.

IS— 2

HETEROGYNA.

(FORMICIDAE.)

Par Aug. Forel.

(i) Ponera kalakauae, nov. spec.

<?. L. 2'8 a 3 mill. Rapprochee de la P. coarctata, mais les mandibules plus
courtes, plus larges, a bord externe moins convexe, n'ont a la partie posterieure de
leur bord terminal que de deux a quatre dents tres obtuses, indistinctes, mais assez
larges, au lieu des petites denticulations serrees de la P. coarctata. L'epistome est
plus court, bien plus concave de chaque cote de son bord anterieur, a convexit6
centrale plus forte. Le i" article du funicule est plus grele, long comme les trois
suivants reunis (ces derniers tres courts) ; chez la coarctata et congeneres, il est plus
court. Les yeux ont de 7 a 8 facettes et sont assez pres du bord anterieur. Tete
rectangulaire allongee, a cotes tres faiblement convexes. Le sillon frontal atteint
presque I'occiput. Le mesonotum, vu de dessus, est presque circulaire, a peu pres
aussi long que le pronotum. La face basale du metanotum, a peine plus longue que
le mesonotum, aussi longue que la face declive, est notablement plus large derriere
que devant (ses deux cotes' convergent tres distinctement en avant) ; elle forme un
angle subitement arrondi, mais approchant de Tangle droit, avec la face declive qui
est plane. Le pronotum est tres convexe devant, mais le reste du dos du thorax
est subdeprime, presque plan, tres faiblement biincise aux sutures. L'ecaille est
epaisse comme chez Yeduardi (plus epaisse que chez la trigona, plus mince que
chez la coarctata), mais bien plus basse, depassant a peine le thorax et I'abdomen.
Abdomen distinctement, mais moderement r^treci apres le i" segment; le second
plus large.

Luisante ; ponctuation bien plus fine, moins dense et moins profonde que chez
la coarctata. La pilosite et la pubescence sont aussi plus fines et plus espac^es.

D'un brun jaunatre sale, avec le front, I'occiput et I'abdomen (sauf le premier
segment et I'extr^mite) bruns. Le pronotum et le mesonotum sont plus fonces que
le metanotum et l'ecaille qui sont plutot d'un jaune brunatre, comme les pattes, les
antennes et les mandibules ; tarses jaunatres.

HETEROGYNA iiy

?. L. 3-5 mill. La suture entre le scutellum et le metanotum tres profonde ;
ce dernier assez long, bien separe par une incisure distincte du reste du thorax, sans
que ses cotes convergent en avant ; une courbe tres arrondie entre les deux faces du
metanotum. Ailes courtes, hyalines, depassant a peine I'abdomen.

Pattes, antennes, mandibules, extremite de I'abdomen d'un jaune brunatre plus
ou moins fonce ; cuisses brunes au milieu. Epistome, scutellum, ecaille et bord des
segments abdominaux d'un brun rougeatre ; le reste d'un brun fonce. Du reste comme
I'ouvriere.

La forme du thorax, les mandibules etc. me semblent justifier la fondation d'une
espece, malgre le dedale deja si complique du groupe coarctata auquel cette forme
appartient.

Hab. Lihue, Kauai, 9 ; the winged ? taken in the town at Honolulu.

(2) Ponera perkinsi, nov. spec.

5 . Extremement semblable d'aspect a Xopaciceps type, mais les pattes et les
antennes sont plus courtes, les articles du funicule sont plus larges et plus courts (les
art. 3 et 4 deux fois plus larges que longs) ; les dents des mandibules sont encore
plus larges et plus espacees, les yeux un peu plus petits, le thorax plus convexe et
la sculpture un peu moins dense et moins mate.

Les scapes atteignent le bord occipital. L'angle metanotal est un peu plus arrondi,
et tout le thorax un peu plus trapu (face basale du metanotum plus courte), I'ecaille
aussi moins haute.

Tout cet ensemble de differences la rapproche de la P. coarctata, dont elle differe
par sa taille bien plus robuste et plus large, sa tete. a cotes convexes, ses yeux
distincts.

D'apres M. Perkins, cette espece, repandue a I'interieur de toutes les iles Hawai,
doit etre la seule forme bien certainement locale de I'archipel. Je crois done que,
malgre ses affinites avec Xopaciceps, il vaut mieux en faire une espece. Elle varie
de couleur jusqu'au rougeatre.

Un exemplaire de I'ouvriere a des yeux a facettes assez gros, sans etre du reste
notablement plus grand que les autres, ni different a d'autres egards. C'est done
exactement le meme cas que celui de la Pone^'a ediiardi Forel, recoltee par moi dans
la Province d'Oran ; mais chez cette derniere les individus ocules sont distinctement
plus grands.

?. L. 37 mill. Ailes hyalines, courtes ; nervures et tache marginale pales. Face
basale du metanotum courte, sans trace d'incisure a ses sutures, passant en avant aux
autres pieces par les memes surfaces, mais abruptement tronquee derriere par la face

ii8 FAUNA HAWAIIENSIS

declive. Du reste comme I'ouvriere, avec les differences ordinaires du polymorphisme
sexuel. D'un noir brunatre ; mandibules rouges ; pattes et antennes d'un brun rougeatre.
Echancrure de I'abdomen faible.

c/'. L. 3 mill. Tete presque carree, a angles post^rieurs arrondis. Les yeux
occupent un peu plus de la moitie anterieure des cotes. Scapes un peu plus courtes
que le 2™^ art. des funicules. Face basale du metanotum extremement courte, face
declive en talus. Abdomen pas ou presque pas retreci apres le i" segment. Sub-
opaque ou luisant ; sculpture bien plus faible que chez les ? et 9 .

D'un brun noir, pattes, antennes et ecaille d'un jaune brunatre sale.

Hab. In the mountains on all the islands, generally from 2000 — 4000 ft.

(3) Ponera gleadowii Forel, r. decipiens, nov. st.

? . Ressemble enormement a la P. ragusai Em. qui me semble aussi etre
une race de la gleadowii. La nouvelle forme a tout a fait la taille et la forme plus
grele et plus allongee de la ragiisai, mais Tecaille de la gleadowii i. sp., avec la face
posterieure aussi haute que la face anterieure. Sa couleur est d'un jaune plus rougeatre
(plus ocreux chez la gleadowii i. sp., brunatre chez la ragusai), sa pubescence plus
faible que chez la ragusai.

Hab. Kauai on the coast. Hindostan, typical form ; Sicily, race ragusai.

(4) Leptogenys falcigera Roger, var. insularis Smith.

? cT. La L. insularis Sm. n'est a mon avis qu'une variete de la falcigera.
Hab. Kauai, Oahu, and Maui. Ceylon and Madagascar, typical form.

(5) Pheidole megacephala Fab. 9 </.
Hab. All the islands from the coast to an elevation of 3000 ft. Cosmopolitan.

(6) Stenamma {^Ischnoiiyrmex) longiceps Smith.
Hab. Honolulu (Rothney). Australia.

(7) Tetrainorium guineense Fab. ? .
Hab. Oahu, Molokai, Hawaii, and probably the other islands. Cosmopolitan.

HETEROGYNA 119

(8) Solenopsis geininata Fab., r. rufa Jerdon.

9. Cette race est celle de I'lnde qui se distingue de la forme americaine par
sa couleur toujours d'un jaune rougeatre, sa forme un peu plus robuste, avec les 9
moins extremes (surtout la tete des 9 major molns enorme), enfin par la presence
d'une dent plus ou moins distincte au bord anterieur du mesosternum.

Hab. Honolulu, Waianae, etc., abundant. Hindostan and Malaisia. [Typical
form North America.]

(9) Pogonomyrmex occidentalis Cresson 9 (de ma collection).
Hab. — ?. North America.

(10) Monomorium fioricola Jerdon <? ?.
Hab. Oahu, Molokai, Lanai, Maui, and probably all the islands. Cosmopolitan.

(11) Mononioriiim vastator Smith 9.
Hab. Honolulu. Cosmopolitan.

(12) Monomorium mimittim Mayr, v. liliiiokalanii, nov. st.

Differe de la forme typique avant tout par les dents de son epistome beaucoup
plus ecartees (un peu moins seulement que les aretes frontales) et plus fortes. Yeux
un peu plus en avant (vers le tiers anterieur) de la tete. Pubescence legerement plus
courte et plus appliquee. Premier noeud du pedicule' d'une idee plus longuement
petiole et a noeud plutot plus bas (plus haut chez la van madecassum).

Hab. Honolulu. Southern Europe, typical form ; varieties in Africa, Mada-
gascar, etc.

(13) Cardiocondyla wroughtonii Forel, v. hawa'iensis, nov. st.

5. Differe du type par sa couleur entierement d'un jaune clair, avec une tache
d'un brun roussatre, nuageuse, de chaque cote de I'abdomen. Les antennes sont un
peu plus greles, les epines un peu plus longues et la sculpture est un peu plus delicate.
Les aretes (bord posterieur) de I'epistome sont aussi lateralement un peu plus aigues,
la ou elles rejoignent le bord anterieur.

Hab. Molokai. Hindostan, typical form. .

I20 FAUNA HAWAIIENSIS

(14) Cardiocondyla mida Mayr, v. minutior, nov. van

L. 1 7 mill. Second noeud du pedicule un peu plus large que long (au moins
aussi long que large chez la forme typique). Sculpture plus forte et surtout le thorax
plus mat que chez le type. Tete, thorax et pedicule plus ou moins d'un rouge brunatre
assez sombre. Cette variete, plus trapue que la forme typique, ressemble un peu en
petit a la v. viauritanica Forel, mais elle est plus mate et a les epines plus longues.

Hab. Honolulu and on Molokai. Polynesia, typical form ; varieties in Hindostan,
Algeria, etc.

(15) Tapinoma melanocephalwn Fab.

9, (La forme typique americaine, pas Xmdicum.)

Hab. Honolulu and Waianae, Oahu ; also on Lanai and Molokai, and no
doubt the other islands. Cosmopolitan.

(16) Prenolepis longicornis Latr.
Hab. Abundant all over the islands on the plains.

(17) Prenolepis obscura Mayr.

Blackburn and Cameron, P. Manch. Soc. xxv. (1885 — 86), p. 174.

Hab. Hawaiian Is. (Blackburn). Not obtained by Mr Perkins, and therefore
not verified by M. Forel. Australia.

(18) Prenolepis bourbonica Forel, r. hawaunsis, nov. r. .

9 ?{/*. Plus massive que la forme typique de la Reunion, plus large et moins
elancee. Yeux des 9 un peu plus gros. Polls de la tete un peu plus longs. La
pubescence est aussi moins abondante et les nuances de couleur plus differenciees
(moins melees). La % est plus noire, I'ouvriere plus claire. Chez le cf, dont les
tarses sont jaunes, les valvules genitales exterieures ont une echancrure mediane
encore plus forte et la dent plus longue que chez la forme typique. Les ailes sont
plus enfumees que chez la r. bengalensis, dont les valvules genitales exterieures la
distinguent du reste.

i

HETEROGYNA 121

La forme du corps de cette forme, sa tete plus large derriere et devant (plus
carree) chez I'ouvriere m'engageraient a en faire une espece, mais la structure des
valvules genitales est trop voisine de celle de I'espece typique.

Hab. Oahu, Molokai, and Hawaii ; from the coast to 4000 ft. Reunion,
typical form ; a race in Hindostan.

(19) P^'enolepis sharpii, nov. spec.

?. L. 4'2 mill. Bien plus petite et plus grele que la precedente. Tete assez
fortement retrecie devant, a cotes convexes. Ailes plus faiblement enfumees. Ecaille
faiblement echancree. D'un brun noiratre, avec les mandibules, les scapes, les pattes,
I'ecaille et le scutellum d'un jaune sale ou legerement brunatre. Funicules brunatres.

</*. L. 2'o a 2'2 mill. Valvules genitales exterieures larges, tres raccourcies, ter-
minees d'un cote par une petite dent suivie de tres pres d'un feston (Fig. i). Valvules
moyennes pourvues de deux prolongements etroits, longs, faiblement courbes, presque

I la

Valvules genitales males.
I, valvule exterieure : la, valvule moyenne; ;', prolongement interne; <■, prolongenient externe.

egaux (I'externe un peu plus long) et fortement denticules a leur moitie periferique et
sur les faces qu'ils tournent I'un contre I'autre (les dents sont noires). L'interne est
en outre coude en dedans pres de sa base (Fig. i"*; e, prol. externe, i, prol. interne).
D'un jaune a peine rougeatre ou un peu brunatre sur le mesonotum. Abdomen et
dessus de la tete brunatres.

9. L. 2-3 mill. Abdomen brun; tete et thorax d'un brun jaunatre. Pattes et
scapes jaunatres. Foils raides, assez epais, bruns. Tete ovale, assez etroite. Du reste
presque impossible a distinguer de la vividula, tandis que les valvules genitales du </
sont absolument differentes.

Par ses valvules genitales cette espece se rapproche surtout des especes de I'lnde,
comme smythiesii etc.

D'apres M. Perkins, cette espece a ete recemment import^e de Chine. Elle est
en effet plus voisine des formes asiatiques que des formes americaines.

Hab. Honolulu, brought with plants from China,
p. F. H. 16

122 FAUNA HAWAIIENSIS

(20) Camponotus niaculatiis F., r. initis Sm., v. haiuaiensis, nov. var.

Cette variete ((/, ? et 9 minor) tient du dulcis et du variegatus. Les tibias sont
un peu plus aplatis et plus prismatiques que chez ces deux varietes, les polls du corps
un peu plus courts ; la pubescence est bien adjacente. Chez la ? le jaune de I'ab-
domen est dispose en taches plus ou moins distinctes ou confluentes.

Hab. In and around houses in Honolulu. A cosmopolitan species.

Si nous jetons un coup d'oeil d'ensemble sur les 20 especes trouvees jusqu'ici
a Hawai, nous y constatons d'abord I'absence des belles especes caracteristiques de
la Faune des iles Viti et Samoa decrites par Mayr {Camponotus schmeltzi etc.).

Ouelques especes absolument cosmopolites et evidemment apportees par les vais-
seaux ne donnent aucun point de repere sur I'origine de la faune. Telles sont le
Tetramoriiim guineense, la Pheidole megacepliala, les Monomorium floricola, et vastaior,
la Prenolepis longicornis et le Tapinoina melanocephaluin.

D'autres ont une grande etendue, mais caracterisent cependant la faune de I'ancien
monde, specialement la faune indo-malaise. Ainsi le Solenopsis geminata r. rit/a, le
Leptogenys falcigera (la var. insularis est hawaienne il est vrai, mais a peine differente
du type), le Camponotus mitis maculatus r.

D'autres appartiennent a la meme faune indo-malaise ou malgache, mais sont
representees aux iles Sandwich par des races ou varietes speciales. Telles sont les
deux Cardiocondyla, la Ponera gleadowii r. decipiens et la Prenolepis bourbonica r.
hawaiensis.

Une autre race hawaienne se rattache a une espece de I'ancien monde :
Monomorium minutum r. liliuokalanii.

Autres sont speciales a Hawai : Ponera kalakanae et perkinsii ; Prenolepis sharpii.

Une {Pogonomyrmex occidentalis) est de I'Amerique du nord (importee probable-
ment, si I'etiquette est exacte). Une [Stenamma longiceps) provient de I'Australie
(sans doute importee). La Prenolepis obscura me parait fort douteuse ; peut-etre
est-ce la bourbonica ?

Somme toute, la faune locale parait se rattacher a la faune indo-malaise surtout
(sous-faune oceanienne).

SMITHSONIAN INSTITUTION LIBRARIES

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nhem qQL345 H3F2
V 1 pt 1 Fauna hawaiiensis;

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V. 3 pt. 3 Fauna hawaiiensis.