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Ces DEPARE MENT OF AGRICULTURE,
BUREAU OF ENTOMOLOGY— BULLETIN No. 93.

L. O. HOWARD, Entomologist and Chief of Bureau.

THE SUGAR-CANE INSECTS OF HAWAIL

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BY

D. L. VAN DINE,
Special Field Agent.

IssuED JUNE 15, 1911.

WASHINGTON:
GOVERNMENT PRINTING OFFIOE.
LOWE

° BUREAU OF ENTOMOLOGY.

L. O. Howarp, Entomologist and Chief of Bureau.
C. L. Martatt, Entomologist and Acting Chief in Absence of Chief.
R.S. Cuirron, Executive Assistant.
W. F. Tastet, Chief Clerk.

IF’. H. CHITTENDEN, in charge of truck crop and stored product insect investigations.
A. D. Hopkins, in charge of forest insect investigations. |

W. D. Hunrer, in charge of southern field crop insect investigations.

F. M. WesstER, 7n charge of cereal und forage insect investigations.

A. L. QUAINTANCE, in charge of deciduous fruit insect investigations.

E. F. Putiies, in charge of bee culture.

D. M. RoceErs, in charge of preventing spread of moths, field work.

Roiia P. Currisg, in charge of editorial work.

Mase. CoucorD, librarian.

SOUTHERN Freip Crop INSECT INVESTIGATIONS.
W. 1D. Hunter, in charge.

W. D. Pierce, J. D. MitcHett, FE. 8. Tucker, T. BK. Hottoway, G. D. Surrna, E. A.
McGregor, Harry Pinxus, W. A. THomas, THomas Lucas, engaged in cotton-boll
weevii investigations.

F.C. BisHopp, W. V. Krna, H. P. Woop, G. N. Waucort, engaged in tick investigations.

A. C. Moraan, G. A. Runner, 8. E. Crump, engaged in tobacco insect investigations.

T. C. Barpnr, C. E. Hoon, engaged in sugar cane and rice insect investigations.

F.C, Pratt, engaged in cactus insect investigations.

D. L. Van Dine, Witmon NEWELL, R. A. Cootey, A. F. Conranl, C. C. KRUMBHAAR,
collaborators.

2

EETRERSOF TRANSMITTAL.

U.S. DEPARTMENT OF AGRICULTURE,
BUREAU OF ENTOMOLOGY,
Washington, D. C., December 22, 1910.
Str: I have the honor to transmit herewith for publication a manu-
script entitled ‘The Sugar-Cane Insects of Hawau,” by Mr. D. L.
Van Dine, recently a special agent of this Bureau, and for several
years entomologist of the Hawaii Agricultural Experiment. Station.
The manuscript includes a discussion of the present status of the |
sugar industry of the Hawaiian Islands and treats of the principal
insect enemies to this important industry, which is rapidly assuming
large proportions in our Southern States owing to the increased
acreage which is being planted to cane. I would recommend its
publication as Bulletin No. 93 of the Bureau of Entomology.
Respectfully,

L. O. Howarp,

Chief of Bureau.
Hon. JAMES WILSON,

Secretary of Agriculture.

PREFACE:

The acreage devoted to sugar-cane culture in the southern United
States has increased rapidly in recent years. Some of the cotton
lands, abandoned because of the depredations of the cotton boll
weevil, are being planted to cane. New lands are being planted to
the crop in the Rio Grande valley and in the reclaimed areas in the
lower Mississippi valley. It is stated that quite an area of land
in process of reclamation in the State of Florida will be planted to
sugar cane. It is desirable that the experience obtained through
investigations of insects injurious to sugar cane in the Hawaiian
Islands be placed at the disposal of the planters in our Southern
States in order that the sugar industry in those States may receive
practical benefit therefrom.

The Hawaiian planters are well provided with expert advice and
have at hand numerous reports dealing with the subject, which latter,
unfortunately, are not available for general distribution. This report
is written primarily, therefore, for the information of our mainland
planters.

Acknowledgment should be made of the courtesies extended to
the writer by the members of the entomological staff of the Hawaiian
Sugar Planters’ Association Experiment Station during his return
visit to the Hawaiian Islands in March and April, 1909.

D. L. Van DINE.
5

CONE Ne LS:

Page
ocation and:elimateontne Hawaiian lslandss 2555225 22.525- 262. 52522-2-5--- 9
he sugar amdustaypemeila wales Ss eee yeh ee. Dea 9
DUP Ar CAMeMMSC Cis ker settee SU to oni Vo niece ae WO Se as oe 11
The sugar-cane leafhopper (Perkinsvella saccharicida Kirk.)....-....---.---- 12
Mistral uibOmepy ee a eee ae DE os Se wlad a2 12
Appearance of the leafhopper in Hawaiian cane fields.......-..-......- 12
Descripmon-otethe leathoppers. 2225. 4--eeeeeas Soe aes ow. Nae eee: 13
Dispersion ot the leathopperssss too ee ee eee 14
iiiteshistonygandshabitssascesatar eis tk oat a eee ee sec 15
SyaUp coms Oleleathop perms sense ee gh ee ST 17
Characterrotemny Uy; tothe °Canens sateen cee 22 oe a ciy Secale 3 18
J Opi VSvawe. Ove MUO LUBE eels 8 Perak mgs cope ee ah i a a 19 |
Hactors responsible for the outbreak of 1903. 2-22. 222-2..2..242.-22-: 20
ihesdeathoppersand, beekeeping tee erst ee) cect once 20
Controloitheleathoppetin- ee ctian see a ors oe oe eek oe aioe see 22
iDirectimeasuressis ee qe es ee eet GE eee we aS reno 22
JS CC LYE TC eS ime rty st Sere acre 8 A alr wk WAGs RE a. eae ao 22
ColllecitonPbyeme tise tease cee A re Sts Sk Bee ala 22
Cutting and burning in the infested centers.-...............-.- 22,
Siappineptineslea vest wee ete ee ear Wee ih a ee tle 2 23
iBurninesoltrashvattersMaryestimeee= see see aes eo oe 23
indinectimcaswress stain yee es eer ee a a tee ie ace ees 23
Selection of varieties of cane for planting..:..-.........-..... 23
Cultural methods on the plantation............. Baan Sie 25
Diversiiication olsCrOops ee asa ct mse heros eet eye 26
Control of the rind disease of sugar cane...........-..-..--- 26
Na turalsememi esters sate Geen ihe ale ee Sea les 28
Species already present in the Hawaiian Islands................-- 28 |
Speciallwimtnro due HONS hs: sees asec ms he a cee Stas ye 29
elNel ate des pe Cles weit Me caipaeneas enn gaara Geen Rea HN yee Se Th 34 |
The Hawatian sugar-cane borer ([Sphenophorus| Rhabdocnemis obscurus |
SOI SC) Sys as enon nem at Cea teeter kh Master ace MN Wek te oe Cn kU ee ea 39 |
Generale charactenistiesesmetvy ccm conte oe elas ie Se ee a i 35
DIS trllo uit] Olesen ieee Ne aa Pen TL gl ati ER ey Sal 36
Occurrencernnukla walle ne sae meee ee Se 8 oo 36
Enea StOmye Maisie tomer we SP ei eet 2 UF aa: 37
Womenolpmensiinesare samen Nee py ete yc Fn eis ist ae ks 39
Selechioniot varieties tor plamtimg a: Sn. 222. see 0s ine) ke 39
GETS AbTOne eee eee eee Ces 8) Wig RT el ae ote oy)
Buraningeyo le trachea torn en eer Na athe cas 39
Selectionxol momimiested seed: canes 5-2. 22-525. 52 245-2 stone. 39
Picking sand jbartimese. 252-4 1 es ae det Ne tes gem PR ee 39
iRelatedispeciocerc see amen ctr EM feceot aos vad 40
The Hawaiian sugar-cane leaf-roller (Omiodes accepta Butl.)...........--- 4]
Marly history, theslawaitanm Iislandse 2-246. 25.2. cese- 2st eee- <5 4]
Wontrolemme ns Utes tes see teste ete eine tec el across o'= Sisjebiciuinidc ies ele 4]
| PRIESTESS StS a Na Paes ee Doe ie ey SO ce le ee 41
7

8 THE SUGAR-CANE INSECTS OF HAWAII.

Sugar-cane Insects—Continued. Page.
The sugar-cane mealy-bug (Pseudococcus calceolarix Mask.)............--- 43
Teen tity: 525 pc oe ae ge ee 43

Related ‘species... 22522 2 BS. sa Re ee oe er, Bes cos, ee 43

Food plantss: ...5 22 sos 235 oe a SE 43

Lhife history“and*habitsis2. Sees eee ee 44

Controls. 2s A Ee ee er Soil 5: 44
Selection of seed* came tes 8s ex were oes 4. i ee 4

Burning of the tras lai. iy eee anon ee eee aise ie age ore eee 44

Natural enemies 22-22. “2335 Se eae ce Scent hs) A Ee 45
Miscellaneous insects affecting sugar cane in Hawaii-.....-..-.....---.--- 45
Ratsimjuring crowing sugar camesune lawl ee wer renee 2 ee 47.
L600 (2) eee Ce wren noe CSU OL i a ate. ae aca sca bees a usies 49

Hb eS TRATIONS.

PLATES.
Page.
Prank Map of the daweaiam alislamc sees se eee eee Frontispiece.
II. The sugar-cane leafhopper (Perkinsiella saccharicida). Fig. 1.—Egg
chambers in midrib of cane leaf, shghtly enlarged. Fig. 2.—Eggs,
greatly enlarged. Fig. 3.—First-stage nymph. Fig. 4.—Second-
stage nymph. Fig. 5.—Third-stage nymph. Fig. 6.—Fourth-
stagemympht > hig. 7-— Adult males) 2.025) see aee eee 16
III. The Hawaiian sugar-cane leaf-roller (Omiodes accepta). Fig. 1.—
Adult moth. Figs. 2, 3, 4, 5.—Larve and details. Fig. 6—Pupa
and details. Fig. 7Apex of cremaster, showing the curled
spines by which the pupa is fastened to the cocoon. Fig. 8.—
Cluster of 4 eggs in groove on surface of leaf. Fig. 9—Eggs more
highly enlarged. Fig. 10.—Leaf spun together for ‘‘retreat”’ or
hiding place of caterpillar; shows where caterpiilar has eaten.
Fig. 11.—Leaf, showing spots where a very young caterpillar has
eaten, leaving one epidermis intact, instead of eating holes
through=the leatsi.. 2 e280 Sane alee eee eee 42
IV. The sugar-cane mealy bug (Pseudococcus calceolarix). Fig. 1.—
Adult mealy-bugs clustered about the base of young cane. Fig.
2.—Adult female, twice natural size. Fig. 3.—A single adult
female, with white mealy-like covering. Fig. 4.—Cocoons of male
an eal y= Ug gx. 5csieg Sete ey aay ae ae ee eg 44

TEXT FIGURES.

Fig. 1. The sugar-cane leafhopper (Perkinsiella saccharicida): Adult female,

much enlarged; ovipositor, greatly enlarged......-.....--.--------- 17
22 An-aplary Near a.sugar-cane field = eee ys a ee ee ee 21
3. Yellow Caledonia sugar cane, a variety which is replacing Lahaina and

Rose Bamboo m the Hawanan Islandss:-- 7.9.5. 555 e eeee eee 24
4. The Hawaiian sugar-cane borer ([Sphenophorus] Rhabdocnemis obscurus):

Kegs; larvee; pupa, cocoon, adults 3525 Saas 5 ee eee one area 35

5. The Hawaiian sugar-cane borer: Work in sugar cane.....-...-- fois Tee el 38

THE SUGAR-CANE INSECTS OF HAWAIL

LOCATION AND CLIMATE OF THE HAWAIIAN ISLANDS.

The mid-Pacific Territory of Hawaii (see Plate I) is situated 2,100
miles to the southwest from San Francisco, the California coast
being the nearest continental area. The islands are separated by
channels varying from 20 to 58 miles in width. The 8 inhabit-
able islands, Hawaii, Maui, Oahu, Kauai, Molokai, Lanai, Kahoolawe,
and Niihau, lie between 18° 54’ and 22° 15’ north latitude; that is,
the northern limit of the islands is just within the Tropics. The
climate of the entire group is, however, only subtropical, due largely
to the prevailing northeasterly trade winds, the cool ocean currents
from the north, and the relatively low humidity. The temperature
varies according ‘to the altitude and the location of the land as
regards the higher mountains. The formation of the islands is of
recent volcanic nature, with the exception of the low-lying coastal
plains, which are of coral origin.

The annual maximum temperature ranges from 88° to 90° F.,
while the annual minimum temperature recorded ranges from 52° to
58° ¥. <A temperature of 29° F. has been recorded at an altitude of
6,685 feet, and freezing temperatures are of frequent occurrence at
these high altitudes. The rainfall varies in amount with the locality.
Places within a few miles of each other are known to differ more than
100 inches in average annual rainfall. The sides of the islands
exposed to the northeast trade winds have abundant rains, while the
opposite sides have little and some localities hardly any.

The soils of the islands are exceedingly fertile and when properly
cultivated yield abundant crops.

THE SUGAR INDUSTRY IN HAWAII.

The production of sugar is the leading industry in the Hawaiian
Islands. Sugar cane is grown on four of the islands. The island of
Hawaii has the largest acreage devoted to cane,.Oahu, Maui, and
Kauai coming next in importance in the order named. There are
more than 200,000 acres planted to cane in the islands. In 1908
521,000 tons of raw sugar were produced, having a value of more
than $40,000,000. The average yield of sugar per acre is 44 tons.

83327°—Bull. 93—11——-2 9

10 THE SUGAR-CANE INSECTS OF HAWATI.

The plant crop is taken off 20 to 22 months from the time of plant-
ing, and the first ratoon or stubble is harvested 18 to 20 months
later. The second ratoon usually goes 18 months again before
it is ground. Sometimes a “‘short ratoon”’ crop is made, in which
case the cane runs about 14 months. The time given for growth
depends on the maturity of the cane, which in turn is governed by
the location and altitude of the land. To some extent also the time
of harvest 1s governed by the labor supply, factory conveniences for
taking off and grinding the crop, and the need of land for planting.
The sugar industry in Hawaii was placed on a basis to insure its
becoming the leading industry by the reciprocity treaty of 1876
between the United States and the Hawaiian Government, the latter

at that time bemg an independent monarchy. The effect of this

treaty in removing the duty on raw sugar exported to the United
States was to increase American influence in the islands and to
strengthen the commercial relations between the two countries. A
second great factor tn the development of the sugar industry was the
annexation of the islands as a Territory of the United States by an
act of Congress passed July 7, 1898, by mutual agreement between
the two countries, Hawaii at that time having overthrown the mon-
archy and become a republic. Annexation insured a free and pro-
tected market to the sugar output of the islands and gave confidence
for the investment of capital. This is of prime importance, as the
production of sugar in the islands is on a corporation basis and any
disturbance in the market is felt at once by every plantation in the
Territory.

Fundamental factors that have attended the development of the
sugar industry are the equable climate of the islands, the natural
productiveness of the soil, the resources of water for irrigation pur-
poses, and the immunity from the more serious depredations by
insects and diseases that retard the development of agricultural

resources in less fortunate parts of the world. Further, there is to -

be found in Hawaii a class of progressive business men who have
developed immense irrigation schemes, made use of the most modern
agricultural and factory machinery, inaugurated advanced methods
of cultivation, fertilization, and irrigation, and united their interests
in a cooperatave association.

This organization, the Hawaiian Sugar Planters’ Association, has,
since April, 1895, maintained a private experiment station, where
important researches have been made and valuable results obtained.
The work has applied to varieties and seedlings, propagation, culti-
vation, irrigation, the use of fertilizers, and the manufacture of
sugar. These investigations, together with the perfection of factory
methods and field machinery, have brought the sugar industry of
the islands to the high standard it holds among the sugar-producing
countries of the world. ;

ee ee ee

pee ee ee ee ae ae ee Te

ee es le

a a a ee

THE SUGAR-CANE LEAFHOPPEB. 1
SUGAR-CANE INSECTS.

The advent of a serious pest into the Hawaiian sugar-cane fields,
the sugar-cane leafhopper (Perkinsiella saccharicida WKirk.), between
1900 and 1902 and the widespread injury of this insect throughout
the sugar-cane districts in 1903 led to the establishment of an ento-
mological division in the Sugar Planters’ Experiment Station in
September, 1904. In this division detailed studies have been made
of the species of insects occurring in the Hawaiian cane fields, the
investigations relating particularly to the leafhopper and its natural
enemies.

Koebele® has earlier discussed the sugar-cane insects. Up to the
time of the leafhopper mvasion the sugar-cane borer ([Sphenophorus]
Rhabdocnemis obscurus Boisd.) was the most injurious species. The
sugar-cane aphis (Aphis sacchaii Zehntner), the sugar-cane mealy-bug
(Pseudococcus calceolarie Maskell), the leaf-roller (Omiodes accepta
Butler), cutworms, and certain other pests occurred locally, but up
to this time no detailed study of their injury had been made.

An insect enemy of sugar cane has exceptional advantages for
development in the Hawaiian Islands. Approximately only one-
half the total area is harvested at any one time. Thus the great
extent of the plant gives an abundant supply of food, while the system
of cropping provides a continuous supply. These conditions,
together with the even climate, favor the uninterrupted breeding
of any enemy of the plant. A further factor in the undue increase
of the cane-feeding insects is the impetus to development arising
from the absence of the special parasitic and predaceous enemies
of the plant-feeding species. The absence of natural enemies is
understood when it is known that the islands are isolated from all
continental areas and that the economic plants are introduced forms
for which the native flora has made way, carrying with it the endemic
species of insects, while the insect enemies of a cultivated plant are
of foreign origin, introduced into the islands with their host plant
but without their natural enemies. These very facts, together with
the almost total absence of secondary parasites as a group and the
opportunity of eliminating them when introductions are made,
furnish ideal conditions for the introduction and establishment of
special parasitic insects. The greatest factor in the successful
establishment of a special parasite is the absence of the secondary
parasites of which it is the host. One can understand why emphasis
has been placed on the use of natural enemies in the control of
injurious species in Hawaii and why also greater success has been

@ Hawaiian Planters’ Monthly, vol. 15, no. 12, pp. 590-598, December, 1896; vol.
17, nos. 5 and 6, pp. 208-219 and 258-269, May and June, 1898; vol. 18, no. 12, pp.
076-578, December, 1899; vol. 19, no. 11, pp. 519-524, November, 1900.

12 THE SUGAR-CANE INSECTS OF HAWAII.

attained in Hawaii than in continental regions where investigations
of this character are under way. From the above remarks it is
apparent that the entomologists of the Hawaiian Sugar Planters’
Experiment Station are justified in placing emphasis on this phase
of insect control. Indeed, their work has been almost entirely
along this line.

THE SUGAR-CANE LEAFHOPPER.
(Perkinstella saccharicida Kirk.)
DISTRIBUTION.

The Hawaiian sugar-cane leafhopper (Perkinsiella saccharicida
Kirkaldy) was introduced into the islands some time prior to 1900
from Queensland, Australia. The species occurs throughout the
sugar-cane areas both in Australia and in Hawaii and has been
recorded from Java.?

APPEARANCE OF THE LEAFHOPPER IN HAWAIIAN CANE FIELDS.

The first appearance of the leafhopper in Hawaii is recorded
by Mr. Albert Koebele in January, 1902.2 Koebele notes the species
under the heading ‘‘Leafhopper (Fulgoride),”’ the species at that
time not having been described. Regarding its appearance Mr.
Koebele says:

According to Mr. Clark a small homopterous insect appeared upon the sugar cane
at the experimental station some twelve months since, affecting the Demerara and
Rose Bamboo plants. Its presence is easily seen by the black and dirty appearance
of the leaves and more or less red midribs.

The insect lives in company with its larva in large numbers behind leaf sheaths,
which it punctures to imbibe the sap of the plant. When mature it is exceedingly
active in its habits, springing with suddenness from its resting place at the least dis-
turbance. The eggs are oviposited into the midrib over a large extent, most numerous
near the base, in groups of about from four to seven, and large quantities are often
present in a single leaf. The surroundings of the sting become red and in advanced.
stages the whole of the midrib becomes more or less of this color and brownish red.

That the species caused littie alarm at this time is indicated by
Mr. Koebele’s further statement in this same article. He says:

Should this insect become numerous on any plantation, they could be kept in
check by careful and repeated stripping and burning, immediately after, of the leaves
containing the eggs. I do not anticipate any serious results from the above insect,
which may have been present upon the island for many years.

In May, 1902, Dr. R. C. L. Perkins under the title ‘‘ Leafhoppers
(Fulgoride),’’ in a report to Mr. C. F. Eckart, director of the Hawaiian

a KirKapy, G. W.—A note on certain widely distributed leafhoppers. <Science,
vol. 26, no. 659; p. 216, 1907.

b KoEBELE, A.—Report of the committee on diseases of cane. <(Hawaiian Planters’
Monthly, vol. 21, no. 1, pp. 20-26, January, 1902.

THE SUGAR-CANE LEAFHOPPER. 13

Sugar Planters’ Experiment Station, mentions the doubtful origin
and identity of the species.” Doctor Perkins again records the insect
under the heading ‘‘The leaf-hopper of the cane” in December of
the same year and says: ‘This small insect is highly injurious to
cane and its destructiveness threatens to exceed that of the cane
borer beetle.’ ?

In response to repeated requests made to the department the
writer was detailed early in May, 1903, to make a report on the
pest. On May 11, 1903, specimens were forwarded by the writer
to Dr. L. O. Howard, Chief of the Bureau of Entomology, Wash-
ington, D. C. Under date of June 1, 1903, Doctor Howard replied
that the species was new to science and that there was in press a
description of the insect under the name Perkinsiella saccharicida
by Mr. G. W. Kirkaldy of the British Museum.

DESCRIPTION OF THE LEAFHOPPER.

The species was described by Mr. G. W. Kirkaldy in 1903 and rep-
resents a new genus which was named after Dr. R. C. L. Perkins.
The description of the genus and species is taken from Mr. Kirkaldy’s
article in The Entomologist, London, for July, 1903, pages 179-180,
and is as follows:

Perkinsiella, gen. nov.

Closely allied to Arxopus Spinola, but distinguished by the first segment of the
antennz being distinctly shorter than the second; distinguished from Dicranotropis
Fieber, to which it bears some resemblance, by the form of the frons, and by the
flattened apically dilated first segment of theantenneze. Type, P. saccharicida Kirkaldy.

Second segment of antennal peduncle about one-half longer than the first; flagel-
lum about one-third longer than the entire peduncle, first peduncular segment much
wider at apex than basally, flattened and explanate; second segment nearly as wide
at base as the apex of the first segment [in Arxopus it is much narrower, while the first
segment is more parallel-sided|. Exterior longitudinal nervure of corium forked near
the base, and its exterior branch forked near its middle; interior longitudinal nervure
forked near the apex. Membrane with six nervures, the fourth (commencing inwardly)
forked; the first area has an incomplete nervure reaching only to the middle. Other
characters as in Arxopus.

P. saccharicida, sp. nov.

Long-winged form & 9 .—Tegmina elongate, narrow, extending far beyond apex of
abdomen, interior half of clavus and corium more or less faintly smoky, a long dark
smoky stripe on middle of membrane, three or four of nervures of the latter smoky at
apex.

Short-winged form, 9 .—Tegmina reaching only to base of fifth segment, costa more
arched, apex more rounded, neuration similar but shortened. Tegmina hyaline,
colourless; nervures pale testaceous brownish, with blackish brown non-piligerous
dots (in both forms).

a Ecxart, C. F.—Precautions to be observed with regard to cane importations.
<Report to Hawaiian Sugar Planters’ Association, May 9, 1902, p. 5.

6 PerKIns, R. C. L.—Notes on the insects injurious to cane in the Hawaiian Islands.
<(Hawaiian Planters’ Monthly, vol. 21, no. 12, pp. 593-596, December, 1902.

14 : THE SUGAR-CANE INSECTS OF HAWAII.

$. Pallid yellowish testaceous. Abdomen above and beneath black, apical mar-
gins and laterally more or less widely pallid. Apical half of first segment and carinate
edges of second segment oi antenne, flagellum, basal half of frons (except the pustules)
and a cloudy transverse band near the apical margin of the same, longitudinal stripes
on femora, cox spotted or banded near the base, a large spot on each pleuron, anterior
and intermediate tibize with two or three annulations, apical segment of tarsi, etc.,
blackish or brownish. First genital segment large, deeply acute-angularly emarginate
above.

2. Like the male, butabdomen aboveand beneath stramineous, irregularly speckled
with brownish. Ovipositor, etc., blackish. Sheath not extending apically so far as
the ‘“‘scheidenpolster.” Long. ¢ 944 mill.; to apex of elytra in long-winged form,
64 mill.

DISPERSION OF THE LEAFHOPPER.

The spread of the insect over the cane districts of the Hawaiian
Islands was apparently very rapid, although it had undoubtedly
occurred in the fields unnoticed by the planters for several years. By
February, 1903, the species became generally abundant throughout
the cane fields of the entire Hawaiian Territory.

The main factor in the distribution of the pest is the habit of the
female of depositing her eggs beneath the epidermis of the internodes
of the cane stalk. It seems probable that the pest was introduced
into the islands and to a great extent distributed over the cane
districts in seed cane. In local distribution other factors present
themselves. The leafhopper is an insect readily attracted by light
at night, as its presence about lamps in the factories and homes on
the plantations testifies. Passengers and steamship officers of the
interisland steamers have frequently stated to the writer on inquiry
that in many instances, especially at night, great numbers of the
insects have come aboard in certain ports or when offshore from
certain plantation districts. These adults have undoubtedly traveled
in this manner from one locality to another so that an uninfested dis-
trict might easily have become infested by adults flying ashore from a

passing steamer previously infested while stopping at or passing by -

an infested locality. Railway trains have been equally active in the
spread of the insect on land.

Another mode of distribution, during the general outbreak of 1903,
under conditions of heavy infestation, was the migration of the pest
from one locality to another during the daytime. These migrations
were observed by many of the planters. The manager of one planta-
tion in the Hamakua district of the island of Hawaii stated to the
writer that in the early evening of April 26, 1903, the atmosphere was
‘thick with hoppers” for a distance of 2 miles and that the “‘hop-
pers” were traveling with the prevailing wind, about southwest.
Similar migrations, described by the observers as “‘clouds,’ were
mentioned by other managers.

THE SUGAR-CANE LEAFHOPPER. 15
LIFE HISTORY AND HABITS.

The writer spent two months in the cane fields during the outbreak
and in the early part of July, 1903, presented a report to the Hawaiian
Sugar Planters’ Association on the occurrence and injury of the
species. Later an account of these investigations was published,
from which a part of the information on the leafhopper presented
herewith is taken.@

‘“‘TLeafhopper” is a popular term applied to a certain group of
plant-feeding insects of the order Hemiptera. The family Fulgo-
ride, to which the Hawaiian sugar-cane leafhopper belongs, is
included in this group. Common characteristics of these insects
are their peculiar habit of springing or jumping when disturbed;
their feeding upon plants by sucking from the tissue the plant juice
or sap through a beak or proboscis, a piercing organ by means of
which they puncture the epidermal layer of the plant; their incom-
plete development (that is, the young upon hatching from the eggs
resembles the adult, except that it 1s smaller in size, wingless, and
sexually immature and by a gradual process of development acquires
the characteristics of the adult); and the fact that their eggs are
deposited in the same plant upon which the young and adult appear
and feed.

The eggs of the sugar-cane leafhopper (Plate II, figs. 1, 2) are
deposited beneath the epidermis of the cane plant in situations
along the midrib of the leaves, in the internodes of the stalk, or, in
the case of young unstripped cane, in the leaf sheath of the lower
leaves. When deposited in the leaves, the eggs are inserted from
either side, but usually from the inside, the greater number being
in the larger portion of the midrib down toward the leaf sheath.
The place of incision is indicated at first by a whitish spot, this being a
waxy covering over the opening. The female accomplishes the process
of oviposition by puncturing the leaf or stem with her ovipositor,
which organ (fig. 1, b) is plainly visible on the lower side of the abdo-
men, attached to the body at the center behind the last pair of legs
and extending backward along the median line of the abdomen,
reaching nearly to the end. By the aid of this structure the female
pierces the epidermis of the cane stalk and through the one opening
forms a cavity or chamber to receive the eggs. The number of
eges deposited in each cavity varies, the writer finding the average
to be between four and six. That a single female is responsible for
many of these clusters has been verified by the writer by observation.
As the growth of the cane continues and the new leaves unfold
toward the top of the plant, the infested leaves naturally occupy

“Van Dine, D. L.—A sugar-cane leaf-hopper in Hawaii, Perkinsiella saccharicida.
<Hawaii Agr. Exp. Sta., Honolulu, Bul. 5, pp. 29, figs. 8, 1904.

16 THE SUGAR-CANE INSECTS OF HAWAII.

the lower position on the stalk. The leafhopper, during a heavy

infestation, will continue to puncture the midribs of the leaves as _

rapidly as the leaves unfold. The older egg chambers of the lower
leaves are distinguished from the newly formed chambers of the
upper leaves by a reddish discoloration.

Under laboratory conditions the writer found that the eggs
deposited in cane growing in rearing cages hatched two weeks there-
after. The period of development of the young to the adult required
34 additional days, making the life cycle 48 days in length.

The length of the egg stage, under certain conditions, is much
longer than the time given above. Mr. C. F. Eckart, director of
the Hawaiian Sugar Planters’ Experiment Station, records that hatch-

ing continued for 38 days from cane cuttings infested with eggs of

the leafhopper.?

The fact that the eggs will Preh from cane cuttings during a

period of at least 38 days is a very important point to bear in mind
in the shipping of infested cane from one locality: or country to
another. Since practically the only means by which the Hawauan
leathopper could be introduced into the cane fields of the Southern
States is by the shipment of seed cane from New South Wales,
Queensland, Java, or Hawaii to this country, the writer would
emphasize the necessity of having all introductions made through
officials engaged in sugar-cane investigations.

On issuing from the cavity, or chamber, the young, newly hatched
leafhoppers appear at first small, slim, wingless nymphs, almost
transparent. During the process of hatching or emerging from
the egg chamber the insects slowly work their way head first to the
surface of the leaf or stalk. The writer found, by timing the opera-
tion, that from 8 to 15 minutes were required, during which time
the nymphs rest occasionally to unfold and dry their legs. When
they become detached from their egg-cases and have emerged to
the surface, they are at once active and scatter over the plant to
feed, congregating at first down within the sheaths of the upper
leaves. In a few hours the body becomes shortened and the outer
covering, on exposure to the air, becomes darker in color. The habit
of the very young in secluding themselves within the lower sheaths

of the leaves renders them quite inconspicuous unless especially

sought for. They may become very abundant and still remain unde-
tected by an ordinary observer until the result of their feeding
becomes apparent. (See nymphs, Plate II, figs. 3-6.)

Ordinarily when disturbed the adult leafhopper does not fly but
moves off in an odd, sidewise fashion to another part of the leaf, or
springs suddenly to another portion of the plant. (See adults,
Plate II, fig. 7, and text fig. 1.)

a Ecxart, C. F.—Report of the Hawaiian Sugar Planters’ Association Experiment
Station for 1903, Honolulu, 1904, pp. 78-79.

ee ee a a ee a a eee

EEE eT

Bul. 93, Bureau of Entomology, U. S. Dept. of Agriculture. PLATE ll.

WwW

THE SUGAR-CANE LEAFHOPPER (PERKINSIELLA SACCHARICIDA).

Fig. 1.—Egg chambers in midrib of cane leaf, slightly enlarged. Fig. 2.—Eggs, greatly enlarged.
Fig. 3.—First-stagenymph. Fig.4.—Second-stagenymph. Fig.5.—Third-stagenymph. Fig.6.—
Fourth-stage nymph. Fig. 7.—Adult male. (After Kirkaldy.)

THE SUGAR-CANE LEAFHOPPER. 17
SYMPTOMS OF LEAFHOPPER INJURY.

The presence of the pest on the plantations was noticed first by
the appearance of a sooty black covering on the lower leaves of the
cane plant. This black covering became known as smut. It isa
fungous growth and finds a niedium for development in the trans-
parent, sticky fluid secreted by the leafhoppers during their feeding
on the plant. This secretion is commonly known as honeydew.

The black smut or fungous growth in the honeydew secretion of
the leafhopper and the red discoloration about the openings to the
ege chambers in the midribs of the leaves are the most pronounced
symptoms of the work of the
leafhopper on cane.

In the case of heavy infesta-
tion a further result is the
appearance of the plant as a
whole. The leaves on which the
insects have been feeding de-
velop a yellowish appearance,
and as the work of the insects
progresses they become dried
and resemble the fully matured
lower leaves of the plant. This
premature death of the leaves
is due to the excessive amount
of juice extracted for food. As
long as the cane plant is able to
produce new leaves its life is
not actually in danger, the in-
jury being a check to the growth
and indicated by the small,
shortened joints in the stalk. Fig. 1.—The sugar-cane leafhopper (Perkinsiella sac-
Leaves thus prematurely rip- charicida): a, Adult female, much enlarged; b,

ovipositor, greatly enlarged. (After Kirkaldy.)

ened do not drop away from

the stalk at the junction of the sheath, as is the case under normal
conditions, but break and hang down at the junction of the leaf to
the sheath, leaving the sheath still wrapped about the stalk. Leaves
in such a condition remain green. for some time, attached to the
sheath by the midrib, and an attempt to strip the cane results in
leaving the sheaths still adhering to the stalk and wrapped about it.

more

SB

SSSS SS
x SSS

In the last stages of an attack, when the plant is actually overcome’

by the pest, the young unfolded leaves at the top do not appear

to have the vitality to unfold and the ‘‘bud” gradually dies out. At

this stage the normal growth of the plant ceases. Many plants in
83327°—Bull. 93—11 3

18 THE SUGAR-CANE INSECTS OF HAWAII.

such a condition will then throw out sprouts from the eyes. This is
a serious circumstance, since the growth of the sprouts is supported
by the stalk, and unless the cane is soon cut and ground the stalk is
rendered worthless.

CHARACTER OF INJURY TO THE CANE.

The first injury to the cane plant by the leafhopper occurs through
the piercing of the epidermal layer by the ovipositor (fig. 1, b) of the
female and the later rupturing of the tissue of the plant on the hatch-
ing of the young. This injury to the tissue in itself is not serious,
but the many openings in the leaves and stalks allow excessive
evaporation to occur. Through these wounds various diseases may
also gain entrance to the tissues of the plant, carried thereto by the
leafhoppers themselves in flying from infested to noninfested plants,
or by other insects, particularly certain flies, which frequent the
cane plant. |

The most serious injury to the plant is the drain upon its vitality
caused by the young leafhoppers in feeding. The structure of the
mouthparts of the leafhopper has been mentioned; that is, a piercing
organ, which is inserted through the outer covering of the tissue, by
means of which the insect sucks the juice or sap from within. The
amount extracted in this manner by any particular individual is small
and of little consequence, but the result of a myriad of individuals work-
ing constantly in this manner upon a plant is readily conceived to be
serious in its consequences. The leafhopper in feeding upon the
cane plant extracts therefrom an amount of juice greatly in excess |
of its own needs for development. This excess is excreted from the
body of the insect upon the cane plant in the form of a sweet, sticky
substance, known as honeydew. It is in this substance that the
black smut develops.

The sooty covering or smut of the leaves referred to is a super-
ficial fungus which bears a close resemblance to the fungi of the genus.
Spheronema. The writer was informed by Dr. A. F. Woods, at that
time Pathologist of the United States Department of Agriculture,
that this fungus may be responsible for the dying back of canes
which followed heavy leafhopper infestation. It is believed, how-
ever, that in the cane the smut affects the plant only by preventing
the assimilation of the elements taken up by the plant from the soil
as food, in cutting off the rays of direct sunlight, and also in closing
the stomata of the leaves, preventing the entrance and escape of
carbon dioxid and oxygen, respectively. In damp localities another
fungus was taken in company with the smut, and was determined
by Dr. Woods as a species of the genus Hypochnus. The resulting
injury to the plant from the leafhopper attack is also complicated by

THE SUGAR-CANE LEAFHOPPER. 19

the presence of the pineapple disease of sugar cane (Thielaviopsis
ethaceticus) and the rind disease (Melanconium sacchari). The latter
species, it is believed, gains entrance to the tissue of the plant through
the wounds made by the leafhopper.

EXTENT OF INJURY.

It was estimated that the leafhopper caused a loss of $3,000,000 to
the planters of Hawaii during 1903 and 1904.¢ In the writer’s
opinion this loss can not be attributed entirely to the leafhopper
injury. Other species of insects and certain diseases were implicated.
The leafhopper was directly responsible for the larger percentage of
loss and indirectly responsible for the unusual development of cer-
tain diseases.

In speaking of the rind disease of sugar cane in Hawaii in 1907
Mr. L. Lewton-Brain says: °:

To bring before you the actual extent of the loss that the rind disease is now causing
in your cane fields, I take the following fact obtained by Doctor Cobb from actual
counts in the field. In one case the cane left on the ground represented about one
ton of sugar to the acre. That is to say, that if the cane left on the field had been
sound cane that portion of it left on an acre would produce about a ton of sugar. The
area counted over, in this particular case, was representative of 200 acres.

A few years ago, when the leaf-hopper was at the height of its glory in reducing
the vigour and vitality of your canes, these figures would have been much higher.
I have been assured that, at that time, there were acres and acres of cane to be seen
on which the majority of the sticks had been ruined by rind disease.

Apart from the direct and indirect injury of the leafhopper (Perk-
imsiella saccharicida Kirk.), the sugar-cane borer (Sphenophorus
obscurus Boisd.), the sugar-cane leaf-roller (Omiodes accepta Butler),
and other minor pests contributed to the loss sustained.

The explanation of, the undue increase on the part of the leaf-
hopper is made clear when it is known that up to the time of the
leafhopper invasion the sugar plantations had been particularly free
from serious attacks of insect and disease pests. The planters were,
therefore, unacquainted with the insect life to be found in their cane
fields. They did not know the source or nature of the leafhopper
attack and had at hand no general knowledge of insect warfare.
The injury of the leafhopper, combined with that of the other species
mentioned, and the complications arising through the development
of certain diseases gave the leafhopper a favorable opportunity to
develop great numbers in those localities where climatic influences
or soil conditions were unfavorable to the sugar cane or where a
deteriorated condition of the cane varieties prevailed.

2 Report Governor of Hawaii for fiscal year 1907, p. 22.
6 LewTon-Brain, L.—Rind Disease of the Sugar-Cane. <(Hawaiian Sugar Plant-
ers, Pxpeista, Dive bath., Bul vei p15. 1907.

No
cw)

THE SUGAR-CANE INSECTS OF HAWAII.
FACTORS RESPONSIBLE FOR THE OUTBREAK OF 1903.

On those plantations where the outbreak of the leafhoppers became
epidemic the writer made careful observations to determine, if pos-
sible, the conditions of season, soil, varieties, or methods of cultiva-
tion which might have contributed to the leafhopper development.
Some of these conditions noted will be mentioned.

(1) The season during which the attack was most serious was not
the growing season, and in some localities the weather was most
unfavorable for the growth of the cane. In one instance, for example,
there were during one month 24 rainy days out of the 30; and since
the temperature on a rainy day is some ten degrees lower than on a
bright day, and because of the absence of sunshine to carry on the
work of assimilation, a less vigorous growth of cane resulted.

(2) The long duration of prevailing high winds.

(3) An impoverished condition of the soil. Certain fields in which
the leafhopper was epidemic had been planted continuously to cane
for over 20 years. The soil in certain parts of some fields, also,
where the leafhopper infestation was greatest was found to be in poor
condition because of lack of drainage.

(4) As the rainy season was foliowed by a long period of dry weather,
without the means of irrigation, the cane lacked sufficient moisture
to enable it to put forth a vigorous growth. This point was demon-
strated on an unirrigated plantation in the district of Kohala, Hawaii.
A portion of a field was seriously attacked by the leafhopper during
the month of September, 1903, after several months of dry weather.
The manager of the plantation, Mr. E. E. Olding, was able to run
water into this portion of the field and irrigated the cane four times
at intervals of about a week, with the result that the cane, although
showing the attack in the smallness of the joints grown during that
time, recovered, and when the writer visited the field during the
month of November of the same year was, in appearance, not unlike
healthy portions of the same field.

(5) The presence of other pests, principally the cane borer (Sphen-
ophorus obscurus) and the leaf-roller (Omiodes accepta).

(6) The lack of thorough cultivation.

(7) The injury to cane on the makai (seaward) fields by the salt
spray or the check to the cane by the cold on the mauka (mountain-
ward) fields.

(8) The deterioration of varieties.

(9) The complications due to the presence of certain diseases.

THE LEAFHOPPER AND BEEKEEPING.

An interesting condition of affairs arising from the leafhopper
attack on sugar cane is the collection of the honeydew by honey bees.
The increase in the production of Hawaiian honey of recent years

THE LEAFHOPPER AND BEEKEEPING. At
: :

corresponds with the advent of the sugar-cane leafhopper into the
cane fields, and the recent extensive proportions which the bee-
keeping business in the islands is assuming is in the vicinity of the
immense areas of land given to cane culture.? (See fig. 2.)

The principal source of floral honey in the islands is the flowers of
the algeroba (Prosopis juliflora). The total production of this floral
honey does not exceed 600 tons. The output of honey for 1910 in
the islands exceeds 1,000 tons, and the remaining 400 tons consists
almost entirely of the product gathered from the honeydew of the
sugar-cane leafhopper. Some 100 tons of this forms a typical

Fig. 2.—An apiary near a sugar-cane field. (From Phillips.)

honeydew honey, the remaining amount consisting of natural blends
of these two types.

Honeydew honey from the sugar-cane leafhopper is noncrystal-
lizable and usually of a very dark color. The aroma is very similar
to that of molasses and the taste insipid. The product is abnor-
mally high in ash, the amount ranging from 1 to 2 per cent, and it
has a decided right-handed polarization, while the floral or algeroba
honey is low in ash and has a left-handed rotation, which is

@Van Dine, D. L.—The Source and Characteristics of Hawaiian Honeys.
<Hawaii Agr. Exp. Sta., Bul. 17, Pt. I, pp. 1-12, 1908.

Puiuures, E. F.—A brief survey of Hawaiian Bee Keeping. <U.S. Dept. Agr.,
Bur. Ent., Bul. 75, Pt. V, Jan. 19, 1909.

99, THE SUGAR-CANE INSECTS OF HAWAII.

characteristic of all floral honeys. The larger amount of honey-
dew is obtained from the insects on the young plant cane,
for there the leafhoppers are more abundant. The amount of
honeydew gathered depends on the maturity of the cane and the
amount of rain which washes the secretion from the leaves.

CONTROL OF THE LEAFHOPPER.
Drrect MEASURES.

Insecticides —Those familiar with the culture of sugar cane will
readily understand the difficulty of getting in and through the
fields after the cane obtains any height. This difficulty renders the
use of insecticides as a remedy unpractical. In Hawaii such a

method becomes still more difficult because of the prevailing slope —

of the cane lands and the manner in which the fields in many dis-
tricts are laid out for purposes of irrigation. The feeding habits
of the leafhopper are such that a contact poison or irritant would be
necessary for its destruction, and the activity of the leafhoppers—
that is, the suddenness with which they disperse at the least dis-
turbance—still further prevents the successful application of a con-
tact insecticide. Then, too, the cane fields of Hawaii are subject
to prevailing winds, which greatly interfere with the use of any
substance in the form of a spray. In the face of the above diffi-
culties the writer attempted the destruction of the leafhopper by
direct measures and found that an application of kerosene emulsion
applied in the shape of a finely divided stream with considerable
force was capable of killmg only a small percentage. A mixture of
lime and caustic soda was also applied, with negative results. Lime,
prepared by reducing fresh stone lime to a powder by the use of
solutions of copper sulphate and caustic soda, was applied as a dust
on cloudy days, or just after showers, and while in comparison to
spraying a much larger area was covered, and the dust came in
contact with a large percentage of the leafhoppers, no appreciable
beneficial results were observed.

Collection by nets—Ordinary sweeping nets supplied with short
handles were placed in the hands of the laborers, and the leafhoppers
were collected by having the laborers go in a body through adjoining
rows and sweep the nets over the cane leaves. The insects collected
were dumped from the nets into buckets of water and kerosene at
the ends of the rows. While immense numbers were captured in
this way, the number collected and the area covered were so small
in comparison to the abundance of the leafhoppers and to the extent
of the infested area that this measure was also discarded.

Cutiing and burning vn the infested centers ——The direct measures
of control advised by the writer were confined to the cutting down

THE SUGAR-CANE LEAFHOPPER. 23

and burning over of those centers in the fields where the species had
become numerous. In this practice it was observed that many of
the adults were able to take flight from the burning cane and escape
to adjoining fields. However, many adults and all of the unhatched
eggs in the leaves and the immature wingless forms were destroyed.
The center of infestation was destroyed, and this gave the ratoon
crop over these areas a chance under more favorable conditions.

Stripping the leaves——For agricultural reasons it was a common
practice in Hawaii to strip the lower mature leaves from the cane
stalk. It was believed at first that this operation would greatly
lessen the numbers of the leafhopper by the exposure of the un-
hatched forms in the leaves of the cane and by removing a place of
shelter for the active forms. Observations made during the summer
months indicated that stripping was beneficial from the standpoint
of the control of the leafhopper. Later observations made during
the winter months, however, when growth of the cane practically
ceases, showed a very serious condition of affairs, namely, that in
heavy infestation the internodes of the stalk of stripped cane con-
tained hundreds of punctures from egg laying, while the internodes
of unstripped cane were protected from such injury by the leaf-
sheaths.

Burning of trash after harvestrng.—The thorough burning of the
trash after the cane is harvested is the most effective method prac-
ticed for the control of the insects of sugar cane. In the case of
the leafhopper many of the adults no doubt take flight, but the
destruction to the eggs and immature forms in the trash is enormous.
The place where the greatest numbers of the leafhopper were noted
in 1903 was on a plantation where the practice of ‘‘burning off”
had been discontinued for several years, and the manager attributed
the unusual increase of the pest to the fact that the trash had not
been burned. Both for the leafhopper and the cane borer, burning off
has become general once more.

INDIRECT MEASURES.

PREVENTIVE METHODS.

Selection of varieties of cane for planting.—There was noticeable
in general throughout the plantations a marked difference in the
power of the different varieties to resist the attack of the leafhopper.
While the same variety would vary in different localities as regards
growth and resistance, still the difference between any two varieties
remained constant. For example, Yellow Caledonia was invariably
the more resistant as compared to Rose Bamboo and Lahaina, and
while the former was more seriously attacked in some localities than
in others, wherever the opportunity offered itself for comparison with
the latter, the Yellow Caledonia made the best showing. It is for

94 THE SUGAR-CANE INSECTS OF HAWAII.

the planter to decide whether or not the advantages of one variety
over another are offset by the ravages of the leafhopper. If the loss
from the leafhopper is greater than the gain in the yield between any
two varieties in the absence of the leafhopper, then it is policy to
select the more resistant cane.

The Yellow Caledonia (fig. 3) is a hardy cane and the plant makes
a vigorous growth. These qualities, together with the showing which
the variety made during the leafhopper epidemic, have made the
cane a popular variety in the Hawaiian Islands. Mr. C. F. Eckart,

Fic. 3.—Yellow Caledonia sugar cane, a variety which is replacing Lahaina and Rose Bamboo in the
Hawaiian Islands. Photograph taken during the leafhopper epidemic of 1903. (Original.)

Director of the Hawaiian Sugar Planters’ Experiment Station,
reports as follows on this cane:

Probably no subject pertaining to the cultivation of cane in the Hawauan Islands
during recent years has held more interest for the planters, in various localities, than
that relating to the introduction and trial of new varieties.

In the Hilo and Hamakua districts, the Lahaina first made way for the Rose Bamboo,
and the latter, after a strong stand for many years, is now being rapidly succeeded by
the more vigorous Yellow Caledonia. This cane with its upright growth and deep
rooting propensities has proved a most valuable acquisition in wet and dry localities
alike. Growing erect, with a natural tendency to shed its dried leaves, it becomes
an admirable cane for rainy districts, where varieties that are prone to fall to the
ground and remain in contact with a frequently saturated soil have shown extreme

a Ecxart, C. F.—Varieties of cane. <Report of the Experiment Station Com-
mittee, Hawaiian Sugar Planters’ Association, for the year ending September 30, 1904,
Appendix IV, p. 31.

THE SUGAR-CANE LEAFHOPPER. 95

sensitiveness. The frequent stripping, required for Lahaina and Rose Bamboo in
these wet places, has necessarily added to the cost of cultivation, and the ready manner
in which Yellow Caledonia tends to strip itself is no small item in favor of economy.
Again the manner in which it keeps down weeds, which were such a menace to its
predecessors on the unirrigated plantations, is another strong point in its favor. In
dry districts subject to occasional drought, it has amply demonstrated its hardihood
over Rose Bamboo, which in turn ismore resistant to such unfavorable climatic features
than Lahaina. By sending its roots down deep into the soil it draws from a larger
reserve supply of water than the older varieties, which are more shallow feeders and
which soon feel the effects of a rainless period.

Dr. R. C. L. Perkins reports as follows on the relative immunity
of different varieties of cane from leafhopper attack :4

It seems certain that some varieties of cane will stand the attack of leaf-hopper
better than others. Mr. Eckart, Director of the Hawaiian Sugar Planters’ Experiment
Station, has furnished me with a list of new varieties of cane (see Appendix, Note II
below), grown there, arranged in order, according to the relative injury that each
sustained from _leaf-hopper.

There may come, however, so severe an attack that no cane can resist it. Thus’

we have seen plants of ‘‘ Yellow Caledonia” (at the extreme end of the list) which
were of the strongest and most thrifty nature previous to the attack, some entirely
destroyed and others very badly injured after a bad outbreak. It is, however, prob-
able that from an attack of hopper which would entirely destroy a field of ‘‘Rose
Bamboo,’’ for instance, a field of ‘‘Yellow Caledonia” might recover.

The following is the note to which Doctor Perkins refers above:

The following list of new varieties (i. e., varieties other than the old standard ones
of these islands) of cane at the Hawaiian Planters’ Experiment Station has been drawn
up for me by Mr. C. F. Eckart, the Director. They are arranged in order, according
to the amount of damage sustained from leaf-hopper attack, Queensland 4 suffering
most and Yellow Caledonia least:

(1) Queensland 4 (10) Tiboo Merd

(2) Queensland 1 (11) Louisiana Striped
(3) Queensland 8A. (12) Striped Singapore
(4) Louisiana Purple (13) Big Ribbon

(5) Demerara 95 (14) Queensland 7

(6) Gee Gow (15) Demerara 117

(7) Cavengerie (16) White Bamboo
(8) Demerara 74 (17) Yellow Caledonia.

(9) Yellow Bamboo

Cultural methods on the plantation.—The writer has already men-_

tioned the fact that the epidemic of 1903 began during the winter
months, in a wet season, and at a time when the cane was making
practically no growth. The centers from which the infestation spread
over the cane fields were invariably unfavorable locations for growth.
It has been noted in this report that all varieties suilered in these

unfavorable locations but that certain varieties made a better show-:

ing. The extension of the acreage of one variety in particular,

@ PERKINS, R. C. L.—The leaf-hopper of the sugar-cane. <Bd. of Agr. and For-
estry, Hawaii, Div. Ent., Bul. 1, p. 13, 1903.
83327°—Bull, 93—11——4

26 THE SUGAR-CANE. INSECTS OF HAWATI.

Yellow Caledonia, will be a leading factor in. preventing another
epidemic. One other point was brought home to the Hawaiian
planters as a result of the leafhopper epidemic, and that was the
importance of intensive cultivation. The grass and weeds must be
kept down by cultivation, the low places drained, and the impover-
ished lands fertilized. Those plantations which were in a high state
of cultivation suffered less from the leafhopper attack, and the estates
provided with the means of irrigation, in addition, suffered the mini-
mum loss. There is a direct relation between intensive cultivation,
fertilization, and irrigation and the amount of insect injury to any
erop, showing that these operations are of great value in lessening
insect damage.

Diversification of crops.—Sugar cane has been the leading crop in
Hawaii since the days when the islands turned from the sandal-wood
trade and the whaling fleet as a source of revenue. Some of the lands
have been under cultivation to cane continuously for over twenty-five
years. The time is at hand when the sugar-cane planters will find
it both necessary and more profitable to diversify their crop. Some
lands at present require a change from sugar cane, and the lands which
are still highly productive will also require such a change as the years
go by. When the general practice of inter-cropping cane with other
plants does come, it will have a direct bearing on the control of the
sugar-cane insects, the leafhopper included. The intermediate crop
may be one of value in itself or one to be plowed under for green
manure. Since it is not wise to cease the practice of burning off the
trash after harvesting the cane, the planters can find no cheaper source
of plant food, or no way in which the requisite texture and water-
holding capacity of the soil can be more easily obtained than by
removing their lands from cane cultivation in regular rotation and
planting some nitrogen-gathering plant to be turned under when the
land is put back into cane. |

Control of the rind disease of sugar cane.—As has been mentioned,
leafhopper injury is aggravated by the presence of the rind disease.
In a discussion of the rind disease (Melanconiwm sacchart) Dr. N. A.
Cobb says: %.

According to my observations on thousands of cuttings dug up on some twenty-five
plantations a considerable part of the cuttings in some fields fail to grow on account
of this disease, which, being present in the cuttings when they are planted, develops
sufficiently to prevent germination. This is a difficult thing wholly to avoid by
means of inspection of the seed, as the disease is sometimes present in cane that looks
sound. It may be suspected to be present in any cane that has been attacked on the
stalks by leaf-hopper or by borers. Other wounds that give admission to the rind
disease fungus are those made by injudicious stripping, cracks at the bottom of the
cane due to the effects of storms, and what are sometimes called ‘“‘growth cracks.’’

a Cops, N. A.—Fungus maladies of the sugar cane... < Hawaiian Sugar Planters’
Exp. Sta., Div. Path., Bul. 5, p. 107, 1906.

THE SUGAR-CANE LEAFHOPPER. OM |

Cane raised specially for seed and not stripped until wanted for planting is more
likely to be free from insect punctures, and will therefore be less likely to develop
rind disease after planting.

Mr. L. Lewton-Brain in a report on the rind disease thus describes
the relation between the leafhopper and the disease: ¢

Under field conditions, of course, the spores gain access to the interior of the plant
through natural wounds. Perhaps the most abundant wounds offered for this pur-
pose are leafhopper punctures; even more favorable for the fungus are the tunnels of
borers, leading as they do right into the heart of the sugar-containing tissue; other
wounds may be made in stripping; in fact, it is a difficult matter to find a ie of
cane without a wound of some sort. The spores are produced in immense numbers
on every stick of rotten cane. They are doubtless distributed partly by the wind,
though the mucilaginous substance by which they are joined does not favor this;
insects are certainly also important distributers of the spores, leafhoppers will get
infected and deposit the spores in their punctures, ants will carry them into borer
and other wounds in their search for food, flies may also serve the fungus in the same
way.

The control of the rind disease of cane on the plantation will be
another factor in reducing leafhopper injury. Since the leafhopper
can not be exterminated and the punctures from this insect will
always occur on a plantation to a greater or less degree, it becomes
particularly essential for the planter to eradicate the RCE.

On the control of the rind disease, Doctor Cobb has the following
on pages 109 and 110 of his report'referred to above:

The number of spores of this disease that exist on every plantation is past calcula-
tion, and almost inconceivable. This abundance of the spores of the disease tends
of course to increase the losses. If there were no spores there could be no rind dis-
ease. Anything that can be done to reduce the number of spores will tend to reduce
the amount of the disease. Something can certainly be done in this direction. Stalks
dead of the disease can be destroyed, and there can be no doubt that in some cases
expenditure in this direction will be well repaid. There can be no doubt that the
collecting and complete destruction of the stalks on the field would be a paying
operation. How to destroy them is the question. The ordinary burning off destroys
only a part of these rind disease stalks, leaving the rest untouched or only partially
roasted, to go on producing their millions upon millions of spores.

It is the custom on all the Hawaiian plantations to leave on the ground after harvest
the sticks of cane that have been attacked by borers or are worthless for other reasons.
The reason for this is easy to understand. Such material is unsuitable to the highest
efficiency of the mill as an extractor of cane juice. It is also of such a nature that
it may interfere with the clarification, evaporation, or crystallization.

Notwithstanding this I think it ould be advisable to consider whether this material,
which is really a menace to the health of future crops, cannot in some way be run
through the mill and burned. This is a practice adopted in some other parts of the
world. On Saturday afternoons a special run of the mill is devoted to the milling of
such refuse as I have mentioned, the “bagasse” being burned. The juice is alone
to run to waste, being first ated by heat.

In Hawaii it is usual to attempt to burn this diseased material, but from careful
observation I am certain that this attempt often ends in failure, that is to say the
disease that exists in the waste-cane is only partially destroyed.

¢ LEwTon-Brain, L.—Rind disease of the sugar cane. <(Hawaiian Sugar Planters”
Exp.-Sta,-Div.Path., Bul. 7, p. 21, 1907.

28 THE SUGAR-CANE INSECTS OF HAWAII.

It may be that it would be better, at least from the disease point of view, if the
harvesting of the fields were more in the nature of a clean sweep. If the diseased
sticks are not too numerous they would not seriously interfere with the working of
the mill. The advantage would be that whatever diseased material was thus dealt

with would be dealt with in the very best manner, that is, it would be utterly de-
stroyed.

NATURAL ENEMIES.

SpeEcIES ALREADY PRESENT IN THE ISLANDS.

Many beneficial species of insects, already present in the islands
at the time of the leafhopper invasion, adapted themselves to the
leafhopper as a source of food. The following species were noted
during 1903:

A ladybird beetle, Coccinella repanda Thunb., one of Mr. Koebele’s
Australian introductions, was particularly abundant in the cane
fields and the larva did good work against the young leafhoppers.
An enemy of this species, the hymenopterous parasite Centistes
americana Riley, has found its way to the islands and will no doubt
reduce the effectiveness of the ladybird. The writer observed also
the ladybird Platyomus liwidigaster “Muls. in the cane fields. A
predaceous bug, Gchalia griseus Burm., was found in large numbers
in the infested cane fields on the Island of Hawaii. The larve of
two lacewing flies, Chrysopa microphya Mclachl., and Anomalochrysa
sp., were observed feeding on the young leafhoppers, the first species
being particularly abundant in some localities.

Several species of spiders were abundant in the cane fields and
were active enemies of the leafhopper. The writer collected two
species, Tetragnatha mandibulata Walck. and Adrastidia nebulosa
Simon. On the writer’s advice large numbers of the ege-nests of
spiders were collected in the localities where they were abundant
and placed in sections where they had not as yet become established
in the cane fields.

In the forest above the Kohala district, on the island of Hawaii,
the writer found a fungous disease infecting to a great extent the
common leafhopper Siphanta acuta Walk., a species belonging to the
same family as the cane leafhopper. Quantities of this fungus
were distributed in the cane fields in the hope that it would infest
the cane leafhopper. No striking results were obtained, though
diseased cane leafhoppers were found in some of the rainy districts.

Several species of ants were very active about the leafhoppers in
the cane fields, the honeydew being an attraction to them.

Doctor Perkins mentions further in his early report a predaceous
bug, Zelus peregrinus Kirk., and describes as new a hymenopterous
parasite of the leafhopper under the name Ecthrodelphax fair-
childii Perk.?

@ Perkins, R. C. L.~—Bd. Comrs. Agr. and Forestry, Hawaii, Div. Ent., Bul. 1,
pp. 20-22.

THE SUGAR-CANE LEAFHOPPER. 29

More recently the species of beneficial insects which were already
present in the islands when the leafhopper was introduced and
which have sought the leafhopper in the cane fields have been reported
upon in detail by the entomologists of the Hawaiian Sugar Planters’

Experiment Station.”
SPECIAL INTRODUCTIONS.

In 1903 Mr. Albert Koebele, after consulting with Dr. L. O. How-
ard, undertook extensive observations on the American parasites of
leafhoppers. In Ohio Mr. Koebele had the assistance of Mr. Otto
H. Swezey. A large quantity of living material was collected both
in Ohio and in California and shipped to Doctor Perkins at Honolulu.
The American material consisted in the main of insects belonging
to the hymenopterous family Dryinide. The Hawaiian parasite
Ecthrodelphax fairchildw Perkins is also a member of this family
and, at the time of Mr. Koebele’s American introductions, was
being reared and distributed over the islands by Doctor Perkins.
These introductions are discussed by Doctor Perkins in Part I of
Bulletin 1, Division of Entomology, Hawaiian Sugar Planters’
Experiment Station, 1905.°

Mr. Koebele also collected during his American investigations
representatives of the order Strepsiptera (Stylopide) and a single
species of an. egg-parasite, Anagrus columbi Perk., belonging to the
family Mymaride. ¢

In the spring of 1904 Messrs. Koebele and Perkins sailed for
Australia to continue the search for parasites of the leafhopper.
They reached Sydney in May and because of the cold weather which
prevailed they proceeded to Brisbane. The results of the work in
Australia are thus summarized by Doctor Perkins:4

Early in June we arrived at Brisbane, and on the first cane that we saw, a few plants
in the public gardens, we at once observed the presence of the cane leaf-hopper. A

a Leafhoppers and their natural enemies. < Hawaiian Sugar Planters’ Exp. Sta.,
Div, Knit. Bull 1,

PERKINS, R. C. L.—Part I, pp. 1-60, May, 1905. (Kcthrodelphax fairchildii.)

Perkins, R. C. L—Part IV, pp. 1138-157, pls. 5-7, September, 1905. (Pipunculide.)

Terry, F. W.—Part V, pp. 159-181, pls. 8-10, November, 1905. (Forficulide,
Syrphide and Hemerobiide.)

Swezey, O. H.—Part VII, pp. 207-238, pls. 14-16, December, 1905.. (Orthoptera,
Coleoptera, and Hemiptera.)

6 Perkins, R. C. L.—Leafhoppers and their natural enemies. < Hawaiian Sugar
Planters’ Exp. Sta., Div. Ent., Bul. 1, Part I, pp. 1-60, May, 1905. (Dryinide.)

c PERKINS, R. C. L.—Leafhoppers and their natural enemies. <Hawaiian Sugar
Planters’ Exp. Sta., Div. Ent., Bul. 1, Pt. III, pp. 86-111, pls. 1-4, August, 1905.
(Stylopide.)

Perkins, R. C. L.—Leafhoppers and their natural enemies. <Hawaiian Sugar
Planters’ Exp. Sta., Div. Ent., Bul. 1, Pt. VI, p. 198, November, 1905. (Anagrus
columbt.)

d PERKINS, R.C.L.—Leafhoppers and their natural enemies. <Hawaiian Sugar
Planters’ Exp. Sta., Div. Ent., Bul. 1, introduction, pp. m, tv, May, 1906.

30 THE SUGAR-CANE INSECTS OF HAWAII.

short stay of about ten days gave ample proof of the existence in Australia of a con-
siderable variety of Hymenopterous parasites of leaf-hoppers, of Dipterous parasites
of the genus Pipunculus, and of Stylopid parasites of the genus Elenchus.

At Bundaberg, about twelve hours by rail north of Brisbane, we spent another
ten days in June. Here is an extensive cane district with our leaf-hopper every-
where present, but never in numbers such as we are accustomed to in these islands.
In fact we never saw the hoppers nearly as numerous as they are on our least affected
plantations. From eggs collected here Mr. Koebele soon bred out specimens of the
Mymarid parasites he had felt so confident of finding.

_From our observations on the habits of the cane leaf-hopper in these islands, it
seemed probable that in tropical Australia this species would be in its greatest nun:-
bers in the colder months, so after a brief stay in Bundaberg, we proceeded north to
Cairns, which place we reached at the beginning of July. This plan seemed very
expedient, for by retreating gradually towards the south, as the hot season advanced,
we hoped to prolong the season during which natural enemies for the cane leaf-hopper
could be obtained. It appeared likely that effective work could cnly be done at
Cairns for a month or two, since without a reasonably large supply of hoppers, it was
evident that the parasites could not be found in sufficient numbers for shipment.
This indeed proved to be the case, and by the end of August, leaf-hoppers and their
eggs had become so scarce in the cane fields, that we came south again to Bundaberg.
At Rundaberg we made a long stay on this occasion, regularly sending off consign-
menis of parasites, until here too, owing partly to the season and partly to the harvest-
ing of the crop, the locality became unprofitable. Aiter a short stay in Brisbane,
at the end of the year, [returned to Honolulu, while Mr. Koebele proceeded to Sydney,
where his attention was largely given to collecting beneficial insects for pests other
than leaf-hopper. On the return journey Mr. Koebele spent one month in Fiji, the
enemies of the cane-hopper in those islands being mostly similar to those already
found in Australia. A fine consignment of the Chalcid egg-parasite (Ootetrastichus)
of Jeaf-hopper was most important, as it SEE e 2 us to establish that important species
without any doubt. ‘

During January and February, 1906, Mr. F. Muir continued the
work in the Fiji Islands begun by Mr. Koebele in the latter part of
1904. He reported as follows concerning the Fijian sugar-cane leaf-
hopper and its parasites :?

The Fijian sugar-cane leaf-hopper (Perkinsiella vitiensis) | found all over the island,
but it does no damage, being kept in check by several natural enemies.

The most important of these are the egg-parasites, Ootetrastichus, Anagrus and
Paranagrus. The first of these was introduced from Fiji into Hawaii by Mr. Koebele,
and the other two appear to me the same as the Queensland species. In some fields
as Many as 90 % of the hopper eggs were parasitized, but in other fields it was lower.
Observations extending over my six months’ stay, and made at the various parts of
the island visited, show that an average of 85 % of hopper eggs were destroyed by
these parasites. These figures are cnly approximate, as I have to estimate that one
Chaicid (Ootetrastichus) destroys four hopper eggs, which is a low estimate. This
Chalcid is more numerous, and on account of destroying the whole batch of hopper
eggs, is of very much higher economic value than the Mymarids.

a Muir, F.—Notes on some Fijian insects. <(Hawaiian Sugar Planters’ Exp. Sta.,
Div. Ent., Bul. 2, p. 3, November, 1906.

THE SUGAR-CANE LEAFHOPPER. jl

~The Australian and Fijian material has been described in detailed
reports with elaborate illustrations by Messrs. Perkins, Terry, and
Kirkaldy.%
Regarding the effectiveness of the various parasites and enemies of
the leafhopper, Dr. Perkins says: °

lf we consider the effectiveness of the four egg-parasites, Paranagrus optabilis, P.
perforator, Anagrus frequens, and Ootetrastichus beatus, in areas where all are well
established, we must rate the first-named as at present by far the most effective. As I
have previously pointed out, this species is capable by itself of destroying about 50
per cent of the cane-hopper’s eggs and Anagrus frequens and P. perforator, extraordi-
narily numerous as they appear, where seen alone, are but as isolated examples in
the crowd, where all are well established in one spot. The Ootetrastichus slowly but
steadily increases In numbers, and on many plantations I expect that it will ulti-
mately be the most efficient of all parasites. I do not think that it can show its full
value till 1908, for each harvesting of the cane crop is necessarily a very great setback
to its natural increase. Anagrus frequens, under which name are probably more than
one species, or at least one or two distinct races of a single species, although it appears
at a disadvantage, when in company with Paranagrus optabilis, is nevertheless a
most abundant parasite. In Part VI of this Bulletin I have compared the habits of
the two and need not refer to the matter here, but I may say that as many as eighty
or a hundred exit holes of the Anagrus have been counted in a single cane-leaf, so
that its great utility is unquestionable. P. perforator, common in Fiji, attacking
eges of hopper laid in thick stems of grass, more rarely those in cane, will probably
gradually wander away from the cane-fields to attack the eggs of native hoppers, that
are laid in stems and twigs, as it now chiefly attacks the cane-hopper eggs when these
are laid in the stems.

Nor must it be forgotten, what valuable aid these egg-parasites receive in the
control of leaf-hopper from other insects parasitic and predaceous, native or introduced.
In fact, had there existed previously no restraint to the multiplication of the pest, no

a Wawaiian Sugar Planters’ Exp. Sta., Div. Ent.:
Perkins, R. C. L.—Bul. 1, Pt. I, pp. 1-69, May, 1905 (Dryinide).
Perkins, R.C.L.—Bul.1, Pt. I, pp. 71-85, figs. 1-3, June, 1905 (Lepidoptera).
Perkins, R. C. L.— Bul. 1, Pt. II, pp. 86-111, pls. 1-4, August, 1905 (Stylo-
pidee).
PrEerxins, R. C. L.—Bul. 1, Pt. IV, pp. 113-157, nike 5 ie FNC s 1905
Gonenia.)
Terry, F. W.—Bul. 1, Pt. V, pp. 177-179, November, 1905 (Syrphidz).
_ Perxins, R. ©. L:—Bul: 1, Pt. VI, pp: 183-205, pls: 11-13, November, 1905
(Mymaride, Platygasteride).
PERKINS, R. C. L.— Bul. 1, Pt. VIII, pp. 239-267, pls. 18-20; January, 1906
(Hymenoptera).
Kirxaupy, G. W.—Bul. 1, Pt. IX, pp. 269-479, pls. 21-32, February, 1906
(Leafhopper).
Perkins, R. C. L.—Bul.1, Pt. X, pp. 481-499, pls. 33-38, March, 1906 (Hy-
menoptera, Diptera).
Kirkatby, G. W.—Bul. 3, pp. 1-186, pls. 1-20, September, 1907 (Leafhop-
pers, Supplement).
Perkins, R. C. L.—Bul. 4, pp. 1-59, May, 1907 (Parasites of Leafhoppers).
6 Perkins, R. C. L.—Leaf-hoppers and their natural enemies. <Hawaiian Sugar
Planters’ Exp. Sta., Div. Ent., Bul. 1, introduction, pp. xv-xvu, May, 1906.

32 THE SUGAR-CANE INSECTS OF HAWATI.

one who has paid the least attention to such matters can doubt that it would some time
since have become impossible to raise any crop ofsugar cane in the islands. Thereason
why these natural enemies have not alone got the upper hand of the hopper is due
to various causes. In the first place, a number of the parasites such as the Dryinid
Ecthrodelphax fairchildi and the parasitic flies of the genus Pipwnculus are of local
occurrence, and in many places cannot (for climatic or other unknown reasons)
maintain their existence. This was well shown by the behavior of the first-named,
which was distributed in thousands by the entomologists and the Plantation man-
agers themselves to all the distsicts in the islands, but in many places did not thrive.
Such, too, is the case with the predaceous black earwig (Chelisoches morio) which, a
natural immigrant to the islands and no doubt acclimatised centuries ago, is found
on comparatively few plantations. Other natural enemies are themselves periodically
decimated by parasites, as is the case with the introduced green cricket (Xiphidium
varipenne), which has its own egg-parasite (Paraphelinus). Other enemies like the
common lady-bird (Coccinella repanda) introduced by Koebele years ago for other
purposes, prey on young leaf-hoppers, in default of more favorite food, and this valu-
able predator too is itself subject to parasitic attack by the common Braconid (Cen-
tistes). At present the whole number of parasites and predaceous insects that attack
cane leaf-hopper to such an extent as to render their services worth noting is consid-
erable, as the following summary shows.

The most valuable are the four egg-parasites, which there is every reason to hope
will become still more effective with reasonable time, one (Ootetrastichus) having as
yet had no chance to show its full effectiveness.

The two Pipunculus flies (Pipunculus juvator and terry’) are restricted to certain
localities and are native species, which have transferred their attacks from native
Delphacids to the cane leai-hopper.

The ubiquitous lady-bird (Coccinella repanda) is valuable as a destroyer of leaf-
hopper, though originally imported by Koebele to destroy Aphis. It is hoped that
other lady-birds, especially Verania strigula, may become established and do good
work, as in Australia and Fiji, whence they were imported.

The earwig Chelisoches morio is a local species, but no doubt useful where it exists
in numbers.

The green cricket (Xiphidium varipenne) is very valuable, but is most unfortunately
heavily attacked at certain seasons by an egg-parasite.

The Dryinid Ecthrodelphax fairchildii is locally valuable. At certain seasons in
suitable, but limited, localities, it destroys a considerable percentage of hoppers.
Its services are underestimated because for a large part of the year it lies as a dormant
larva in the cocoon, and parasitized hoppers at such a time are naturally hardly to be
found. /

There are many other natural enemies of more or less importance, e. g. the various
predaceous Hemiptera, and the several lace-wing flies (Chrysopinz).

In addition to these insect enemies, we must mention the two fungous diseases of
hoppers (amounting locally and at certain seasons to epidemics) which, long previ-
ously known to kill the native leaf-hoppers, have become transferred to the introduced
pest. We also found one or more fungous diseases attacking leaf-hopper eggs in Fiji
and Australia in all localities. With material imported from these countries, I easily
infected eggs of the cane leaf-hopper under cover, and subsequently established the
fungus at large in the field. As it was most probable that parasitized and healthy
hopper eggs would be affected alike by the disease, and consequently many of the egg-
parasites would be destroyed, it became a subject of discussion whether we should
attempt to establish the fungus or not. As, however, throughout Australia, the
fungus and parasite both attacked the eggs, Mr. Koebele was of opinion that we
should try and establish the same conditions here. Consequently with the first

THE SUGAR-CANE LEAFHOPPER. oe

cages sent to the plantations the cane cuttings and the cane itself were well sprayed
with water containing spores of the fungous disease, so that these would be certainly
carried abroad by the emerging hoppers and parasites. I imagine there is no doubt
as to this disease becoming established in all suitable localities.

In speaking of the necessity for the continued propagation and dis-
tribution of the introduced parasites of the leafhopper, Doctor
Perkins reports as follows: 7

Owing to the manner in which cane is cultivated in these islands, the entomologist
working along the lines that have been adopted to control the leaf-hopper pest, meets
with a serious obstacle such as is not encountered in dealing with insects injurious to
our other vegetation. I refer here to the universal custom of burning off the trash over
great acreages, after the crop has been harvested. I have been told that on the Colo-
nial Sugar Refining Company’s estates in Australia no such burning off is allowed. If

-this is correct, it may help to account for the insignificant numbers of our cane-leaf
hopper there, as well as of several other insects of the same group, which are fortunately
not known in our cane fields. As, however, burning of trash is an established fact here,
it becomes necessary to see what steps can be taken to provide against this serious disad-
vantage. I will first show whereof this disadvantage consists. The parasitic enemies
of the leaf-hopper are mostly delicate and minute creatures, not accustomed to take
prolonged flights. Their wings serve well to bear them from plant to plant, but for fur-
ther distribution they are dependent on air-currents. If when a field of cane is cut the
wind blows towards another cane field, no doubt some or many parasites will reach it,
but if otherwise, probably none will do so. In burning over a field it is quite certain
that almost every parasite yet present will be destroyed, but the adult leaf-hoppers on
the other hand are well able to take care of themselves. When, as an experiment, a
patch of about nine acres of cane, so heavily attacked by leaf-hopper as to be useless,
was set on fire all around to destroy these, it was noticed that the adult hoppers rose
from the cane in a cloud and spread to other fields; so this plan for destroying them was
of no value. I have in an earlier publication shown how quickly the leaf-hoppers
spread to new fields of very young cane, and with what regularity they distribute them-
selves over the young plants. It cannot be hoped that the parasites will (except under
rare and fortuitous circumstances, such as constant favorable winds) spread themselves
in like manner, and in the same time. Yet it is essential that the parasites should be
on the spot when the leaf-hopper begins to lay in order to secure proper control. Ii the
supply of laying hoppers at the beginning of the great breeding season is very small, it
means that there is not time for the attack to become serious before that season is over.
It is when the hopper is least abundant, that one wants to be assured that it is being
attacked by all possible enemies. When a field is already seriously injured and
swarming with hoppers, not much immediate help can be given for obvious reasons. It
will be easier to prevent such a condition than to findaremedy. If one could provide
that in each large area of cleared land, ready for planting, there should be in the middle
a small patch of some variety of cane most susceptible to the attack of leaf-hoppers,
that this cane should be kept well stocked with these, and with a variety of parasites
and predaceous insects, and itself be of sufficient growth to afford good shelter to all
these, the condition from an entomological standpoint would be ideal. This patch of
cane, being already of suitable age and growth and stocked as aforesaid, at the time
the much younger cane of the rest of the field began to be infested with hoppers, would

@ PERKINS, R.C. L.—Leaf-hoppers and their natural enemies. <Hawalian Sugar
Planters’ Exp. Sta., Div. Ent., Bul. 1, introduction, pp. xviu-xx1, May, 1906.

34 THE SUGAR-CANE INSECTS OF HAWAII.

daily be distributing thousands of natural enemies, that should control these. Al-
though such a plan or modification of it might be adopted on some plantations, on
others (at least such as are under irrigation) it would either be difficult, or altogether
impracticable. Only in the case ofsome fields of long ratoons would the matter be very
simple, when a small area of the original ratoon growth in each field could be left uncut,
and if well supplied with hoppers and their natural enemies would serve later on to
stock the rest of the field. Unfortunately, owing to the fact that ratoons are (except in
unusual cases) not severely attacked as compared with plant-cane, this matter becomes
one of minor importance. Otherwise, in the majority of cases, owing to the clearing of
large areas and the burning of trash, it is probable that new fields will have to be sup-
plied by cages similar to those already used. ‘Two things will be absolutely necessary:
(1) that the new fields be well supphed with parasites; (2) that they be stocked imme-
diately the hoppers enter them and commence laying. This plan, though less satisfac-
tory than would be the other method, is nevertheless simple, and does not call for
much expenditure of time, nor for skilled labor. The one thing necessary to be posi-
tively ascertained is that the spot whence the cuttings for distribution are taken is well -
supplied with al/ the kinds of parasites that it is desired to establish in new fields. It
is now well known to us that all these destroyers are not yet established in all parts of
all plantations, and therefore at present unless an entomologist previously test samples
from the spot, whence distribution is to be made, it is quite likely that some of the
most valuable parasites will not be taken to the new fields. Iiasample be submitted
to the entomologists, it can be passed as fit to supply all necessary parasites to new
fields, or if not, cages of the deficient species can always be supplied from the cane in
the grounds of the Experiment Station in Honolulu. As the parasites are continually
spreading and increasing, such expert examination will at the most be necessary for a
year or two; for it is perfectly certain that by that time all the species will be so gen-
eral that it will be quite impossible to take any extensive sample of cane-leaves that
bear eggs of leaf-hopper, which will not contain all: Such in fact is now the case in the
cane at the Experiment Station. To sum up, the clearing of all cane from large acre-
ages is a decided obstacle to the complete success of natural enemies of leai-hopper, and
the burning of trash ageravates the difficulty. As an offset to these conditions new
fields shou!d be supplied artificially with natural enemies, and they should be supplied
as soon as any leaf-hoppers enter them. Of course future observation may prove this
distribution unnecessary, but for the present it should be adopted.

RELATED SPECIES.

The Hawaiian sugar-cane leafhopper does not occur on the mainland
of the United States. The insect is closely related to the corn leaf-
hopper (Dicranotropis maidis Ashm.), common on corn in the South-
ern States. A West Indian species of leafhopper is recorded as inju-
rious to sugar-cane, by Westwood, in 1841, under the name Delphaz
saccharwora and is a member of the same family of insects as the
Hawaiian sugar-cane and the corn leafhoppers.? Three further spe-
cies of this same family, the Fulgoride, are recorded as sugar-cane
pests in Java by W. van Deventer.°

@ QuainTANCE, A. L.—Fla. Agr. Exp. Sta., Bul. 45, 1898.

6 Westwoop, J. O.—Mag. Nat. Hist., vol. 6, p. 407, 1841.

¢ Phenice maculosa, Dicranotropis vastatriz, and Eumetopina kriigeri. Van Deventer,
Handboek ten dienste van de Suikerriet-cultuur en de Rietsuiker-Fabricage op Java,
II. De Dierlijke vijanden van het Suikerriet en hunne Parasieten. Amsterdam,
pp. 167-169, 1906.

THE HAWAIIAN SUGAR-CANE BORER. 35

THE HAWAIIAN SUGAR-CANE BORER.
([Sphenophorus] Rhabdocnemis obscurus Boisd.)
GENERAL CHARACTERISTICS.

The suear-cane “‘borer” ([Sphenophorus| Rhabdocnemis obscurus
Boisd.) (fig. 4), infesting the cane stalk in Hawaii is the erub of a beetle
belonging to the weevil family Calandride. The sugar-cane stalk-
borer of the southern United States is the caterpillar of a moth,

Fie. 4.—The Hawaiian sugar-cane borer ([Sphenophorus] Rhabdocnemis obscurus): 1, Eggs, natural size.
2, Eggs in situ, much enlarged: a, Section of egg passage with egg, c; b, egg placed unusually near the
rind, d. 8, Larve, just hatched and older, natural size. 4, Full-grawn larva, natural size. 5, Larva,
side view, enlarged: a, Spiracles; b, cervical shield. 6, Larva, front view, enlarged. 7, Pupa, enlarged;
a, Rostrum or beak; b, antenna; c, elytron or wing cover; d, folded wing. 8, Pupal case or cocoon,
enlarged. 9, Adult, enlarged. (After Terry.)

Datrea saccharalis Fab. Entomologically the two species are
widely separated, belonging to entirely different orders of insects, but
in the character of their injury to the cane stalk these two insects
are quite similar—that is, they both develop within the cane stalk, and

36 THE SUGAR-CANE INSECTS OF HAWAII.

by feeding on the interior cause great destruction to the plant. Com-
paratively, the Hawauan borer is more destructive and, because of the
habits of the adult, a more persistent species to combat. The adult
beetle of the Hawaiian borer is a stronger flyer than the adult moth
of the mainland borer and therefore has a wider range over any
infested territory. As the adult of the Hawaiian borer, too, can
emerge from any reasonable depth when buried in the soil, this
renders the question of infested seed cane a serious one in Hawaii,
while on the mainland the careful covering of infested seed cane is
effective in preventing the emergence of the adult moth. These
points are mentioned to bring out the fact that we are discussing
here a species in no way related to the cane borer of the Southern
States and in many ways not subject to the same means of control.

[Sphenophorus] Metamasius sericeus Oliv. is a species injurious to
cane in the West Indies, being recorded from Jamaica, Barbadoes,
St. Kitts, Antigua, St. Lucia, and British Guiana.

In Porto Rico S phenophorus sexguttatus Drury is recorded by Busck4
as boring in the stalks of sugar cane.

DISTRIBUTION.

The sugar-cane borer of Hawaii is recorded also from Fiji, New
Guinea, New Ireland, Tahiti, Queensland, and the Malay Archipelago
and probably occurs pretty generally throughout the islands of the
southern Pacific.

OCCURRENCE IN HAWATI.

This species is a pest of long standing in the islands. The insect is
recorded from the Island of Oahu in 1885 by the Rev. Thomas Black-
burn,? who found the species breeding in the stems of bananas in the
mountains, and the files of the Bureau (then Division) of Entomology,
record the receipt of the borer from the Hawaiian Islands, as early as
1888.° It is believed that the sugar-cane borer was introduced into’
the islands from Tahiti in the stems of the banana plant during the
early communications between the Hawatan Islands and those of
the South Seas. Hon. H. P. Baldwin, of Puunene, Maui, informed
the writer that to his personal knowledge the beetle was injurious to
sugar cane in the vicinity of Lahaina, the ancient capital of the
islands, as early as 1865.

Aside from the banana plant and sugar cane, the beetle infests the
coconut palm, the sago palm, the royal palm, the wine palm, (Cary-
ota wrens), and the papaia (Carica papaya).

aU.S8. Dept. Agr., Bur. Ent., Bul. 22, p. 89, 1900.

b BLACKBURN, Rev. T., AND SHARP, D.—Memoirs on the Coleoptera of the Hawaiian
Islands. <(Sci. Trans. Roy. Dublin Soc., 2 ser., vol. 3, pp. 119-290, pl. 1, 1885.

¢ General Notes, Bureau of Entomology, No. 4332b.

THE HAWAIIAN SUGAR-CANE BORER, 37

Until the recent injury by the leafhopper (Perkinsiella saccharicida)
the sugar-cane borer was the principal insect affecting cane in the
islands.

The species was determined by the Bureau of Entomology at
Washington, D. C., in 1888 from specimens forwarded by the late
King Kalakaua and was discussed under the title “‘The Sandwich-
Island Sugar-cane Borer,” in Insect Life, vol. 1, No. 6, pages 185-189,
December, 1888.

In 1896 Mr. Koebele gave the following record on the work of
the borer in Hawaii: %

This may be classed as the most injurious enemy of the sugar cane present on these
islands. Its ravages will exceed those of all other insects combined. Its attacks on
the sugar cane, however, seem confined to the more damp localities, whilst in drier
places, such as Lahaina, the borer is hardly noticed. I have been informed that the
Lihue Plantation has recently suffered severely from the attacks of the borer. Not
only sugar cane is damaged by this insect, but many other plants are damaged by it,
chiefly the bananas and cocoanuts. A grove of the latter was shown me in Hilo, in
1894, that was badly infested by the beetles. Setting fire to the dry leaves was rec-
ommended; this was done and the plants have since entirely recovered. Dying
cocoanut palms were examined and in the tender heart of the palm were found great
numbers of the insects, in all stages.

More recently (1907) Mr. F. W. Terry has discussed the sugar-cane
borer in the Hawaiian Islands in a circular of the Hawaiian Sugar
Planters’ Experiment Station. ?

LIFE HISTORY AND HABITS.

The eggs are found beneath the epidermis of the cane stalk, or
more rarely in the tissue of the leaf sheath, having been placed singly
in small cavities. The cavity is made by the female with her proboscis
before depositing the egg.

The young grub or larva, on hatching from the egg, bores on into
the stalk of the cane, completely honeycombing the interior with
tunnels running lengthwise with the stalk (see fig. 5). The evidence
of its work is not indicated by the outward appearance of the stalk.
Many times ‘a stalk, seemingly in a normal condition, is found on
examination to be utterly destroyed. The life of the borer within
the stalk of the cane is estimated to be about seven weeks by Mr.
Koebele,“ who points out the fact that the length of the larval life

@ KoEBELE, ALBERT.—Report on insect pests. <(Hawaiian Planters’ Monthly, vol.
15, no. 12, p. 590, December, 1896.

6 Terry, F. W.—Hawaiian Sugar Planters’ Exp. Sta., Div. Ent., Cir. 3, pp. 22,
plates 2, fig. 1, December, 1907.

¢ KoEBELE, ALBERT.—Hawailian Planters’ Monthly, vol. 19, no. 11, p. 520,
November, 1900.

38

Fic. 5.—Work of the Hawaiian sugar-
cane borer in sugar cane: a, a, a, Emer-
gence holes made by the larva before
pupation; 5, 6, ‘‘rupture’’ holes, ap-
parently accidental and made by the
larva while feeding; c, holes made by
the female borer for the reception of
her eggs; d, cocoon; e, larva; f, 7,
“‘frass’? or undigested cane fiber,
passed by thelarva. One-half natural
size. (After Terry.)

THE SUGAR-CANE INSECTS OF HAWATI.

depends to a great extent upon the con-
dition of the food plant and climatic
conditions; that is, the development will
be more rapid in softer cane and during
the warm summer months than during the
low temperatures of winter.

When ready to pupate—that is, to trans-
form to the inactive stage preparatory to
emerging from the stalk as an adult
beetle—the larva (fig. 5, a) forms about
itself a cocoon (fig. 5, 6) from the fiber of
the stalk within the tunnels it has made
in feeding. The adult beetle on issuing
from this cocoon bores its way through
the side of the stalk to the exterior, and
this opening in the lower joints of the cane

is the first distinct symptom of the pres-

ence of the borer. The length of the
pupal period is as variable as that of the
larval, the average time for transforma-
tion and emergence being from two to
three weeks.

The beetles are night flying and hide
during the day down within the sheaths
of the lower leaves. The softer varieties
of cane are more subject to attack than
the hardier varieties, and the borer is more
abundant in the wet districts than in the
dry. Cane which has received an abun-
dant supply of water by irrigation suffers
more from the work of the borer than un-
irrigated cane. The borers occur in the
largest numbers in young cane and the
suckers are infested to a much greater
degree than thestalks. The borers always
occur in the largest numbersin the vicinity
of the track used to haul cane to the fac-
tory, issuing from infested stalks that have
dropped from the cars and have not been
collected and destroyed afterwards.

The borer is a strong flyer and spreads
from field to fieldinthismanner. Itisdis-
tributed in infested seed cane and also
develops from the stalks left in the field
after harvest or dropped from the wagons
or cars in hauling to the factory.

THE HAWAIIAN SUGAR-CANE BORER. 39

CONTROL MEASURES.
SELECTION OF VARIETIES FOR PLANTING.

As has been mentioned, the softer varieties are more subject to
attack than the hardier ones. The Yellow Caledonia, a variety
which is replacing to a great extent the common Lahaina and Rose
Bamboo in Hawaii, is injured to a much less extent than other
varieties. The infestation is not necessarily less in Yellow Caledonia,
but the borer meets with greater resistance in its feeding and conse-
quent development because of the firmness of the fiber.

IRRIGATION.

Excessive irrigation favors the development of the pest, since
cane in a succulent condition is more easily infested by the borer
and its development within the stalk is more rapid. It is plain that
in fields heavily infested by the borer the minimum amount of water
should be used in irrigation.

BuRNING OF TRASH.

The burning of trash after harvesting the cane is the most effectual
method of keeping the borer in check. In this practice not only
should the fields be burned over, but all the unburned stalks left in
the fields and all stalks dropped from carts and cars along the roads
and tracks used in hauling the cane to the factory should be collected
and burned. One plantation found it necessary to collect such
stalks in piles and use crude oil on them in order to destroy them
completely, and by a careful estimate of the labor and cost of mate-
rial found that the money had been well invested, as was shown by
the reduction in the numbers of borers in the fields the following
season.

SELECTION OF NONINFESTED SEED CANE.

The Hawaiian sugar-cane borer is able to emerge to the surface
from any reasonable depth when planted with seed cane. For this
reason great care should be exercised in the selection of cane for
planting purposes, since new areas can in this way be readily stocked
with the pest. It is not practical to treat successfully cane infested
with the borer, since the borer is fully protected within the stalk.
Therefore, next in importance to the thorough burning of all trash
after harvest is the selection of noninfested seed cane.

PicKING AND BalItTIna.

The most effective direct measure employed against the cane
borer is the collecting of the adults during the daytime from their
hiding place within the lower leaf sheaths. The supply of labor will

40 THE SUGAR-CANE INSECTS OF HAWAII.

influence the ability to use this method. The method is mre Tensile .

where the plantation is so situated that women and children can be
employed for the work. Care should be exercised in this work in
order that the growing leaves may not be broken down. It is
obvious that a larger number of beetles will be collected when the
wages are based on the numbers collected, but the results are more
satisfactory, as regards breaking down the cane, when the wages of
the laborers are fixed at a certain amount per day.

In the Fiji Islands a method of baiting the beetles is employed,
which consists of splitting cane stalks and placing pieces about the
edges of the field and within the rows at certain intervals. The
methed as practiced in Fiji is thus described by Mr. Koebele.?

At the request of the Colonial Sugar Company we looked ‘nto the matter with a.

view of getting rid of the beetles the best way possible; all sorts of devices were em-
ployed and none worked better than pieces of split cane about 12 inches long, placed
along the edges of the field and through the same at intervals of 12-18 feet; thus with
seven little Indian girls, I collected over 16,000 beetles in some four hours, and the
same little girls alone brought in the following noon over 26,000 beetles.

This method was kept up, and followed on all the plantations jor the next three
years, or until no more of the borers could be found. Tons of the same were brought
in at the Nausori mill alone, and the expenses of collecting were practically nothing
compared to the cost at Lihue, where such work has to be done by the day laborers.
About four cents per pint of the insects was paid tothe children. The result has been
highly satisfactory, for, ever since the last five years, the cane borer has not been a
pest in those islands.

An important point regarding this split cane is that the females
usually infest these pieces heavily with eggs and the young resulting
grubs bore into the split stalks and perish as the pieces of cane become
dry. In dry localities the pieces of split cane should be placed in the
irrigation ditches during the day and placed out as bait in the even-
ing, otherwise they dry out rapidly and cease to attract the beetles.

RELATED SPECIES.

The Hawaiian sugar-cane borer is represented in the United States

by the ‘‘corn bill-bugs,” of the genus Sphenophorus, several species
of which in the adult stage attack the leaves of corn, but rarely breed
in the stalk of corn as does the Hawaiian Sphenophorus in the stalk
of cane. The Hawaiian cane borer does not occur on the mainland of the
United States.

a KoEBELE, ALBERT.—Hawaiian Planters’ Monthly, vol. 19, no. 11, p. 522, Novem-
ber, 1900.

THE HAWAIIAN SUGAR-CANE LEAF-ROLLER. 41°

THE HAWAIIAN SUGAR-CANE LEAF-ROLLER.
(Omiodes accepta Butl.) (Plate IIT.)

EARLY HISTORY IN THE HAWAIIAN ISLANDS.

During the investigations relating to the leafhopper in 1903 the
writer found the Hawaiian sugar-cane leaf-roller, the caterpillar of
a native moth, doing serious damage to cane in the upper fields of
plantations in the Kohala district, Island of Hawaii. The larve
were collected also from Hilo grass (Paspalum conjugatum) growing
wild above the cane areas. The species, primarily a grass feeder,
occurs in the higher altitudes and invades the bordering fields from
these locations. It is recorded by Meyrick % in 1899 from the islands
of Hawaii, Maui, Molokai, and Kauai at elevations ranging from
1,500 to 5,000 feet. The caterpillar was described for the first time
by Dr. H. G. Dyar, of the United States National Museum, from
specimens collected by the writer on cane in the Kohala district. °

Swezey states that the leaf-roller occurs on practically all of the
plantations of the islands, but is less abundant in the dry districts.
Regarding its injury he says:¢ —

It is present in some fields of cane sometimes in such large numbers as to do consid-
erable damage; in fact, cases have been reported where the young cane has been entirely
stripped of leaves. Such instances are not numerous, however, and even in the worst
cases would not result in entire destruction of the crop of cane as it would grow again
after the caterpillars had obtained their growth, or their parasites had got them checked.
It is not usually to be considered a serious pest. Possibly it is not so abundant now
as it was a few years ago when reports were made of cane fields having been entirely
stripped by them.

At present there are a number of parasites preying upon this species and this keeps
them well in check.

In this same report, page 10, the author describes the habits of the
caterpillar as follows:

On sugar cane the very young larve feed in the crown of the plant where the young
leaves have not yet unrolled. They are thus protected between the natural rolls of
the leaf; later on they roll over the margin of a leaf forming a tube for their “ retreat.’’
When nearly full grown, they are usually found in tubes towards the tip of the upper
leaves. These tubes are easily observed if the ragged leaves where the larve have
fed, are examined. The work of the smaller larvee shows as oval or elongate dead
spots on leaves which have unrolled in the growing of the cane after the young larvee
have fed upon them.

When disturbed in its retreat, as by its being torn open, or violently shaken, or
jarred, the larva wriggles verylively and drops to the ground for escape. This habit is

a4 Meyrick, E.—Fauna Hawaiiensis, vol. 1, Pt. II, p. 204, 1899.

6 Dyar, H. G.—Note on the larva of an Hawaiian pyralid (Omiodes accepta Butler).
<Proc. Ent. Soc. Wash., vol. 6, no. 2, p. 65, 1904. -

¢ Swezey, Orro H.—The sugar-cane leaf-roller, Omiodes accepta. <Hawaiian
Sugar Planters’ Exp. Sta., Div. Ent., Bul. 5, p. 7, August, 1907.

“42 THE SUGAR-CANE INSECTS OF HAWAII.

probably to escape from parasites, many of which prey upon them. Theretreat which
it constructs is undoubtedly for the same purpose, as well as for protection from wasps
and birds which prey upon it.

The caterpillars are full grown in about three weeks from hatching. They molt
five times at intervals of about three to five days, and five to seven days between the
fifth molt and the spinning of the cocoon and pupation. Pupation takes place within
a slight cocoon of white silk in the “‘retreat’’ where the caterpillar has lived; how-
ever, the cocoon is sometimes made beneath the leaf-sheaths of cane, and in other
favorable places.

CONTROL MEASURES.

No special remedies are employed in cane fields against this pest.
Swezey suggests that in fields of young cane a spray of Paris green
or arsenate of lead might be used with effect, and mentions that at
times laborers have been sent over the field to pinch the caterpillars
in their retreat between the folded cane leaves.

PARASITES.

The species is attacked, fortunately, by several introduced para-
sites. Regarding the natural enemies of the species of moths belong-
ing to the genus Omiodes, Mr. Swezey reports as follows on pages 36
and 37 in his article above referred to:

Omiodes caterpillars are attacked by a large number of species of parasites, some of
which are native, and several which are the most valuable have been introduced.
The most of the species are kept in check by their natural enemies, so that they do
not become very numerous; in fact, several of them are very rare. Two species feed
so numerously on cultivated plants that they become serious pests; accepta on sugar
cane, and blackburni on palms. These two species are preyed upon very extensively
by the parasites and checked considerably, but not sufficiently to keep them from
doing considerable injury in certain localities and at certain seasons. Apparently the
moths are more prolific in the winter months (about December to March) and the
parasites are scarcer owing to their having had fewer caterpillars for them to keep
breeding on during the preceding summer. Hence, when the winter broods of cater-
pillars appear, there may be two or three generations of them before the parasites
breed up to sufficient numbers so that they produce any noticeable check on the
number of the caterpillars; then in another generation or two the caterpillars may be
much reduced in numbers and a large percentage of them found to be parasitized; for
example, on one occasion 75 % of the cane leaf-rollers in a field at Hutchinson plan-
tation, Hawaii, were found to be destroyed by one species of parasite; at Olaa plan-
tation, Hawaii, in a certain field, on one occasion a much higher percentage of them
than that were killed; in Honolulu, of a large number of the palm leaf-roller cater-
pillars collected, 90 % were parasitized.

Since there are so many species of parasites preying on the leaf-rollers which are
pests, it might be asked “Why do they not become exterminated, or at least cease to
be pests?”? Apparently, with all of the parasites, they are still not numerous enough
to overbalance the prolificness of the pest, even though they do kill such high per-
centages of them at times. Since so many are killed by parasites, and yet there are
enough left to do considerable injury at times, one cannot help but wonder to what
extent these pests might increase were there no parasites preying on them, and how
many times more serious would be the damage done by them. The extreme difficulty
and impracticability of treating sugar cane fields, or large palm trees, artificially, for

Bul. 93, Bureau of Entomology, U. S. Dept. of Agriculture. PLATE III.
t

sy SR x SS
pat N SSS esate

THE HAWAIIAN SUGAR-CANE LEAF-ROLLER (OMIODES ACCEPTA).

Fig.1.—Adultmoth. Figs. 2, 3,4,5.—Larve and details. Fig.6.—Pupa. Fig. 7.—Apex of cremaster,
showing thecurled spines by which the pupa is fastened to the cocoon. Fig. 8.—Cluster of 4 eggs
in groove on surface of leaf. Fig. 9.—Eggs more highly enlarged. Fig. 10.—Leaf spun together
for ‘‘retreat”’ or hiding place of caterpillar; showing where caterpillar has eaten. Fig. 11.—Leatf,
showing spots where very young caterpillar has eaten, leaving one epidermis intact, instead of
eating holes through the leaf. (After Swezey.)

THE SUGAR-CANE MEALY-BUG. 43

the destruction of these pests, makes it all the more important that there are so many
valuable parasites preying upon them; and shows the value of introducing natural
enemies to control a pest, for the four best parasites of these leaf-rollers are introduced
species, viz., Macrodyctium omiodivorum, Chaleis obscurata, Frontina archippivora and
Trichogramma pretiosa. -

THE SUGAR-CANE MEALY-BUG.
(Pseudococcus calceolarix Mask.) (Plate IV.)

IDENTITY.

This insect (see Pl. IV, from photographs by Mr. T. C. Barber) is
identical with the sugar-cane mealy-bug common on cane in the
southern parishes of Louisiana. The species is recorded by Mrs.
Maria E. Fernald from Australia, Hawaii, Fiji, Jamaica, and Florida.?
Koebele earlier records this mealy-bug on cane in Hawau..?

RELATED SPECIES.

The mealy-bug of the cane belongs to a very large family of insects,
Coccidxe, which are world-wide in their distribution. Two other
species of this family, Pseudococcus sacchary Ckll. and Aspidiotus
cyanophylli Sign., have recently been recorded from Hawai by Mr.
J. Kotinsky.¢

Three species, namely, Pseudococcus calceolariex, P. sacchari, and
Aspidiotus sacchari Ckll., are known to attack sugar cane in the
West Indies.¢

Van Deventer records several scale insects, among them Lecanium
krugert Zehntn., Aspidiotus saccharicaulis Zehntn., Chionasprs spp.,
and a species of Pseudococcus very similar to P. calceolarix, on cane
in Java. é

In Mauritius two species of related insects, Jcerya seychellarum
Westw. and Pulvinarna iceryi Guér., are reported as pests of sugar

cane/
FOOD PLANTS.

Mrs. Fernald gives the food plants of the sugar-cane mealy-bug
as Calceolaria, Danthoma, Phormium tenaz, Cordyline australis, and

a@ FERNALD, Mrs. Maria E.—A Catalogue of the Coccide of the World. <Bul. 88,
Hatch Exp. Sta., Mass. Agr. Coll., p. 98, 1903.

6 KoEBELE, ALBERT.—Hawailan Planters’ Monthly, vol. 15, no. 12, p. 596, Decem-
ber, 1896; vol. 17, no. 5, p. 209, May, 1898.

¢ Kotinsky, JAcoB.—Coccide not hitherto recorded from these islands. < Proc.
Hawaiian Ent. Soc., vol. 2, no. 3, pp. 127-131, 1910.

d Battou, H. A.—Review of the insect pests affecting the sugar cane. <West
Indian Bul., vol. 6, no. 1, p. 41, 1905.

€ DEVENTER, W. vAN.—Handboek ten dienste van de Suikerriet-cultuur en de
Rietsuiker-Fabricage op Java. II. De Dierlijke vijanden van het Suikerriet en
hunne Parasieten, Amsterdam, pp. 227-266, 1906.

f FERNALD, Mrs. Marta E.—A Catalogue of the Coccide of the World. <Hatch
Exp. Sta. Mass. Agr. Coll., Bul. 88, pp. 27, 133, 1903.

44 THE SUGAR-CANE INSECTS OF HAWATI.

sugar cane. In Louisiana the mealy-bug infests, aside from sugar
cane, the Johnson grass (Sorghum halepense) and the saccharine
sorghums.. ;

LIFE HISTORY AND HABITS.

The feeding habits of the mealy-bug are similar to those of the
cane leafhopper; that is, ther mouthparts are formed for piercing —
the epidermis of the plant and sucking the plant sap from the inner
tissues. _ The distinction m the feeding habit is that the leafhopper
is active throughout its entire life cycle, and jumps or flies from
plant to plant, while the mealy-bug when partly grown remains
practically stationary and feeds upon but one portion of the same
plant.

Where the cane mealy-bugs occur in Hawaii, they can be found
about the lower leaves of the cane, congregating for the most part
behind the older leaves near the ground. The species may be recog-
nized by the white mealylike covering of the adult female, to which
the common name applies. The insects occur in a mass and when
abundant are readily observable by the white covering of the females.
This white covering serves as a receptacle for the eggs, which, upon
close examination, may be observed embedded therein.

In Louisiana the insects occur not only about the lower leaves of
the plant, but are to be found also around the crown (Plate IV, fig. 1)
and beneath the surface of the ground about the roots of the plant.
In this latter location they hibernate during the cold months of
winter on both cane and Johnson grass.

The young mealy-bugs upon hatching from the eggs are quite
active and disperse over the cane plants, finally congregating when
partly grown about the lower nodes of the stalk. The females are
practically inactive, remaining in a mass about one of the nodes or
beneath the leaves throughout their development and secreting about
themselves in these locations the characteristic white covering
(Plate IV, fig. 3). The young males do not remain stationary on
the plant, but, after completing their development, spin a narrow
white cocoon (Plate IV, fig. 4) within which they transform to a
delicate winged adult.

CONTROL.

Selection of seed cane.—Since the common method of distribution
is by the transportation of infested seed cane from plantation to
plantation or from one part to another of the same plantation, care
should be exercised to select clean stalks and not those which are
infested, for seed cane.

Burning of the trash.—The practice of burning the trash after
harvest is very effective in destroying this insect, smce those remain-

Bul. 93, Bureau of Entomology, U. S. Dept. of Agriculture. PLATE IV.

res

i
t
|

t
‘
(
THE SUGAR-CANE MEALY-Bu@G (PSEUDOCOCCUS CALCEOLARIA).
Fig. 1.—Adult mealy-bugs clustered about the base of young cane. Fig. 2.—Adult female, ;
twice natural size. Fig. 3.—A single adult female, with white mealy-like covering.
Fig. 4.—Cocoons of male mealy-bug. (Original.)
"
i

a

= é ‘

OTHER SUGAR-CANE INSECTS IN HAWAII. 45

ing on the stalks are killed in the process of milling, and the remaining
forms on the discarded stalks and leaves in the field are destroyed
by the fire.

NATURAL ENEMIES.

There is present in Hawaii a ladybird beetle, Cryptolemus mon-
trouziert Muls., which is a special mealy-bug feeder. This ladybird
is one of Mr. Koebele’s introductions from Australia. It has proved
particularly beneficial in feeding upon the sugar-cane mealy-bug
in the Hawaiian cane fields, and through its work the numbers of the
mealy-bug have been greatly reduced in recent years. This impor-
tant predator has been established in California, and the Bureau of
Entomology at Washington, D.C., has under way at present negotia-
tions to import this beetle into the cane fields of southern Louisiana
which are infested by the mealy-bug.

The ladybird is thus described by Prof. W. W. Froggatt, govern-
ment entomologist of New South Wales.%

This beetle is very variable in size, measuring from under 2 to 3 lines in length,
with the head, thorax, extreme tip of both wing covers light orange-yellow; the whole
of the under surface reddish-brown, and both the upper and under surface clothed
with fine hairs. In a number of specimens the under surface is variable in colora-
tion, the middle and hind pairs of legs with the thorax dark reddish-brown to black.

The larva is of the usual smoky-brown tint, but so thickly clothed on the upper

surface with white filaments that it appears to be of a uniform white, the pupa hidden
beneath the larval skin and the immature beetle are pale yellow.

MISCELLANEOUS INSECTS AFFECTING SUGAR CANE IN HAWAII.

An aphis, Aphis sacchari Zehntn., is occasionally injurious to sugar
cane. Koebele records an outbreak of the species on the Island of
Kauai in 1896 under the name Aphis sp.? The species was deter-
mined by Kirkaldy in 1907.° This insect is known to occur on cane
inJava. In Hawaii, the species is fed upon by the ladybird Coccinella
repanda Thunb., though the benefit from this beetle is offset by the
work of its braconid parasite, Centistes americana Riley. 7

In some districts where the cane fields are situated in moist loca-
tions, a mole cricket, Gryllotalpa africana Beauv., is sometimes
abundant enough to be injurious. Another species of mole cricket,
Scapteriscus didactylus Latr., is a most important pest of sugar cane

@ Froacatt, W. W.—Australian ladybird beetles. <Agr. Gazette of New South
Wales, vol. 13, pt. 9, pp. 907, 908, September, 1902.

6 KoEBELE, ALBERT.—Hawaiian Planters’ Monthly, vol. 15, no. 12, pp. 596-598,
December, 1896.

c KrrKaupy, G. W.—On some peregrine Aphide in Oahu. <Proc. Hawaiian Ent.
woc., vol. 1, pt. 3, pp. 99, 100, July, 1907.

46 THE SUGAR-CANE INSECTS OF HAWAII.

in the island of Porto Rico.* Regarding the work of the Hawaiian
mole cricket, Prof. Koebele reports as follows:?

A species of mole cricket has appeared in very large numbers in some of the moist
valleys on Oahu, it is likely another Asiatic introduction, as a rule these crickets
are found around the muddy borders of shallow pondsand watercourses where they live
in burrows resembling those cf moles, and like that animal their food consists chiefly
of earth worms and the larva of various insects. The opinionsas to its habits are as
yet divided; whilst some authorities claim that it is beneficial, others place it amongst
the injurious insects.

Specimens kept in confinement here with pieces of sugar cane would hardly touch
them, yet they readily devoured a large number of the larva of the Adoretus or Japanese
beetle, as well as those aphodius and a number of earth worms, all within 24 hours.

The ground infested by these crickets was examined and found to be very wet and
completely riddled with the burrows down to a depth of three and even four feet, as
many as three and four specimens were brought to hght in a single shovel full of the
soil. In such localities there is no question as to the injurious effects of the crickets
on young cane plants, wherever they were numerous almost all of the seed cane was
destroyed; they would burrow into the seed from ali sides, destroying all the eyes,
where the plants had made a growth of a couple of feet the cricket would burrow in
below the ground and eat to the center, killing the plant. This is the only instance
so far observed of the depredations of these crickets here. In rice and taro fields no
damage has been observed as yet, and the only damage that is likely to occur to cane
is when it is planted in wet swampy land, as the cricket can only live and thrive in
such places, and is not found in ordinary arable land; even in the swamp where the
cricket was very numerous, it did not attack the old cane but paid its attention sclely
to the newly planted seed and very young plants.

This cricket, although living in marshy land, cannot live under water, yet it is a
good swimmer; the only remedy that can be recommended at present is to flood the
land with water and collect the crickets as they come to the surface, destroying them
by placing them in a vessel containing kerosene and water.

The fungoid so contagious to many insects and larva here, does not seem to have any
effect on this lively cricket, nor will he have anything to do with poison given in the
style of bran, sugar and arsenic.

Certain army worms and cutworms, among them Heliophila uni-
puncta Haw., Agrotis ypsilon Rott., and Spodoptera mauritia Boisd.,
are occasionally known to strip fields of young cane. ‘These species
and related forms, together with their natural enemies, are discussed
in a recent report by Mr. O. H. Swezey. °

A bud moth, Lreunetis flavistriata Wlsm., is found generally
throughout the Hawaiian cane fields and at times is quite numerous.
Regarding its injury Swezey says:4

2 Barrett, O. W.—The changa or mole cricket in Porto Rico. <Porto Rico Agr.
Exp. Sta., Bul. 2, pp: 19; fie. 1, 1902:

6 KOEBELE, ALBERT.—Hawauan Planters’ Monthly, vol. 15, no. 12, pp. 594-596,
December, 1896.

¢ Swezey, O. H.—Army worms and cutworms on sugar cane in the Hawaiian
Islands. <(Hawaiian Sugar Planters’ Exp. Sta., Div. Ent., Bul. 7, pp. 32, pls. 3,
November, 1909.

@Swezey, O. H.—The Hawaiian sugar cane bud moth (Ereunetis flavistriata)
with anaccountof someallied speciesand naturalenemies. <(Hawaiian Sugar Planters’
Exp. Sta., Div. Ent., Bul. 6, pp. 40, pls. 4, October, 1909.

RATS INJURING SUGAR-CANE. AT

It is usually not particularly injurious as it customarily feeds on the dead and drying
tissues of the leaf-sheaths of sugar cane; but when very numerous and on particularly
soft varieties of cane the caterpillars do considerable eating of the epidermis, and also
eat into the buds and destroy them, occasioning a good deal of loss where the cane is
desired for cuttings to plant.

The grasshoppers Xiphidium varipenne Swezey and Oxya velox Fab.
feed to some extent on the leaves of cane. The former species is also
predatory in habit, attacking the young leafhoppers and the larvee
of the sugar-cane leaf-roller.

Two species of beetles which occasionally invade the cane fields
from their common food plants and attack the leaves of the sugar
cane are Fuller’s rose beetle, Aramigus fullert Horn,* and the Japanese
beetle, Adoretus tenuimaculatus Waterh.°

RATS INJURING GROWING SUGAR CANE IN HAWAII.

The so-called roof-rat (Mus alecandrinus) in former years was
very common in the cane fields of Hawati and did considerable
damage by eating the stalks. This is also the cane-field rat of the
island of Jamaica. The species in Hawaii lives now for the most part
in trees and the upper stories of dwellings, since it has been driven
to a great degree from the cane fields by the introduced mongoose.
The introduction of the mongoose was a benefit as regards its destruc-
tion to the rats in the cane fields, but the animal is an undesirable
acquisition to the fauna of the islands for the reason that in recent
years it has included in its dietary the eggs and young of ground-
nesting birds and domestic fowls. The destruction of the ground-
nesting birds is most regrettable.

a@Van Dine, D. L.—Hawaii Exp. Sta., Press Bul. 14, p. 5, October, 1905.
6 KoEBELE, ALBERT.—Hawaiian Planters’ Monthly, vol. 17, no. 6, pp. 260-264,
June, 1898.

INDEX.

Page
Adonctus tenuimaciiatus, myurious) LO) SUPAT CAMCH. 4c54ce)-22 2 cece a ene 2 eee 47
Adrastidia nebulosa, enemy of Perkinsiella saccharicida............-.-+-.-+--- 28
Agrotis ypsilon, injurious to sugar cane.........---.-- UB ewe any lett ow cs ore 46
Algeroba. (See Prosopis juliflora.)
Anagrus columbi, parasite of Perkinsiella saccharicida........-.-----.------------ 29
frequens, parasite of Perkinstella saccharicida.........-.---+-+-+-+--+--- 31
parasite of Perkinsiella vitiensis. Si oa nee cies Samet ier 30
Anomalochrysa sp., enemy of Perkinsiella pe hona Bes ge Sid pied ye aly Mot 28
MAL ISESU COROT MOLEC NOM COCCINELUG FEDORA = saneiae ines trie sels tele ee ere 45
sugar-cane pest in Hawaiian Tellevorls Bs YA Sep ae Reis cya Ri cat 11, 45
sugar cane. (See Aphis sacchari.)
ARMOGLS Oily Myson Owes Ko) SUKI CNG oe Ada eek sags ae ee oeos Sanaa SHoBee ar 47
NEVA WOLMS MAUI OUS CONS USAT CAMS soem ere puts aati as oo sraa pee ote 46
Arsenate of lead against Hawaiian sugar-cane leaf-roller....................... 42
AsMIdioliscyanopnylle. recorded irom Elawalls 22202922254. e cs ee = ee eens 43
SAECROMCHMS SUCAT-CAMeMCSt AM Vaso. 4. e sees eileia fs Seles 43
sacchor., sucar-came pestaim West Indies: 4) 25.22 .26-...-52--..52- 43
Baiting Hawaiian sugar-cane borer........-:-------- nasa aM ene a Wet ea 39-40
inanana, 100daplamtiofeihabdocnemis. OOSCunus=. 9252-225. 22-1 2 nse one 36
Beekeeping in Hawalian Islands, relation to sugar-cane leafhopper..........- 20-22
Beetle, Japanese. (See Adoretus tenuimaculatus. )
Borer, Hawaiian sugar-cane. (See Rhabdocnemis obscurus.)
Bud moth of sugar cane. (See Hrewnetis flavistriata. )
Durning against, Hawaiam sugar-came bOrer...-2 4... 5.--...-25224 a2 + eee =. ce 39
SUgar-Cane Lean ICH wee ee Vanen nore es 16 | eee ea i ae 22, 23
Ld aC PeW 95] ON es ithe et eee Cae noe AAR ek ee 44-45
Calceolaria, food plant ol Pseudococews calccolamixs-<-.-.-.-- Cen ree oe. aaa 43
Cane-field rat of Jamaica. (See Mus alexandrinus.)
Canica papaya, food plant ot Rhabdocnemis obscurnus. _.2- 22 .).-2-.22+.246--5-- 36
Canjota unens, 100d plamtiot mhabdocnemis obscunus.- 225.45. - 522) eee 36
Caustic soda and lime against sugar-cane leafhopper....................-.-.- 22
lime, and copper sulphate against sugar-cane leathopper ee ae ge 22
Wcentistes americana, parasite ol Coccinellarepanda.-...5.5-+5..-.-----.---.22. 28,45
Chalcis obscurata, parasite of Omiodes accepta and 0. black: homah. Sta MO nat a 43
Changa. (See Scapteriscus didactylus.)
Chelisoches morio, enemy of Perkinsiella saccharicida................-.-.-+----- 32
Clionas pis) sppe sSupar-Came Woests mins davar yaaee nscale ee oc oo. 43
Chrysopa microphya, enemy of Perkinsiella saccharicida..................----- 28
Climateyot Hawaiian Islandsic. erik oe See yee es se aa ce tence = 9
Coccinella repanda, enemy of Aphis sacchari..........-...-. Sa eit eet Cr ae et 45
IPG AMD ING SHEE NOPUCOIIA, LO a ok AA ee oe 28, 32
host of Centistes americana.....-- Se Set OO Corgis meee Bn Vine 28, 45
Collection by nets against sugar-cane leafhopper.............-.....-.-+----+-- 22

49

50 THE SUGAR-CANE INSECTS OF HAWAII.

Page.
Copper sulphate, lime, and caustic soda against sugar-cane leafhopper........ 22
Cordyline australis, food plant of Pseudococcus calceolarix...............-----.- 43
Corn, food plant of Dicranotropis mardiss 5 = ee 34
leafhopper. (See Dicranotropis maidis.)
Crop diversification against sugar-cane leafhopper.-.-.............:..-- Ree 26
Crypiolemus MontrOouUcrerd ne QESCTIP LION. 35 ee eee ee 45
enemy of Pseudococcus calceolariz.............--.- 45
Cultural methods against sugar-cane leafhopper-......-.-........-...........+ 25-26
Cutting and burning against sugar-came leathopper----2-.-.-...2--2-. 2 -* ees
CutwOrms InjUPIOUS tOSUSaT CANC soe 6 ee ae eee ee ce ena 46
Danthonia; -tood- plant of Pseudococcus calecolanie== soe ee 43
Delphax saccharwora on sugar cane in West Indies: = se 295". 522-5 ae 34
Diatrzxa saccharalis, sugar-cane pest, comparison with Rhabdocnemis obscurus... 35-36
Dicranotropis maidis on corn in Southern States... ..-........2-.....:...2..--: 34
vastatrix, Oe ee oe nee a4
Diseases of sugar cane, spread by -Rerkinsiella*saccharicida epee ee 19
Diversification of crops against sugar-cane leafhopper.......-..-.....---.-- 26
Ecthrodelphax fairchildu, parasite of Perkinsiella saccharicida..........--.--- 98, 29, 32
Elenchus; parasite of Perkinstellassaccharicidass== 5 2ssn 9 ee 30
Breunetis jlavistriata, myurious-to;sugar Caner = sss eee 46-47
Eumetopina kriigeri, sugar-cane pest in Java.........---.---- ipeeme so) 34
Frontina archippivora, parasite of Omiodes accepta and O. Sieroter. AER See 48
Fungous diseases of leafhoppers i IM Ha wail 22cces 52 ae See eevee oe ee eee 32-33
enemy of Siphanta acuta and Perkinsiella saccharicida.............-.-- 28
Grass, Hilo. (See Paspalum conjugatum. )
Johnson. (See Sorghum halepense.)
Gryllotalpa africana, injurious tO susar Cane] 22 es see | ee 45-46
Hand destruction against Hawaiian sugar-cane leaf-roller............-.......- 42
picking agaist Hawaiian sugarcane Doret.----- 4-25.54 455 see. 3940
Hawanan Islands, climate and location: 32. < ce ee ee ee eee 9
SUSAT-CANC THSECLS is es eee le a eo see 1147
TMG Ustry s e e eee 9-10
Heliopiiia unipuncta; injurious to susar cane- 22 52 2-8o 5s. - = 46
Honeydew honey in Hawaiian Islands-..--<=2. 222-22 2-5 eso) a ee 21-22
Hypochnus, fungus accompanying injury to sugar cane by Perkinsiella sac-
CATION. se 2S RSE SS Sn a ee 18
Icerya seychellarum, sugar-cane pest in Mauritius..............-....------.--- 43
Insecticides agamst sugar-cane leafhoppers=-<2-22-2 = = ee ee “22
Insects injuring sugar cane in Hawaiian Islands. ---..-..-......---.--.-+---- 1147
Irrigation, excessive, favorable to Hawaiian sugar-cane borer..-....-.--..----- 39
Kerosene emulsion against sugar-cane leafhopper.............-...--..------- 22
Leafhopper, corn. (See Dicranoiropis maidis.)
sugar-cane (see also Perkinsiella saccharicida).
prey of Xvphdium varipenne= 322-3... eee 47
Leafhoppers and their natural enemies, bibliographic reference......-...--.. 29-34
Leaf-roller, Hawaiian sugar-cane (see also Omiodes accepta).
preyed upon by Xiphidiwm varipenne.....-. 47
palm. (See Omiodes blackburni.)
Eecanwum, krugert, sugar-cane pest 1n Javas.s.---<cse + 52 2. oe ee ee 43
Lime and caustic soda against sugar-cane leafhopper...-...-...------------ E 22
copper sulphate, and caustic soda against sugar-cane leafhopper ...-.---- 22
Macrodyctium omiodivorum, parasite of Omiodes accepta and O. blackburni....-. 43

Mealy-bug, sugar-cane. (See Pseudococcus calceolariz.)

INDEX. D1
Page
WEN IEOe ITD, SHPO; COMM) |. od soba e eee canes cas eo ence ese Se aee een rn acoces 27
spread by Hawaiian sugar-cane borer..............-.-- 26-27
Perkinsiellansacchanmeida ==. soe 2525 ee .. 19, 26-27
Metamasius sericeus, sugar-cane pest in West Indies....................-.---- 36
Mole cricket. (See Gryllotalpa africana and Scapteriscus didactylus.)
Miovee Ose sii IBENWEN 252 o.oo RRA eae eee ee abc: Greece eens peeves eee te 47
MiUSAlecOnari nus pny UROWS LO) SUSAT CANCra cee. oe elec ete se ee 47
Natural enemies of injurious insects, importance of introduction into Hawaiian
iss ex ra GS ee Spee eras 8 hg aye ee Seas een ee EEE, SP SS Se eal as 11-12
@icholva griseus, enemysot Perkinsiella saccharicida..---- 5. .+ 52-22-5220. 22- 22: 28
OTmNOdes ACCe PLU COMMOMCASUTES 2 32s ee ee Stee ies eye eee) este! ers ele ates 42
earlvenistoryain Ela watlamel slamd sess a see fesse ec s ee a 41-42
J OWN GR PSh tes se Cpe ee pal eee rare ae els Pan a ee Re 41-42
TiN UI Ta eae eet eee Oa ve ecole re eenis, lM ap a SR lcyeh sl oaralort 41
PORTALS LCS eng seme ee ree ie cee Myth caver Rca ret Te gk 23 eas aero 42-43
sugar-cane pest in Hawaiian Islands............-.-.. 11, 19, 20, 41-43
Blackout ln uIOUeNtO, pallinisi een eee ee i Le ie ee 42
Ootetrastichus beatus, parasite of Perkinsiella saccharicida....-..---.---- Cael see Silas
: DUMENSUSE Brower © Mod ao OER ay oh Res ade 30
Ralm-ecoconut. food: plant ol habdocnemis Obscurus- === 2-6-2450 ee se ee 36
leaf-roller. (See Omiodes blackburn.)
TOV Al arOOd: PlamtirOl iiWodOChemUs OOSCUNUS 252-224-545 255 see eee 36
Savon 1OOdsplamt Olea DdOCMeMIUSHOUSCUMUS= = amen: sah eins see ae 5 eee 36
wine. (See Caryota urens.)
alimnic stoods planitsror Omrodes: OlackOUinVarsaa sete ee a nes Se ee 42
Papaia. (See Carica papaya.)
Paranagrus optabilis, parasite of Perkinsiella saccharicida.........---.--------- Bil
OALASICCR OL MICTICUIESUCLUG VOLIEISIS= sam iae te ao) ee oe Sea ne 30
perforator, parasite of Perkinsiella saccharicida..........-...-..-.-- 31
Earaplelimus, parasiterot <ophidiwm varypenne -222--.2..2..22.-.5..).22..2.- 32
Parasitic enemies of injurious insects, importance of introduction into Hawaiian
cena Spee ty eterna ae in a PRE te eee si nk ia So Siege gh yo. lt tk eepatn ees 11-12
Paris green against Hawaiian sugar-cane leaf-roller....................-..-..- 42
LUspanimrconjugaviney 1ood plant of Omiodesjaccepta = 2. 2.12 one an2 8.5) e- 41
J ACHRUNSICLLOMGESCHIp OM Of memis =. a2. to) alae. 2s eGo ee eee cs ee 13
saccharicida, appearance in Hawaiian Islands..................-- 12-13
COMET Opera yale Ase mnny eee taue, | eA a eine i A 22-28
GESEIIP TOM sac eee el res Oe 13-14
GISWERSIOI tes ry Pas earn eos Meee tS eee 14
GIStri ONE eT ea a ees See os AU ae pao gS ee eee 12
factors responsible for outbreak of 1903... ... pee ee 20
MUMS OUSCISEASO sar west Pets See ee eS seep Bee 28
) IY ODER eA Se Rae ret aa AR sites ea OE 15-18
UY UTA SO KEM eae mm et mete he te hry nh ee 19
torcane scharactenseee wae mech o 1) Serer 18-19
Vay] Ta SOE es aa a ca ee 15-18
MAGUTVIRCME MA CSE tae eet er ean eee Ke He 28-34
KOLA CES WCCLES a Ce ry ise eRe ee et he EL 34
Kelanoneroupeckecepimnosen eaten. 6 wa). Lr (oss. 20-22
sugar-cane pest in Hawaiian Islands.............. 11,,12-34
OUMEISIS OATS LE DES os SS aE es ca ie OR Ec 30

Phenice maculosa, sugar-cane pest in Java
Phormium tenax, food plant of Pseudococcus calceolariv.............2..---- ae 43

—

,
|
¢

De THE SUGAR-CANE INSECTS OF HAWATI.

Pineapple disease of sugar cane. (See Thielaviopsis ethaceticus.) Page.
Pipunculus juvator, parasite of Perkinsiella saccharicida-...-.-.....-.....------ 32
lerryi, Parasite Ob Perkinsiella soccharicida-- = 0.2 se 32
Platyomus lividigaster, enemy of Perkinsiella saccharicida .............-.------ 28 |
Predaceous enemies of injurious insects, importance of introduction into —
Hawatian Islands: <2: see ots ste ens ee 11-12
Prosopis juliflora, honey plant in Hawaiian Islands.......................--- 21 |
iP SCUAOCOCEUS COLCEOLOFED © COMMON 2. 52 oo ee 44-45 |
food plants 22-2 hese en ee ee ee ee 43-44
abuts 2/225 Sis Ss Soe eee ee 44 .
identity: 25 520 Oe ee gen ee 43 :
life history. 225 42502. ee ee 44
natural enemies ....._...- She cee ee 2 es eee 45
related: SPeCles* 3255 5a5 ees sk 2 epee eee eee 43 ;
sugar-cane pest in Hawaiian Islands. -.....--....- 11, 43-45
West: bndiéer a= =. Sage eee 43
saccharz, recorded: trom’ Ha wait os se ee ee ee 43 |
sugar-cane pest in West Indies. ---..-..--- Sa sre yy 43
sp., near calceolariz, sugar-cane pest In Java_.....--...--------- 43 |
iPulwinarua iceryl, Sugar-cane pest m-Mauriituss..2- 2-222) see 8 43 ;
Ramiall of Hawanan ‘Islands: 5242 soso ee ee ee ee 9
Rais murine Subar Cane. = 5 5 he ee Se rs ee ee 47
iehabdocnemts OUScuTUus: ECONO! MEASUFES. 5) ee ee ee 39-40
distibttion e229 2 a, Gi ee es oe eee 36 .
food: planiseuse 755 ae ee ae Se eee 36
general charicteristiGs: =. > = a ee ee 39-36
halbitss.. < S26 he Sat 37-38
life Wistory.2. = 222 Se Se ee eee 37-38
OCCUFFENCE In Ha wail). 12 2 ee ee ee 36
related species! 222.555: 2a 25> Se ee ee eee 40
sugar-cane pest in Hawalian Islands..-.-..--- 11, 19, 20, 35-40

|

Rind disease of sugar-cane. (See Melanconium sacchari.)
Rooi-rat. (See Mus alexandrinus.) :
_» Rose beetle, Fuller’s. (See Aramigus fulleri.)

'¥ Scapteriseus didactylus, injurious to sugar cane..........----------------+----- 4546
Seed cane, noninfested, selection as preventive against Hawaiian sugar-cane

DOLer 22. tees 39

sugar-cane mealy-

bigs eae 44

Siphania acuta, attacked by fungous disease. ..........-.------------2---.- 28

Smut, black, of sugar cane, accompanying injury by Perkinsiella saccharicida. . 18

Solsio: Hawatdn Islands.222 ee: se ee Oe ee Sie eee 9

Sorghum halepense, food plant of Pseudococcus calceolarix..........-.--------- 44
Sphzronema, fungus resembling species of this genus accompanying injury by

Perkinsvella saccharigda On. CIN 32 ese 2 ns Be oe ee 18

Sphenophorus obscurus. (See Rhabdocnemis obscurus.)
sericeus. (See Metamasius sericeus.)

sexguttatus, sugar-cane pest in Porto Rico..............-------- 36
Spodoptera mauritia; injurious to'sugar Canes_... =. 22-2... 2 ee 46

Stalk-borer, sugar-cane. (See Diatrxa saccharalis.)
Stripping leaves against sugar-cane leafhopper. .--.....--------------------- 23

INDEX. 58

Sugar cane aphis. (See A phis sacchari.) Page.
borer, Hawaiian. (See Rhabdocnemis obscurus.)
bud moth. (See Ereunetis flavistriata. )
Gamage Dyes OlChO NONI US same eerete cies) l=. 21a) = a a Sees 47
diseases, spread by Perkinsiella saccharicida........-.....---------- 19
food plamtiot Adorctus tenuimaculatws: -.-- 2-2-2222 22.- 22-222 ---- 47
PAGE OLUSU) SULOM Geter en ee Seen ee a caste 46
VAUDIISESACCHGI er pre ee Ae ee od eS os se See ela 11, 45
PARC TIUUG AES: URUUCTE UR a creer eres Crs ee nt! SAO coh eid 47
A SININOHIS SUCO UHM Sido coouts Shc eeceteeo ees nase Oe 43
SOCCHOTUCUIUS a marian) (2 <i Joe ec eae 43
OMNGONGSPUSISD Disses one t See Cok oe 43
IDA NYO SKI NT PUUOTUA oemn as age sso beeeeaan esses 34
Diatrea saccharalis..-. 22-2. Se rs ci ee OE ee 36
DNCRAMOURODISUASUAUIIT Sere = er tan payee ee 34
J OUALS JOC T UD ote Ba as Bs oe ee Eee 46-47
TELUMIVCLO [UMUC CNT CRU ee mate eam, ear ee eerie 34 A
Grilotal pana miCand tn eel te eee ea.) Se ee 45-46 f
AO UID WG UMC eco os 55a5ssdaus6e5se os e8uaas5 s5 46
cemuanscu Chel aii Niananen aya nee or eee 43 i
ME CCUM UUM TET UEG Chad aye iach eee red eae A cafes she, Ue 43
IVC EOIUGS ULES S CHU CUSO waar ani we <r h Nay a) at yee ea) a 36
Omiodesacce pias ana ee ie ge ce 11, 19, 20, 41-43
JAG EODSVANIO. SUCO MUCUS se Oooo oe eee ese ee soes 11, 12-34
UR IVCN IU CCRNUUCULO SO a ena at Me et A ye eon lye eet ee on Ue anne 34
WIS CUAOCOCEUUSKCCLC COATING aye et ae eee ce ger 11, 48-45
SOCCIUGI treat Ce Pg Miia eye cs. i ae Sy aan 43
Sen Weak CalccOlaniaoe ama cle ts a. te tees 43
I US HOU DON VOU CT OAS SE cee y ae eee ee es ae Soe 43
RNGOdOCMENLUS OOSCUNUS == 2 455 fie te 11, 19, 20; 35-40
IS COD UCIISCUSIQLOCELYL USmrenin Stl a nee Weiee seiete yam ne 45-46
SPILEOP LOTUS ySCLOQUELOUUS se eee See ese a ee 36
IS DOU OM UCHOMIUAUTULUE ee te ea tees ee ey Em ae es yee 46 |
MNSeCis) Olpblawearulame lishing. ce See eS ik ay Ser cee eee 11-47
leafhopper (see also Perkinstella saccharicida).
preyed upon by Xtphidium varipenne......----....--- 47

Fijian. (See Perkinsiella vitiensis.)
leaf-roller, Hawaiian (see also Omiodes accepta).

preyed upon by Xiphidium varipenne................-- 47
mealy-bug. (See Pseudococcus calceolarix.)
pineapple disease. (See Thielaviopsis ethaceticus.)

rind disease. (See Melanconium sacchari.)

stalk-borer. (See Diatrxa saccharalis.)
Yellow Caledonia, resistant to leafhopper attack................... 23-25
sugar-cane borer, Hawaiian......... 39 |
varieties and their relative resistance to leafhopper attack......... 23-25
least injured by Hawaiian sugar-cane borer.............. 39
INCMUStRVeIMy a walianelslaG smerny heh los eee ee ee 9-10
hemiperacureOisklawallamgis lam Csr ye eg si et ai rene hens to ST 9
Tetragnatha mandibulata, enemy of Perkinsiella saccharicida................--- 28
Thielaviopsis ethaceticus, spread by Perkinsiella saccharicida...............----- 19

rap bavtacainst: Hawallan suoar-came boren- 2222-222. 52c+o.2+20eness-e oe 39-40

54 . THE SUGAR-CANE INSECTS OF HAWAII.

Trichogramma pretiosa, parasite of Omiodes accepta and O. blackburni........-.-

Verania strigula, enemy of Perkinsiella saccharicida..............--..----.-----
Xiphidium varipenne, enemy oi Perkinstella saccharicida..........---..--.----
sugar-cane leafhopper and _ sugar-cane leaf-

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OllSUgar Cane ss .c. cece te eee te es 5
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