The Great Basin naturalist

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The Great Basin Naturalist

VOLUME XXIII, 1963

Editor: Vasco M. Tanner

Assistant Editor: Stephen L. Wood

Assistant Editor: Wilmer W. Tanner

Published at Provo, Utah, by
Brigham Young University

. ^TABLE OF CONTENTS

^ /6 b c(

Volume XXIII

NUMBERS 1-2 — JUNE 14, 1963

A Revision of the Bark Beetle Genus Dendroctonus Erichson
(Coleoptera: Scolytidae) Illustrated. By Stephen L.
Wood

NUMBERS 3-4 — DECEMBER 16, 1963

A Survey of the Herpetofauna of the Death Valley Area.

By Frederick B. Turner and Roland H. Wauer -.

The Systematics of Crotaphyius Wislizeni, the Leopard

Lizards. Part I. Illustrated. By Wilmer W. Tanner and

Benjamin H. Banta -.

New Lacebugs from the Eastern Hemisphere. Illustrated.

By Carl J. Drake -.

Undescribed Species of Nearctic Tipulidae (Diptera). By

Charles P. Alexander

Scissor-Tailed Flycatcher in Death Valley, California.

By Roland H. Wauer

New Distributional and Host Data for the Tick Derma-

centor hunteri Bishopp. By Elias P. Brinton and

Glen M. Kohls

A New Species of Craniotus (Coleoptera: Tenebrionidae).

Illustrated. By Vasco M. Tanner

Index

II

ureal Bastn

Volume XXni

June 14, 1963

TABLE OF CONTENTS

LIBRARY

AUe 1 8 1966

UNIVERSITY

•^L.

A Revision of the Bark Beetle Genus Dendroctonus Erichson

(Coleoptera: Scolytidae) Illustrated. By Stephen L. Wood 1

Index 1 1 7

Published by
Brigham Young University

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The Great Basin Naturalist

Published at Provo, Utah by
Brigham Young University

Volume XXIII June 14, 1963 ' Jj'^^^^^ljS^

AUG 1 8 1966

hMrxvMrXLJ

A REVISION OF THE BARK BEETLE GENUS ^ SIT Y
DENDROCTONUS ERICHSON
(COLEOPTERA: SCOLYTIDAE)^

Stephen L. Wood'

Abstract

This taxonomic revision of all known species of Dendroctonus
is based on an analysis of anatomical and biological characters.
Among the anatomical structures found to be of greatest use in char-
acterizing species were the seminal rod of the male genital capsule,
the surface features of the frons, and the features of the elytral
declivity. Characters of the egg gallery, position and arrangement
of egg niches and grooves, and the character and position of the
larval mines provided features for field recognition of species that
were equal to, if not superior to, anatomical characters.

Following the general discussion and key each of the fourteen
species recognized is treated separately, including a synonymy with
an extensive list of references, anatomical description of the adult
male and female, type locality, hosts, distribution and a description
of the life history and galleries. Figures of anatomical parts, gallery
systems and geographical distributions are included.

The species treated and their synonymy were: (1) brevicomis
Leconte {^barberi Hopkins); (2) frontalis Zimmerman (=ariz-
onicus Hopkins, mexicanus Hopkins); (3) parallelocollis Chapuis
{^approximatus Dietz) ; (4) adjunctus Blandford (^convexi frons
Hopkins); (5) ponderosae Hopkins (:=monticolae Hopkins, jeffreyi
Hopkins); (6) aztecus Wood, new species; (7) terebrans (Olivier);
(8) valens Leconte (=:^^c^^n Thatcher); (9) micans (Kugelann);
(10) punctatus Leconte {-r^iohanseni Swaine) ; (11) murrayanae
Hopkins (=rufipennis Hopkins, nee. Kirby) ; (12) obesus (Man-
nerheim) {=zrufipennis Kirby, similis Leconte, piceaperda Hopkins,
engelmanni Hopkins, borealis Hopkins); (13) simplex Leconte;
(14) pseudotsugae Hopkins.

^This study was supported by a research grant from the National Science Foxindation, number
B-6532.

^Zoology and Entomology Department. Brigham Young University, Provo, Utah. Scolytoidea
contribution no. 24.

The Great Basin Naturalist
2 STEPHEN L. WOOD Vol. XXIII, Nos. 1-2

Introduction

The genus Dendroctonus consists of thirteen American species
that range throughout the coniferous forests from Guatemala to the
northern limits of tree growth in Canada and Alaska, and one Eur-
asian species that inhabits spruce forests from northern France to
Siberia. All species infest coniferous hosts, principally representa-
tives of the genera Pinus, Picea, Pseudotsuga and Larix, where
their aggressiveness has marked them as the greatest tree killers
known. Fantastic losses of standing timber resources, conservatively
estimated as averaging more than five billion board feet annually,
have resulted from epidemics of these insects.

All species in the genus bore in the inner bark of the bole of the
host where they feed primarily upon the phloem tissue. They gen-
erally attack only living trees larger than about eight inches in
diameter, either standing or prostrate, that have been weakened by
age, drought, or other ecological factors; however, vigorous, healthy
trees are not immune from attack, particularly during an epidemic.
Their success in overcoming a tree is partly due to their gregarious
nature, and partly to their association wdth blue-stain fungi and
yeast organisms which interfere with normal physiology of the host
thereby assuring success of the bark beetle attack. All fourteen
species, with the possible exception of aztecus, are wddely distributed
geographically but are rather limited in host range. All species,
with the. possible exception of pseudotsugae and valens, confine their
attacks to a single genus of host tree, and usually to a limited group
of species within that genus, except during epidemic outbreaks when
almost any conifer may exhibit signs of attack.

History

As originally described by Erichson (1836:52), the genus Den-
droctonus included five species listed in the following order: (1)
Bostrichus micans Kugelann, (2) Scaly tus terebrans Olivier, (3)
Dermestes piniperda Linnaeus, (4) Hylesinus minor Hartig, and
(5) Hylesinus minimus Fabricius withdut the designation of a type
species. Later, Eichhoff (1864:25) divided the group and described
the genus Blastophagus for Dermestes piniperda Linnaeus and Hyle-
sinus minor Hartig, and the genus Carphoborus (Elichhoff 1864:27)
for Hylesinus minimus Fabricius. Since that date there has been no
question concerning the identity or validity of the name Dendroc-
tonus and no synonyms or subgenera have been described. Every-
one treating this genus since its description, however, has over-
looked the fact that Westwood (1838:39) designated Dermestes
piniperda Linnaeus as the type species of the genus Dendroctonus
just two years after its description. Hopkins' (1909:5) designation
of Bostrichus micans Kugelann as the types species is, therefore,
technically invalid.

Latreille (1802:203) described the monobasic genus Tomicus
with Hylesinus piniperda Fabricius, which by definition (Fabricius,

June 14, 1963 revision of dendroctonus 3

1801:392) was Dermestes piniperda Linnaeus, as the type species.
Because of an unfortunate error in identification, Latreille's name
Tomicus became associated with another genus {Ips DeGeer) for
approximately a hundred years before the error was detected, but
the correct usage of Latreille's name was never restored by European
writers. Meanwhile, Dermestes piniperda Linnaeus was designated
as the type species of Dendroctonus Erichson (1836) by Westwood
{loc. cit.), of Blastophagus Eichhoff (1864) (nee. Blastophagus Gra-
venhorst, 1827, or Blastophaga Gravenhorst, 1829, order Hymen-
optera), by Lacordaire (1866:360), and of Myelophilus Eichhoff
(1878:400) (nee. Myelophila Treitschke, 1835, order Lepidoptera).
Since all four genera have, by definition or subsequent assignment,
Dermestes piniperda Linnaeus as the type species, they are objective
synonyms of one another with Tomicus Latreille having priority by
at least 34 years.

By strict application of the Law of Priority the name Den-
droctonus is unavailable for use in designating the genus to which
Bostrichus micans and its allies belong. However, because of its un-
questioned, consistent usage for more than a hundred years, because
of the voluminous published literature concerning it, because of
the tremendous economical and biological importance of the species
involved, and because the original generic description applies to mi-
cans, the first species listed by Erichson (with a five-segmented
antennal funicle), and not to piniperda, the third species listed (with
a six-segmented funicle), an appeal was made to the International
Commission on Zoological Nomenclature (Wood, 1961) to exercise
its plenary powers in order to conserve the name Dendroctonus
Ericnson, with Bostrichus micans Kugelann as the type species as
designated by Hopkins (1909:5), and to invalidate Westwood's {loc.
cit.) type designation of Dermestes piniperda Linnaeus. The recom-
mended action has now been taken that permanently fixes the
name Dendroctonus to the genus treated here, wdth Bostrichus mic-
ans Kugelann as its type (Opinions and Declarations Rendered by
the International Commission on Zoological Nomenclature, Opinion
No. 670, in press).

To Bostrichus micans and Scolytus terebrans that were included
in the original diagnosis of the genus by Erichson, Zimmerman
(1868:149) added his new species frontalis, and also cited terebrans.
Leconte (1860:59) described valens and similis as new species, then
later (1868:173) added Hylurgus obesus Mannerheim, Hylurgus
rufipennis Kirby and described as new punctatus and simplex; he
also listed frontalis and mentioned valens as a synonym of terebrans.
Chapuis (1869:34) recognized micans, valens, obesus and terebrans,
and described parallocollis as new. Leconte (1876:384-386) listed
terebrans (^valens), similis, rufipennis (:=obesus), punctatus, sim-
plex, frontalis and a new species brevicomis. Dietz (1890) recog-
nized terebrans, rufipennis (=:similis). simplex, and frontalis
(=brevicomis) and described approximatus as new to the genus.
Blandford (1897:146-147) recognized terebrans {^valens), parallel-
ocollis, approximatus, and his new adjunctus. In many, if not most

The Great Basin Naturalist
4 STEPHEN L. WOOD Vol. XXIII, NoS. 1-2

of the above citations the specimens under consideration by the
various authors did not belong to the species named, and each
writer in attempting to clarify the classification of Dendroctonus
only added to the confusion of species.

In a series of papers published between 1892 and 1909, and
summarized in his monumental monograph of the genus, Hopkins
(1909) presented a new classification in which he added as new
the names barberi, convexifrons, arizonicus, mexicanus, monticolae,
ponderosae, jeffreyi, pseudotsugae, piceaperda, engelmanni, borealis
and murrayanae. He also recognized as valid the previously des-
cribed species brevicomis, frontalis, parallelocollis, approximatus,
simplex, obesus (=similis)^ rufipennis, punctatus, micans, terebrans,
valens and adjunctus.

Alterations in the genus since the monograph by Hopkins in-
clude the addition of two names, johanseni by Swaine (1919:5E)
and beckeri by Thatcher (1954:4), and the placement of approxi-
matus as a synonym of parallelocollis by Schedl (1955:11), and of
beckeri as a synonym of valens by Schedl (1955:15).

Discussion of Morphological Characters

General features. — Although characteristic of the various species
in a general way, body size could be used only in conjunction with
other characters because the smallest specimens of the largest species
{valens) were almost as small as the largest specimens of the small-
est species {frontalis). Body form ranged from moderately stout to
rather slender, but differences were too slight and individual vari-
ation too great to distinguish between any but the extremes of body
form. Mature body color was very characteristic of groups of species;
for example, the first seven species listed in the key were uniformly
black (or very dark brown), valens was a distinctive reddish brown,
micans and punctatus a rather dark brown, and the last four species
listed were very dark brown with much lighter reddish brown ely-
tra. The vestiture was characteristic of one species only, brevicomis,
where it was uniformly short.

Head. — The general surface sculpturing of the facial region was
of extreme value and provided perhaps the most reliable external
characters in establishing a workable classification of the genus. In
general, the facial region is convex from the slightly elevated, smooth
epistomal margin to the vertex, with a conspicuous epistomal pro-
cess developed immediately above and overlapping the median
portion of the elevated rim of the epistomal margin.

The epistomal process varied in width from a distance equal to
one-fourth to one-half the distance between the eyes, with the lat-
eral margins oblique and diverging from its horizontal apical por-
tion towards its base by an angle as small as 20° in males of valens
(Fig. 15) to one exceeding 80° in pseudotsugae (Fig. 23). In aztecus,
micans, simplex and pseudotsugae the process was either transverse-
ly convex or flat with the lateral margins rather sharply rounded.

June 14, 1963

REVISION OF DENDROCTONUS

3 FRONTALIS Q

4 FRONTALIS CT

10. PARALLELDCOLLIS Cf

Figs. 1-4, 7-8. Cephalic aspect of head of Dendroctonus spp.: 1, brevicomis
9 ; 2, brevicomis $ ; 3, frontalis 9 ; 4, frontalis $ ; 7, parallelocollis 9 ; 8, par-
allelocollis $ .

Figs. 5-6, 9-10. Lateral aspect of head and prothorax of Dendroctonus
spp.; 5, frontalis 9; 6. frontalis $ : 9. parallelocollis 9 ; 10, parallelocollis $.

The Great Basin Naturalist
6 STEPHEN L. WOOD Vol. XXIII, Nos. 1-2

In all other species the lateral arms were variously elevated thereby
making the process transversely concave. In almost every species
the epistomal process was somewhat wider with the lateral margins
or arms, if elevated at all, more prominently elevated in the males
than in the females. It should be emphasized that considerable in-
dividual variation in the size and shape of the epistomal process
was apparent and could often be used with confidence only in
combination with other characters.

The general contour of the facial region exhibited several con-
sistent and reliable secondary sexual and interspecific variations.
For example, in brevicomis, frontalis, parallelocotlis and adjunctus
(Figs. 1-12) a conspicuous median frontal groove below the upper
level of the eyes was present with the areas lateral to it rather con-
spicuously elevated; both the groove and the elevations were more
highly developed in the male than in the female. In the males of
these species, except in adjunctus, the lateral elevations bear one or
two dorsomedially directed, enlarged, almost hornlike tubercles. In
valens (Fig. 16) and, to a lesser degree, in terebrans the female has
a small median region elevated at the upper level of the eyes. In
punctatus, micans and murrayanae there is a feeble median groove
which on the lower third of the frons becomes a more or less defin-
ite median carina. In ponder osae there are remnants of a median
groove at the upper level of the eyes and also on the lower half of the
irons; in aztecus there is often a comparable, almost scarlike rem-
nant of this impression on the lower half of the frons. In perhaps the
majority of species the surface sculpturing, such as punctures and
granules, appeared to be very slightly coarser in the female than in
the male. In punctatus, micans, murrayanae and obesus (Figs. 18-21)
the most minute details of surface features, the relative numbers of
punctures and granules, offer the only really reliable method of
separating species without resorting to dissection of the male genital
capsule.

The eyes varied conspicuously in the genus from short and oval
to long and slender. As illustrated by Hopkins (1909, fig. 15), how-
ever, the variation between individuals of the same species is so great
that use of the eyes in classification at the species level is virtually
impossible. The antennae are also exceedingly variable within a
species and, consequently, were not utilized in this classification;
this infraspecific variation probably was due more to variation in
the way museum specimens dried than to variation in basic struc-
ture.

Prothorax. — The outline of the pronotum as seen from the dor-
sal aspect, although somewhat variable, offers useful characters in
classification when used in combination with other features. The
basal margin is somewhat bisinuate in all species; the lateral mar-
gins are arcuate to varying degrees in the different species and
usually more or less converging anteriorly. In aztecus (Fig. 25) the
transverse constriction just behind the shallowly emarginate an-
terior margin (Figs. 6, 10) is scarcely visible; in females of brevi-

June 14. 1963

REVISION OF DENDROCTONUS

16. VALENS 9

17 VALENS 9

Figs. 11-16. Cephalic aspect of head of Dendroctonus spp.; 11. adjunctus $ :
12, adjunctus 9; 13. ponder osae $; 14, terebrans 9; 15, valens 5; 16,
ualens 9 .

Fig. 17. Dorsal aspect of head and prothorax of Dendroctonus valens 9.

The Great Basin Naturalist
8 STEPHEN L. WOOD Vol. XXIII, NoS. 1-2

comis, frontalis (Fig. 5), parallelocollis (Fig. 9) and adjunctus the
constriction is largely filled by an elevated callus; in the last nine
species listed in the key the constriction is rather well developed.

The punctures on the disc of the pronotum vary considerably,
both intra- and interspecifically. Because of their variability they
were used only sparingly in separating species, this is in contrast to
the great emphasis given pronotal punctures by Hopkins (1909:11,
etc. ) . The proepisternal areas vary from punctured with very minute
granules to rather coarsely granulate with the punctures almost
entirely obliterated. Use of proepisternal characters was made only
once in the key, with some reluctance, since the characters are
seen with some difficulty unless the proper lighting conditions are
employed.

Elytra. — The basic proportions of the elytra vary slightly, but
do not reflect characters of value. There also is an increase in the
average number of marginal crenulations at the base of each ely-
tron from nine to twelve in the genus. This may have evolutionary
significance, but appears too slight and too unreliable to use in di-
agnosing species.

The elytral striae and interstriae are of considerable value in
recognizing species if used with sufficient caution. The interstriae
vary from about equal width to more than twice the width of the
striae. The striae and strial punctures vary somewhat in depth, but
this feature is rather unreliable since lighting conditions may com-
pletely change the appearance of this character. The sculpturing
of interspaces is rather variable within the genus and usually
provides reliable characters for species diagnosis. In only one species,
simplex, were simple, non-granulate interstrial punctures apparent
on the disc. In aztecus some of the transverse crenulations on the
disc were so coarse and long that they extended across striae and
interstriae alike; in most of the species these crenulations varied
within definite limits and were very useful when used with other
characters in determining species.

Although conservatively sculptured the characters of the elytral
declivity are, in many cases, the most easily observed and reliable
external features available for the diagnosis of species. In brevicomis
and frontalis (Figs. 27, 28) the second striae are straight and the
second interspace is as wide as one and three; in simplex and pseu-
dotsugae the second interspace is gradually narrowed and on at
least the lower half is narrower than one or three; in all other spe-
cies the second striae curve toward the suture at least near the ely-
tral apex, causing an abrupt tapering of interspace two on less than
the lower fourth of the declivity (Figs. 29, 30). Interspace two is
at least shallowly impressed except in frontalis, aztecus, murray-
anae, punctatus and micans; the first interspace is very strongly
elevated in simplex and pseudotsugae, and rather weakly to not at
all raised in the other species. The size of strial punctures and the
sculpture of interspaces on the declivity usually are characteristic
of species and offer excellent characters for diagnosis. In obesus.

June 14, 1963 revision of dendrocton us

18 PUNCTATUS

19 MURRAYANAE Q

20 OBESUS 9

21 MICANS 9

22 SIMPLEX d' ^^- '^^'-'DOTSUGAE (f

25. AZTEOJS 9

24. AZTECUS 9

26. AZTECUS 9

Figs. 18-24. Cephalic aspect of head of Dendroctonus spp.: 18. punctatus 9;
19, murrayanae ?; 20, obesus 9 ; 21, m/caw 9; 22, simplex 5; 23, pseudot-
sugae $ ; 24, aztecus 9 .

Figs. 25-26. Head and prothorax of Dendroctonus aztecus: 25, dorsal aspect;
26, lateral aspect.

The Great Basin Naturalist
10 STEPHEN L. WOOD Vol. XXIII, Nos. 1-2

murrayanae, simplex, pseudotsugae, and to a lesser extent in other
related species, the interstrial granules on the declivity were greatly
reduced or absent in the male, thereby providing a convenient, al-
though not entirely reliable, means of distinguishing the sexes.

Legs. — The legs are rather characteristic of the genus, but pres-
ent no consistent variations of sufficient magnitude to be useful in
classification.

Male genitalia. — Although not suitable for rapid field identifica-
tion, the characters of the genitalic capsule of the male (Figs. 31-42)
included, in several cases, the only truly dependable method for
recognizing species. When this study was initiated it was considered
virtually impossible to separate murrayanae, obesus, micans and
punctatus or to find sufficiently reliable evidence to place some of
Hopkins' names in synonymy, because of the apparently tremen-
dous individual variation involved, until genitalic characters were
studied. When this was done the seemingly incomprehensible mass
of variation fell into orderly patterns and very minute characters,
particularly on the frons and declivity, which had been meaning-
less before, became useful and reliable means of diagnosing diffi-
cult species. The structure having taxonomic value was designated
by Hopkins (1915:118) as the seminal rod.

Generic features. — Of the genera known to the writer, Tomicus,
Hylurgus, Pachycotes and Hylurgonotus appear to be more closely
allied to Dendroctonus than others. They share the symmetrical,
more or less flattened antennal club; the finely faceted, entire eye;
the absence of a presternal ridge between the coxae and the anterior
margin of the prothorax; the bilobed third tarsal segments; the
hairlike vestiture; and many other characters. In Pachycotes and
Hylurgonotus (brunneus only) a distinct, though poorly developed
epistomal process is evident, but both have the posterolateral ridge
extending along the mandible acutely elevated; the other genera
lack both characters, although the mandibular modification is ap-
parent in Hylurgus. The male frons is noticeably impressed
above in Pachycotes, Hylurgonotus and Hylurgus, almost imper-
ceptibly so in Tomicus, and not all impressed in most Dendroctonus.

Discussion of Biology

Biology. — All species of Dendroctonus may pass the winter in
almost any stage of development, however, some species are repre-
sented by a preponderance of one stage. In adjunctus and pondero-
sae the larval stage predominates, and in simplex, pseudotsugae,
terebrans and perhaps valens the adult is the principal overwinter-
ing stage. In the other species one stage may be represented more
commonly in hibernation than another, but not as disproportionately
as those mentioned.

Flight activity for most species begins in the spring whenever
daytime temperatures reach about 45° to 50°F., usually about
April or May, and continues more or less without interruption until

June 14, 1963

REVISION OF DENDROCTONllS

11

30. VALENS §

Figs. 27-30. Dorsolateral aspect of elytral declivity of Dendroctonus spp.
27, brevicomis; 28, frontalis; 29, terebrans $ ; 30, valens 9 .

The Great Basin Naturalist
12 STEPHEN L. WOOD Vol. XXIII, Nos. 1-2

late September or October. There are, however, conspicuous periods
of increased flight activity that correspond with the emergence of
overwintered young adults and of each new generation during
the summer months. A notable departure from this usual pattern
occurs in ponderosae where emergence ordinarily does not begin
before late July and subsides by mid-September.

All species may, on occasion, attack standing, vigorous trees.
Under normal endemic conditions, however, some species, noteably
parallelocollis, valens, terebrans, murrcnyanae, micans, punctatus,
obesus, simplex and pseudotsugae, prefer stumps or prostrate trees
or logs. Others, such as bervicomis, frontalis, aajunctus, ponderosae,
and possibly aztecus, seldom are found anywhere except in standing
trees. Under endemic conditions the standing trees selected for
attack ordinarily are either overmature, unthrifty, or weakened
by disease, lightning, drought or other factors.

The pattern of attack on a particular standing tree usually is
characteristic of the species. For example, parallelocollis, valens,
terebrans, murrayanae, and possibly punctatus and aztecus ordin-
arily confine their attacks to the basal portion of the tree, seldom
striKing higher than two or three feet above the ground level. In
adjunctus, micans, obesus and ponderosae (except on mature large
trees) the attacks begins on the lower third of the bole and prog-
resses upward; in brevicomis, frontalis, pseudotsugae, possibly sim-
plex, and ponderosae (at least in overmature sugar pine) the attack
begins in the upper midbole area and progresses upward and down-
ward from that point. The attack, depending on tne beetle popula-
tion in a given area, may be concentrated into a few days, or it may
extend over more than a year and involve two or more successive
generations in some species if competing species do not occupy
the available bark.

The individual attack is made by the female usually in a crevice
of the bark. When the inner bark is reached and resin ducts are
severed the tunnel may be invaded by quantities of pitch that must
be removed as the burrow advances. The ability of the female to cope
with this material is remarkable. The pitch and frass resulting from
the excavation are pushed out of the entrance hole where they ad-
here to the bark forming a characteristic pitch tube. The presence of
these pitch tubes or scattered frass ordinarily is the first indication
that the tree is under attack. The size, color and general character
of the pitch tubes may indicate the species of beetle making the
attack.

Normally, about the time or shortly after the female reaches
the phloem tissues she is joined by a male. If the male does not
appear the gallery may be advanced, complete wdth egg niches or
grooves until he does arrive, or it may be abandoned and a new
attack started. Mating evidently first occurs within a few hours
after the phloem tissues are reached; it evidently occurs in the first
two or three centimeters of gallery where the gallery is shaped dif-
ferently and wide enough to permit mating. Mating evidently oc-

June 14, 1963

REVISION OF DENDROCTONUS

13

40 OBESUS

41 SIMPLEX

42 PSEUDOTSUGAE

Fig. 31. Dorsal aspect of male genital capsule of Dendroctonus brevicomis
vith the internal position of the seminal rod indicated (posterior end up).
i± Figs. 32-42 Seminal rod of Dendroctonus spp.: 32, brevicomis; 33, frontalis;
+, parallelocollis; 35, adjunctus. 36, ponderosae; 37, valens; 38, terebrans;
iy. murrayanae; 40, obesus; 41, simplex; 42, pseudotsugae

The Great Basin Naturalist
14 STEPHEN L. WOOD Vol. XXIII, Nos. 1-2

curs repeatedly, since during this study it was observed in five spe-
cies in galleries more than half complete. Following mating the male
may abandon the gallery in search of another female, but more
commonly he remains and takes over the function of removing frass
and pitch from the tunnel, thereby permitting the female to con-
centrate on extension of the gallery and egg deposition. After the
gallery is fairly well advanced the frass is packed in the lower or
older regions of the gallery thereby closing the entrance tunnel. At
any time during the development of the gallery the male may
abandon the gallery by extending a ventilation tunnel, or he may
remain until death. The female also may remain until death, or
she may emerge from the completed gallery and make a second or
even a third attack.

There is considerable variation in the character of the egg gal-
leries among the various species of Dendroctonus. All are formed in
the phloem tissues and scarcely, if at all, engrave the wood. In gen-
eral they are more or less straight, linear, and follow the grain of
the wood; however, in brevicomis, frontalis, parallelocollis, and
adjunctus (Figs. 46, 47, 49, 51) they are strongly sinuate. In brevi-
comis the total lateral displacement^ of a gallery usually is equal
to or greater than the total longitudinal displacement; the whole
complex forms an intertwining network of winding, branching
galleries (Fig. 43). In frontalis the pattern is very similar to that
of brevicomis, except that the total longitudinal displacement of
one gallery usually exceeds its lateral displacement. Basically the
galleries of parallelocollis are sinuate, forming a coarse branching
and anastomosing criss-cross pattern entirely peculiar to this species.
In adjunctus the total longitudinal displacement of a gallery is about
three to four times greater than the lateral dispalcement; each suc-
cessive curve, following the first large one, becomes smaller until
the final part of the gallery may be virtually straight. In valens
(Fig. 56), and to lesser extent in terebrans, certain parts or perhaps
all of the gallery is expanded into a broad, flat cave from which
the larvae mine, in congress, thereby enlarging the cave to an area
that may cover several square feet of bark surface.

Placement of the eggs along the sides of the gallery varies con-
siderably in the genus. In brevicomis, frontalis, parallelocollis, ad-
junctus and ponderosae the eggs always are placed individually in
niches that are constructed alternately on the sides of the gallery.
In ponderosae (Fig. 53) instead of individual niches alternating,
from one to eight niches are formed on one side of the gallery then
a comparable number are formed on the other. In parallelocollis
(Fig. 49) the niches are formed in the sides of the gallery farthest
from the cambium; the other four species mentioned above place

'Lateral displacenient refers to deviations from or toward the main vertical axis of a gallery-
For example, if the first tum of an egg gallery extends four centimeters to the right, then curves
back to the imaginary vertical axis, the total displacement of that turn would be eight centimeters.
If this gallery continued three centimeters to the left of the central axis and returned in making a
second curve, the total lateral displacement of both turns would then be eight plus six, or 14 centi-
meters. Longitudinal displacement may be calculated in a similar mamier by using a horizontal axis
instead of a vertical one.

June 14, 1963

REVISION OF DENDROCTONUS

15

Fig. 43. Dead Ponderosa pine with bark peeled to expose egg galleries of
Dendrotconus brevicomis (after Swaine, 1914).

The Great Basin Naturalist

16

STEPHEN L. WOOD Vol. XXIII, Nos. 1-2

Fig. 44. Stages in the development of Dendroctonus brevicomis: A, eggs;
B, larva; C. pupa; D, adult (after Miller and Keen, 1960).

their niches next to the cambium (Figs. 46, 47, 51, 53). The re-
maining species deposit their eggs in masses of about 20 or more in
specially prepared grooves along the sides of the gallery. Ordinarily
these grooves are placed alternately along the sides. In pseudotsugae
(Fig. 63) and possibly in simplex (not observed), the eggs in each
mass are oriented in a definite way; this habit of orienting or plac-
ing each egg in a special position did not appear to occur in other
species. In obesus (Fig. 61 ) the characteristic habit was to place
egg masses in grooves, but frequently some or even all of the eggs
in a gallery were placed in individual niches; evidently this occur-

June 14, 1963 revision of dendroctonus 17

red most often when the beetle encountered unfavorable environ-
mental conditions. The habits of aztecus were not observed.

The pattern of larval mines also varied among the different
species in the genus. In brevicomis, frontalis, parallelocoUis, adjunc-
tus and, perhaps to a lesser extent, ponderosae and simplex, the
larval mines are separate from one another and increase only slightly
during the first and second instars. They then expand suddenly into
an irregular feeding area where the last two larval instars occur.
In parallelocoUis (Fig. 49) the entire larval mine is between the
inner and outer bark and is not exposed on the surface of peeled
bark. In brevicomis (Fig. 46) and in about half of the frontalis
(Fig. 47) mines the slender initial part of the larval mine is in con-
tact with the cambium and exposed on peeled bark, the expanded
portion in both species always is concealed in the inner or outer
bark, (except frontalis in thin bark). In adjunctus (Fig. 51) and
ponderosae (Fig. 53) the entire larval mine is in contact with the
cambium and is exposed on the surface of peeled bark. In terebrans,
valens, micans, punctatus, murrayanae (Fig. 59) and obesus (us-
ually) (Fig. 61) the larvae feed in congress, forming a common
cave for at least part of the larval period. In terebrans and valens
this communal feeding continues until pupation, except for an oc-
casional larva that forms a short individual tunnel just before pu-
pation. In murrayanae, and presumably in punctatus and micans,
the larvae feed in congress for six or eight centimeters when indi-
vidual groups separate then later rejoin one another leaving islands
of unexcavated bark in the feeding area; they may cover consider-
able distances in the process, but usually the larvae are in a com-
mon area by the end of their development. In o.besus (Fig. 61) the
larvae mine in congress for about the second and third instars when
each separates from the others and constructs a separate mine, un-
less crowding is severe. In pseudotsugae (Fig. 63) the larvae con-
struct individual mines that increase in width gradually throughout
their length.

Pupation in all brevicomis, frontalis and parallelocoUis, and in
some adjunctus and pseudotsugae, takes place in the outer bark; in
the remaining species it occurs at the end of the larval mine or in
the frass of the common feeding chamber in the area of the cam-
bium and is exposed on peeled bark.

The only species known to have a special overwintering habit
is obesus. About half of the young adults emerge from the brood
galleries and re-enter the base of their own or another brood tree
or other suitable tree where they construct feeding tunnels. They
emerge the following season to commence their attacks on new trees
to begin another generation. This habit has not been reported in
other species, but is suspected in murrayanae and perhaps in one or
two other closely related species.

The number of generations each year varies from one to five or
more. In brevicomis and frontalis three or more generations are com-
mon in the southern parts of their distributions, with fewer genera-

The Great Basin Naturalist
18 STEPHEN L. WOOD Vol. XXIII, NoS. 1-2

tions in cooler areas. In the other species one generation and a par-
tial second generation is typical, except in the extreme southern
areas where cool temperatures do not interrupt development, or in
northern areas where one summer is not sufficient to complete lar-
val development. In ponderosae one generation each year appears
to be the rule in all areas, except in southern California where two
and a partial third generation may occur.

Host specificity. — Under endemic conditions each species of
Dendroctonus characteristically restricts its attacks to certain pre-
ferred species of coniferous trees. Each of the 14 species includes
more than one host species in its preferred list; only two infest
more than one host genus. Eight species normally attack only trees
of the genus Pinus; these are brevicomis, frontalis, parallelocollis,
adjunctus, aztecus, ponderosae, terebrans and murrayanae. Three
species attack only trees of the genus Picea; these include micans,
punctatus and obesus. One species, simplex, prefers only the species
of Larix. The species of Pseudotsuga are preferred exclusively by
pseudotsugae, except in northeastern British Columbia where Larix
evidently is a normal host of endemic populations. The most un-
restricted species in the genus is valens; it occurs most commonly in
species of Pinus, but also is found in Picea, Larix, Abies and per-
haps other genera of coniferous trees.

A phenomenon that has caused considerable controversy in the
past and probably wdll continue to do so in the immediate future,
occurs in several species. It is best illustrated by the distinctive,
easily recognized pseudotsugae. Over most of its range the only
host of this species is Douglas fir; understandably, it may also at-
tack Big Cone spruce, Pseudotsuga macrocarpa, in areas where that
host occurs. In northeastern British Columbia endemic populations
evidently breed successfully in Larix occidentalis, although they
presumably are unable to do so where both Douglas fir and West-
ern larch occur together in other parts of the beetle's distribution.
In murrayanae a similar situation presumably occurs in the Great
Lakes area where Red pine {Pinus resinosa) and Eastern white
pine (Pinus strobus) apparently are acceptable hosts of endemic
populations; in all other parts of its distribution Jack pine (Pinus
banksiana) or the virtually identical Lodgepole pine (Pinus con-
torta) are the only hosts. It is not impossible in this instance, how-
ever, that the Red pine and Eastern white pine infestations resulted
from the overflow of an epidemic of this beetle in neighboring Jack
pine. A similar, but much more complex problem appears to occur
in ponderosae.

In ponderosae local endemic populations may exhibit a prefer-
ence for any one of several hosts even though more than one of those
on the preferred list may occur in mixed stands with the one ac-
tually selected in that area. For example, in certain parts of Califor-
nia Jeffrey pine (Pinus jeffreyi) is selected; in parts of Oregon and
Washington it may be Western white pine (Pinus monticola) ; in
parts of Idaho, Montana, Wyoming and Utah it may be Lodgepole

June 14, 1963 revision of dendroctonus 19

pine; in parts of Colorado, Utah and the Black Hills it may be Pon-
derosa pine {Pinus ponderosa) ; in parts of Colorado, Utah, New
Mexico and Arizona it may be Pinon pine (Pinus edulis) ; etc.
Whether these preferences result from genetic differences in the
local beetle populations, from competition between species attempt-
ing to occupy the same ecological niche, from differences in the
host species, from differences in climate, or from other factors is
uncertain. Experienced forest entomologists disagree concerning the
behavior of endemic populations of this species in mixed stands of
two or more of the preferred hosts. For example, it was reported
by reliable, experienced workers that outbreaks of this species in
Jeffrey pine did not spread into neighboring stands of Ponderosa
pine. Other workers of equal reliability and experience reported
that approximately equal numbers of the two host species were
attacked when they occurred in mixed stands but that tradition re-
quired them to attribute the Ponderosa attacks to Dendroctonus hre-
vicomis. Personal investigations conducted for very brief periods at
each of three widely separated localities in the area in question, in
three different seasons, have led me to the following conclusions
for this particular area of controversy. First, in pure stands of
Ponderosa pine at the lower elevations ponderosae ordinarily is not
present, all beetle-killed trees appeared to be occupied by brevicomis;
in pure stands of Jeffrey pine at higher elevations ponderosae has
no competition from other aggressive species of Dendroctonus and,
consequently, is present in all beetle-killed trees. At the higher ele-
vations where mixed stands of the two hosts occurred both were
attacked with approximately equal frequency by ponderosae, brev-
comis occasionally was present in some of the Ponderosa pine trees.
At the intermediate to lower elevations, rather near mixed stands
of these hosts, both species of Dendroctonus occurred in the same
Ponderosa pine trees, but ponderosae evidently occurred only in the
lower third of the bole where its galleries were intermixed with
those of brevicomis. It appeared that the colder winter temperatures
encountered at the upper elevations, where mixed stands occurred,
were a definite factor in retarding the development of brevicomis
sufficiently that ponderosae could compete successfully in Ponderosa
pine. At the lower elevations where mixed stands occurred it ap-
peared that the temperature advantage enjoyed by ponderosae was
absent and that the only reason this species was represented in
Ponderosa pine at all was the nearby reservoir of Jeffrey pine where
it enjoyed freedom from competition. In this area of California
climatic factors appeared to be much more iinportant than genetic
factors. The principal California area considered here was in Lassen
National Forest from Old Station to Black's Mountain south to Las-
sen Park; the elevation varied from about 3200 to about 7000 feet.

In the Uinta Mountains of Utah pure stands of Lodgepole pine
occur in certain areas and pure stands of Ponderosa pine occur in
others. Between the pure stands are areas where mixed stands of
these trees are found. In the absence of usable published data, per-
sonal communication from local rangers and other Forest Service

The Great Basin Naturalist
20 STEPHEN L. WOOD Vol. XXIII, Nos. 1-2

personnel familiar with the area indicate that some outbreaks of
ponderosae occur in Lodgepole, but not in Ponderosa pine, and
that other outbreaks occur in Ponderosa. but not in Lodgepole
pine. Other workers reported that these outbreaks ordinarily
sweep from one host species to the other. It was also reported
that an attempt was made to rear beetles coming from one host
species on the other host species, but was unsuccessful. Whether the
failure resulted from genetic differences of the beetles or from faulty
experimental procedure is unknown. Personal studies in these mixed
stands indicated that beetles developing in an area where a mild
outbreak in Lodgepole was in progress, were attacking Ponderosa
pine. It appeared that a physiological adjustment requiring one or
two successive generations was necessary before the normal survival
rate of the brood was attained. The rate of survival of brood in the
first Ponderosa pine trees attacked in this area was very low.

The above three paragraphs, although intentionally improperly
documented to protect confidences, presents a phenomenon not ade-
quately investigated; that is, host- restricted races may arise and be-
have as species in many respects. These possibly arise when tem-
porarily altered factors of ecology, genetics, or other factors, permit
the invasion of a host species different from that normally occu-
pied in a given area. Whether this comes about from relaxed com-
petition, from relaxed resistance of the host, or from other opportun-
ities, the resulting gene flow from one population to another has the
effect of preventing species formation. To effectively prevent spe-
cies formation this need not occur more than once in numerous
generations, nor must it occur in more than a few areas within the
total distribution of the beetle species. The above example involving
pseudotsugae appears to be a clear-cut example of a change in host
selectivity. The lack of uninimity of opinion as to what occurs in pop-
ulations of the apparently host-restricted races of ponderosae, partic-
ularly in view of my Uintah Mountain observations and the appar-
ent absence of anatomical indicators of genetic change throughout
its range, suggests a fertile field of research.

Infraspecific Variation

Morphological differences between species in Dendroctonus are,
at best, rather poor and when complicated by tremendous individ-
ual variation the identification of specimens is made exceedingly
difficult. Because of this, greater dependence in past years has been
placed on locality and host data by specialists in identifying species
than on specimens themselves. An analysis of this supposed hope-
lessly chaotic assemblage of variabiHty appeared impossible until the
reliabihty of genitahc characters in the male was established. Once
their reliabihty was estabhshed genitalic characters served as a basis
for sorting individual, sexual and geographic variations into com-
prehensible, predictable patterns and made possible the grouping
of several populations, previously regarded as distinct, into recog-
nizable species.

June 14, 1963 revision of dendroctonus 21

Individual Variation. — The greatest degree of individual varia-
tion was in size. Although it was actually demonstrated in only a
few species it appeared that the largest specimen found in a partic-
ular species was almost exactly twice as large as the smallest spec-
imen examined in that same species (2.5 and 5.0 mm. in brevicomis;
2.3 and 4.5 mm. in frontalis; 3.7 and 7.5 mm. in ponderosae; etc.).
The size differences mentioned here possibly result from unusually
favorable or unfavorable environmental conditions rather than gen-
etic or other factors; in the three examples cited the largest and
smallest individuals came from the same geographical area. Other
variations in epistomal processes, antennae and eyes were treated and
illustrated by Hopkins (1909:19-23) and were either avoided be-
cause of unreliability or were described in the systematic treatment
of each species on the following pages.

Individual variations of present concern include usually reli-
able characters of taxonomic value that occasionally are altered or
entirely missing in certain specimens. For example, the male de-
clivity of valens ordinarily bears numerous fine, confused gran-
ules, but in an occasional specimen (fewer than five precent of the
males) only a few median granules are present on each interspace
with the locations of others marked by deep punctures. In other
cases, an otherwise normal female of obesus (about two or three per
cent) will have the punctures of the declivital striae two or three
times as large as the interstrial punctures; and in males of murray-
anae (about five percent of those from the west) the interstrial
punctures of the declivity may be as much as half as large as the
strial punctures. When odd examples such as these are encountered
accurate identification may be possible only when they are associ-
ated with a long series of normal specimens.

Sexual Variation. — Secondary sexual characters are conspicuously
developed in the species of Dendroctonus. As with most other genera
in the subfamily Hylesininae, the posterior margin of the seventh
abdominal tergum in the male bears a pair of closely set median stri-
dulating processes that work against the roughened adjacent surface
of the elytra. The squeaking noise of stridulation heard when a
specimen is held next to the ear is a convenient field method of
identifying males of all species in the genus. The absence of stridu-
lation does not necessarily mean the specimen is a female, since
males cannot always be induced to stridulate.

In brevicomis, frontalis, parallelocollis aiid adjunctus the frons
has a median groove with the lateral areas elevated. This groove and
the lateral elevations are much more highly developed in the males
of these species than in the females and, in all but adjunctus, the
lateral elevations of the males bear one or two pair of large, almost
hornlike tubercles on their dorsomedian margins. In these same
species the well developed transverse constriction found just behind
the anterior margin of the pronotum in the male is largely filled
by a conspicuously elevated transverse callus in the female (Figs.
5, 9). In valens (Fig. 16) and, to a lesser extent, in terebrans, the

The Great Basin Naturalist

22 STEPHEN L. WOOD Vol. XXIII, Nos. 1-2

female frons bears a small, rather well developed median elevation
at the upper level of the eyes. In all six species mentioned above,
and other related species, the male frons is usually a little larger and
more prominent and the female frons, pronotum and elytra are very
slightly more coarsely sculptured.

In pseudotsugae, simplex, obesus, possibly valens, and to a much
lesser extent ponderosae, micans, punctatus and murrayanae, the
declivital tubercles on the elytra are moderately large in the female
and smaller to entirely absent in the male. Field use has been made
of this character in obesus giving about 90 percent accuracy; these
tubercles would be much more reliable in determining the sex of
pseudotsugae and simplex.

Geographical Variation. — Geographical variation was detected
in five species. In each instance Hopkins (1909) employed these
variations to characterize new species. Since they are minor, diffi-
cult to measure, and involve a minority of the population in any
given area they were not used here to characterize geographical
races.

Body size varied conspicuously in ponderosae; in general, speci-
mens from the northwestern parts of its distribution (Washington
and British Columbia) were distinctly smaller than those from the
southern areas, particularly the southeastern parts of its distribu-
tion. However, there was a gradual transition in size through Idaho,
Oregon and northern California. This variation was somewhat ob-
scured by an ecological complication, since thin-barked pines which
predominate as hosts of this species in the northwest normally pro-
duce smaller beetles than do hosts with thick bark. Size variations
of less than one millimeter, associated with geographical location,
involved populations of obesus east of eastern Alberta, of brevicomis
from California to British Columbia, of frontalis from the United
States, and of murrayanae from the western United States.

In obesus there was a greater tendency for fully mature (se-
nile?) specimens to turn black with age in the western part of its
range. Since this also occurs with Trypodendron lineatum (Wood,
1957:340), and possibly with other bicolored scolytid species, it may
be caused by ecological factors. The frons of obesus also tended to be
more densely granulate in western specimens, however, this char-
acter affected less than half of any series examined.

The frons varied conspicuously in frontalis from locality to lo-
cality. Almost every local population exhibited its own frontal char-
acters which were consistent within that population. It was of in-
terest, however, that one extreme variation in a series from Prescott,
Arizona, also appeared in a West Virginia series.

The size of punctures on the pronotal disc varied tremendously
between individuals of almost any local population, but variations
apparently dependent on geographical origin were detected in two
species. In ponderosae from central or southern California the pro-
notal disc commonly was uniformly, minutely punctured. These
specimens always occurred with specimens tending to be more coars-

June 14, 1963 revision of dendroctonus 23

ely punctured. This character gradually faded from the population
toward northern California. This variation was not associated with
Jeffrey pine or any other host, as reported by Hopkins (1909). A
somewhat similar variation in murrayanae probably occurs, but too
few specimens were available to consider it fully.

Geographical variation in brevicomis involving the sculpture of
the elytra was reported by Hopkins (1909). While his observations
tend to be correct, it was observed that the most coarsely sculptured
individual specimens of this species examined during this study came
from northern California; the most finely sculptured came from
western Chihuahua. Since this character cannot be measured with
accuracy, and since definite patterns in the distribution could not
be established using this character, it could not be employed to char-
acterize geographical races. Somewhat similar variations were re-
ported by Hopkins (1909) in parallelocollis, but may be attributed
to the inadequacy oiF series available for study at that time.

Phylogeny

In treating the relationships of Dendroctonus to other genera of
Scolytidae it is apparent that certain morphological and biological
characters exist that might be useful in analyzing the lines of spec-
ialization observed within this genus. For example, only the most
closely related of the genera allied to Dendroctonus have an evident
epistomal process; elaborations of this structure within the genus
would, then, appear to represent specialization of this character, and
the absence of special modifications would appear to represent a
primitive condition. Frontal grooves and tubercles and the special-
ized transverse callus of the pronotum are absent in allied genera,
as well as in most species of Dendroctonus; therefore, their presence
in brevicomis, frontalis, parallelocollis and adjunctus (groove only)
evidently represents specialization. These four species also share
the habits of constructing sinuate egg galleries and of placing their
eggs in individual egg niches alternately on the sides of the gallery.
The sinuate gallery is a departure from the typical straight, vertical
hylesinine gallery, but the alternate placement of eggs definitely
is primitive.

Among the largest species of the genus, increased size appears
to be a departure from allied genera, hence is a specialization. An-
other specialization appears to be the reduction in size of the strial
punctures on the declivity. In pseudotsugae and simplex extension
of the epistomal process toward the epistomal margin and the deeper
second declivital interspace are departures exhibiting specialization.
The most striking specializations among the larger species, however,
are biological; of special importance are the methods of egg deposi-
tion and of larval excavation. In all of these species the egg galleries
basically are straight. Eggs are deposited in individual niches in
ponderosae with niches placed in groups of one to eight first on
one side of the gallery and then on the other. In the remaining

The Great Basin Naturalist

24 STEPHEN L. WOOD Vol. XXIII, Nos. 1-2

species eggs are deposited in grooves along the sides of the egg gal-
lery in batches of one to several dozen. In pseudotsugae and pos-
sibly simplex (not observed) each egg is oriented in a definite way;
in the remaining species they are deposited at random without
orientation. The larvae of pseudotsugae and simplex construct indi-
vidual mines that seldom cross one another. In the remaining
species observed during this study that share this method of egg
deposition, the larvae feed in congress. This communal feeding
continues in obesus until about the second instar when each larva
constructs an individual mine that may cross and recross those of
other larvae. In valens and terebrans communal feeding usually
continues until pupation. In murrayanae groups of second instar
larvae separate from one another, but reunite later into a common
chamber. It is presumed that micans and punctatus share this latter
habit, although neither was observed during this study.

When all morphological characters are considered aztecus un-
doubtedly is the most primitive species in the genus. The epistomal
process, frons, prothorax, elytral declivity and absence of sexual
differences match rather closely those of the hypothetical ancestor
of the genus. It also bears a deceptive resemblance to Hylurgus or
Tomicus. Unfortunately, the biology of aztecus was not studied in
sufficient detail for use in a consideration of phylogeny.

On the basis of this study the following groups of closely allied
species occur in the genus; they are listed in the order of increasing
specialization, although the evolutionary relationships among the
groups is uncertain.

1. frontalis, brevicomis, parallelocollis .

2. aztecus, valens, terebrans.

3. adjunctus, ponderosae.

4. obesus, murrayanae, punctatus, micans.

5. simplex, pseudotsugae.

It is clearly evident that frontalis and brevicomis, valens and
terebrans, murrayanae, punctatus and micans, and simplex and
pseudotsugae are geographical replacements of one another that de-
veloped in comparatively recent geological time. With the exception
of micans, however, their distributions now overlap in some parts
thereby removing all doubts concerning their specific identities. Al-
though much more remote, it is also evident that parallelocollis
arose in a similar manner from common ancestry with frontalis-
brevicomis, ponderosae from adjunctus ancestry, and obesus from
murrayanae-punctatus-micans ancestry. The structural bases for
these conclusions are included in the key to species, and in the
treatment of the various species.

Genus DENDROCTONUS Erichson

Dendroctonus Erichson, 1836, Archiv f. Naturgesch. 2(1):52; Ratzeburg, 1837,
Die Forstinseketen, p. 217; Eichhoff, 1864, Berliner Ent. Zeitschr. 8:26;

June 14, 1963 revision of dendroctonus 25

Lacordaire, 1866, Genera des Coleopteres 7:360; Zimmennan, 1868, Tans.
American Ent. Soc. 2:148; Leconte, 1868, Trans. American Ent. Soc. 2:172;
Chapuis, 1869, Synopsis des Scolytides, p. 34 (1873, Mem. Soc. Roy. Sci.
Liege (2)3:242); Leconte, 1876, Proc. American Philos. Soc. 15:384; Pro-
vancher, 1877, Fauna Ent. Canada 1:572; Lindeman, 1879, Bull. Soc. Imp.
Nat. Moscou 54:53; Eichhoff, 1880 (1881), Die Europaischen Borkenkafer,
p. 125; Leconte and Horn, 1883, Coleoptera of North America, p. 523,
Reitter, 1884, Verh. naturf. Ver. Briinn 33:53; Dietz, 1890, Trans. American
Ent Soc 17:27; Blandford, 1897, Biol. Centr.-Amer., Coleoptera 4(6): 146;
Lovendai, 1898, De Danske Barkbiller, p. 86; Hopkins, 1899, West Vir-
ginia Agric. Expt. Sta. Bull. 56:392; Barbey, 1901, Scolytides I'Europe
Central, p. 55; Hopkins, 1902, Proc. Ent. Soc. Washington 5(1) :3; For-
manek, 1907, Kurovici v Cechach a na Morave zyici, p. 21; Swaine, 1909,
New York St. Mus. Bull. 134:95; Hopkins, 1909, U. S. Dept. Agric. Bur.
Ent. Tech. ser. 17(1): 1-64 (monograph); Hagedom, 1910, Coleopterorum
Catalogus 4:19; Hagedorn, 1910, Genera Insectorum 111:59; Reitter, 1913,
Wiener Ent. Zeit. 32(Behheft) :47; Saalas, 1914, Medd. F. et Fl. Fenn. 40:77;
Hopkins, 1914, Proc. U. S. Natl. Mus. 48(2066): 120; Hopkins, 1915, U. S.
Dept. Agric. Bur. Ent. Tech. ser. 17 (2): 168; Blatchley and Leng, 1916,
Rhyncophora or weevils of N. E. America, p. 652; Swaine, 1918, Dom.
Canada Dept. Agric. Ent. Br. Bull. 14(2) :60; Leng, 1920, Cat. Coleopt.
America north of Mexico, p. 338; Blackman, 1922, Mississippi Agric. Expt.
Sta. Tech. Bull. 11:56; Spessivtseff, 1925, Svensk Insektfauna 3:164;
Spessivtseff, 1931, Opredelitel Korojedov, p. 86; Schedl, 1932, in Winkler,
Cat. Coleopt. reg. palaearcticae, p. 1635; Dodge, 1938, Univ. Minnesota
Agric Expt Sta. Tech. Bull. 132:26; Chamberlin, 1939, Bark and timber
beetles of North America, p. 144; Schedl, 1940 (1939), Ann. Esc. Nac.
Cienc. Biol. (Mexico) 1:339; Blackwelder, 1947, U. S. Natl. Mus. Bull.
185:784; Balachowsky, 1949, Faune de France 50:134; Stark, 1952, Fauna
U.S.S.R. 33:184; Schedl, 1955, Zeitschr, angew. Ent. 38:7; Pfeffer, 1955,
Fauna C.S.R. (Czechoslovakia), p. 121; Chamberlin, 1958, Scolytoidea of
the Northwest, p. 64. Biol.: Smith, 1877, Shade trees . . . and Insects that
infest them, p. 52; Cockerell, 1893, Trans. American Ent. Soc. 20:336;
Judeich-Nitsche, 1895, Forstinsekten 1:445; Chittenden, 1899, U. S. Dept.
Agric Div. For. Ent. Bull. 18 (5): 55; Felt, 1906, New York St. Mus.,
Mem. 8, 2:337; Hopkins, 1909, U. S. Dept. Agric. Bur. Ent. Bull. 83(1): 169;
Herrick, 1910, Rur. New York, p. 896; Yates, 1910, Engineer News, p. 517;
Craighead, 1928, Jour. For. 26(7): 886; Inda, 1930, Mexico Forest. 8(8): 173;
Keen, 1938, U. S. Dept. Agric. Misc. Pub. 273:98; Shull, 1944, Idaho Expt.
Bull. 252:5; Keen, 1949, U. S. Dept. Agric. Yearbook 1948:427.

Dendroctonus is not very closely allied to any known genus, but
unquestionably is related to Hylurgus Latreille and Tomicus Lat-
reille (=Blastophagus Eichhoff) of Europe and Asia, to Pachy cotes
Sharp of Australia and New Zealand, and to Hylurgonotus Schedl
of South America. It differs from these genera, however, by the well
developed, unique epistomal process (very poorly, narrowly indicat-
ed in Hylurgonotus brunneus Schedl and in Pachycotes), by the
five-segmented antennal funicle, by the absence of a broad impress-
ion on the frons of the male (very feebly indicated in Tomicus),
and by the strongly flattened antennal club.

Description. — Length 2.5-9.0 mm., 2.3-2.6 times as long as wide;
body color dark brown to black, some species with reddish brown
elytra.

Frons convex, with or without secondary sexual characters ex-
pressed as elevations, tubercles, etc.; epistomal margin laterally el-
evated, smooth, shining; epistomal process well developd just above

The Great Basin Naturalist

26 STEPHEN L. WOOD Vol. XXIII, Nos. 1-2

elevated portion of epistomal margin, overlapping and extending
almost to or flush with median portion of epistomal margin, its
basal width equal to a distance one-fourth to one-half as great as
distance between eyes, flat or transversely concave between its lat-
eral margins (arms); surface varying from smooth and punctured
in some species to densely granulate in others; vesiture hairlike,
moderately long, fine, sparse, inconspicuous. Eye ovate, short and
broad to rather long and narrow; entire; finely granulate. Antennal
scape elongate, clavate; funicle five-segmented, increasing strongly
in width from segment two to five, pedicle only slightly wider than
two; club strongly flattened, subcircular in outline, with three
weakly to strongly procurved sutures indicated only by setae.

Pronotum 1.2-1.4 times as wide as long, widest on basal third;
sides feebly to moderately arcuate and more or less converging to-
ward the broadly, shallowly emarginate anterior margin, with or
without a prominent constriction just behind anterior margin; sur-
face smooth and shining, with conspicuous, rather deep punctures
of variable size more or less characteristic of each species; basal
margin almost straight to bisinuate; lateral margins rounded. Ves-
titure hairlike, sparse to moderately abundant, short to rather long.

Elytra 2.1-2.5 times as long as pronotum; sides straight and sub-
parallel on basal two-thirds, rather broadly rounded behind; scutel-
lum rather small, somewhat depressed in basal notch between ely-
tra; basal margins somewhat arcuate and bearing a row of about
nine to twelve moderately large, raised, overlapping crenulations,
with several smaller submarginal ones particularly on interspaces
two and three; striae impressed or not, the punctures rather large
and moderately deep; interstriae feebly to not at ^1 convex, about
one to two times as wide as striae, armed by variable transverse
crenulations. Declivity rather steep, convex; variously sculptured.
Vestiture hairlike; variable.

Type species. — Bostrichus micans Kugelann, subsequent desig-
nation (Hopkins, 1909:5) (cf. discussion of history above).

Key to the species of Dendroctonus

1. Frons with a rather deep, narrow median groove extending
frorn just above epistomal process to upper level of eyes; if
median impression obscure in male the lateral areas of frons
rather strongly protubrant and usually armed by one or
two tubercles (except adjunctus) , if protubrance obscure
in female then anterior constriction of pronotum with a
transverse elevated callus (Fiffs. 5, 9) laterally and dor-
sally (obscure laterally in adjunctus) ; epistomal process
very broad with the lateral margins prominently raised;
smaller species 2.5-7.4 mm., in Pinus 2

Frons without a median groove or impression below upper
level of eyes; lateral elevations of frons and transverse ele-
vated callus of pronotum never present in either sex; epis-

June 14, 1963 revision of dendroctonus 27

tomal process usually narrower and less prominent, the
lateral margins raised or not; larger species 5.0-9.0 mm.
(rarely as small as 3.7, or 3.4 in simplex), in Pinus and
other conifers 5

2. Punctures and/or granules of second declivital interspace more

abundant, confused; second declivital interspace as wide as
one and three, not constricted apically (Fig. 27); smaller
species, 2.5-5.0 mm 3

Granules of second declivital interspace rather sparse and uni-
seriate; second declivital interspace narrower than one and
three or strongly constricted apically (Fig. 30); larger spe-
cies, 3.8-7.4 mm 4

3. Declivital pubescence rather abundant and uniformly short,

not longer than a distance equal to half the width of an
interspace; transverse discal rugae on posterior half of
discal interspaces almost never longer than half the width
of an interspace; declivital striae usually not impressed,
obscure; punctures of declivital interspaces more abundant

and feebly if at all granulate (Fig. 27)

brevicomis Leconte

Declivital pubescence less abundant, at least some hairs twice
as long as wddth of an interspace; at least a few rugae on
posterior half of elytral disc as wide as the interspace; de-
clivital striae usually impressed, the punctures larger and
distinct from those of interspaces; punctures of declivital
interspaces less abundant and more coarsely granulate
(Fig. 28) frontalis Zimmerman

4. Granules on declivital interspaces one and (usually) three more

abundant, confused; transverse elevation of female prono-
tum very prominent laterally; male frons with prominent
lateral tubercles (Figs. 7-10); larger, 4.5-7.4 mm.; stouter,
2.5 times as long as wide parallelocollis Chapuis

Granules on declivital interspaces one and three sparse, uniser-
iate; transverse callus of female pronotum obscure later-
ally; male frons without lateral tubercles (Figs. 11-12);
smaller 3.8-6.0 mm.; more slender, 2.65 times as long as
wide adjunctus Blandford

5. Declivital interspaces dull (minutely rugulose) or shining,

if shining the punctures virtually all granulate in both sexes
and strial punctures distinct and larger; epistomal process
rather broad, the distance between eyes not more than 2.2
times its basal width; episternal area of prothorax more
coarsely granulate, the punctures obscure or absent 6

Declivital interspaces smooth and shining, most of the punc-
tures impressed, a few of them granulate in female; epis-
tomal process rather narrow, the distance between eyes

The Great Basin Naturalist

28 STEPHEN L. WOOD Vol. XXIII, Nos. 1-2

three or more times its basal width; epistemal area of pro-
thorax punctate, the granules minute or entirely absent .... 9

6. Surface of declivity opaque (usually rugulose) ; second decliv-

ital interspace impressed, usually flat, interspace one strong-
ly and three weakly elevated; declivital interspaces usually
uniseriately granulate and with scattered fine punctures
ponderosae Hopkins

Surface of declivity usually shining, the second interspace not
impressed and sutural interspace weakly if at all elevated;
virtually all of the rather numerous punctures on declivital
interspaces granulate, the granules close, confused 7

7. Epistomal process broad, flat, the margins not elevated (Fig,

24) ; strial punctures rather small and obscure, rugae of
discal interspaces very coarse, many as wide as interspace,
a few crossing striae; frons strongly evenly convex; pro-
notum gradually narrowed anteriorly, vvdthout an abrupt
constriction (Figs. 25-26) aztecus, new species

Epistomal process broad, transversely concave, the margins
strongly elevated (Figs. 14-16); strial punctures larger,
never traversed by the smaller discal rugae; frons irregu-
larly less strongly convex; pronotum feebly if at all nar-
rowed anteriorly, with an abrupt constriction just behind
anterior margin (Fig. 17) 8

8. Body color of mature specimens black; punctures on disc of

pronotum rather coarse, those near lateral margin much
larger; declivital tubercles usually larger, apparently more

numerous (Fig. 29); southeastern United States

terebrans (Olivier)

Body color of mature specimens reddish brown; punctures of
pronotum not as coarse, those near lateral margin similar
to those on disc; declivital tubercles usually smaller, appar-
ently less numerous (Fig. 30) ; North America, except
southeastern United States valens Leconte

9. Declivital striae weakly if at all impressed, the second apically

curved toward sutural striae; declivital interspace one feebly
elevated, two as wide or wider than one or three (except
near apex); discal striae less than half as wdde as inter-
striae; epistomal process usually transversely concave (ex-
cept micans), rather broad, the lateral margins moderately
oblique (less than 55° from the horizontal) (Figs. 18-21)
10

Declivital striae strongly impressed, the second straight; decliv-
ital interspace one strongly elevated, two weakly impressed
and narrower than one and three; discal striae almost as
wide as interstriae; epistomal process flat or convex, nar-
row, the lateral margins strongly oblique (about 80° from

June 14, 1963 revision of dendroctonus 29

the horizontal) (Figs. 22-23) 13

10. Frons smooth and polished, with deep close punctures, but al-

most entirely without granules between punctures (Figs.
18, 21); strial punctures on declivity rather large, three or
more times as large as those of interstriae 11

Frons rather finely granulate between the close, deep punctures
(granules sometimes obscure in murrayanae) (Figs. 19-20);
strial punctures on declivity usually minute, seldom more
than twice as large as those of interstriae 12

11. Epistomal process flat; stouter, 2.3 times as long as wide; strial

punctures more strongly impressed; larger, 6.0-8.0 mm.;
northern Europe and Asia micans Kugelann

Epistomal process shallowly, transversely concave; more slen-
der, 2.4 times as long as wide; strial punctures shallowly im-
pressed; smaller, 5.4-6.5 mm.; northeastern North America
to Alaska, in Picea punctatus Leconte

12. Frons coarsely, distinctly punctured, the granules between

them usually isolated from one another, often very sparse
(Fig. 19); male genitalia as figured (Fig. 39); from
Pinus murrayanae Hopkins

Frons very closely, more coarsely granulate, the punctures us-
ually obscure in central area (Fig. 20) ; male genitalia as
figured (Fig. 40); from Picea obesus (Mannerheim)

13. Frons moderately protubrant, smooth with rather coarse, deep

punctures (Fig. 22); punctures of pronotum rather large;
discal interstriae with fine punctures interspersed ^vith
small rugae; smaller, 3.4-5.0 mm.; eastern North America
to Alaska; from Larix simplex Leconte

Frons strongly protubrant, irregular, granulate, with rather
fine, deep punctures (Fig. 23); punctures of pronotum ra-
ther small; discal interstriae without fine punctures dis-
persed among rugae; larger, 4.4-7.0 mm.; western North

America; from Pseudotsuga and Larix

pseudotsugae Hopkins

Dendroctonus brevicomis Leconte

Figs. 1-2, 27, 31-32, 43-46.

Dendoctonus brevicomis Leconte, 1876, Proc. American Philos. Soc. 15:384,386;
Hopkins, 1902, Proc. Ent. Soc. Washington 5:3; Hopkins, 1909, U. S.
Dept. Agric. Bur. Ent. Tech. ser. 17(1): 81; Swaine, 1909, New York St.
Mus. Bull. 134:96; Swaine, 1918, Dom. Canada Dept. Agric. Ent. Br. Bull.
14(2) :62; Hagedorn, 1910, Coleopteroum Catalogus 4:20; Hagedorn, 1910,
Genera Insectorum 111:60; Hopkins, 1915, U. S. Dept. Agric. Bur.
Ent. Tech. ser. 17 (2): 211; Chamberlin, 1939, Bark and Timber Beetles
of North America, p. 153; Chamberlin 1960, Scolytoidea of the Northwest,
p. 68. Biol.: Packard, 1887, U. S. Ent. Comm. Bull. 7:177; Packard, 1890,

The Great Basin Naturalist
30 STEPHEN L. WOOD Vol. XXIII, Nos. 1-2

U. S. Ent. Comm. Kept. 5:722; Hopkins, 1899, U. S. Dept. Agric. Div. Ent.
Bull. 21:13; Hopkins, 1899, West Virginia Expt. Sta. Bull. 56:395; Hopkins,
1901, Proc. Soc. Prom. Agric. Sci. 22:66; Hopkins, 1902, U. S. Dept. Agric.
Div. Ent., n. s.. Bull. 37:21; Hopkins, 1903, U. S. Dept. Agric. Yearbook,
1902:281; Hopkins, 1904, U. S. Dept. Agric. Div. Ent. Bull. 48:18; Currie,
1905, U. S. Dept. Agric. Div. Ent. Bull. 53:74; Webb, 1906, U. S. Dept.
Agric. Yearbook, 1905:632; Webb, 1907, U. S. Dept. Agric. Yearbook,
1906:515; Howard, 1907, U. S. Dept. Agric. Div. Ent. Kept, 1906:15;
Hopkins, 1908. U. S. Dept. Agric. Yearbook 1907:162; Webb, 1908, U. S.
Dept. Agric. Div. Ent. Bull. 58(2): 17; Hopkins, 1909, U. S. Dept. Agric.
Bur. Ent. Bull. 83(1 ):42; Hopkins, 1910, U. S. Dept. Agric. Bur. Ent. Bull.
58:59; Hopkins, 1910, U. S. Dept. Agric. Bur. Ent. Circ. 125:2; Hopkins,
1912, U. S. Dept. Agric. Bur. Ent. Circ. 143:5; Swaine, 1913, Ontario Ent.
Soc. Kept. 43:90; Swaine, 1914, Dom. Canada Dept. Agric. Expt. Farms
Bull. 17, ser. 2, Div. Ent. Bull. 7:13; Swaine, 1915, Canadian For. Jour.
11:89; Hopping, Proc. Soc. American For. 10:185; White, 1916, American
Lumbei-man 2169 (Dec. 9):30; Burke, 1917, Proc. Ent. Soc. Washington
19:88; Hopkins, 1920, Sci. Monthly 8:504; Swaine, 1920, Agric. Gas. Can-
ada 7:642; Chamberlin, 1920, Oregon Agric. Expt. Sta. Bull. 172:1-33;
Chamberlin. 1920, Timberman 21(10):38; Chamberlin, 1920, Timberman
22(1):35; Miller, 1921, Timberman 23(1):40; Hopping, 1921, Canada
Dept. Agric. Ent. Br. Circ. 15:9; Hopping. 1922, Canadian Ent. 54(6): 129,
132; Boyce, 1923, U. S. Dept. Agric. Bull. 1140:1; Boyce, 1923, Timber-
man 24(7): 157; Keen, 1923, American For. 29:689; Gibson, 1923, Canada
Dept. Agric. Ent. Br. Kept., 1919:16; Patterson, 1923, Timberman 24(8) :38;
Elliott, 1924, Oregon St. For. Kept. 14:43; Felt, 1924, Manual of Tree
and Shrub Insects, p. 250; Baker, 1924, American For. 30:599; Craighead,
1925, Jour. Forestry 23:341; Hopping, 1925, Jour. Forestry 23:932;
Boone, 1925, Timberman 26(7) :58; Caverhill, 1925, British Columbia
Dept. Lands For. Br. Kept. 1924:E16; Snyder, 1925, Nature Mag. 5:311;
Burke, 1926, Proc. Pacific Coast Ent. Soc. 2:57; Keen, 1926, Timberman
27(5): 178; Evenden, 1926, Timbei-man 27(4): 178; Miller, 1926, Jour.
Forestry 24:897; Craighead, 1927, U. S. Dept. Agric. Circ. 411:6; Miller
and Patterson, 1927, Jour. Agric. Res. 34:597; Patterson, 1927, U. S. Dept.
Agric. Tech. Bull. 3:2; Person, 1928, Jour. Forestry 26:564; Keen, 1928,
California Dept. Nat. Res. Div. For. Bull. 7:31; Keen, 1929, Pan-Pacific
Ent. 5:108; CoUingwood, 1929, American For. 35:652; Ebeling, 1929,
California Countrym. 15(7): 9; Nelson and Beal, 1929, Jour. American
Phyto. Soc. 19:1101; Craighead, 1930, U. S. Dept. Agic. Misc. Pub. 74:5;
Krauch, 1930. Jour. Forestry 28(8): 1085; Hosmer, 1930, American For.
36:716; Miller, 1930, U. S. Forest Serv. Forest Worker 6(1): 17; Anony-
mous, 1930, Mexican Agric. Formenta, Principales Plagas, p. 230; Struble,

1930, California Univ. Publ. Ent. 5(6): 105; Marlatt, 1931, U. S. Dept.
Agric. Bur. Ent. Rept. 1930:45; Craighehd et al, 1931, Jour. Forestry
29:1004; Salmon and Baumhofer, 1931, Jour. Econ. Ent. 24:776; Black-
man, 1931, New York St. Coll. For.. Syracuse Univ. Bull. 4(4), Tech. Pub.
36:37, 45, 57; Keen, 1931, U. S. Dept. Agric. Yearbook 1931:428; Miller,

1931, Jour. Agric. Res. 43:303; Person, 1931, Jour. Foestry 29:696;
Rumbold, 1931, Jour. Agric. Res. 43:851; Miller, 1933, Jour. Forestry
31:443; Marlatt, 1933, U. S. Dept. Agric. Bur. Ent. Rept. 1932:22; Marlatt,
1934, U. S. Dept. Agric. Bur. Ent. Rept. 1933:28; Heisley. 1933, U. S. Dept.
Agric. Muse. Pub. 162:23; Salmon, 1933. California Agric. Mo. Bull.
22:136; Salmon, 1934, Jour. Forestry 32:1016; Beal, 1934, Jour. Econ.
Ent. 27:1132; Weaver, 1934, Jour. Forestry 32:100; Doane et al., 1936,
Forest Insects, p. 2, 9, 54, 68. 76, 78; Hoist, 1936. Jour. Agric. Res. 53:513;
Strong. 1936, U. S. Dept. Agric. Bur. Ent. PI. Quar. Rept. 1935:23;
Stump, 1936, California Highways Publ. Works Jour., April, p. 10. 26, 32;
Keen, 1936, Jour. Forestry 34:919; Keen and Furniss, 1937, Jour. Econ.
Ent. 30:482; Hopping, 1937. in Mulholland, British Columbia Dept. Lands
For. Serv., p. 62; Hawley, 1937, Forest Protection, p. 91; Martin, 1937,
American For. 43:122, 144; Stodieck, 1937. Nevada Ext. Bull. 84:10; Gor-

June 14, 1963 revision of dendroctonus 31

don, 1938, Proc. West. Shade Tree Conf. 5:69; De Gryse, 1938, Pulp
and Paper Mag. Canada 39:27; Keen, 1938, U. S. Dept. Agric. Misc.
Pub. 273:99; Keen, 1938, West Coast Lumberm. 65(6) :48; Keen, 1939,
Rocky Mtn. Conf. Ent. Kept. 15:5; Miller, 1939, Rocky Mtn. Conf. Ent.
Rept. 15:4; Strong, 1939. U. S. Dept. Agric. Bur. Ent. PI. Quar. Rept.
1938:21; Westveld, 1939, Appl. Silvicult. U. S., p. 472, 500; Coyle, 1940,
Our Forests, p. 90; Johnson, 1940, Jour. Econ. Ent. 33:773; Person, 1940,
Jour. Forestry 38:390; Ringle, 1940, Sci. American 162:348; Wheeler,
1940, California Cult. 87:636; Wallace, 1941, U. S. Dept Agric. Sec.
Rept. 1940:169; Yuill, 1941, Jour. Econ. Ent. 34:702; Annand, 1941,
U. S. Dept. Agric. Bur. Ent. PI. Quar. Rept. 1940:25; Annand, 1942
U. S. Dept. Agric. Bur. Ent. PI. Quar. Rept. 1941:13; Craighead, 1942,
Smithsn. Inst. Rept. 1941, Pub. 3665:368; Keen and Salman, 1942, Jour.
Forestry 40:854; Orr, 1942, West Coast Lumberm. 69(4) :42; Carter,
1942, Timberman 44(2) :46; Annand, 1943, U. S. Dept. Agric. Bur. Ent.
PI. Quar. Rept. 1942:8; Furniss, 1943, Proc. West. For. Conserv. Assoc.
34:33; Keen, 1943, Jour. Forestry 41:249; Weaver, 1943, Jour. Forestry
41:8; Hall, 1944, Proc. West. For. Conserv. Assoc. 35:25; Annand, 1944,
U. S. Dept. Agric. Bur. Ent. PI. Quar. Rept. 1943:6; Miller, 1945, U. S.
Dept. Agric. Bur. Ent. PI. Quar. Ins. Pest Surv. 1944:14; Patterson, 1945,
Univ. Washington Publ. Biol. 10:149; Furniss and Struble, 1946, U. S.
Dept. Agric. Bur. Ent. PI. Quar. Ins. Pest Surv. 1945:21; Hall, 1946,
Timberman 48(2):54,62; Keen, 1946, Pan-Pacific Ent. 22:2; Bongberg,
1947, Timberman 48(7): 128; De Gryse, 1947, Forest Ent. Canada, p. 3;
Annand. 1947, U. S. Dept. Agric. Bur. Ent. PI. Quar. Rept. 1945-46:21;
Sand and Bryan, 1947, U. S. Dept. Agric. Farmers Bull. 1989:28; Anony-
mous, 1947, California Dept. Natl. Res. Div. For. 1946:8; Anderson, 1948,
Jour. Econ. Ent. 41:596; Struble, 1948, Jour. Forestry 46:129; Anonymous,
1949, U. S. Dept. Agric. Bur. Ent. PL Quar. Ins. Pest Surv. 1948:19;
Johnson, 1949, Jour. Forestry 47:277; Anonymous, 1950, U. S. Dept. Agric.
Bur. Ent. PI. Quar. Ins. Pest Surv. 1949:25; Keen, 1950, Jour. Forestry
48:186; Pearson, 1950, U. S, Dept. Agric. Monogr. 6:154; Beal, 1951,
Proc. West. For. Conserv. Assoc. 41:59; Anonymous, 1951, U. S. Dept.
Agric. Bur. Ent. PI. Quar. Ins. Pest Surv. 1950:24; Anonymous, 1951,
U. S. Dept. Agric. Bur. Ent. PI. Quar. Ins. Surv. 1951 (4) :6; Johnson,
1951, Northwest Sci. 25:32; Whiteside, 1951, U. S. Dept. Agric. Circ.
864:1-11; Anonymous, 1952, U. S. Dept. Agric. Bur. Ent. PL Quar. Coop.
Econ. Ins. Rept. 1 (Sp. Rept. 4):91; Keen, 1952, U. S. Dept. Agric. Misc.
Pub. 273:p,?; Keen, 1952, U. S. Dept. Agric. Yearbook 1952:688; Hoyt,
1953, U. S. Dept. Agric. Bur. Ent. PL Quar. Rept. 1951:40; Callaham,
1953, U. S. Dept. Agric. Bur. Ent. PL Quar. E. T. 311:1; Hoyt 1954,
U. S. Dept. Agric. Bur. Ent. PL Quar. Rept. 1952:19; Orr, 1954, U. S.
Dept. Agric. For. Serv. Intenntn. For. Range Expt. Sta. Rept. 1953:2;
Lively, 1954, Nature Mag. 47:205; Ross, 1954, Canada Dept. Agric. For. Ins.
Dis. Surv. Rept. 1953:142; Cowlin, 1955, U. S. Dept. Agric. For. Serv.
Pac. N.W. For. Expt. Sta. Rept. 1954:34; Jemison, 1955, U. S. Dept.
Agric. California For. Range Expt. Sta. Rept 1954:30; Keen, 1955, U., S.
Dept. Agric. Forest Pest Leaflet 1:1-4; Bailey, 1956, U. S. Dept. Agric.
For. Serv. Intermtn. For. Range Expt. Sta. Rept. 1956:29; Buckhorn, 1956,
U. S. Dept. Agric. For. Serv. Pacific N. W. For. Range Expt. Sta. Ochoco N.
F. Rept. 1945-54:1; Jemison, 1956, U. S. Dept. Agric. California For. Range
Expt. Sta. Rept. 1955:50; Whiteside, 1957, U. S. Dept. Agric. Pacific N. W.
For. Range Expt. Sta. For. Ins. Condit. 1956:2, 17, 31; Moore, 1957, Jour.
Econ Ent. 50:548; Price, 1957, U. S. Dept. Agric. Rocky Mtn. For. Range
Expt. Sta. Rept. 156:99; Miller and Keen, 1960, Biology and Control of
the Western Pine Beetle, 381 p.
Dendroctonus barberi Hopkins, 1909, U. S. Dept. Agric. Bur. Ent. Tech. ser.
17(1): 85 {new synonymy); Swaine, 1918, Dom. Canada Dept. Agric. Ent.
Br. Bull. 14(2) :62; Hagedorn, 1910, Coleopteroum Catalogus 4:20; Hage-
dorn, 1910, Genera Insectorum 111:60; Hopkins, 1915, U. S. Dept. Agric.
Bur. Ent. Tech. ser. 17(2):211; Chamberlin, 1939, Bark and Timber
Beetles of North America, p. 155. Biol.: Hopkins, 1909, U. S. Dept. Agric.

The Great Basin Naturalist

32 STEPHEN L. WOOD Vol. XXIII, Nos. 1-2

Bur. Ent. 83(1 ):49; Miller and Wales, 1929, Jour. Econ. Ent. 22:436; Craig-
head, 1930, U. S. Dept. Agric. Misc. Publ. 74:5; Blackman, 1931, New
York St. Coll. For., Syacuse Univ. Bull. 4(4), Tech. Publ. 36:32; Craig-
head et al., 1931, Jour. Forestry 29:1008; Keen, 1938, U. S. Dept. Agric.
Misc. Publ. 273:100; Beal, 1939. U. S. Dept. Agric. Farmers Bull. 1824:10;
Pearson, 1950, U. S. Dept. Agric. Monogr. 6:154; Anonymous, 1951, U. S.
Dept. Agric. Bur. Ent. PI. Quar. Ins. Pest Surv. 1951 (4) :8; Anonymous,
1952, U. S. Dept. Agric. Bur. Ent. PI. Quar. Coop. Econ. Ins. Kept. l(Sp.
Kept. 4): 94; Orr, 1954, U. S. Dept. Agric. Intermtn. For. Range Expt. Sta.
For. Ins. Condit. 1953:3; Price, 1955, U. S. Dept. Agric. Rocky Mtn. For.
Range Expt. Sta. Rept. 1955:23; Price, 1956, U. S. Dept. Agric. Rocky Mtn.
For. Range Expt. Sta. Rept. 1956:91, 97; Bailev, 1956, U. S. Dept. Agric.
Intermtn. For. Range Expt. Sta. Rept. 1956:37; Yasinski, 1956, U. S.
Dept. Agric. Rocky Mtn. For. Range Expt. Sta. Paper 23:1; Massey, 1961,
Ann. Ent. Soc. America 54:354.

Dendroctonus brevicomis var. barberi Hopkins, 1905, Proc. Ent. Soc. Washing-
ton 7:147 {nomen nudum) .

Dendroctonus arizonicus Hopkins, 1902, Proc. Ent. Soc. Washington 5:3 (in
part; nomen nudum).

Dendroctonus brevicornis: Dietz, 1890, Trans. American Ent. Soc. 17:32.

Dendroctonus frontalis: Dietz, 1590, Trans. American Ent. Soc. 17:32 (in part).

Dendroctonus n. sp., Hopkins. 1904, U. S. Dept. Agric. Div. Ent. Bull. 48:42, 44.

This species is very closely related to frontalis, but is readily
distinguished by the uniformly short declivital pubescence, by the
less strongly impressed declivital striae, by the more numerous, more
finely granulate punctures of the declivital interspaces, by the larger
average size, and, in part, by the distribution.

Male. — Length. 2. 5-5.0 mm. (average about 4), 2.4 times as long
as wide; mature color very dark brown.

Frons convex, with a pair of lateral elevations on median half
just below upper level of eyes separated by a deep median groove,
the summits of elevations armed at their dorsomedian margins by
one or two prominent, somewhat dorsomedially oriented granules;
epistomal margin elevated, its surface smooth and shining; epistomal
process half (0.50 times) as wide as distance between eyes, its arms
oblique (about 40° from the horizontal) and elevated, the horizontal
portion about half its total width, transversely concave, overlap-
ping and ending just above epistomal margin and bearing under its
distal margin a dense brush of conspicuous yellowish setae; surface
punctate-rugulose above eyes, more deeply punctured and subgran-
ulate below. Vestiture, except epistomal brush, short, sparse, in-
conspicuous.

Pronotum 1.4 times as wide as long, widest on basal third; sides
rather strongly arcuate on basal three-fourths, rather strongly con-
stricted just behind the broadly, shallowly emarginate anterior
margin; surface smooth with rather fine, shallow, close punctures
on median third, becoming more finely punctured laterally; an in-
distinct median line apparent. Vestiture very short, rather sparse,
inconspicuous.

Elytra 2.2 times as long as pronotum; sides straight and sub-
parallel on basal two-thirds, rather broadly rounded behind; basal

June 14, 1963 revision of dendroctonus 33

margins arcuate and bearing a row of about nine moderately
large, raised, overlapping crenulations, with several smaller sub-
marginal ones particularly on interspaces two and three; striae
weakly impressed, the punctures rather small and shallow; inter-
striae about twice as wide as striae and armed by abundant, con-
fused, small, transverse crenulations, each averaging about one-
third the width of an interspace, never more than half as wide on
posterior half of disc. Declivity moderately steep, convex with a
feeble impression between first and third striae; strial punctures
reduced in size; interstrial punctures ranging from finely granulate
to not at all granulate, abundant, confused (about three to four
irregular ranks across width of an interspace). Vestiture rather
abundant, short, averaging about half as long as width of an inter-
space, never as long as its entire width.

Female. — Similar to male except lateral elevations of frons less
prominent and unarmed, with median groove consequently less
conspicuous; arms of epistomal process less strongly elevated; pro-
notal constriction largely filled by a prominent transverse elevated
callus both laterally and dorsally; punctures of pronotal disc very
slightly larger and deeper; transverse crenulations of elytral disc
very slightly larger; and declivital granules much finer, only a few
punctures with a minute granule on upper margins.

Type locality. — Middle California (Williams, Arizona, for bar-
beri). The types of both descriptions were examined.

Hosts.- — Pinus ponderosa, and P. coulteri. Rarely, particularly
during epidemics, other species of Pinus may be attacked.

Distribution. — North America west of the Rocky Mountains from
Chihuahua to British Columbia wherever the principal host tree,
Pinus ponderosa, occurs.

Specimens from the following localities were examined (Fig. 45). Arizona:
Carr Canyon, Chiricahua Mts., Coconino N. F., Crow King, "Deadmans Flat"
(Coconino Co.), Flagstaff, Ft. Apache, "Fort Valley," Grand Canyon N. P.,
Groom Ck. (Prescott N. F.), Huachuca Mts., "Pleasant Valley," Prescott, San
Francisco Mts., Santa Catalina Mts., Santa Rita Mts., Springerville, Walnut
Canyon N. M.. Williams, "Willow Rock," and Young. California: Alta,
"Atwell's Mill," Badger, Ballard, "Barton Flat" (San Bernardino N. F.), Bass
Lake, "Battle Creek R. S." (Shasta Co.), "Bear Flat" (Warner Mt.), Berkeley,
"Better Waller R. S.," Black's Mt., Blue Canyon, Blut Mt., Bray, Breckenridge
Mt., "Buck Ck.," Bumey, "Butte Ck. Basin" (Butte Co.), "Campbell Hot
Springs," "Capanero Ck.," Carrville, Castella, Cayton, Cecilville, Cedar Grove
(Kings Can. N. P.), "Cedar Ridge" (Glenn Co.), Chester, Cisco, "Clairsville,"
Coarsegold, Corte Madera, Crane Valley, "Cummings R. S. (Eldorado Co.),
Cuyamaca Rancho St. P., Crystal Lake, "D. & H. Mill" (Madera Co.), Deep
Creek, Diamond Springs, "Dixie Valley" (Lassen Co.), Dunlap, Elk Creek,
"Figueroa Mt.," Fish Camp, Foresthill. Giant Forest, Hackamore, Happy Camp,
"Harvey Valley" (Alameda Co.), Hayfork, "Hazel Green," Hobergs, Hot
Springs, Idyllwild, Jackson Ck., Julian, "Kangai-oo R. S.," Kaweah, Kaweah
River, Kelsey, Kings Canyon, Klamath N. F., Kyburz, "Lagunas," Lake Almanor,
Lake Arrowhead, "Little Humbug R. S.," "Little Yosemite," Long Bai-n, Look-
out, Los Olivos, "Lumgray R. S.," Mather, McCloud, McLears Resort (Plumas
Co.), Meadow Valley, Miami R. S., Milford, "Millwood," Miramonte, Modoc
N. F., "Madrone Spring," Moffit Ck., "Mosquito," Mt. Hermon, "Nash Mine"

34

The Great Basin Naturalist

STEPHEN L. WOOD Vol. XXIII, Nos. 1-2

Fig. 45. Probable geographical distribution of Dendroctonus spp. with col-
lection sites indicated: 1. brevicomis (circles); 2. frontalis (triangles).

(Trinity Co.), "Nigger Spring" (Lassen Co.). North Fork, N. Fk. Eel River,
"Norton's Mill (Siskiyou Co.). "Norvell Flats" (Lassen Co.), "Oak Flat Camp"
(Fresno Co.), "Onion Valley," Placerville, Plumas N. F., Pinecrest, Pinehurst,
Pine Valley, "Pinoche R. S." (Mariposa Co.), Prattville, "Quintette," Santa
Cruz, Shasta Springs. Sisson, Stirling City. Sugar Pine. "Summerdale," "Summit
Lake" (Shasta Co.), Tenaya Lake, Three Rivers, Timber Mt.. Tuolomne Mea-
dows, Wawona, "Whitehall," White Hills, Willow Ranch. Wishon. Yosemite
N. P., and Yreka. Color.ado: Dolores, Ft. Garland, "Vallecito R. S." (La Plata
Co.), Monte Vista, and Uncompahgre N. F. Id.aho: Roise. Cedar Mt.. Center-
ville, Couer d'Alene, Garden Valley, Kooskia. Moscow, Pioneer, Placerville,
Smith's Ferry, Stites. and Troy. Mont.an.^: Missoula. Nev.^da: Las Vegas.
New Mexico: Capitan Mts., Cloudcroft, Datil, Gloriela Mesa, Mescalero, Mim-
bres, Ruidoso, Santa Fe. Santa Catalina Mts.. Zuni Mts., and Jermejo Park.
Oregon: Ashland, Rend. Rlue Mts., Rl}', Rurnt River. Chiloquin, Cold Springs,
Colestin, Corvallis. "Dutch Ck.." Fremont N. F.. Ft. Rock, Grants Pass, Jenny
Ck., Joseph, Keno, Klamath Falls. Klamath Indian Res.. Prineville. "Pringle
Falls," Siskiyou Mts., Sisters, Sumpter, and Wallowa Mts. Tex.j^s: Rig Rend
and Davis Mts. Ut.ah: Daves Hollow (Dixie N. F.), Escalante, Panguitch,
Pin Hollow (Fish Lake N.F.), and Ashley N. F. W.'vshington: Rlue Mts., Ruck-
eye, Chelan, Dayton, Kooskooskie. Northport. Pullman, and Toppenish. Rritish
Columbia: Aspen Grove, Little Shuswap Lake. "Midday Ck." in Indian Meadow,
Midday Valley, "Spious Ck." Summerland. "Trepan Ck.," and "Trepanier Ck."
Chihu.'vhu.'S. Tres Rios.

Geographical variation. — Specimens from the eastern parts of
the range of this species, Arizona. Utah and Colorado, tend to aver-
age slightly larger in size (less than 1 mm. larger); the elytral

June 14, 1963 revision of dendroctonus 35

striae tend to be somewhat more deeply impressed; and the elytral
crenulations tend to average slightly larger. These differences, how-
ever, are not sufficiently consistent in a long series from any par-
ticular locality to permit the recognition of distinct geographic races
as was done previously by Hopkins (1909:70). It is of interest to
note that the smallest, most coarsely sculptured specimens came from
northern California; the most finely sculptured specimens, from
Chihuahua, had rather strongly impressed striae (equal to speci-
mens from any other locality); and numerous specimens, particu-
larly females, from Utah and Arizona cannot be distinguished from
the average West Coast series. The Chihuahua series, particularly,
exhibited every degree of morphological intergradation between ex-
treme eastern and western populations.

Biology. — This species probably has destroyed more merchant-
able timber in North America than any other organism in historic
time. Estimates indicate that approximately two billion board feet
of standing timber have been destroyed annually since studies com-
menced over half a century ago.

Overwintering parent adults and brood may become active at
any period when subcortical temperatures become sufficiently high,
probably somewhere in the vicinity of 45° to 50° F. The dates at
which favorable conditions for flight occur in the spring vary con-
siderably from year to year and from locality to locality depending
on exposure, altitude, latitude, weather, and other ecological factors.
In general the first of the overwintering adults and brood emerge
to attack new trees about the first of May. Attacks from these beetles
ordinarily continue until the latter part of June. A paricularly
early or late season, or a change in latitude north or south of the
center of distribution may alter these dates by as much as a month.
In the extreme southern limits of distribution it is possible that
some flight activity may continue throughout the year. Because
beetles do not emerge simultaneously, but do so slowly over a con-
siderable period of time, and because of overlapping broods some
flight activity continues throughout the summer season with periods
of greatest flight activity coinciding with the emergence of each new
brood. Flight activity is discontinued in October or November when
daytime temperatures fall below 50°.

Trees selected for attack usually are living, standing and larger
than 12 inches D.B.H. Prostrate trees are seldom attacked. In the
absence of competing species the attack normally is distributed from
the ground level upward to areas as small as four to eight inches
in diameter where cork plates of the bark have formed. Younger
bark of limbs or upper bole and of smaller trees where cork plates
have not developed are rarely attacked. In the presence of compet-
ing species of Dendroctonus, particularly adjunctus, and to a less-
er extent ponderosae, the area of attack by brevicomis is forced up-
ward from the ground level a variable distance depending on the
comparative abundance of competing species.

The attack usually begins in the upper midbole area of the host

36

The Great Basin Naturalist

STEPHEN L. WOOD Vol. XXIII, Nos. 1-2

tree then progresses upward and downward. The attack is slow and
continuous, without any sudden or concerted swarming of the
beetles. Its duration is variable, evidently depending upon the pop-
ulation density of beetles in the area, upon resistance of the host,
or upon climatic or other ecological factors peculiar to the season
or locality. It may be completed in as little as seven days, or it may
continue over the greater part of a year. Characteristically the at-
tack will be concentrated on one particular tree until it is overcome,
even when the beetle population is high, before an attack is started
on a second nearby tree. There is no attempt to occupy all avail-
able bark; the density of individual attacks may be as low as an
average of about five per square foot of suitable bark on a sus-
ceptible tree, or higher than 20 per square foot on a vigorous or
resistant tree. In general, single tree attacks suggest an endemic
condition, while group attacks suggest an epidemic condition.

Fig. 46. Dendroctonus brevicomis: Egg galleries sinuate, predominantly
transverse; egg niches large, placed individually on alternate sides of gallery;
larval mines turn into outer bark and expand after a brief contact with the
cambium.

The winding egg galleries (Figs. 43, 46) are constructed almost
entirely in the inner bark or phloem tissues; they are in continual
contact with and very lightly score or stain the woody or xylem
tissues. Their total lateral displacement usually is equal to or greater
than the total longitudinal displacement, although an occasional
gallery may be decidedly longitudinal.

The diameter of an individual egg gallery is slightly greater
than the width of a beetle; it averages approximately 35 cm. in

June 14, 1963 revision of dendroctonus 37

length, although exact measurements of fully formed galleries are
virtually impossible to obtain because of the tendency for the wind-
ing galleries to branch, to anastomose, and to cross and recross
one another. It is not uncommon for more than one pair of beetles
to occupy one gallery, usually each pair being found in different
branches that use the same entrance hole. Presumably this habit
has suggested a tendency toward polygamy to some workers, par-
ticularly when the male was late in arriving or failed to arrive at
all.

The initial attack is made by the female, usually in a crevice
of the bark. About the time she reaches the phloem tissues where
the pitch begins to flow she is joined by the male who then assists
her by pushing the excavated frass out of the entrance hole. Con-
tinuation of the parental or egg gallery is performed entirely by the
female beetle. After several inches of gallery have been cleared and
the frass ejected from the entrance hole, the male then packs the
frass in the lower regions of the gallery thereby closing the entrance
hole and tightly filling the gallery except for a few inches in the area
where the beetles are working. It has been estimated that (Miller
and Keen, 1960:16) about two-thirds of an inch of new gallery is
formed each day. Mating occurs only after the female has been
joined by the male, never on the surface of the tree before the at-
tack begins. Although seldom seen, mating evidently occurs re-
peatedly, since it has been observed in various stages of gallery con-
struction.

Ordinarily, but not always, the entrance tunnel is without a
nuptial chamber or other means of turning around until the first
ventilation tunnel or branch in the gallery is reached. Ventilation
tunnels (indicated by dotted circles in Fig. 46) are placed at irregu-
lar intervals and are not always present. Their presence appears
related to the stage of gallery construction, thickness of the bark,
and activity of the beetles. Usually they are not constructed before
the entrance hole is plugged by frass; they are less abundant or
sometimes entirely absent in trees having comparatively thin bark;
and they appear to be more numerous in galleries constructed by
unusually active beetles. Seldom are they spaced at intervals less
than five centimeters.

Oviposition ordinarily begins about eight days after the attack
and continues for approximately 10 to 49 days (Miller and Keen,
1960:20), except when egg-laying is interrupted by winter in which
case it is greatly extended. Although estimates of the number of
eggs produced by a female based on the average number of eggs
per inch of gallery have suggested a figure much higher, the high-
est number actually reported is 41 (Miller and Keen, 1960:19).
Usually a majority of the eggs are deposited in the first third of
the gallery, the number declining significantly in the final third.

Egg niches are symmetrical and ordinarily are constructed on
the sides of the gallery, usually in direct contact with the cambium.
They are broad and deep, the depth being equal to about one-fourth

The Great Basin Naturalist

38 STEPHEN L. WOOD Vol. XXIII, Nos. 1-2

to one-third the diameter of the egg gallery. The deepest point is
rounded, matching rather well the anterior profile of the parent
beetle as seen from the dorsal aspect. Unfilled egg niches often can-
not be distinguished from the beginning of a new branch of the
gallery. The number and spacing of niches depends on many fac-
tors, but usually the minimum distance between eggs on a particu-
lar side of a gallery is one centimeter. When considering both sides
of the gallery and the alternating placement of eggs this distance
is reduced by half. Eggs are deposited individually in the niches;
each niche is then filled by specially prepared frass packed to the
original level or contour of the gallery.

Following the period of oviposition the gallery may be continued
in an irregular feeding tunnel of somewhat greater diameter than
usual until death of the parent bettle, or the beetles may construct
an exit tunnel, often independent of one another, by extending one
of the ventilation tunnels and emerge to attack another host tree.
It has been estimated that as many as 50 percent of the parent
beetles emerge to produce a second brood, and a few of these re-
emerge to produce their third brood of the season (Miller and Keen,
1960:18). Of those beetles that re-emerge from the host males pre-
dominate significantly.

The incubation period has not been determined precisely. Av-
ailable figures suggest that seven days are required for hatching
under optimum conditions (Miller and Keen, 1960:20), presum-
ably with longer periods required when less favorable conditions
exist. The newly-hatched larvae mine the phloem next to the cam-
bium for approximately one centimeter at right angles to the egg
gallery. They then move into the inner bark and end their tunnels
near the outer bark where an area is cleared for pupation. Under
optimum conditions larval development may be completed in as
little as 30 to 35 days (Miller and Keen, 1960:24); however, they
do not develop at the same rate and some may require as much as
300 days to complete the larval stage of development. In the pupa-
tion cell the larva undergoes physiological changes to become a
quiescent prepupa for about two to seven days before pupation oc-
curs (Miller and Keen, 1960:30); mature larvae overwinter as
prepupae, never as pupae. Under normal conditions about 6 to 20
days are required to complete the pupal stage (Miller and Keen.
1960:31), unfavorable conditions may extend this period. A matur-
ation period between attainment of the adult stage and emergence
from the host varies from 7 to 14 days (Miller and Keen, 1960:31),
except in the spring months when it may be somewhat longer.

The number of generations each year is complicated by pecul-
iarities of a particular season, by re-emergence of parent adults to
produce a second or a third brood, and by overlapping generations.
In the northern parts of its range one complete and a partial second
generation appears normal, in southern California and in Arizona
three complete and perhaps a partial fourth generation might be
expected.

June 14, 1963 revision of dendroctonus 39

Dendroctonus frontalis Zimmerman
Figs. 3-6, 28, 33, 45, 47.

Dendroctonus frontalis Zimmerman, 1868, Trans. American Ent. Soc. 2:149;
Leconte, 1868, Trans. American Ent. Soc. 2:173; Leconte, 1876, Proc.
American Philos. Soc. 15:386; Dietz, 1890, Trans American Ent. Soc. 17:32
(part); Hopkins, 1902, Proc. Ent. Soc. Washington 5:3; Swaine, 1909, New
York St. Mus. Bull. 134:96; Hopkins, 1909, U. S. Dept. Agric. Bur. Ent.
Tech. ser. 17(1):90; Hagedorn, 1910, Coleopterorum Catalogus 4:20;
Hagedorn, 1910, Genera Insectorum 111:60; Hopkins, 1915, U. S. Dept.
Agric. Bur. Ent. Tech. ser. 17(2):211; Blatchley and Leng, 1916, Rhynch-
ophora or weevils of North Eastern America, p. 653; Chamberlin, 1939,
Bark and Timber Beetles of North America, p. 165. Biol,: Packard, 1890,
U. S. Ent. Comm. Kept. 5:722; Hopkins, 1892, Poc. Ent. Soc. Washington
2:353; Hopkins, 1892, Science, July 29, 20:64; Hopkins, 1893, West Vir-
ginia Agric. Expt. Sta. Bull. 31:143, 32:213; Hopkins, 1893, Insect Life
5:187; Riley, 1893, Insect Life 6:140; Hopkins, 1893, Insect Life 6:126; Hop-
kins, 1894, Canadian Ent. 26:280; Lintner, 1894, Gardening 2:292; Hop-
kins, 1896, Canadian Ent. 28:250; Chittenden, 1897, U. S. Dept. Agric.
Div. Ent. n. s.. Bull. 7:67; Schwarz, 1898, Proc. Ent. Soc. Washington
4:81; Hopkins, 1898, Proc. Soc. Prom. Agric. Sci. 19:103; Hopkins, 1899,
West Virginia Agric. Expt. Sta. Bull. 56:395; Hopkins, 1899, Proc. Ent.
Soc. Washington 4:343; Hopkins, 1899, U. S. Dept. Agric. Div. Ent. Bull.
21:13, 14, 27; Lugger, 1899, Minnesota Agric. Expt. Sta. Bull. 66:315;
Chittenden, 1899, U. S. Dept. Agric. Div. Foestry Bull. 22:55; Hopkins,
1901, U. S. Dept. Agric. Div. Ent. Bull. 28:pl. XII.; Hopkins, 1902, U. S.
Dept. Agric. Div. Ent., n. s, Bull. 37:20; Hopkins, 1903, U. S. Dept. Agric.
Yearbook 1902:270; Hopkins, 1903, Canadian Ent. 35:59; Hopkins, 1904,
U. S. Dept. Agric. Div. Ent. Bull. 48:41, 44; Hopkins, 1904, U. S. Dept.
Agric. Yearbook 1904:270; Hopkins, 1905 (1906), Proc. Ent. Soc. Wash-
ington 7:80; Currie, 1905, U. S. Dept. Agric. Div. Ent. Bull. 53:100; Felt,
1905, New York St. Mus., Mem., 8, 1:6; Webb, 1906, U. S. Dept. Agric.
Yearbook 1905:632; Webb, 1906, U. S. Dept. Agric. Yearbook 1906:515;
Zavitz, 1906, Ontario Ent. Soc. Kept. 36:126; Howard, 1906, U. S. Dept.
Agric. Div. Ent. Kept. 1906:14; Hopkins, 1908, U. S. Dept. Agric. Year-
book 1907:163; Zavitz, 1908, U. S. Dept. Agric. Yearbook 1907:549; Fiske,
1908, Proc. Ent. Soc. Washington 9:24; Hopkins, 1908, Proc. Ent. Soc.
Washington 9.131; Zavitz, 1909, U. S. Dept. Agric. Yearbook 1908:574;
Hopkins, 1909, U. S. Dept. Agric. Bur. Ent. Bull. 58:58; Hopkins, 1909, U.
S. Dept. Agic. Bur. Ent. Bull. 83:56; Hopkins, 1910, U. S. Dept. Agric.
Bur. Ent. Circ. 125:1; Hopkins, 1911, St. Louis Lumberman, July 1, p.
669; Hopkins, 1911, U. S. Dept. Agric. Farmers Bull. 476, 15 p.; Mason,
1911, South. Lumberman, Sept. 30, p. 35; Hinds, 1912, Alabama Poly.
Circ. 15; Mattoon, 1915, U. S. Dept. Agric. Bull. 244:35: Murphy, 1917,
U. S. Dept. Agric. Bull. 544:27; Hopkins, 1919, American Lumberm.
2299:43; Hopkins, 1919, Sci. Month. 8:503; Boving and Champlain, 1921,
Proc. U. S. Natl. Mus. 57:575; Hopkins, 1921, U. S. Dept. Agric, Farmers
Bull. 1188, 15 p.; Blackman, 1922, Mississippi Agric. Expt. Sta. Tech. Bull.
11:58; Berckes, 1924, American Lumberm. 2554:80; Berckes, 1924,
Lumberman 73(1025): 10; Felt, 1924, Manual of Tree and Shrub
Insects, p. 252; Howard, 1924, U. S. Dept. Agric. Bur. Ent. Kept.
1924:26; Middleton, 1924, U. S. Golf Assoc. Green Sec. Bull. 4:148;
St. George, 1924, Lumber Trade Jour. 86(9) :37; St. George, 1924,
Proc. South. Logging Assoc. 14:79; Wyman, 1924, U. S. Dept. Agric. For-
est Serv. Bull. 8(40) :2; Anonymous, 1924, Natl. Lumberman 73:10;
Craighead, 1925, Jour. Forestry 23:349; Craighead, 1925, Jour. Econ. Ent.
18:557; St. George, 1952, American Lumberm. 2607:50; Schoene, 1926,
Virginia St. Crop Pest Comm. Quar. Bull. 7:4, 23; Beal, 1927, Jour. For-
estry 25:741; Craighead, 1927, U. S. Dept. Agric. Circ. 411:9; Craighead,
1928, Jour. Foresty 26:886; Craighead and St. George, 1928, Forest Worker
4(2): 11; St. George, 1928, Forest Worker 4(5): 15; Nelson and Beal, 1929,

The Great Basin Naturalist
40 STEPHEN L. WOOD Vol. XXIII, Nos. 1-2

Phytopathology 19:1101; St. George and Beal, 1929, U. S. Dept. Agric.
Farmers Bull. 1586, 8 p.; St. George and Beal, 1929, South. Lumber
Jour. 33(17) :37; Bentley, 1930, Tennessee Bien. Kept. 1929:105; Craig-
head, 1930, U. S. Dept. Agric. Misc. Pub. 74:4; Craighead and St. George,
1930, Science 72:433; St. George, 1930, Jour. Econ. Ent. 23:826; Lutken
1930, South Carolina Wkly News Notes 19:23; Marlatt, 1930, U. S. Dept
Agric. Bur. Ent. Kept. 1930:47; Rumbold, 1931, Jour. Agric. Res. 43:851
St. George, 1931, Forest Worker 7(6): 16; Gary, 1932, Naval Stores Rev,
17:14, 18:14, 20, 19:14, 18; Moore, 1932, South Lumberm. 145(1833):21
Rumbold, 1932, Bull. Ecol. Soc. America 13(4): 17; Beal, 1933, Jour,
Forestry 31:329; Marlatt, 1933, U. S. Dept. Agric. Bur. Ent. Rept. 1933:29
Knull, 1934, Jour. Econ. Ent. 27:716; Beal. 1934. Jour. Econ. Ent. 27:1132
Nelson, 1934, Phytopath. Ztschr. 7:327; Caird, 1935, Bot. Gaz. 96(4) :709
Bramble and Hoist, 1935, Phytopathology 25:7; Craighead, 1935, U. S
Dept. Agric. Misc. Pub. 209:134; Hoist, 1936, Jour. Agric. Res. 53:513
Hoist, 1937, Jour. Econ. Ent. 30;676; Elliott and Mobley, 1938, South
For. 1938:332; Strong, 1938, U. S. Dept. Agric. Bur. Ent. PI. Quar. Rept
1937:17; Muesebeck, 1938, Proc. Ent. Soc. Washington 40:286; Ross and
Mattoon, 1939, U. S. Off. Educ. Vocat. Div. Bull. 196:45; Bramble and
Hoist, 190, Phytopathology 30:881; Craighead, 1940, Phytopathology
30:976; Harrar and Ellis, 1940, Proc. Virginia Acad. Sci. 1:211; Harrar
and Martland, 1940, Proc. Virginia Acad. Sci. 1:211; Mattoon, 1940,
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Alabama Ent. Circ. 198:3; Hetrick, 1940, Jour. Econ. Ent. 33:554; Hetrick
1941, Proc. Ent. Soc. Washington 43:168; Carruth, 1941, Naval Stores
Rev. 51(19):6; Friend, 1942, Yale Univ. School For. Bull. 49:144; Cruik-
shank, 1943, U. S. Dept. Agric. Misc. Pub. 533:58; Hetrick, 1943, South
Planter 104(3) :30; Nieland, 1943, Git. Indus. 24(6) :8; Anonymous, 1944,
South Carolina Ext. Bull. 107:26; Beal and Massey, 1945, Duke Univ.
School For. Bull. 10:82; Upton, 1945, Proc. Trans. Texas Acad. Sci.
28:100; Hoffman and Anderson, 1945, Jour. Forestry 43:436; O'Byme, 1946,
Virginia Ext. Circ. 403:1; Anderson, 1947, Texas For. Serv. Bull. 33:2;
Barnhill, 1947, Alabama Ext. Handb. Alabama Agric. Ed. 4:221; Flory,
1947, South Carolina Ext. Bull. 107:26; Fronk, 1947, Virginia Agric. Expt.
Sta. Tech. Bull. 108, 12 p.; Sand and Bryan, 1947, U. S. Dept. Agric.
Farmers Bull. 1989:28; Underbill and Fronk, 1947, Virginia Agric. Expt.
Sta. Rept. 1946:33; Anderson, 1948, Jour. Econ. Ent. 41:596; Gerhart
and Abler, 1949, Jour. Forestry 47:636; Hetrick, 1949, Proc. Assoc. South.
Agric. Workers 46:93; Hetrick, 1949. Jour. Econ. Ent. 42:466; Anony-
mous, 1949, U. S. Dept. Agric. Bur. Ent. PI. Quar. Ins. Pest Surv. 1948:20;
Craighead, 1950, U. S. Dept. Agric. Misc. Pub 657:p?; Anonymous, 1950,
Virginia Adv. Counc. Virginia Econ. Com. For., p. 25; Anonymous, 1950,
Texas For. Serv. Circ. 26, 7p.; Folweiler, 1951, For. & People 1(3): 10;
Anonymous, 1951, U. S. Dept. Agric. Bur. Ent. PI. Quar. Ins. Pest Surv.
1951 (4):7; Anonymous, 1951, U. S. Dept. Agric. Bur. Ent. PI. Quar. Ins.
Pest Sum. 1950:24; Ford, 1951, North Carolina Res. Farm. 10(Prog. Rept.
2):3; Beal, 1952, Duke Univ. School For. Bull. 14:48; Hoyt. 1952, U. S.
Dept. Agric. Bur. Ent. PI. Quar. Rept. 1950-1:17; Cann, 1952, South
Lumberm. 185(2321) : 150; Anonymous, 1952, U. S. Dept Agic. Bur. Ent.
PI. Quar. Coop. Econ. Ins. Rept. 1(4):89; Dyer, 1953, Georgia Agric. Ext.
Bull. 578:8; Jones and Ford, 1953, North Carolina Ext. Serv. Folder 100,
6 p.; Barker and Nettles, 1954, South Carolina Ext. Circ. 239, 6 p.; Coyne,
et al., 1954, Proc. Assoc. Agric. Workers 51:98; Jackson, et al., 1954,
For. Dis. Ins. Georgia's Trees, p. 25; Lee, 1954. Jour. Forestry 52:767; Lee,
1954, Texas Forest News 33:5; Demmon, 1955. U. S. Dept. Agric. S. E. For.
Expt. Sta. Rept. 1954:70; Bennett, 1955, Texas For. Serv. Circ. 43:2, 10;
Flory, et al.. 1955, South Carolina Agric. Ext. Serv. Bull. 116:10; Heller,
et al., 1955. Jour. Foestry 53:483; Merkel, et al., 1955, South. Lumberm.
190(2389) :60; Speers, et al., 1955, Proc. Assoc. South. Agric. Workers
52:100; Briegleb. 1955, U. S. Dept. Agric. South. For. Expt. Sta. Rept.
1954:66; Anonymous, 1955, U. S. Dept. Agric. Imp. For. Ins. 1954:14;
Anonymous, 1955, U. S. Dept. Agric. South. For. Expt. Sta. Pest Rept.

June 14. 1963 revision of dendroctonus 41

nos. 6, 9; Bennett. 1956, U. S. Dept. Agric. South. For. Expt. Sta. Pest
Kept. 10:3; Biegleb. 1956. U. S. Dept. Agric. South. For. Expt. Sta. Kept.
1955:49; Briegleb. 1956, U. S. Dept. Agric. S. E. For. Expt Sta. Kept.
1956:68; Demmon. 1956, U. S. Dept. Agric. S. E. For. Expt. Sta. Kept.
1955:71. 78; McArdle. 1956. U. S. Dept. Agric. For. Serv. Kept. 1953:3,
12; Merkel, 1956. Proc. Assoc. South. Agric. Workers 53:130; Merkel
and Kowal. 1956. U. S, Dept. Agric. S. E. For. Expt. Sta. Paper 67:2;
Clausen. 1956. U. S. Dept. Agric. Tech. Bull. 1139:67; Speers, 1956,
Proc. Assoc. South. Agric. Workers 53:130; Walker, 1956, Georgia For.
Res. Counc. Kept. 2:1, 6, 8; Nagel and David, 1956, Proc. N. Centr. St.
Br. Ent. Soc. America 11:20; Davis and Nagel, 1956, Jour. Econ. Ent.
49:210; Nagel. et al, 1956, Jour. Forestry 55:894; Anonymous, 1956,
U. S. Dept. Agric. Hort. Crops Res. Br. PI. Dis. Rept. 241:220; Massey,
1957, Proc. Helminthol. Soc. Washington 24(1 ):29; Osgood, 1957, U .S.
Dept. Agric. S. E. For. Expt. Sta. Paper 80, 19 p.; Anonymous, 1957,
U. S. Dept. Agric. South. For. Expt. Sta. Pest Rept. 16:2; McCambridge
and Kowal, 1957, U. S. Dept. Agric. S. E. For. Expt. Sta. Paper 76:2;
Pechanec, 1957. U. S. Dept. Agric. S. E. For. Expt. Sta. Rept. 1956:39;
Anonymous, 1957. U. S. Dept. Agric. South. For. E.xpt. Sta. Pest Rept. 17:1;
Aldrich. 1958, Jour. Forestry 56:200; Heller. 1959. Photogram. Engin.
25:595; Anderson. 1960, Forest and Shade Tree Entomology, p. 218;
Dixon and Osgood, 1961. U. S. Dept. Agric. S. E. For. Expt. Sta. Paper
128, 34 p.; Thatcher. 1961, Forest Entomology, p. 184.

Dendroctonus arizonicus Hopkins, 1902. Proc. Ent. Soc. Washington 5:3 (nomen
nudum); Hopkins. 1909, U. S. Dept. Agric. Bur. Ent. Tech. ser. 17(1) :95
{new synonymy)., Hagedorn, 1910, Coleopterorum Catalogus 4:20; Hag-
edorn, 1910, Genera Insectorum 111:60; Hopkins, 1915, U. S. Dept. Agric.
Bur. Ent. Tech. ser. 17 (2): 211; Chantiberlin, 1939, Bark and Timber Bee-
tles of North America, p. 158. Biol.: Hopkins, 1904., U. S. Dept. Agric.
Bull. 48:42, 44; Hopkms, 1909. U. S. Dept. Agric. Bur. Ent. Bull. 83(1): 72;
Keen, 1939, U. S. Dept. Agric. Misc. Pub. 273:102; Anonymous, 1955,
U. S. Dept. Agric. For Sei-v. For. Ins. 1954:9.

Dendroctonus mexicanus Hopkins. 1905 (1906), Proc. Ent. Soc. Washington 7:80
(preprint) [new synonymy); Hopkins, 1909. U. S. Dept. Agric. Bur. Ent.
Tech. ser. 17(1) :97; Hagedorn, 1910, Coleopterorum Catalogus 4:20;
Hagedorn. 1910. Genera Insectorum 111:60; Hopkins, 1915, U. S. Dept.
Agric. Bur. Ent. Tech. ser. 17(2): 211; Chamberlin, 1939, Bark and Timber
Beetles of North America, p. 145; Schedl. 1940 (1939), An. Esc. Nac. Cienc.
Biol. (Mexico) 1:339; Johnston, 1942, Proc. American Sci. Congr. (State
Dept., Washington), 8:245; Muesebeck, 1950, Jour. Econ. Ent. 43:125,
131; Perrv. 1951, Unasylva (Mexico) 5:159; Becker, 1951, Zeitschr. angew.
Ent. 33:186; Becker, 1952, Trans. Ninth Internatl. Congr. Ent. 1:582;
Becker, 1954. Zeitschr. angew. Ent. 36:20; Becker, 1955, Zeitschr, angew.
Ent. 37:11; Schedl, 1955, Zeitschr. angew. Ent. 38:10. Biol.: Hopkins,
1909, U. S. Dept. Agric. Bur. Ent. Bull. 83(1): 74.

This species is very closely related to brevicomis, but is readily
distinguished by the longer declivital pubescence, by the more
strongly impressed declivital striae, by the more sparsely but more
coarsely granulate punctures of the declivital interspaces, by the
smaller average size, and, in part, by the distribution (Fig. 45).

Male. — Length 2.3-4.5 mm. (average about 3), 2.4 times as long
as wide; mature color very dark brown.

Frons convex, with a pair of lateral elevations on median half
just below upper level of eyes separated by a deep median groove,
the summit of elevations armed at their dorsomedian margins by
one or two prominent, somewhat dorsomedially oriented granules;
epistomal margin elevated, its surface smooth and shining; epis-

The Great Basin Naturalist

42 STEPHEN L. WOOD Vol. XXIII, Nos. 1-2

tomal process slightly wider than half (0.58 times) the distance
between eyes, its arms oblique (about 40° from the horizontal)
and elevated, the horizontal portion about half its total width,
transversely concave, ending just above epistomal margin and
bearing under its distal margin a dense brush of conspicuous yel-
lowish setae; surface punctate-rugulose above eyes, coarsely, rather
deeply punctured and subgranulate below. Vestiture, in addition
to epistomal brush, rather long, sparse.

Pronotum 1.4 times as wide as long, widest on basal third; sides
rather weakly arcuate on basal three-fourths, rather feebly con-
stricted just behind the broadly, shallowly emarginate anterior mar-
gin; surface smooth with rather coarse, moderately deep, close punc-
tures; punctures somewhat shallower and less abundant laterally
but not reduced in size; a raised median line not apparent. Vesti-
ture rather long, fine sparse.

Elytra 2.2 times as long as pronotum; sides straight and subpar-
allel on basal two-thirds, rather broadly rounded behind; basal mar-
gins arcuate and bearing a row of about nine, moderately large,
raised, overlapping crenulations, with several smaller submarginal
ones particularly on interspaces two and three; striae rather
strongly impressed, the punctures rather small, moderately deep;
interstriae moderately convex, about one and one-half times as
wide as striae and armed by a single very irregular row of rather
coarse transverse crenulations, each averaging well over half the
width of an interspace. Declivity moderately steep, convex; striae
rather strongly impressed, the punctures only slightly smaller than
on disc; interstriae convex, virtually all punctures rather coarsely,
transversely tuberculate, arranged in an irregular single or partly
double rank (never more than two ranks across an interspace).
Vestiture rather abundant, rather long, length of most hairs equal
to width of an interspace, a few twice as long.

Female. — Similar to male except lateral elevations of frons less
prominent and unarmed, with median groove consequently less
conspicuous; arms of epistomal process less strongly elevated; pro-
notal constrictions largely filled by a prominent transverse elevated
callus both laterally and dorsally; punctures of pronotal disc very
slightly larger and deeper; transverse crenulations of elytral disc
very slightly larger; and declivital granules somewhat finer, a few
punctures along edges of interspaces often wdthout granules.

Type locality. — Carolina (Sacramento, Amecameca, Mexico for
mexicanus; Williams, Arizona, for arizonicus) . The types oi all
three descriptions were studied.

Hosts. — Pinus ayacahuite, echinata, glabra, lawsoni, leiophylla,
montezumae, oocarpa, palustris, ponderosa, rigida rudis, strobus,
taeda, teocotl, and virginiana. Records, presumably during epi-
demics, also come from Picea excelsa, and rubens.

Distribution. — North America south of a line drawn from New
Jersey to central Arizona, south to Honduras.

June 14, 1963 revision of dendroctonus 43

Specimens from the following localities were examined (Fig. 45). Ala-
b.\ma: Calhoun and Montgomery. Arkansas: Hampton. Arizona: "Crook
N. F.." Crown King. Flagstaff, Graham Mts., Hassayampa Lake, Jerome, Pine,
"Pleasant Valley," Portal, Prescott, Prescott N. F., Rustler Park, Santa Catalina
Mts., Sitgreaves N. F.. Williams and Young. Florida: Haw Ck., and Taylor
Co. Georgia: Clyo, Demorest, and Thomasville. Louisiana: Singer, and Wil-
son. Maryland: Cumberland. New Mexico: Bandelier N. M., Cloudcroft,
and Mimbres. North Carolina: Asheville, Biltmore, Black Mts., Boardman,
Fletcher. "Mt. Graybeard," Pisgah Ridge, and Tryon. Oklahoma: "Western
Indian Terr." Pennsylvania: Mt. Alto. South Carolina: "Ben Quan,"
Clemson, Georgetown, and Pregnall. Tennessee: Ducktown. Texas: Beau-
mont. Call. Deweyville, and Kirbyville. Virginia: Arlington, Auburn, Chase
City. Cob Island, Glen Allen, Green Bay, King and Queen Co., Port Republic,
and Virginia Beach. District of Columbia: Washington. West Virginia:
Greenbrier. Hampshire, Hardy, Kanawha, Monongalia, Pendleton, Pocahontas,
Raleigh. Randolph, Tucker, and Wood Cos. Chiapas: Huixtla. Chihuahua:
Tres Rios. Distrito Federal: Mexico, and Tacubaya. Hidalgo: Jacala.
Mexico: Amecameca, Chapingo, San Rafael, Texcoco, and Tlalmanalco.
Micho.'\can: "Michoacan." Morelos: Cuernavaca, and Tlayacapan. Puebla:
Texmelucan. Tlaxcala: Tlaxcala. Zacatecas: Laguna Balderama. Guatemala:
Godenez, and Santa Cruz del Quiche. Honduras: Olanchita, and Tegucigalpa.

Geographic variation. — Specimens from southern Mexico tend
to average slightly larger in size (less than 1 mm. larger) and slight-
ly darker in color than do those from the eastern United States. The
frons varies conspicuously from area to area, but with no general
trends in any direction. For example: a series from West Virginia
has the frons very strongly protrubant; in series from neighboring
areas the character is absent or nearly so, but reappears in a slightly
modified form in one locality in central Arizona. These characters
appear to characterize local populations and cannot be used to de-
fine geographic races.

Biology. — Estimates of the volume of timber destroyed annually
by this insect are clouded by the difficulty of field identification in
the southwestern United States and by the absence of such estimates
for Mexico and Guatemala. Tremendous losses have been sustained,
however, in the southeastern United States, Mexico and Guatemala
which suggest the total damage resulting from activities of this
insect may equal that of the Western Pine Beetle.

The winter is passed in all stages, including eggs, with larvae
predominating. As with brevicomis, activity might resume whenever
subcortical temperatures become favorable during or following the
winter months. Because all stages overwinter and emerge from the
host as they mature, there is an extreme overlapping of generations
resulting in an almost continuous period of flight from April when
the first flights of overwintering adults begin until December when
activity ceases in the northern parts of the range. In southern Mex-
ico and Guatemala it is expected that flight activity continues
throughout the year without interruption. In any particular locality,
however, there are periods of greatest flight activity that tend to
coincide with the emergence of each new brood. According to Hop-
kins (1909b: 62) a peculiarity of this species is its tendency to mi-
grate considerable distances from the brood tree to begin a new at-

The Great Basin Naturalist

44

STEPHEN L. WOOD Vol. XXIII, NoS. 1-2

tack; subsequent workers (Dixon and Osgood, 1961:6) also indi-
cate that trees selected for attack may be either nearby or consider-
able distances from the point of emergence.

Trees selected for attack ordinarily are living, standing and
larger than about six inches D.B.H. The attack usually is con-
centrated on the upper half of the bole, but may reach the ground
level. The attack is slow and continuous; its duration depending on
numerous factors such as the size and resistance of the host, the
population density of beetles in the area, the climatic and other
ecological factors peculiar to the area. The duration and pattern of
attack on a host tree evidently are similar to those of brevicomis.

The egg galleries are almost entirely in the phloem tissues, not
engraving, but staining the xylem slightly. They are winding.

Fig. 47. Dendroctonus frontalis: Egg galleries sinuate, predominantly
longitudinal; egg niches large, placed individually on alternate sides of gallery;
larval mines may retain continual contact with cambium (left), or they may
expand into outer bark (right).

June 14, 1963 revision of dendroctonus 45

elongate galleries (Fig. 47), often branching, anastomosing or cross-
ing one another. The complicated interwoven series resembles ra-
ther closely that of brevicomis, except that there is a greater ten-
dency for the galleries to be longitudinal; that is, for the total
longitudinal displacement to exceed the total lateral displacement.
The diameter of each egg gallery is slightly greater than the width
of a parent beetle; in length they average approximately 30 cm.,
although the winding, complex character of the galleries makes
accurate measurement virtually impossible.

As with other species of the genus, the initial attack is made by
the female, usually in a crevice in the bark. The male joins the
female about the time the pitch begins to flow; he then pushes the
frass from the entrance hole while the female extends the gallery.
After the gallery has been extended several centimeters he then
packs the lower areas with frass thereby blocking the entrance hole,
leaving only the area where the beetles are working free for their
activities. The gallery may or may not have a nuptial chamber;
ventilation tunnels may be spaced irregularly as in brevicomis. It
has been reported (Dixon and Osgood, 1961:6) that extension of the
egg gallery may occur at the rate of about 2.5 cm. per day.

Published data pertaining to the period of oviposition, egg pro-
duction by individual females, and details of gallery formation are
not sufficient for conclusive statements concerning them. The small
amount of published information, however, permits the following
comments.

Drawings, photographs (Hopkins, 1909b: 58-68; Fronk, 1947:9;
Dixon and Osgood, 1961:7; etc.), and limited personal observations
of egg galleries indicate that egg niches are placed alternately along
the sides of the gallery in contact with the cambium. They are
symmetrical and about one-third as deep as the width of the gallery
and slightly wider than deep. The spacing of niches appears var-
iable, but evidently they may be as close as 6 mm., with an average
of 17 mm. between niches on one side (accurate measurements
should provide figures much lower than these). Eggs are deposited
individually and each is packed in its niche with specially prepared
frass to the original contour of the gallery.

Fronk (1947:10) found that under optimum conditions the eggs
hatch in from 3 to 9 days, with an average of 5.5 days; unfavorable
conditions such as occur during the winter evidently may lengthen
the incubation period to several months. Each newly hatched larva
mines the phloem in contact with the cainbium, approximately
perpendicular to the egg gallery. This mine of the first instar larva
is of uniformly thin diameter for about one centimeter, or several
times this length in an unfavorable environment (Hopkins, 1909:
61), it then widens abruptly into a short, irregularly oval area where
the remaining larval instars are passed (Fronk, 1947:8). This enlarg-
ed area may be in contact with the cambium and visible on peeled
bark, or in thick bark it may be entirely in the inner bark as in
brevicomis. Toward the end of the fourth instar the larva bores into

The Great Basin Naturalist

46 STEPHEN L. WOOD Vol. XXIII, Nos. 1-2

the outer bark where it clears a pupal chamber and enters the
quiescent prepupal stage. The larval period under optimum con-
ditions varies from 25 to 38 days and the pupal period about 8 to 11
days (Fronk. 1947:6); either or both stages might be lengthened
several months by unfavorable conditions. In Virginia the lift cycle
was completed under near optimum conditions in from 40 to 54 days
(Fronk, 1947:7).

The number of generations completed in one year varies from
3 to 5 in the eastern United States; in Mexico and Guatemala the
number undoubtedly is greater.

Dendroctonus parallelocollis Chapuis

Figs. 7-10, 34, 48-49

Dendroctonus parallelocollis Chapuis, 1869, Synopsis des Scolytides, p. 36 (1873,
Mem. Soc. Roy. Sci. Liege (2)3:244); Blandford, 1897, Biol. Centr.-Amer.,
Coleopt. 4(6): 147; Hopkins. 1905 (1906). Proc. Ent. Soc. Washington 7:81;
Hopkins, 1909, U. S. Dept. Agric. Bur. Ent. Tech. ser. 17(1) :99; Hagedorn,
1910, Coleopterorum Catalogus 4:22; Hagedorn, 1910. Genera Insectorum
111:60; Hopkins, 1915, U. S. Dept. Agric. Bur. Ent. Tech, ser. 17(2) :211;
Chamberlin, 1939, Bark and Timber Beetles of North America, p. 144;
Schedl. 1940 (1939), An. Esc. Nac. Cienc. Biol. (Mexico) 1:339; Schedl,
1955, Zeitschr, angew. Ent. 38:11. Biol.: Hopkins, 1909, U. S. Dept.
Agric. Bur. Ent. Bull. 83(1): 75; Muesebeck, 1950, Jour. Econ. Ent. 43:119,
131; Perry, 1951, Unasylva (Mexico) 5:159; Becker, 1951, Zeitschr.
angew. Ent. 33:186; Becker. 1952, Trans. Ninth Internatl. Congr. Ent.
1:582; Becker, 1954. Zeitschr. angew, Ent, 36:20; Becker, 1955, Zeitschr.
angew, Ent, 37:11.

Dendroctonus approximatus Dietz. 1890, Trans. American Ent. Soc. 17:28, 31;
Blandford, 1897, Biol. Centr.-Amer., Coleopt, 4(6): 147; Hopkins, 1905
(1906), Proc, Ent, Soc, Washington 7:81; Hopkins, 1909, U. S, Dept.
Agric, Bur. Ent. Tech, ser, 17(1): 101; Swaine, 1909, New York St. Mus.
Bull. 134:95; Hagedorn, 1910, Coleopterorum Catalogus 4:19; Hagedorn,
1910, Genera Insectorum 111:60; Hopkins, 1915, U, S. Dept, Agric. Bur.
Ent. Tech, ser, 17(2):211; Chamberlin, 1939, Bark and Timber Beetles of
North America, p, 159; Schedl, 1940 (1939). An, Esc, Nac, Cienc. Biol.
(Mexico) 1:322. Biol.: Schwarz, 1902, Proc, Ent. Soc, Washington 5:32;
Hopkins, 1903, U. S, Dept. Agric. Yearbook 1902:281; Hopkins. 1903,
Canadian Ent, 35:61; Hopkins. 1904, U, S, Dept, Agric, Div, Ent, Bull.
48:44; Hopkins, 1904, U. S, Dept, Agric, Yearbook 1904:281; Hopkins,
1905, U. S, Dept, Agric. Bur. Ent, Bull, 56:11; Burke, 1908, Proc. Ent.
Soc. Washington 9:115; Hopkins, 1909, U, S, Dept, Agric, Bur, Ent. Bull.
83(1):77; Swaine, 1909, New York St. Mus, Bull, 134:95; Felt, 1924,
Manual of Shade Tree and Shrub Insects, p, 251; Blackman, 1931, New
York St, Coll, For.. Syracuse Univ. Bull, 4(4), Tech. Pub. 36:30; Keen,
1938, U. S, Dept, Agric, Misc, Pub, 273:102; Beal. 1939, U. S, Dept.
Agric, Farmers Bull, 1824:11; Muesebeck, 1950, Jour, Econ, Ent, 43:122,
131; Pearson, 1950, U, S. Dept. Agric. Monogr, 6:154; Anonymous, 1951,
U. S. Dept. Agric. Bur, Ent. PI, Quar, Ins, Pest Surv,, Sup, 4:8; Anony-
mous, 1952, U, S. Dept. Agric. Bur. Ent. PI, Quar, Coop, Econ, Ins. Kept.
1(4): 94; Anonymous. 1954, U. S, Dept, Agric, For, Serv. For, Ins. Kept.
1954:10; Yasinski, 1956, U. S, Dept, Agric. Rocky Mtn. For, Expt. Sta.
Paper 23:1.

Dendroctonus parallelocollis var. approximatus: Biol.: Fall and Cockrell, 1907,
Trans, American Ent, Soc, 33:145.

This species is rather closely allied to frontalis and adjunctus.

June 14, 1963 revision of dendroctonus 47

but is larger and more coarsely sculptured than either. From fron-
talis it may also be distinguished by the more nearly flattened de-
clivital interspaces with the second weakly impressed, by the uni-
seriate, rounded granules on the second declivital interspace, and by
the larger, more closely set crenulations of the elytra! disc. From
adjunctus it is also distinguished by the more strongly impressed
declivital striae, by the interspacial granules being uniseriate only
on declivital interspace two (rarely also on one) and much more
closely spaced, by the much larger, more numerous crenulations
of the elytral disc, and by the more prominent transverse pronotal
callus of the female and large frontal, almost hornlike, tubercles
of the male.

Male. — Length 4.5-7.4 mm. (average about 6.0), 2.5 times as
long as wide; mature color very dark brown to black.

Frons convex, with a pair of lateral elevations on median half
just below upper level of eyes separated by a deep median groove,
the summit of elevations armed at their dorsomedian margins by
one or two prominent, somewhat dorsomedially oriented tubercles;
epistomal margin elevated, its surface smooth and shining; episto-
mal process slightly wider than half (0.57 times) the distance
between eyes, its arms oblique (about 40° from the horizontal)
and elevated, the horizontal portion about half its total width, trans-
versely concave, ending just above epistomal margin and bearing
under its distal margin a dense brush of conspicuous yellowish
setae; surface punctate-rugulose above eyes, coarsely, rather deeply
punctured and subgranulate below. Vestiture, in addition to epis-
tomal brush, rather long, sparse.

Pronotum 1.4 times as wide as long, wddest at base; sides feebly
arcuate and converging very slightly to the almost imperceptable
anterior constriction just behind the broadly, very shallowly emar-
ginate anterior margin; surface smooth and shining, the punctures
rather small, moderately deep, close (size, depth and arrangement
variable in a series) ; a raised median line feebly indicated anter-
iorly. Vestiture sparse, inconspicuous; moderately long at sides.

Elytra 2.2 times as long as pronotum; sides straight and sub-
parallel on basal two-thirds, rather broadly rounded behind; basal
margins arcuate and bearing a row of about nine, moderately large,
raised, overlapping crenulations. with several smaller submarginal
ones particularly on interspaces two and three; striae weakly im-
pressed, the punctures usually rather small and shallow with an-
terior margins raised, subcrenulate; interstriae about twice as wide
as striae and armed by abundant, confused, transverse crenulations,
each averaging at least half the width of an interspace, some as wide
as an entire interspace on posterior half of disc. Declivity moder-
ately steep, convex, with interspace two weakly impressed; striae
narrowly, moderately impressed, the punctures smaller than on
disc, distinctly impressed, one and two almost straight, three curv-
ing away from suture on upper half, toward suture on lower half;
interspaces scarcely if at all convex, about equal in width (except

Tlie Great Basin Naturalist

48 STEPHEN L. WOOD Vol. XXIII, Nos. 1-2

for expanded portion of three), each bearing a series of moderately-
large rounded granules, those on one and three usually confused,
uniseriate on two, usually with a few to many fine punctures in
addition to granules; granules on interspace two separated from one
another by an average distance equal to one-half width of the inter-
space. Vestiture not abundant, longer on sides and declivity, the
longest setae about one and one-half times as long as width of an
interspace.

Female. — Similar to male except lateral elevations of frons less
prominent and unarmed, with median groove consequently less
conspicuous; arms of epistomal process less strongly elevated; pro-
notal constriction largely filled by a prominent transverse elevated
callus both laterally and dorsally; punctures of pronotal disc very
slightly larger and deeper; transverse crenulations of elytral disc
and declivital granules somewhat larger.

Type locality. — Mexico (Colorado for approximatus) . The type
of approximatus was studied ,-^ parallelocollis was based on Hopkins'
material that was compared to the type.

Hosts. — Pinus apacheca, arizonica, ayacahuite., chihuahuana,
hartwegi, leiophylla, montezumae, patula, ponderosa, rudis, and
teocotl.

Distribution. — Central Utah and Colorado south to Honduras.

Specimens from the following localities were examined (Fig. 48). Arizona:
Black Mesa F. R., Chiricahua Mts., Flagstaff, Fort Apache, Graham Mts.,
Grand Canyon N. P., Kaibab N. F., Paradise, Pine, Portal, Prescott, Rincon
Mts., Santa Catalina Mts., Santa Rita Mts., Show Low, Tucson, and Williams.
CoLOR.'^DO: Brookvale, Glen Haven, Las Animas, La Veta, Monte Vista, Palmer
Lake. New Mexico: Capitan Mts., Carson N. F., Cloudcroft, Lincoln N. F.,
Santa Fe, and Sierra Blanca. Utah: Bryce Canyon N. P., Dixie N. F., Escal-
ante, Kamas, Long Hollow, Panguitch, Panguitch Lake, and Pin Hollow in
Fishlake N. F. Chihuahua: Chuichupa, and Tres Rios. Durango: El Salto, and
Sierra Durango. Distrito Federal: Mexico. Mexico: Ixtaccihuatl. Michoacan:
Jacona. Morelos: Jonacatepec. Oaxaca: Oaxaca. Puebla: Texmelucan. Tlaxa-
CALA: Tlaxacala. Vera Cruz: Jalapa and Vera Cruz. Guatemala: Quezalten-
ango, Santa Cruz del Quiche, and Tecpan. Honduras: San Pedro Sula.

Geographical variation. — Constant differences associated with

feographical origin were not apparent. The features used by Hop-
ins (1909a: 70) in establishing geographical races refer to indi-
vidual differences that can be found in a long series from almost
any locality throughout its range.

Biology. — This is not an aggressive species, consequently, dam-
age caused by it is comparatively minor. It is a secondary enemy of
pine, entering the host only after the tree has been overcome by
the more aggressive species of Dendroctonus or of Ips.

Adults and larvae in all stages of development overwinter in
their galleries at the base of the host tree, or, in the case of felled
trees, on the lower side of the trunk next to the ground. They become
active somewhat later than other species and usually extend their

June 14, 1963 revision of dendroctonus

49

Fig. 48. Probable geographical distribution of Dendroctonus parallelocollis
with collection sites indicated.

old galleries for a period, with the adults resuming egg-laying ac-
tivities, before emerging from the host. In the northern parts of
the range the flight period begins early in June and continues until
October, with the principal period of activity occurring in June and
early July. In southern Mexico and Guatemala activity probably
continues throughout the year without seasonal interruptions. Em-
ergence from the host occurs gradually over a long period of time,
consequently, large numbers of beetles are not in flight at the same
time making a concerted attack on one tree by this species exceed-
ingly difficult.

The trees selected for attack are those previously selected by
and largely overcome by other species, or those felled more than
six weeks prior to the attack. This species, usually occupies the basal
portion of the bole from the ground level up to a height of six or
eight feet; in the northern parts of its range, where it competes
with adjunctus for space in the basal parts of the host, its galleries
seldom extend more than two or three feet above the level of the
ground. It also breeds in felled trees (Blackman 36:30), usually only
on the lower side, particularly in those areas in contact with the
ground. The smallest trees observed in which this species was breed-
ing were 12 inches D.B.H., although this probably does not repre-
sent the minimum size acceptable to the species.

50

The Great Basin Naturalist

STEPHEN L. WOOD Vol. XXIII, NoS. 1-2

Ordinarily the attack is directed at the butt of the tree in areas
of bark not occupied one to three weeks previously by other species.
In an injured tree the attack may extend over a rather long period
of time as successive generations slowly girdle it.

Basically the galleries (Fig. 49) are longitudinal and winding;
they are coarser than those of associated species, particularly ad-
junctus, and present a strikingly different overall pattern. Branch
galleries, many of which cross or join other galleries, are numer-
ous, causing the entire network of galleries to form an apparently

Fig. 49. Dendroctonus parallelocoUis: Egg galleries form an apparent
haphazard criss-cross pattern; egg niches large, placed alternately on gallery
wall opposite cambium (upper left); larval mines entirely in outer bark, never
exposed on surface of peeled bark.

June 14, 1963 revision of dendroctonus 51

aimless criss-cross pattern. As with other species the galleries are
almost entirely in the inner bark, very faintly grooving or at least
staining the cambium.

The egg galleries are rather coarse, averaging about 5 mm. in
diameter. Gallery systems may be extensive, but because of their
branching and anastomosing character it is virtually impossible
to measure the work of individual beetles.

As with other species the initial attack is made by the female.
Soon after she reaches the phloem tissues she is joined by the male.
As with other species he then expels excess frass from the entrance
hole or later packs the lower or more remote areas of the gallery
with excess frass in order to keep clear the area where the female
is working. Egg niches are very different from other species; they
are not in contact with the cambium, but are located alternately
on the sides of the wall farthest from the cambium. The niches are
cup-shaped, larger than usual, and extend into the non-living por-
tion of the bark. Each niche may contain, according to BlacKman
(1936:30), one to four eggs; not more than one egg per niche was
found during this study. The larval mines are entirely in the bark,
mostly in the outer bark, and do not contact the cambium at any
time. Their length is variable and not easily measured, but evidently
they are rather short. Pupal chambers are almost always in the
outer bark.

Oviposition apparently begins about a week after the attack and
probably continues over a substantially longer period than is the case
with related species. The position of the egg niches and the possible
deposition of several eggs in each makes it difficult to count with
any degree of accuracy the number of eggs produced by any one
female, since many of the eggs are destroyed by the observer's at-
tempt to locate the niches. From the number of niches found, how-
ever, it is estimated that the number is not large, probably seldom
exceeding 40 eggs per female. As with other species, a majority
of the eggs apparently were deposited in the first third of the
egg gallery. The exact spacing of egg niches, and the periods of
incubation, larval and pupal development were not determined.

In the northern parts of its range one generation per year ap-
pears to be normal.

Dendroctonus adjunctus Blandford

Figs. 11-12, 35, 50-51.

Dendroctonus adjunctus Blandford, 1897, Biol. Centr.-Amer., Coleopt. 4(6): 147;
Hopkins, 1909, U. S. Dept. Agric. Bur. Ent. Tech. ser. 17(1): 157; Hagedom,
1910, Coleopterorum Catalogus 4:19; Hagedom, 1910, Genera Insectorum
111:60; Chamberlin, 1939, Bark and Timber Beetles of North America, p.
144; Schedl, 1955, Zeitschr. angew. Ent. 38:8. Biol.: Johnston, 1942,
Proc. Amer. Sci. Congr. (Washington, May 10-18, 1940) 8:245; Becker,
1951, Zeitschr. angew. Ent. 33:186; Becker, 1952, Trans. Ninth Internatl.
Congr. Ent. 1:582; Becker, 1954, Zeitscher. angew. Ent. 36:20-61; Becker,
1955, Zeitschr. angew. Ent. 37:1.

The Great Basin Naturalist

52 STEPHEN L. WOOD Vol. XXIII, Nos. 1-2

Dendroctonus convexifrons Hopkins, 1909, U. S. Dept. Agric. Bur. Ent. Tech.
ser. 17(1):87 {new synonymy)., Hagedorn, 1910, Coleopterorum Catalogus
4:20; Hagedorn, 1910, Genera Insectorum 111:60; Chamberlin, 1939, Bark
and Timber Beetles of North America, p. 158; Schedl, 1940 (1939), An.
Esc. Nac. Cienc. Biol. (Mexico) 1:339. Biol.: Hopkins, 1909, U. S. Dept.
Agric. Bur. Ent. Bull. 83(1 ):53; Felt, 1924, Manual of Shade Tree and
Shrub Insects, p. 252; Blackman, 1931, New York St. Coll. For., Syracuse
Univ. Bull. 4(4), Tecli. Pub. 36:29; Keen, 1938. U. S. Dept. Agric. Misc.
Pub. 273:102; Beal, 1939, U. S. Dept. Agric. Farmers Bull. 1824:11; Pear-
son, 1950, U. S. Dept. Agric. Monogr. 6:154; Anonymous, 1951, U. S.
Dept. Agric. Bur. Ent. PI. Quar. Ins. Pest. Surv., Sup. 4:8; Anonymous,
1952, U. S. Dept. Agric. Bur. Ent. PI. Quar. Coop. Econ. Ins. Kept. 1(4):94;
Anonymous, 1955, U. S. Dept. Agric. For. Serv. For. Ins. 1954:10; Yasinski,
1956, U. S. Dept. Agric. Rocky Mtn. For. Expt. Sta. Paper 23:1.

Dendroctonus approximatus: Dietz, 1890, Trans. American Ent. Soc. 17:31
(part); Schwarz, 1902, Proc. Ent. Soc. Washington 5:32 (part).

This species occupies a position between the two major groups
within the genus, more or less compromising the characters of par-
allelocollis and ponderosae. AUhough the relationship is not close,
it is allied to parallelocolUs, but is readily distinguished by the more
slender body form, by the more widely spaced, uniseriate granules
on the first three declivital interspaces, by the more finely sculp-
tured elytral disc, and by the absence of frontal tubercles in the
male and more poorly developed transverse pronotal callus in the
female. In many respects it is similar to ponderosae but may be dis-
tinguished by the more slender form, by the smooth, shining de-
clivital interspaces, by the stronger median frontal groove, and, in
the female, by the transverse pronotal callus.

Male. — Length 3.8-6.0 mm. (average about 5.2), 2.65 times as
long as wide; mature body color rather dark brown.

Frons convex, with a pair of unarmed lateral elevations on med-
ian half just below upper level of eyes separated by a rather in-
conspicuous median groove; epistomal margin elevated, its surface
smooth and shining; epistomal process half (0.50 times) as wide as
distance between eyes, its arms oblique (about 40° from the hori-
zontal) and elevated, the horizontal portion about half its total wddth,
transversely concave, ending just above epistomal margin and bear-
ing under its distal margin a dense brush of conspicuous yellowdsh
setae; surface punctate-rugulose above eyes, more deeply punctured
and subgranulate below. Vestiture. except epistomal brush, sparse,
inconspicuous, rather long.

Pronotum 1.4 times as wide as long, widest on basal third; sides
rather strongly arcuate on basal three-fourth, rather strongly con-
stricted behind the broadly, shallowly emarginate anterior margin;
surface smooth with rather fine, shallow, close punctures on median
third, becoming more finely punctured laterally; an indistinct med-
ian line apparent. Vestiture rather sparse, long, becoming coarse
laterally.

Elytra 2.5 times as long as pronotum; sides straight and sub-
parallel on basal two-thirds, rather narrowly rounded behind; basal
margins arcuate and bearing a row of about nine, moderately

June 14, 1963 revision of dendroctonus 53

large, raised, overlapping crenulations, with several smaller sub-
marginal ones particularly on interspaces two and three; striae
weakly impressed, the punctures rather small and shallow; inter-
striae about twice as wide as striae and armed by rather abundant
confused, transverse crenulations, each averaging about one-half the
width of an interspace, a few almost as wide as the interspace on
posterior half of disc. Declivity moderately steep, convex, with inter-
space two weakly impressed; striae weakly impressed, the punctures
greatly reduced, one straight, two curving slightly toward suture
on lower third, three diverging from suture on upper half, curving
toward suture on lower third; interspace one slightly raised, two
impressed and flat, three feebly convex, each bearing a uniseriate
row of sparse, rounded or pointed granules and in addition several
confused, minute punctures; granules on two separated from one
another by an average distance equal to width of the interspace.
Vestiture rather sparse, longer on sides and declivity, the longest
setae about one and one-half or two times as long as width of an
interspace.

Female. — Similar to male except lateral elevations and median
frontal groove poorly developed; arms of epistomal process less
strongly elevated; pronotal constriction with a feebly developed
transverse elevated callus; punctures of pronotal disc very slightly
larger and deeper; and transverse crenulations of elytral disc and
granules of declivity very slightly larger.

Type locality. — Totonicapam, Guatemala (Williams, Arizona,
for convexifrons) . The type of convexifrons was studied; the type of
adjunctus was compared to my material by R. T. Thompson.

Hosts. — Pinus ayacahuite, chihuahuana,, montezumae, ponder-
osae, pseudostrobus, rudis, and tenuifolia.

Distribution. — Southern Utah and Colorado south to Guatemala.

Specimens from the following localities were examined (Fig. 50). Arizona:
Flagstaff, Fort Apache, Graham Mts., Grand Canyon N. P., Jacobs Lake, Kai-
bab N. F., Paradise, Rustler Park, Santa Catalina Mts., Show Low, and Will-
iams. CoLOR.^DO: Durango, Ft. Garland, Las Animas Co., La Veta, Monte Vista,
Rye, San Isabel N. F., and "Vallecito R. S." New Me.xico: Capitan. Carson
N. F. Cloudcroft, Ft. Wingate, "Hermit Peak," Las Vegas, Lincoln N. F., Sierra
Blanca Mts., and Vermejo. Utah: Escalante, Long Hollow in Dixie N. F.,
Manti-LaSal N. F., Panguitch Lake, and Sanford Canyon. Mexico: Nevado
de Toluca, and Penuela La Gavia. Guatemala: Cerro Quemado, Chuchuma-
tanes, Guatemala, La Esperanza, Las Trojadas, Montana de las Nubes, Poptum,
Quetzaltenango, Sierra Maria Tecum, Tecpn, and Totonicapan.

Geographical variation. — Not observable in the limited material
at hand.

Biology. — This species generally works in concert with other
species of Dendroctonus to overcome a tree. Its galleries resemble,
superficially at least, those of other species and, consequently, the
resulting misidentifications have attributed much of the damage
actually done by this species to others having more formidable repu-

54

The Great Basin Naturalist

STEPHEN L. WOOD Vol. XXIII, Nos. 1-2

Fig. 50. Probable geographical distribution of Dendroctonus adjunctus with
collection sites indicated.

tations as tree killers. In the absence of an epidemic of other species
it appears much more aggressive than the available literature would
indicate, frequently initiating the primary attack on a tree.

Although any stage of development may be represented, the
winter usually is passed as half grown larvae or as adults starting a
new attack in the fall but without commencing oviposition. Larval
development is resumed and egg deposition is started or resumed
as soon as spring temperatures become sufficiently high. The brood,
both young adults and larvae, completes its development and be-
gins to emerge to seek new hosts in May or early June, usually
several weeks after the emergence of brevicomis and ponderosae.
Its habits of commencing attacks in the fall and the late emergence
in the spring are important factors in the apparent lack of aggres-
siveness of this species, since the timing of its flight activity coin-
cides with the period when other species have overcome host trees
but have not yet occupied the lower portions of the bole. Although
some flight activity occurs throughout the summer months, two per-
iods of increased activity occur. The first is in May and early June,
the second and greatest occurs between the latter part of August and
the middle of October. The attack on a particular tree is spread over
a considerable period of time and usually involves a relatively small
population of this species.

Trees selected for attack are weakened standing trees larger than
about ten inches D. B. H. Galleries have been observed in stumps,
but not in prostrate trees or logs. In the absence of competing spe-
cies the area of attack may extend from ground level to a height of
about 10 or 12 feet. When competing species, particularly pondero-

June 14, 1963

REVISION OF DENDROCTONUS

55

sae, are present in large numbers this species may be restricted to
less than the lower three feet of the bole.

The attack appears to begin in the upper parts of the area occu-
pied by this species; that is, the bole about 4 to 12 feet above the
ground level, with successively newer attacks occurring below this
area until the level of the ground is reached. The attack may be
completed in a few days when populations are high, or it may ex-

Fig. 51. Dendroctonus adjunctus: Egg galleries slightly to rather strongly
sinuate (example at right about average); individual egg niches placed alter-
nately on sides of gallery; larval mines transverse, usually in cambium but may
extend into outer bark, seldom cross one another.

The Gredt Basin Naturalist

56 STEPHEN L. WOOD Vol. XXIII, Nos. 1-2

tend over the greater part of a year, particularly when the first at-
tacks are made in the fall.

Egg galleries (Fig. 51) are sinuous and almost always extend
upward from the entrance hole. As with other species of this genus
they are almost entirely in the phloem, very lightly scoring or at
least staining the wood. The total longitudinal displacement of an
egg gallery usually is about three to four times as great as the total
lateral displacement. Ordinarily the gallery extends horizontally
either right or left from the entrance hole about four to seven centi-
meters then curves upward; about two to four broad sinuous curves
are included in its vertical ascent. From the principal longitudinal
axis of the gallery the first of these curves diverges about four to
six centimeters, the remaining curves diverge about one-half to two
centimeters from this axis. Of 36 egg galleries studied in the Pan-
guitch, Utah, area during the last week of June, 1960, the average
gallery length was 31 cm., the maximum was 89 cm.; the average
width was about 4 mm. Although it appeared that an effort was
made by the beetles to avoid doing so, galleries did cross or anasto-
mose occasionally. Approximately one gallery in 25 descended ver-
tically, evidently to avoid crowding or crossing neighboring galler-
ies; more rarely one was primarily transverse. Branching or side
galleries extending from the main egg tunnel were uncommon.
When such branches did occur they usually did not exceed three
centimeters in length and did not contain egg niches.

The initial attack is made by the female. As with other species
this usually occurs in a crevis of the bark; ordinarily she is joined
by the male about the time the entrance tunnel reaches the cam-
bium. The male, as with other species, ejects frass from the ent-
rance hole while the female extends the gallery. When sufficient
working space is available he then packs the lower portions of the
gallery with the excess frass.

Ventilation tunnels occur at irregular intervals; the minimum
observed distance between two of them was 1.7 cm.; in trees having
relatively thin bark they may be entirely absent. The average dis-
tance between ventilation tunnels in the 36 galleries measured for
this study, was 5.2 cm. The first most commonly is placed within
one centimeter, either above or below, the first egg niche; the aver-
age distance from the entrance hole to the first egg niche was
3.5 cm.

Egg niches are arranged alternately in the phloem on the sides
of the gallery in contact with the cambium. Each is symmetrical,
slightly deeper than wide and, compared to the foregoing species,
is rather small. Each niche is very slightly larger than the egg it
contains. The number and spacing of egg niches is variable; the
minimum observed distance between two niches located on the same
side of a gallery was 1.5 mm., the average distance was about 3.5
mm. The average number of egg niches in the 36 galleries mention-
ed above was 44.1; the maximum was 119. About one-tenth of the
niches were located exactly opposite one another on the different

June 14, 1963 revision of dendroctonus 57

sides of the gallery; this was a notable departure from the consist-
ently alternate placement of niches in the preceding species where
such an occurrence was exceedingly uncommon. Eggs are depos-
ited individually in the niches; each niche is then filled by specially
prepared frass to the original level of the gallery.

The period of incubation has not been determined precisely, but
evidently it requires about a week under optimum conditions. The
newly hatched larvae construct narrow tunnels in the cambium
region perpendicular to the egg gallery. The larval mine extends
about one to four centimeters along a straight to winding route,
without increasing in diameter. It then expands abruptly into an
oval to irregular feeding chamber approximately one-half to one
centimeter wide and about one or two centimeters long. The entire
larval mine usually is in contact with the cambium and is visible
on the inner bark. Some of the larvae pupate in this chamber,
however, most of them mine into the outer bark for pupation.

The number of generations may vary from one complete and
a partial second generation per year to one generation in two full
years (Hopkins 1909b: 55). Although not reported, it appears pos-
sible that two generations might be completed in favorable years
and localities in the southern parts of its range.

Dendroctonus ponderosae Hopkins

Figs. 13, 36, 52-53.

Dendroctonus ponderosae Hopkins, 1902, U. S. Dept. Agric. Div. Ent. Bull.
32:10; Hopkins, 1902, Proc. Ent. Soc. Washington 5:3; Hopkins, 1909,
U. S. Dept. Agric. Bur. Ent. Tech. ser. 17(1): 109; Swaine, 1909, New York
St. Mus. Bull. 134:98; Hagedorn, 1910, Coleopterorum Catalogus 4:22;
Hagedorn, 1910, Genera Insectorum 111:60; Hopkins, 1915, U. S. Dept.
Agric. Bur. Ent. Tech. ser. 17(2) :211; Swaine. 1918, Dom. Canada Dept.
Agric. Ent. Br. Bull. 14(2) :65; Chamberlin, 1939, Bark and Timber Beetles
of North America, p. 156. Biol.: Hopkins, 1902, U. S. Dept. Agric. Div.
Ent. Bull. 37:21; Hopkins, 1903, U. S. Dept. Agric. Yearbook 1902:275,
282; Hopkins, 1903, Canadian Ent. 35:59; Gillette, 1903, Colorado Agric.
Bept. 24:118; Hopkins, 1904, U. S. Dept. Agric. Div. Ent. Bull. 48:41,
43, 44; Hopkins, 1905, U. S. Dept, Agric. Yearbook 1904:275, 281; Hop-
kins, 1905, Proc. Ent. Soc. Washington 7:147; Hopkins, 1905, U. S. Dept.
Agric. Div. Ent. Bull. 56:10; Currie, 1905, U. S. Dept. Agric. Div. Ent.
Bull. 53:100; Burke, 1906, Proc. Ent. Soc. Washington 7:4; Hopkins,

1906, Proc. Ent. Soc. Washington 7:147; Hopkins, 1906, Proc. Ent. Soc.
Washington 8:4; Webb. 1906. U. S. Dept. Agric. Yearbook 1905:631; Webb,

1907, U. S, Dept. Agric. Yearbook 1906:515; Howard, 1907, U. S. Dept.
Agric. Div. Ent. Kept. 1906:13; Hopkins, 1908, U. S. Dept. Agric. Year-
book 1907:162, 548; Hopkins, 1908, West Virginia Lumberm.. Jan. 10:11;
Hopkins, 1909, U. S. Dept. Agric. Bur. Ent, Bull. 58:59, 76; Hopkins, 1909,
U. S. Dept. Agric. Bur. Ent. Bull. 83(1 ):90; Hopkins, 1909, U. S. Dept.
Agric. Yearbook 1908:574; Hopkins, 1910. U. S. Dept. Agric. Bur. Ent.
Circ. 125:2; Howard. 1910, U. S. Dept. Agric. Bur. Ent. Bept. 1909:21;
Hopkins, 1912. U. S. Dept. Agric. Bur. Ent. Circ. 142:7; Butterick, 1912,
Jour. Econ, Ent. 5:456; Swaine, 1913, Ontario Ent. Soc. Kept. 43:90;
Brues, 1920. Insects and Human Welfare, p, 70; Miller, 1923, Timberman
26(2) :50; Felt, 1924, Manual of Tree and Shrub Insects, p. 256; Craig-
head, 1925, Jour. Forestry 23:347; Craighead. 1927, U. S. Dept. Agric.
Circ. 411:7; Nelson and Beal, 1929. Phytopathology 19:1101; Craighead,

The Great Basin Naturalist
58 STEPHEN L. WCM3D Vol. XXIII, NOS. 1-2

1930, U. S. Dept. Agric. Misc. Pub. 74:4; Craighead et al, 1931, Jour.
Forestry 29:1016; Blackman. 1931, New York St. Col. For., Syracuse
Univ. Bull. 4(4), Tech. Pub. 36, 97 p.; Rumbold, 1931, Jour. Agric. Res.
43(10): 848; Doane, Van Dyke, Chamberlin and Burke, 1936, Forest
Insects, p. 80; Beal, 1937, U. S. Dept. Agric. Bur. Ent. PL Quar. E 403,
5 p.; Hanna, 1937, Western Farm Life 39(7): 10; Davis, 1938, Colorado
Bur. PL Ins. Control Kept. 1938:31; Keen, 1938, U. S. Dept. Agric. Misc.
Pub. 273:106; Strong, 1938, U. S. Dept. Agric. Bur. Ent. PL Quar. Kept.
1937:18; Wygant, 1938, Rocky Mtn. Conf. Ent. Rept. 14:15; Beal, 1939,
Rocky Mtn. Conf. Ent. Rept. 15:6, 13; Beal, 1939, U. S. Dept. Agric.
Farmers Bull. 1824, 21 p.; DeLeon, 1939, Rocky Mtn. Conf. Ent. Rept.
15:13; Hester and Edwards, 1939, Colorado Bur. PL Ins. Control Rept.
1939:15; Stahl, 1939, Wyoming Stockm.-Farm. 45(7):p. ?; Wygant, 1939,
Rocky Mtn. Conf. Ent. Rept. 15:14; Hester, 1940, Colorado Bur. PL Ins.
Control Rept. 1940:8; Strong, 1940, U. S. Dept. Agric. Bur. Ent. PL Quar.
Rept. 1939:23; Woodward, 1940, South Dakota Sf. Hort. Soc. Rept. 37:49;
Annand. 1941, U. S. Dept. Agric. Bur. Ent. PL Quar. Rept. 1940:26;
Isely, 1941, Methods of Insect Control, ed. 2, pt. 1. p. 102; Strong, 1941,
American Yearbook 1940:492; Cook, 1942. Western Farm Life 44(10) :4, 8;
Craighead, 1942, Smithsn. Inst. Rept. 1940-41:368, 371, 378; Beal, 1943,
Jour. Forestry 41:359; Wygant, 1945, D. S. Dept. Agric. Bur. Ent. PI. Quar
Ins. Pest Surv. 1944:14; Poyner, 1946, Colorado Bur. PL Ins. Control Rept
1945:24; Annand. 1946, U. S. Dept. Agric. Bur. Ent. PL Quar. Rept. 1945:30
Gates, 1947, Rocky Mtn. Conf. Ent. Rept. 18:7; Gates, 1947, Colorado Bur. PI
Ins. Control Rept. 1946:28; Annand, 1948, U. S. Dept. Agric. Bur. Ent
PL Quar. Rept. 1947:26; Snyder, 1948, Colorado Bur. PL Ins. Control Rept
1947:35; Anonymous, 1948, U. S. Dept. Agric. Bur. Ent. PL Quar. Ins
Pest Surv. 1947:17; Keen, 1950, Jour. Forestry 48:147; Pearson, 1950
U. S. Dept. Agric, Agric. Monogr. 6:154; Snyder, 1950, Colorado Dept
Agric. Rept. 1:75; Anonymous, 1950, U. S. Dept. Agric. Bur. Ent. PI
Quar. Ins.' Pest Surv. 1949:26; Beal, 1951, Proc. West. For. Conserv. Assoc
41:58; Anonymous, 1951, U. S. Dept. Agric. Bur. Ent. PL Quar. Ins
Pest Surv. Sup. 4:6; Anonymous. 1951. U. S. Dept. Agric. Bur. Ent. PI
Quar. Ins. Pest. Surv. 1950:24; Gates, 1951, Colorado Dept. Agric. Rept
2:38; Hoyt, 1952, U. S. Dept. Agric. Bur. Ent. PL Quar. Rept. 1950:16.
Massey et al., 1952, Jour. Econ. Ent. 45:861; Anonymous. 1952, U. S
Dept. Agric. Bur. Ent. PI. Quar. Coop. Econ. Ins. Rept. l(Sup. 4):92.
Massey et al., 1953, Jour. Econ. Ent. 46:601; Knight and Wilford, 1954
U. S. Dept. Agric. Rocky Mtn. For. Range Expt. Sta. For. Ins. Cond. 1953:3,
Orr, 1954, U. S. Dept. Agric. Intermtn. For, Range Expt. Sta. For. Ins
Cond. 1953:2; Price, 1955, U. S. Dept. Agric. Rocky Mtn. For. Range Expt
Sta. Rept, 1954:15; Mogren, 1955, Michigan Univ. Diss. Abs. 15:1477,
Anonymous, 1955, U. S. Dept. Agric. For. Serv. Imp. For. Ins. 1954:8,
Baile3% 1956, U. S. Dept. Agric. Intermtn. For. Range Expt. Sta. Rept
1956:30, 33. 37; Ostmark and Wilford, 1956. U. S. Dept. Agric. Rocky
Mtn. For. Range Expt. Sta. Paper 22:4, 13; Price, 1956, U. S. Dept. Agric
Rocky Mtn. For. Range Expt. Sta. Rept. 1955:21; Yasinski, 1956, U. S
Dept. Agric, Rocky Mtn. For. Range Expt. Sta. Paper 23:2, 5, 7; Knight
and Yasinski, 1956, U. S. Dept. Agric. Rocky Mtn. For. Range Expt. Sta
Res. Notes 21, 4 p.; Hay, 1957 (1956), Ann. Ent. Soc. America 49:567;
Price, 1957, U. S. Dept. Agric. Rocky Mtn. For. Range Expt. Sta. Rept.
1956:81, 84, 90, 99; Knight, 1958. For. Science 4:35.
Dendroctonus monticolae Hopkins. 1901, Proc, Soc. Prom. Agric. 22:67 (new
synonymy); Hopkins, 1902, U. S. Dept. Agric. Div. Ent. Bull. 37:21; Hop-
kins, 1902, Proc, Ent. Soc. Washington 5:3; Hopkins, 1905, U. S. Dept.
Agric. Bur. Ent. Bull. 56:11; Hopkins, 1909, U. S. Dept. Agric. Bur. Ent.
Tech. ser. 17(1):105; Swaine, 1909, New York St. Mus. Bull. 134:97;
Hagedorn, 1910. Coleopterorum Catalogus 4:22; Hagedorn, 1910. Genera
Insectorum 111:60; Hopkins, 1915. U. S. Dept. Agric. Bur. Ent. Tech.
ser. 17(2): 211; Swaine, 1918, Dom, Canada Dept. Agric. Ent. Br. Bull.
14(2) :65; Chamberlin, 1939, Bark and timber beetles of North America,
p. 155; Chamberlin, 1959, Scolytoidea of the Northwest, p. 71. Biol.:

June 14, 1963 revision of dendroctonus 59

Hopkins, 1899, U. S. Dept. Agric. Div. Ent. Bull., n. s., 21:14, 26; Hop-
kins, 1904, U. S. Dept. Agric. Div. Ent. Bull. 48:19, 42, 45; Webb, 1907,
U. S. Dept. Agric. Yearbook 1906:515; Hopkins, 1908, U. S. Dept. Agric.
Yearbook 1907:162, 548; Burke, 1908, Proc. Ent. Soc. Washington 9:12,
115; Hopkins, 1909, U. S. Dept. Agric. Yearbook 1908:574; Hopkins, 1909,
U. S. Dept. Agric. Bur. Ent. Bull. 58(5) :59; Hopkins, 1909, U. S.
Dept. Agric. Bur. Ent. Bull. 83(1 ):80; Hopkins, 1910, U. S. Dept.
Agric. Bur. Ent. Circ. 125:2; Hopkins, 1912, U. S. Dept. Agric. Bur. Ent.
Circ. 143:4; Hopkins, 1914, Ent. News 25:133; Brunner, 1914, U. S. Dept.
Agric. Bull. 111:4; Swaine, 1914, Dom. Canada Dept. Agric. Expt. Farms
Bull, ser. 2, 17:20, 26; Hewitt, 1915, Canada Dept. Agric. Div. Ent. Kept
1915:29; Swaine, 1916, Can. For. Jour. 12:632; Hopkins, 1917, Jour. Econ
Ent. 10:92; Hopkins, 1919, Sci. Month. 8:506; Burke, 1919, Proc. Ent
Soc. Washington 21:123; Swaine, 1920, Agric. Gaz. Canada 7:642; Brues
1920, Insects and human welfare, p. 69; Miller, 1921, Timberman 23(1 ):40
Hopping, 1921, Dom. Canada Dept. Agric. Ent. Br. Circ. 15:7, 11; Hopping,
1922, Canadian Ent. 54:129; Boyce, 1923, U. S. Dept. Agric. Bull. 1140
7 p.; Boyce, 1923, Timberman 24(7): 157; Gibson, 1923, Dom. Canada
Dept. Agric. Ent. Br. Kept. 1919-20:16; Baker, 1924, American For. 30:599
Elliott, 1924, Oregon St. For. Kept. 14:43; Evenden and Hopping, 1924,
Lumber World Rev. 47:12, 43; Felt, 1924, Manual of Tree and Shrub In-
sects, p. 255; Hopping, 1924, Canadian Ent. 56:126; Boone, 1925, Tim-
berman 26(7) :58; Caverhill, 1925, British Columbia Dept. Lands For. Br.
Kept. 1924:E16; Craighead, 1925, Jour. Forestry 23:348; Evenden, 1925, Am-
erican For. 31:593; Evenden, 1925, Timberman 26(11):63; Craighead, 1927,
U.S. Dept. Agric. Circ. 411:5, 6, 8; Keen, 1928, California Dept. Nat. Res. Div.
For. Bull 7:33; Craighead, 1930, U.S. Dept. Agric. Misc. Pub. 74:4; Patterson,
1930, U.S. Dept. Agric. Tech. Bull. 195, 19 p.; Evenden, 1930, Northwest Sci.
4:52; Marlatt, 1930, U.S. Dept. Agric. Bur. Ent. Rept. 1930:45; Patterson,
1930, U.S. Dept. Agric. Tech. Bull. 195, 19 p.; Cushman, 1931, Jeur. Wash-
ington Acad. Sci. 21:301; Weir, 1931, Canada Min. Agric. Rept. 1930-31:
128; Craighead et al, 1931, Jour. Forestry 29:1009; Evenden, 1931, U. S.
Dept. Agric. Yearbook 1931:391; Gibson, 1931, Jour. Econ. Ent. 24:575;
Hastings, 1931, Outdoor Amer. 10(5): 17; Morse, 1931, U. S. Dept. Agric.
Yearbook 1931:430; Steiner, 1932, Jour. Agric. Res. 45:437; Marlatt, 1932,
U. S. Dept. Agric. Bur. Ent. Rept. 1932:23; Marlatt, 1933, U. S. Dept.
Agric. Bur. Ent. Rept. 1933:29; Richmond, 1933, For. Chron. 9:60; Sal-
mon, 1933, California Agric. Month. Bull. 22:135; Swaine, 1933, Sci.
Agric. 14:26; DeLeon, 1934, Canadian Ent. 66:51; DeLeon, 1934, Jour.
Forestry 32:430; Twinn, 1934, Ent. Soc. Ontario Rept. 65:123; Weaver,
1934, Jour. Forestry 32:100; DeLeon, 1935, Ann. Ent. Soc. America 28:411;
DeLeon, 1935, Ent. Amer. 15:59; Rust, 1935, Jour. Econ. Ent. 28:688;
Thome, 1935, Jour. Agric. Res. 51:131; Evenden, 1935, Idaho For. 17:12;
Flint, 1935, Northwest Sci. 9(2) :5; Strong, 1935, U. S. Dept. Agric. Bur.
Ent. PI. Quar. Rept. 1935:22; Hopping and Mulholland, 1937, For. Res.
British Columbia 1937:62; Martin, 1937, American For. 43:122, 144; Bed-
ard, 1938, Jour. Forestry 36:35; Twinn, 1938, Ent. Soc. Ontario Rept.
69:133; Keen, 1938, U. S. Dept. Agric. Misc. Pub. 273:102; Keen, 1939,
Rocky Mt. Conf. Ent. Rept. 15:5; Evenden, 1939, Rocky Mtn. Conf.
Rept. 15:12; Westveld, 1939, Appl. Silvicult. U. S., p. 398, 418; Evenden
and Gibson, 1940, Jour. Forestry 38:271, 275; Ringle, 1940, Sci. American
162:348; Wheeler, 1940, California Cuh. 87:636; Annand, 1941, U. S.
Dept. Agric. Bur. Ent. PI. Quar. Rept. 1940:26; Eaton, 1941, Jour. Forestry
39:710; Peirson, 1941, American For. 47:413; Smith, 1941, Jour. Econ.
Ent. 34:10; Struble and Carpelan, 1941, man-Pacific Ent. 17:153; Yuill,

1941, Jour. Econ. Ent. 34:702; Craighead, 1942, Smithsn. Inst. Rept. 1940-
41:368, 371, 378; Gardiner, 1942, Canada Min. Agric. Rept. 1941:55; Twin,

1942, Ent. Soc. Ontario Rept. 72:55; Struble, 1942, Pan-Pacific Ent. 18:97;
Struble, 1942, Jour. Econ. Ent. 35:840; Brown, 1942, Canada Dept. Agric.
Div. Ent. For. Ins. Serv. Rept. 6:8; Brown, 1943, Canada Dept. Agric. Div.
Ent. For. Ins. Serv. Rent. 7:8; DeGryse, 1943, For. Chron. 19:142; Even-
den et al., 1943, U. S. Dept. Agric. Circ. 664, 25 p.; Furniss, 1943, (Trans.)

The Ciieat Basin Natuialibt
60 STEPHEN L. WOOD Vol. XXIII, NoS. 1-2

West. For. Conserv. Assoc. 143:34; Gibson, 1943, Jour. Econ. Ent. 36:396;
Offalax, 1943, For. Chron. 19:186; Twinn, 1943, Ent. Soc. Ontario Kept.
73:70; Twinn, 1943, Canada Ins. Pest. Rev. 21:8; Weaver, 1943, Jour.
Forestry 41:8; Leech, 1944, Canada Dept. Agric. Div. Ent. For. Ins. Surv.
Kept. 1943:63; Evenden and Struble. 1945, U. S. Dept. Agric. Bur. Ent.
PI. Quar. Ins. Pest. Serv. 1944:13; Leech, 1945. Canada Dept. Agric. Div.
Ent. For. Ins. Serv. Rept. 1944:64; Hopping and Mathers, 1945, For.
Chron. 21:98; Patterson, 1945. Univ. Washington Pub. Biol. 10:147; An-
nand, 1945, U. S. Dept. Agric. Bur. Ent. PI. Quar. Rept. 1944:7; Annand,

1946, U. S. Dept. Agric. Bur. Ent. PI. Quar. Rept. 1945:21; Furniss and
Struble, 1946, U. S. Dept. Agric. Bur. Ent. PI. Quar. Ins. Pest Surv. 1945:20;
Gardiner. 1946, Canada Min. Agric. Rept. 1945:75; Leech. 1946, Canada
Dept. Agric. Div. Ent. For. Ins. Surv. Rept. 1945:62; Mathers, 1946, Can-
ada Ins. Pest Rev. 24:120; Anderson, 1947, U. S. Dept. Agric. Sec. Rept.
1947:140; Annand, 1947, U. S. Dept. Agric. Bur. Ent. PI. Quar. Rept.
1946:34; DeGryse, 1947, Forest Entomology in Canada, p. 3; Gardiner,

1947, Canada Min. Agric. Rept. 1946:93; Leech, 1947, Canada Dept. Agric.
Div. Ent. For. Ins. Surv. Rept. 1946:79; Richmond, 1947, Canada Ins. Pest
Rev. 25:73; Sand and Bryan, 1947, U. S. Dept. Agric. Farmers Bull.
1989:28; Anonymous, 1947, California Dept. Nat. Res. Div. For. Ins. Cond.
1946:9; Anonymous, 1947, U. S. Dept. Agric. Bur. Ent. PI. Quar. Ins. Pest.
Surv. 1946:18; Anderson. - 1948, Jour. Econ. Ent. 41:596; Annand, 1948.
U. S. Dept. Agric. Bur. Ent. PI. Quar. Rept. 1947:26; Hoffman and
Merkel, 1948, Jour. Econ. Ent. 41:467; MacKay, 1948, Cauda Dept. Agric.
Div. Ent. For. Ins. Surv. Rept. 1947:93; Hopping and Beull, 1948, For.
Chron. 24:141; Anonymous, 1948, U. S. Dept. Agric. Bur. Ent. PI. Quar.
Ins. Pest Surv. 1947:16; Anonymous, 1949, U. S. Dept. Agric. Bur. Ent. PI.
Quar. Ins. Pest Surv. 1948:19; McGuffin, 1949. Canada Dept. Agric. Div.
Ent. For. Ins. Surv. Rept. 1948:105; MacKay, 1949, Canada Dept. Agric.
Div. Ent. For. Ins. Surv. Rept, 1948:114; Evans. 1950. Canada Dept.
Agric. Div. Ent. For. Ins. Surv. Rept. 1949:107; Gardiner, 1950, Canada
Min. Agric. Rept. 1949:105; Keen. 1950, Jour. Forestry 48:146; Kenney
et al, 1950. British Columbia Lands For. Serv. Rept. 1949:73; McGuffin.
1950, Canada Dept. Agric. Div. For. Ins. Surv. Rept. 1949:100; MacKay,
1950, Canada Dept. Agric. Div. For. Ins. Surv. Rept. 1949: 113, 121,
Anonymous, 1950, U. S. Dept. Agric. Bur. Ent. PI. Quar. Ins. Pest Surv
1949:25; Beal. 1951, Proc. West. For. Conserv. Assoc. 41:58; Evans and
Dyer, 1951, Canada Dept. Agric. Div. E.it. For. Ins. Surv. Rept. 1950:110
Hopping, 1951, For. Chron. 27:26; Kenney et al.. British Columbia Dept
Lands For. Serv. Rept. 1950:63; McGuffin and Reid. 1951, Canada Dept
Agric. Div. Ent. For. Ins. Surv. Rept. 1950:99; Ross and Jones. 1951, Can-
ada Dept. Agric. Div. Ent. For. Ins. Surv. Rept. 1950:113, 121, 123.
Hopping, 1951, Ent, Soc. Ontario Rept. 81:74; Kolbe, 1951, Proc. West
For. Conserv. Assoc. 41:15; Anonymous, 1951, U. S. Dept. Agric. Bur
Ent. PI. Quar. Ins. Pest Surv. Sup. 4:5; Anonymous. 1951. U. S. Dept
Agric. Bur. Ent. PI. Quar. Ins. Pest Surv. 1950:24; Orchard et al, 1952,
British Columbia Lands For. For. Serv. Rept. 1951:85; Ross and Jones,
1952, Canada Dept. Agric. For. Ins. Dis. Surv. Rept. 1951:109. 118;
Anonymous, 1952, U. S. Dept. Agric. Bur. Ent. PI. Quar. Div. For. Irts.
Econ. Ins. Rept. 1(4):90; Clements, 1953. U. S. Dept. Agric. California
For. Range Expt. Sta. For. Res. Notes 89. 5 p.; McGuffin, 1953, Canada
Dept. Agric. For. Ins. Dis. Surv. Rept. 1952:116; Richmond. 1953, British
Columbia Dept. Lands For. For. Serv. Rept. 1952:86; Ross and Jones, 1953,
Canada Dept. Agric. For. Ins. Dis. Surv. Rept. 1952:132; Orr, 1954. U. S.
Dept. Agric. Intermtn. For. Range Expt. Sta. For. Ins. Cond. 1953:2;
Ross. 1954. Canada Dept. Agric. For. Ins. Dis. Surv. Rept. 1953:141;
Kinghorn. 1955. Jour. Econ. Ent. 48:501; Reid, 1955, Canadian Ent. 87:316;
Silver and Ross. 1955. Canada Dept. Agric. For. Ins. Dis. Surv. Rept.
1954:118; Struble and Johnson. 1955. U. S. Dept. Agric. For. Pest Leaflet
2, 4 p.; Anonymous, 1955, U. S. Dept. Agric. For. Serv. Imp. For. Ins.
1954:3, 7; Anonymous, 1955, U. S. Dept. Agric. Pac. N. W. For. Range
Expt. Sta. For. Ins. Rept. 1954:26. 37; Gardiner, 1955. Canada Min. Agric.

June 14, 1963 revision of dendroctonus 61

Rept. 1954:16; Anonymous, 1955, For. Pest. Control Act. Comm. For. Ins.
Cond. California 1954:6; Bailey, 1956, U. S. Dept. Agric. Intermtn. For.
Range Expt. Sta. Rept. 1956:30, 37; Jemison, 1956, U. S. Dept. Agric. Califor-
nia For. Range Expt. Sta. Rept. 1955:5, 45, 50; Moreno Noriega, 1956, Fito-
filo 9(15):20, 23, 25, 28. 31; Ostmark and Wilford, 1956, U. S. Dept.
Agric. Rocky Mtn. For. Range Expt. Sta. Paper 22:5, 13; Price, 1956,
U. S. Dept. Agric. Rocky Mtn. For. Range Expt. Sta. Rept. 1956:81;
Silver and Ross, 1956. Canada Dept. Agric. For. Ins. Dis. Surv. Rept.
1955:94; Hay, 1957 (1956), Ann. Ent. Soc. America 49:567; Khan, 1957,
Canadian Jour. Zool. 35:519; Whiteside, 1957, U. S. Dept. Agric. Pacific
N. W. For. Range Expt. Sta. For. Ins. Cond. 1956:2, 13, 31, 43.

Dendroctonus jeffreyi Hopkins, 1909, U. S. Dept. Agric. Bur. Ent. Tech. ser.
17(1):114 {new synonymy); Hagedorn, 1910, Coleopterorum Catalogus
4:20; Hagedorn, 1910, Genera Insectorum 111:60; Chamberlin, 1939, Bark
and Timber Beetles of North America, p. 159; Chamberlin, 1958, Scoly-
toidea of the Northwest, p. 72. Biol.: Hopkins, 1909, U. S. Dept, Agric
Bur. Ent. Bull. 83:101; Hopkins, 1909, U. S. Dept. Agric. Yearbook 1909:
574; Hopkins, 1912, U. S. Dept. Agric. Bur. Ent. Circ. 143:5; Burke, 1919,
Proc. Ent. Soc. Washington 21:123; Hopping, 1922. Canadian Ent. 54:130;
Patterson, 1923, Timberman 24(9): 156; Felt, 1924, Manual of Tree and
Shrub Insects, p. 256; Craighead, 1927, U. S. Dept. Agric. Circ. 411:8;
Keen, 1928, California Dept. Nat. Res. Bull. 7:37; Craighead, 1930, U. S.
Dept. Agric. Misc. Pub. 74:5; Craighead et al., 1931, Jour. Forestry 29:1016;
Keen, 1938, U. S. Dept. Agric. Misc. Pub. 273:107; Patterson, 1945, U. S.
Dept. Agric. Bur. Ent. PI. Quar. Ins. Pest Surv. 1944:14; Anonymous,
1947, California Dept. Nat. Res. Div. For. For. Ins. Cond. 1946:9; Anony-
mous, 1949, U. S. Dept. Agric. Bur. Ent. PL Quar. Ins. Pest. Surv. 1948:20;
Anonymous, 1951, U. S. Dept. Agric. Bur. Ent. PI. Quar. Ins. Pest Sui-v. Sup.
4:8; Anonymous, 1952, U. S. Dept. Agric. Bur. Ent. PI. Quar. Coop. Econ.
Ins. Rept. l(Sup. 4):94; Anonymous, 1955, U. S. Dept. Agric. For. Serv.
Imp. For. Ins. 1954:3; Anonymous, 1955, California For. Pest Control Act.
Comm. For. Ins. Cond. 1954:6; Eaton, 1956, U. S. Dept. Agric. For. Serv.
For. Pest Leaflet 11, 7 p.; Anonymous, 1957, U. S. Dept. Agric. PI. Pest
Control Div. Coop. Econ. Ins. Rept. 7:864.

This distinctive species appears to be more closely allied to
adjunctus than to others in the genus, but is readily distinguished
by the absence of lateral frontal elevations and a median groove,
by the opaque surface of the elytral declivity, by the impressed
declivital striae, by the stout body, and, in part, by the distribu-
tion (Fig. 52).

Male. — Length ?>.7-7.S mm. (average about 5.5; size evidently
dependent on moisture conditions regulated by thickness of bark of
host tree), 2.3 times as long as wide; mature body color black.

Frons convex from eye to eye, from vertex to epistoma, median
line narrowly impressed above upper level of eyes, rather broadly
protrubrant over an indefinite median area below upper level of
eyes, often with remnants of a narrowly impressed median line;
epistomal margin elevated, its surface smooth and shining; episto-
mal process half as wide (0.50 times) as the distance between eyes,
its arms oblique (about 30° from the horizontal) and elevated along
their median halves, the horizontal portion about half its total width,
transversely concave, overlapping and ending just above epistomal
margin and bearing under its distal margin a dense brush of con-
spicuous yellowish setae; surface punctate-rugulose above eyes,

The Great Basin Naturalist

62 STEPHEN L. WOOD Vol. XXIII, Nos. 1-2

coarsely, rather deeply punctured and subgranulate below. Vesti-
ture, in addition to epistomal brush, rather long, sparse, inconspic-
uous.

Pronotum 1.4 times as wide as long, widest at base; sides feebly
arcuate, almost straight on basal two-thirds, converging slightly to-
ward the well developed constriction just behind the broadly, shal-
lowly emarginate anterior margin; surface smooth, shining, with
very close, rather small, moderately deep punctures (variable), be-
coming granulose laterally; a median line feebly indicated, more
prominent anteriorly. Vestiture scanty, usually evident only at sides.

Elytra 2.1 times as long as pronotum; sides straight and sub-
parallel on basal two-thirds, rather broadly rounded behind; basal
margins arcuate and bearing a row of about nine, moderately large,
raised, overlapping crenulations, with several smaller submarginal
ones particularly on interspaces two and three; striae weakly im-
pressed, the punctures rather small, rather deep; interstriae about
twice as wide as striae and armed by rather coarse, confused, trans-
verse crenulations, each averaging about half the width of an inter-
space. Declivity rather steep, convex, with interspace two rather
strongly impressed; striae rather narrowly impressed, the punctures
smaller than on disc; striae one slightly, two rather strongly, three
very strongly curved toward suture; interstriae usually at least
slightly convex, minutely rugulose, dull, the punctures fine, con-
fused, distinct to obscure or subgranulate; each interspace with a
sparse, more or less definite median row of rather large granules.
Vestiture scanty, longer and more conspicuous on declivity, longest
setae slightly longer than a distance equal to width of an inter-
space.

Female. — Very similar to male, but evidently epistomal process
less well developed, and elytral crenulations and declivital granules
a little larger.

Type locality. — Spearfish, South Dakota (Kootenai, Idaho, for
monticolae; and Little Yosemite. California, for jeffreyi). The types
of all three descriptions were studied.

Hosts. — Pinus albicaulis^ balfouriana, contorta, coulteri, edulis,
flexilis, jeffreyi, lamhertiana, monophylla, monticola, murrayana,
ponderosa, and strobiformis. During an epidemic it was recorded
from Picea engelmanni.

Distribution. — Southern British Columbia to the Black Hills of
South Dakota, and south to northern Mexico.

Specimens from the following localities were examined (Fig. 52). Arizona:
Chiricahua Mts., "Crook N. F.," Flagstaff, Fredonia, Kaibab N. F., and San
Francisco Mts. California: "Alder Ck.," Anthony Ck., Bass Lake, Bear Ck.
R. S., Ben Lomond. Big Bear Lake, Big Bend. Big Meadows, Blacks Mt.,
Blue Canyon, Bray, Bunnel. Burnt Corral Meadows, Butte Lake, Carrville,
"Cassidy Ridge," Cecilville, Chester. "Chiquito Basin," Clover Valley, Coulter-
ville. Cow Ck., Crestline. Crocker R. S., Deep Ck., Dorrington, Duck Lake,
Eagleville. Echo Lake, Eiler Lake, Facht, Fallen Leaf Lake, Favingers Camp,
Fawn Ck., Floriston, Ft. Jones, Fulda, "Gasquet R. S.," General Grant N. P.,

June 14, 1963

REVISION OF DENDROCTONUS

63

Fig. 52. Probable geographical distribution of Dendroctonus ponderosae
with collection sites indicated.

Gordon Meadow, "Grant Pk.," Grassy Lake, "Gray Meadows," "Gray Mesa,"
Hackamore, Haeckle's, Hat Ck., Hoffman, Hope Valley, "Huckleberry Mea-
dow," Hume, Huntington Lake, Inyo Co., Idyllwild, "Kangaroo R. S.," Kern
Co., King's Ck. Rd., Kyburz, Laguna Mt., Lake Almanor, Lake Arrowhead,
Lake Ostrander, Lake Tahoe, Lake Valley R. S., Lamoine, "Leland Meadow,"
Lemon Canyon, Lion Meadow, "Little Kern," Little Shasta, Little Yosemite,
Lloyd Meadows, Lookout, Lush Meadows, Mammoth, Mariposa Grove, Massack
Mill, Mather, McCloud, "McCreary," Medicine Lake, Miami R. S., Middle Fk.
Eel River, "Millwood," Mineral, Moffit Ck., Mohawk, Moraine, Mt. Brewer,
Myers, Nevada City, North Fork, Norval Flats, Ockenden, Onion Valley,
"Painted George," Pinecrest, Placerville, Plantation, Pollock Pines, Pyramid
R. S., Robbers Ck., "Round Meadow," "Samson Flat," San Bernardino Mts.,
San Gabriel Canyon, "Saples Flat," "Scoffold," "Self R. S.," Sequoia N. P.,
Shaver, Sisson, "Snowline Camp," Soda Springs, "Soquel Basin," "Squaw
Dome," Stirling City, "Summerdale," Summit Lake,, "Swaines," Tallac, Tenaya
Lake, Three Rivers, Timber Mt., Tioga Rd., Trinity N. F., Wawona, "Willow
Meadows," Willow Ranch, "Woodward Ck.," "Wright's Lake," Yreka, and
Yuba Gap. Colorado: Bailey, Brookvale, Cascade, "Cat Mt.," Cuchetopa, Dur-
ango. Eagle, Elictra Lake, Estes P., Florissant, Ft. Garland, Glenwood Springs,
Gunnison N. F., Gould, Green Mt. Falls, Hahns Pk., Husted, Idaho Springs,
"Indian Ck.," Jones Ranch, "Kennedy Sta.," Larkspur, Las Animas, La Veta,
Longs Pk., Manitou, Medicine N. F., Meeker, Monte Vista, Montrose, Monte-
zuma N. F., "Ouray N. F.," Pogosa Springs, Palmer Lake, Pikes Pk., Pine,
Pingre Pk., Poncho Springs, Porter, Saguache, San Isabel, San Juan Co., San
Juan N. F., Uncompahgre N. F., "Ute Pass," Westcliffe, and White River N. F.
Idaho: Cedar Mt., Centerville, Coeur d'Alene, Coeur d'Alene N. F., Collins,

The Great Basin Naturalist

64 STEPHEN L. WOOD Vol. XXIII, Nos. 1-2

Kootenai, "Moscow Mts.," Sandpoint, Smith's Ferry, and Weiser. Montana:
Apgar, Bigfork, Blackfeet Indian Res., Columbia Falls, Helena, "Iron Mt.," Lame
Deer, Lewis and Clark N. F., Logan Pass, Lolo, Madison N. F., Missoula, Sal-
tese, and Sula. Nevada: Baker, Crystal Bay, Glenbrook and Las Vegas. New
Mexico: Gila N. F., Tres Ritos, and Vermejo P. Oregon: Ashland, "Auburn,"
Austin, Baker, Bly, Buck Lake. Cold Springs, Crater Lake N. P., Diamond
Lake, Elk Ck., "Ferris Ranch," Grants Pass, Haines, "Highland Mine," Joseph,
Keno, Klamath Falls, Klamath Indian Res.. "Loves Sta.," Meryl Ck., North
Powder, Ochoco N. F., Pinehurst, "Pokegama," Round Lake. Sparta, Sumpter,
and Wallowa. South Dakota: Black Hills, Custer, Deadwood, Elmore, Hill
City, Lead, Nemo, Piedmont, and Sylvan Lake. Ut.jih: Ashlej' N. F., Bryce
Canyon N. P., Duck Lake, Escalante, Kamas, Logan Canyon, Manti-LaSal N. F..
Panguitch Lake, Uintah and Ouray Indian Res., Wasatch Mts., and Wasatch
N. F. Washington: Crescent Lake, Dayton, Fairfax, "Kamiak Butte," Long-
mire Spring, Metaline Falls, Moran, Mt. Rainier, Mt. Rainier N. F., Northport,
"Pialschie," Pullman. Randle, Seattle, Spokane, Washington N .F., and White
River. Wyoming: Bear Lodge in Black Hills N. F., "Downington," Elk Mt.,
Encampment. Fremont Lake. "Keystone," North Fork, and Wapiti. Alberta:
Edmonton. British Columbia: Adams Lake, Alleyne Lake, Arrowhead, Aspen
Grove, Babine Lake, Blue River P. O., Big Loon Lake. Cowichan Lake, Downie
Ck., Forester Ck., Frances Ck., Grand Forks, "Hope Mts.," Kamloops, Kootenay
N. P., Little Fish Ck., Little Shuswap Lake, Midday Valley, Morrison Lake,
Mud Lake, Na Kusp, "Nehalliston For.," Peachland, Princeton, Puntchesakut
Lake, Revelstoke, Seymour Narrows, Shuswap Lake, Steamboat Mt., Sugar
Lake, Sugarloaf Mt., Takla Lake, Tarnezell Lake, "Trepan Ck.," Trout Lake,
Upper Arrow Lake, Whitetail Lake, Windermere, and Yoho N. P. Baja
California: Sierra San Pedro Martir.

Geographical variation. — Specimens from the southeastern parts
of the range tend to average considerably larger than specimens
from the northwestern areas. The explanation for this, however, ap-
pears to be at least partly environmental rather than genetic, since
most of the specimens from southeastern areas are from Pinus pon-
derosa, a host in which greater size is normally attained from all
areas, while those from the northwestern areas are mostly from
other host species. It was apparent after examining numerous series
from the various host species that a particular average size was
more or less characteristic of a host species. The average size in a
particular tree appeared to be correlated with the average thickness
of the bark of the host.

There are conspicuous differences in the size and depth of pro-
notal punctures in almost any series. In specimens from California
they tend to average much smaller and shallower than from other
areas. This variation in California appears to be associated with
geographical origin, intensifying gradually from north to south
(Lassen N. F. to the Yosemite area), rather than with host as
reported by Hopkins (1909a: 71), since large specimens with very
small shallow punctures, the distinguishing features of Hopkins'
jeffreyi, can be found in series from any host of this species in
California.

Biology. — This has been referred to (Craighead et al., 1931:
1009) as the most destructive species of Dendroctonus. Estimates of
losses in our timber resources due to this insect are scattered, con-
flicting and confused by the fact that this species has been known
concurrently by three separate scientific names. Considering all

June 14, 1963 revision of dendroctonus 65

factors, the average annual loss attributed to it since 1895 possibly
may approach two billion board feet.

For the most part the winter is passed as second and third instar
larvae, although a few parent adults may survive hibernation and
a few larvae may reach the prepupal stage. Activity is resumed in
the spring whenever temperatures become sufficiently high, prob-
ably about 50°F. A small fraction of the overwintered parent adults
may resume egg laying activity in the spring, but usually most of
them extend their galleries without ovipositing; very few of them
re-emerge. Ordinarily by mid-June half of the immature stages have
pupated (Blackman, 1931:14) and by mid-July most have matured.
The young adult beetles do not emerge immediately from the brood
tree, but enlarge the pupal chamber, often removing sufficient of
the inner bark that their excavations join one another. One of these
enlarged chambers may contain as many as 50 beetles. The period
of flight is concentrated, seldom beginning before July 15 and rarely
continuing later than August 25. In those areas of California where
more than one generation occurs each year there may be notable
departures from the usual activity cycle. Whether these deviations
are the result of genetic or ecological factors is uncertain.

Trees selected for attack by endemic populations of this insect
usually are overmature or weakened standing trees larger than six
inches D. B. H. Windfalls or cull logs occasionally may provide fav-
orable breeding places (Evenden, 1943:7), particularly when the
bole is inclined. During epidemics the more vigorous, rapidly grow-
ing trees may be preferred (Beal, 1939:2), and coniferous host
species not belonging to the genus Pinus may be attacked. Under
endemic conditions the area of a particular tree attacked by this
species may be restricted or forced upward from the base of the
bole by such competing species as adjunctus, or downward from
upper parts of the bole by brevicomis. Under endemic conditions
in a given area the local population may exhibit a strong prefer-
ence for one host species even though other acceptable host species
may be intermixed. The preferred host in a given area may be Pon-
derosa, Lodgepole, Limber. Western white, Jeffrey or other pine
species. In a given area during an epidemic any acceptable host,
or sometimes any conifer, may be attacked, but following the epi-
demic the attacks may or may not be confined to the same host
species originally favored. Climatic factors or competition usually
re-establish the original conditions, however. These local races per-
haps may indicate the existence of genetic factors that could lead
to the formation of distinct species of beetles, but all available data
suggests that the present stage of their evolution has not reached
the point where geographical races (subspecies) can be recognized.

The attack evidently may follow either of two patterns depend-
ing on the age and vigor of the host tree and on the presence or
absence of certain competing species of bark beetles. In mature
sugar pine where aggressive competing species are virtually absent,
the attack usually begins in the upper crown; the lower sections of

The Great Basin Naturalist

66 STEPHEN L. WOOD Vol. XXIII, Nos. 1-2

the tree may then be attacked by one or more successive generations
over a period of two or more years (Evenden, 1943:9). In younger
trees of this and other species the attack usually begins at or near
the base and extends upward. Compared to other species the attack
is concentrated into a relatively short period of time. It coincides
with the period of emergence from about July 15 to August 25, sel-
dom requiring more than five weeks and possibly requiring as little
as three or four days during an epidemic. The beetles strike the
tree individually, not in dense swarms as some popular accounts of
the attack might suggest. According to Blackman (1931:21) the
number of entrance tunnels per square foot of bark surface of a
successful attack on an average tree ranges from about four to nine.
He also observed that the number of attacks was higher in trees
where four to nine trees were killed in a group (5.90 per sq. ft.)
than where only one to four trees were killed in a group (5.23
per sq. ft.

The vertical linear egg galleries (Fig. 53) usually are almost
straight, although occasionally an environmental peculiarity may
cause some to wind slightly. They are constructed primarily in the
soft inner bark or phloem, continually in contact with the cambium
and very lightly scoring the wood.

The diameter of an individual egg gallery is slightly greater than
the width of the beetle which constructed it. Its length varies con-
siderably, but evidently it depends more on enivronmental than on
hereditary factors. In Lodgepole pine on the Wasatch National For-
est in Utah, 35 egg galleries selected at random averaged 32.6 cm.,
the maximum length was 67.5 cm.; in Ponderosa pine on the Dixie
National Forest in Utah, 35 egg galleries averaged 47.5 cm., the max-
imum length was 79.0 cm. Both series of measurements were made
in drought areas in July 1960. In June of 1961 similar measure-
ments made in Jeffrey pine on the Tahoe National Forest in Cal-
ifornia, averaged 41.7 cm. for 35 galleries, with the maximum
length 66.0 cm. Measurable galleries in Ponderosa pine in California
and Oregon and in Western white pine in Oregon gave comparable
results, but were too few in number to provide reliable data. Pre-
sumably the character of galleries observed during a severe epi-
demic of this species in the Black Hills area led Hopkins (1909a:
112) to assume that a completely different species existed in that
area as compared to an endemic Pacific Coast form which appar-
ently constructed much longer galleries. Actually, under endemic
conditions in comparable environments, the eastern, western, north-
ern and southern populations appear indistinguishable when meas-
urements, bark samples or photographs of gallery systems are com-
pared.

The initial attack is made by the female, usually in a crevice
of the bark. About the time she reaches the cambium tissues where
the pitch begins to flow she is joined by the male who then assists
her by pushmg the excavated frass out of the entrance hole. Con-
tinuation of the egg gallery is performed entirely by the female

June 14, 1963

REVISION OF DENDROCTONUS

67

Fig. 53. Dendroctonus ponderosae: Egg
galleries straight; individual egg niches placed
in groups of one to eight on alternate sides of
gallery; lai-val mines exposed on surface of
peeled bark throughout their length, they com-
monly join one another about the time pupal
cells are formed.

The Great Basin Naturalist

68 STEPHEN L. WOOD Vol. XXIII, Nos. 1-2

beetle. After several centimeters of gallery have been cleared and
the frass ejected from the entrance hole, the male then packs the
frass in the lower regions of the gallery thereby closing the entrance
hole and tightly filling the gallery except for a few centimeters
in the area where the beetles are working. It is not uncommon , fol-
lowing mating, for the male to leave the gallery, either before the
entrance is blocked or through a ventilation tunnel, in order to join
a second female.

From the entrance hole the gallery usually ascends diagonally
about three to five centimeters before turning directly upward. In
about half of the gallery systems studied this diagonal portion ex-
tended to the right of the entrance hole, about a third went to the
left, and in the remainder the diagonal portion was absent. This
oblique part of the tunnel ordinarily is more irregular in width
than the remainder of the egg tunnel and ordinarily is sufficiently
wide to permit turning or to act as a nuptial chamber. Ventilation
tunnels usually are placed at irregular intervals along the egg gal-
lery, but are not always present. Their presence appears to be re-
lated to the stage of gallery construction, to the thickness of the
bark, and to the activity of the beetles. Evidently they are not con-
structed until after the entrance has been plugged. In thin barked
Lodgepole pine 18 of the 35 galleries measured (see above) included
ventilation chambers, of these 18 only three contained more than
two ventilation tunnels, the maximum number was four in one
gallery. In the relatively thick-barked Ponderosa pine 33 of the 35
galleries measured (see above) included ventilation tunnels and ^
only three of the 33 included fewer than five; the maximum num-
ber in one gallery was 13.

The initial part of gallery construction progresses rapidly. Ovi-
position usually begins when the gallery is about one or two centi-
meters above the oblique portion, probably about four to five days
after the attack. Egg-laying evidently continues until interrupted
by cold weather. The eggs are deposited individually in compar-
atively small niches, although it is not uncommon for tw^o eggs to
be in one niche.

Egg niches are comparatively small, each is just large enough
to accommodate an egg and a very small amount of specially pre-
pared frass. The niches are both narrower and more shallow than
those of the foregoing species. They are distributed in a pattern pe-
culiar to this species, with alternating groups of one to eight niches
placed along the sides next to the cambium. The size and spacing
of these groups varies tremendously from gallery to gallery and
even within the same gallery, depending upon the prevailing en-
vironmental conditions. Ordinarily about half of these "groups"
consist of one niche each, seldom do they exceed five in number.
It is not uncommon for one or two niches to occur opposite one of
these groups, a departure from their strictly alternate arrangement.
In a third of the galleries studied there were no niches in the upper
or last half of the gallery; in an additional one-tenth there were

June 14, 1963 revision of dendroctonus 69

none in the last third. When niches occurred in the terminal reg-
ions of the gallery it appeared, in many cases, that the adult female
either abandoned the gallery prior to the onset of cold weather or
died before or during the winter months.

Following oviposition the parent beetles may continue the gal-
lery, often ending it in a somewhat irregular feeding tunnel, or they
may abandon the gallery in order to commence a new attack. Even-
den (1943:12) estimated that 10 to 30 percent of the parent adults
from sugar pine and almost 100 percent of those from western
white pine re-emerged in order to begin a second attack. These
values appear to be higher than the estimated re-emergence rate
observed during this study, but support the observation that there
is a greater tendency for re-emergence to occur when the bark of
the host tree is either comparatively thin or subject to rapid drying
for various other reasons.

The length of the incubation period has not been determined pre-
cisely, but has been estimated by various workers to require about
seven to ten days. The larval mines are continuously in contact
with the cambium and are somewhat irregular, but usually their
main axis tends to be perpendicular to the egg gallery. Their
length varies considerably with the amount of moisture or crowd-
ing present. They may be only one or two centimeters in length, in-
creasing very slightly in wddth before reaching the suddenly ex-
panded irregular feeding area where the last two or three instars
and pupation are passed, or they may extend 10 or 20 centimeters
and increase substantially in width before the pupal cell is en-
countered. It is not uncommon to find both extremes in the same
system of galleries. The larvae may pass the winter in any instar,
but apparently second and third instar larvae predominate. Because
of overwintering in this stage and, since only one generation oc-
curs each year, the average length of the larval period is near 300
days. During the latter part of the larval period a pupal cell is clear-
ed of the frass in the enlarged feeding area, still in contact with the
cambium. Here the prepupal and pupal stages are passed, the latter
evidently requiring about two to four weeks for completion. A ma-
turation period of about one month usually follows the pupal stage
before emergence occurs.

Dendroctonus aztecus, new species

Figs. 24-26, 54.

Dendroctonus adjunctus: Gibbson and Carrillo, 1959, Sec. Agric. Ganderia Foil.
Misc. 9:141.

It is presumed that many of the records published as adjunctus
since Blandford's description refer, at least in part, to this species.

Superficially this species appears to be more closely allied to
certain species of Blastophagus, Pachycotes, Hylurgus and Hylur-
gonotus than to other species of Dentroctonus and, in many respects,

The Great Basin Naturalist
70 STEPHEN L. WOOD Vol. XXIII, NoS. 1-2

appears to resemble the hypothetical ancestor of this genus. Al-
though definitely more primitive, it is, however, rather closely allied
to terebrans from which it differs by the flat epistomal process, by
the more broadly, evenly convex frons, by the subcylindrical pro-
notum without a conspicuous anterior constriction, by the more
coarsely sculptured elytral disc, and by the distribution (Fig. 54).

Male. — Length 5.5 mm. (paratypes 5.2-6.9), 2.65 times as long
as wide; mature body color black.

Frons almost uniformly convex between eyes from vertex to
epistomal process, with a small, rather indefinite median impres-
sion on lower third well above base of epistomal process; epistomal
margin elevated, its surface smooth and shining; epistomal process
slightly narrower than half (0.44 times) the distance between eyes,
its lateral margins oblique (about 45° from the horizontal) and not
at all elevated, the horizontal portion slightly more than half its
total width, flat, overlapping and very slightly exceeding epistomal
margin and bearing under its distal margin a dense brush of con-
spicuous yellowish setae; surface rather coarsely, closely, deeply
punctured with rather abundant, isolated granules interspersed.
Vestiture, in addition to epistomal brush, moderately long, sparse,
inconspicuous.

Pronotum 1.2 times as wide as long, widest on basal half; sides
weakly arcuate, almost subparallel on basal half, then converging
gradually to the rather poorly developed transverse constriction just
behind the broadly, shallowly emarginate anterior margin; surface
smooth and shining with moderately small, close, rather deep punc-
tures, becoming rather shallow laterally and very minutely gran-
ulate on lateral rim; a median line obscurely indicated anteriorly.
Vestiture scanty, becoming more abundant, longer, and rather coarse
anteriorly and laterally.

Elytra 2.3 times as long as pronotum; sides straight and sub-
parallel on basal two-thirds, rather broadly rounded behind; basal
margins arcuate and bearing a row of nine, moderately large, raised,
overlapping crenulations, with several smaller submarginal ones
particularly on interspaces two and three; striae weakly impressed,
the punctures rather small and moderately deep; interstriae almost
twice as wide as striae and armed by abundant, confused, transverse
crenulations, each averaging about two-thirds the width of an inter-
space, a few wider than an interspace and sometimes crossing
striae. Declivity steep, uniformly convex; striae one to three straight,
the punctures almost as large as on disc; interstriae one to three
about equal in width and bearing rather abundant, somewhat con-
fused (usually arranged in widely staggered single row), moder-
ately large tubercles. Vestiture much longer and more abundant on
declivity, a few setae twice as long as width of an interspace.

Female. — Similar in all respects to male except pronotum evi-
dently a little more coarsely punctured and the elytra somewhat
more coarsely sculptured.

Type locality. — San Raphael, Mexico, Mexico.

June 14, 1963

REVISION OF DENDROCTONUS

71

Hosts. — Pinus leiophyUa and Pinus sp.

Distribution. — Central Mexico (Sinaloa) to Guatemala (Fig. 54).

Type material. — The male holotype, female allotype and one
paratype were taken at the type locality on September 11, 1949,
from Pinus leiophyUa, by J. P. Perry, Jr.. collection no. 49-16028.
Five para types were taken at IJalmanalco, Mexico, on January
8 and April 16. 1950, from the same host, ' by the same col-
lector; two paratypes were taken at Uruapan, Michoacan, Mexico,
July 12; one paratype was taken 20 mi. N. E. Copala, Sinaloa, Mex-
ico, by S. L. Wood, from Pinus; and eight paratypes are labeled
"Guatemala, C. A., Pinus, Hopk. U. S. 9929 Gl."

Fig. 54. Probable geographical distribution of Dendroctonus aztecus with
collection sites indicated (only two of the eight Guatemala records could be
verified).

The holotype, allotype and seven paratypes are in my collection;
the remaining paratypes are in the California Academy of Sci-
ences and in the U. S. National Museum.

The Guatemala locations marked on the distribution map for
this species are listed under adjunctus. At least some and possibly
all of the series taken in Guatemala included this species: part of
the series in question were unavailable for this study.

Geographical variation. — Not observed in the limited material
at hand.

Dendroctonus terebrans (Olivier)

?igs. 14, 29, 38, 55.

Scolytus terebrans Olivier, 1795, Entomologie 4(Gen. 78) :6.

Dendroctonus terebrans: Erickson, 1836. Archiv f. Naturgesch. 2(1):53; La-

cordaire, 1866, Genera des Coleopteres 7:360; Zimmerman, 1868, Trans.

American Ent. Soc. 2:149; Leconte, 1868. Trans. American Ent. Soc. 2:173;

Chapuis, 1869, Synopsis des Scolytides, p. 35 (reprint of 1873, Mem. Roy.

Soc. Sci. Liege, ser. 2, 3:243); Leconte, 1876, Proc. American Philos. Soc.

The Great Basin Naturalist

72 STEPHEN L. WOOD Vol. XXIII, Nos. 1-2

15:384; Schwarz, 1878, Proc. American Philos. Soc. 17:469; Hopkins, 1906,
Proc. Ent. Soc. Washington 7:81; Hopkins, 1909, U. S. Dept. Agric. Bur.
Ent. Tech. ser. 17(1): 147; Provancher, 1877, Fauna Ent. Canada 1:572;
Provancher, 1878, Fauna Ent. Canada 1 (Add. et Cor.):13. 14; Schwarz,
1886, Ent. Americana 2:56; Schwarz, 1888. Proc. Ent. Soc. Washington
1:80; Dietz, 1890, Trans. American Ent. Soc. 17:28, 29; Blandford 1897,
Biol. Centr.-Americana, Coleopt. 4(6): 146; Hopkins, 1899, Proc. Ent. Soc.
Washington 4:343; Smith, 1900, Cat. Ins. New Jersey, p. 364; Hopkins, 1905,
Proc. Ent. Soc. Washington 7:81, 145, 147; Snow, 1907, Trans. Kansas
Acad. Sci. 20 (2): 64; Swaine, 1909. New York St. Mus. Bull. 134:100;
Blatchley and Leng, 1916, Rhynchophora or weevils of N. E. America,
p. 654; Hagedorn, 1910. Colopterorum Catalogus 4:23; Hagedorn, 1910,
Genera Insectorum 111:60; Hopkins. 1915, U. S. Dept. Agric. Bur. Ent.
Tech. ser. 17 (2): 211; Beal and Massey, 1945, Duke Univ. School For.
Bull. 10:80; Chamberlin, 1939, Bark and timber beetles of North America,
p. 167. Biol.: Thomas, 1876, Nox. Ins. Illinois Kept. 1:146; Smith, 1877,
Insects that Infest Shade Trees, etc., p. 55; Packard, 1887. U. S. Dept. Agric.
Ent. Comm. Bull. 7:177; Packard, 1890. U. S. Dept. Agnc. Ent. Comm.
Kept. 5:721. 853; Hopkins. 1893. West Virginia Agric. E.xpt. Sta. Bull.
31:143, 32:213; Hopkins, 1894, Canadian Ent. 26:280; Hamilton, 1895,
Trans. American Ent. Soc. 22:346, 378; Hopkins, 1899, U. S. Dept. Agric.
Div. Ent. Bull. 21:27; Hopkins, 1899, West Virginia Agric. Expt. Sta. Bull.
56:392. 415, 421; Chittenden, 1899. U. S. Dept. Agric. Div. For. Bull.
22:56; Lugger. 1899, Minnesota Agric. E.xpt. Sta. Bull. 66:317; Felt, 1901,
Forest, Fish and Game Comm. Kept. 7:480; Hopkins, 1901, U. S. Dept.
Agric. Div. Ent. Bull. 28:pl. 12; Smith, 1901, Ent. News 12:92; Felt,
1902, U. S. Dept Agric. Div Ent. Bull. 31:64; Ulke. 1902, Proc. U. S.
Natl. Mus. 25:36; Hopkins. 1902. U. S. Dept. Agric. Div. Ent. Bull.
32:10; Hopkins, 1904, U. S. Dept. Agric. Div. Ent. Bull. 48:pl. 7; Felt,
1906, New York St. Mus.. Mem. 8. 2:333, 338. 342; Hopkins, 1909, U. S.
Dept. Agric. Bur. Ent. Bull. 58:62; Hopkins, 1909, U. S. De-pt. Agric.
Bur. Ent. Bull. 83(1): 146; Blackman, 1922, Mississippi Agric. Expt. Sta. /
Tech. Bull. 11:56; Felt, 1924. Manual of Tree and Shrub Insects, p. 262;
Nelson and Beal. 1929, Phytopath. 19:1102; Craighead et al, 1930, U. S.
Dept. Agric. Misc. Pub. 74:4; Craighead, 1935, U. S. Dept. Agric. Misc. Pub.
209:136; Adams, 1937. Arborists News 2(5) :3; Friend, 1942, Yale Univ.
School For. Bull. 49:145; Felt and Bromley, 1942. Jour. Econ. Ent. 35:170;
Felt and Bromlev. 1944. Jour. Econ. Ent. 37:213; O'Byrne, 1946, Virginia
Agric. Ext. Circ. 403:1, 7; Anderson, 1947, Texas For. Serv. Bull. 33:7;
Anonymous, 1951, U. S. Dept. Agric. Bur. Ent. PI. Quar. Ins. Pest Surv.
Sup. 4:8; Beal et al., 1952. Duke Univ. School For. Bull. 14:50; Hoyt, 1952,
U. S. Dept. Agric. Bur. Ent. PI. Quar. Kept. 1950-51:16; Anonymous, 1952,
U. S. Dept. Agric. Bur. Ent. PL Quar. Coop. Econ. Ins. Kept. 1 (Sup. 4):93;
Cross, 1953, South. Lumberm. 187(2336) :34; Hoyt. 1953. U. S. Dept. Agric.
Bur. Ent. PI. Quar. Kept. 1951-52:40; Lee and Smith. 1953, Proc. Assoc.
South. Agric. Workers 50:105; Barker and Nettles, 1954. South Carolina
Agric. Ext. Circ. 239(rev.):6; Hoyt, 1954. U. S. Dept. Agric. Bur. Ent.
PI. Quar. Kept. 1952-53:22; Jackson et al., 1954, For. Dis. Ins. Georgia's
Trees, p. 26; Smith. 1954. South. Lumberm. 189(2369) :155; Smith. 1954,
Proc. South. Agric. Workers 51:100; Briegleb, 1955, U. S. Dept. Agric.
South. For. Expt. Sta. Kept. 1954:68; Demmon. 1955. U. S. Dept. Agric.
S. E. For. Expt. Sta. Kept. 1954:74; Flory et al, 1955, South Carolina Agric.
Ext. Bull. 116:8; Lee and Smith, 1955, U. S. Dept. Agric. South. For.
Expt. Sta. Res. Notes 76, 2 p.; Ostrow, 1955, Proc. Conf. For. Tree Improv.
3:104; Smith. 1955, Proc. South. Agric. Workers 52:99; Anonymous, 1955,
U. S, Dept, Agric. For. Serv. Mor Imp. For. Ins. 1954:14; Bennett. 1955,
Texas For. Serv. Circ. 43:2. 8; Bennett. 1956. U. S. Dept. Agric. South.
For. Expt. Sta. For. Rptr. 10:10; Briegleb, 1956, U. S. Dept. Agric. South.
For. Expt. Sta. Rept. 1955:50; Demon. 1956. U. S. Dept. Agric. S. E. For.
Expt. Sta. Rept. 1955:74; Jordan and Dyer. 1956. Georgia Agric. Ext. Circ.
404, 12 p.; Merkel and Kowal. 1956, U. S. Dept. Agric. S. E. For. Expt.
Sta. Paper 67:4; Walker. 1956. Georgia For. Res. Counc. Rept. 2:1, 3, 7;

June 14, 1963 revision of dendroctonus 73

Livingston et al., 1956. Alabama Rept. 64/65:55; Briegleb, 1957, U. S.
Dept. Agric. South. For. Expt. Sta. Rept. 1956:67; McCambridge and Kowal,
1957, U. S. Dept. Agric. S. E. For. Expt. Sta. Paper 76:4; Pechanec, 1957,
U. S. Dept. Agric. S. E. For. Expt. Sta. Rept. 1956:41; Smith, 1957, Jour.
Econ. Em. 50:241; Smith and Lee, 1957, U. S. Dept. Agric. For. Serv. For.
Pest Leaflet 12, 7 p.; Anonymous. 1957, U. S. Dept. Agric. South. For.
Expt. Sta. South. For. Rptr. 16:4.

This species is very closely related to valens, but is readily
distinguished by the black body color, by the much larger punc-
tures on the lateral areas of the pronotum, by the larger, more
abundant declivital tubercles, and, in part, by the distribution
(Fig. 55).

Male. — Length 5.0-8.0 mm. (average about 6.5), 2.3 times as
long as wide; mature body color dark brown to black.

Frons rather evenly convex, with a shallow median impression
about a third of distance from upper level of eyes to epistomal mar-
gin, very feebly elevated lateral to impression; epistomal margin el-
elevated, its surface smooth and shining; epistomal process broad,
about half as wide (0.50 times) as distance between eyes, its arms
oblique (about 30° from the horizontal), elevated only at median
angles of arms, the horizontal portion about two-thirds its total
width and broadly, transversely concave, overlapping and ending
just above epistomal margin and bearing under its distal margin a
dense brush of yellowish setae. Vestiture, in addition to epistomal
brush, moderately long, sparse, inconspicuous.

Pronotum 1.4 times as wide as long, widest at base; sides weakly
arcuate and converging very slightly toward the moderately strong
constriction just behind the broadly, shallowly emarginate anterior
margin; surface smooth and shining, the punctures moderately
large, rather shallow, close, becoming two to three times larger
in diameter near lateral margins; bottom or floor of each punc-
ture irregularly reticulate; a partly impunctate, feebly raised med-
ian line indicated on posterior two-thirds; vestiture scanty, longer
and more evident laterally.

Elytra 2.1 times as long as pronotum; sides straight and sub-
parallel on basal two-thirds, rather broadly rounded behind; basal
margins arcuate and bearing a row of about twelve moderately
large, raised, overlapping crenulations, with several smaller sub-
marginal ones particularly on interspaces two and three; striae
weakly impressed, the punctures small and rather shallow; inter-
striae more than twice as wide as striae and armed by abundant,
confused, transverse crenulations, each averaging about half the
width of an interspace, a few about two-thirds as wide on posterior
half of disc. Declivity rather steep, convex; strial punctures slightly
smaller than on disc; interstrial punctures confused and all rather
coarsely granulate, the largest forming a somewhat definite median
row on each interspace. Vestiture moderately abundant, longer on
declivity, longest setae slightly greater than a distance equal to
width of an interspace.

The Great Basin Naturalist

74

STEPHEN L. WOOD Vol. XXIII, Nos. 1-2

Female. — Similar to male except a median frontal elevation evi-
dent at upper level of eyes; epistomal process less well developed;
pronotal punctures very slightly larger; and discal crenulations and
declivital granules a little larger.

Type locality. — Southern United States (probably (leorgia). The
concept of this species was based on Hopkins' material; the type was
not studied.

Hosts. — Pinus echinata, elliotti, palustris, rigida, rubens, sero-
tina, strobus, and taeda.

Distribution. — The United States south of a line drawn from
New Jersey to eastern Texas.

Specimens from the following localities were examined (Fig. 55). Alabama:
Aburn, Barton, Calhoun, "DeSoto S. P.," Grand Bay, Mobile and "Redland."
Arkansas: Hot Springs. Delaware: "Delaware." District of Columbi(: "Tax-
oma." Florida: Baker Co., Dunedin, Ft. Lauderdale, Gainesville, "Juniper

Fig. 55. Probable geographical distribution of Dendroctonus spp. with col-
lection sites indicated: 1, valens (circles); 2, terebrans (triangles). Several addi-
tional records from southern Mexico and Guatemala have been published for
valens.

June 14, 1963 revision of dendroctonus 75

Springs," Largo, Levy Co., Miami. Nassau Co., O'Leno S. P., Opa Locka, Tampa,
and Winter Park. Georgi.\: Clayton, Cornelia, Ft. Valley, Kingsland, Myrtle,
Thomasville, and Waverly. Louisi.\n.a: "Hart." M.'VRYL.'\nd: "Baden." New
Jersey: Clementon, lona, "Lahaway," Lakewood, Mt. Misery, and New Bruns-
wick. New York: Islip, Rockaway Beach and Bay Shore on Long Island.
North C.'^rolin.^: Asheville, and Southern Pines. Pennsylvania: Chinchilla.
South Carolina: Chicora Place, Lumber, "New Landing," Pregnall, and Spar-
tanburg. Tex.\s: Austin. Call, Deweyville, Kirbyville, and Turlington. Vir-
ginia: Ashland, "Camp Pickett," Falls Church, "Glen," and King. West
Virginia: Kanawah Station, Marion Co., Morgantown, Romney, "Roosevelt,"
and Crow.

Geographical variation. — Distinct differences correlated with
geographical origin were not evident.

Biology. — This is a secondary enemy of pines, and less com-
monly, other coniferous trees; consequently, economic damage at-
tributed to it is slight when compared to some of the other species
of Dendroctonus.

Since this species has not been observed during the course of this
study the following comments are based on personal observations
made on two occasions a decade ago, and on the reports of Hopkins
(1909b: 147) and of Blackman (1922:57).

The principal overwintering stage is the adult, either in the
bark of the brood tree or in newly started galleries of another host;
they may also pass the winter as partly grown larvae. In the spring
the adults became active in March or April and either begin or ex-
tend their new galleries as the period of oviposition commences.
Overwintering larvae complete their development in the spring and
evidently emerge from the brood tree prior to mid-July. The per-
iod of flight activity evidently continues more or less gradually
from March to December. In the southern parts of its range activ-
ity may continue without interruption throughout the year .

Stumps more than four inches in diameter of recently cut trees,
or of injured or weakened trees, are selected for attack. Their gal-
leries ordinarily extend downward into the roots; occasionally they
extend upward as much as two or three feet above the ground level,
except in the southwestern parts of its distribution where they may
extend more than 12 feet above the ground (Smith & Lee, 1957:3).
Frequently the attacks are made in the vicinity of a wound at the
base of the tree. Even though such attacks do not kill the host im-
mediately they may interfere with normal growth, reduce vitality,
thereby inviting other insect or disease causing agents to attack the
tree.

The attack ordinarily begins at or just above the ground level,
usually with only a few pairs of beetles participating. The female
constructs the entrance tunnel and normally is joined by the male
shortly after she reaches the cambium. If the amount of pitch en-
countered is excessive the gallery usually is extended upward, other-
wise it is extended downward after ascending a centimeter or two.
The egg gallery varies considerably in length, but seldom exceeds
30 centimeters. It may be linear, slightly wider than the beetle

The Great Basin Naturalist

76 STEPHEN L. WOOD Vol. XXIII, Nos. 1-2

making it, or it may be branched; ordinarily it is irregularly wid-
ened at various places. As with other species, the male removes the
frass from the working area, ejecting it from the entrance hole at
first, then later packing it into the unused areas.

There are no individual egg niches. Groups of eggs are deposited
rather loosely at one side of the gallery in one of the widened areas.
These groups are then separated from the main areas of the gallery
by a rather tightly packed partition of frass.

The periods of incubation and of larval development have not
been precisely determined. The larvae do not construct individual
tunnels, but work together in the phloem tissues in contact with
the cambium, extending the cavity started by the parents. In some
instances these cavities are said to cover several square feet of the
inner bark (Blackman, 1922:58). These extensions by the larvae
appear to wander aimlessly, favoring no particular direction. Lar-
vae from eggs laid in the spring evidently pupate by mid-July and
emerge in the fall. There is one complete and a partial second gen-
eration each year in most areas; two complete generations may oc-
cur in the extreme southern parts of its range.

Dendroctonus valens Leconte
Figs. 15-17, 30, 37, 55-56.

Scolytus terebrans: Harris, 1826, New England Farmer 5:169; Harris, 1862,
A treatise on Some of the Insects Injurious to Vegetation, p. 56.

Hylurgus terebrans: (Biol.) Harris, 1841, A Report on the Insects of Mass-
achusetts Injurious to vegetation, p. 72; Harris, 1842, A Treatise of Some
of the Insects of New England which are Injurious to Vegetation, p. 72,
1852, p. 76; Fitch, 1858, Trans. New York St. Agric. Soc. 18:728; Harris.
1862, A Treatise on Some of the Insects Injurious to Vegetation, p. 86;
Harris, 1863, A Treatise on Some of the Insects Injurious to Vegetation,
Flint edition, p. 84; Thomas, 1876, Illinois State Entomologist Rept. 6:146;
Smith, 1877, in Stewart, Shade Trees. Indigenous Shrubs and Vines, p. 52.

Dendroctonus terebrans: Zimmerman, 1868, Trans. American Ent. Soc. 2:149
(in part); Leconte. 1868, Trans. American Ent. Soc. 2:173 (in part);
Leconte, 1876, Proc. American Philos. Soc. 15:385 (in part); Provancher,
1877, Faun. Ent. Canada 1:572; Dietz, 1890, Trans. American Ent. Soc.
17:29 (in part); Blandford, 1897. Biol. Centr.-Americana 4(6): 146; Hop-
kins, 1899, Proc. Ent. Soc. Washington 4:343 (in part). Biol.: LeBaron,
1871. Prairie Farmer 42:p.?; Pachard. 1887, U. S. Dept .Agric. Ent. Comm.
Bull. 7:175, 243 (in part); Pachard. 1890, U. S. Dept. Agric. Ent. Comm.
Rept. 5:721 (in part); Hopkins, 1892. Science 20:64; Hopkins, 1893, West
Virginia Agric. E.xpt. Sta. Bull. 31:143 (in part); Hamilton, 1895, Trans.
American Ent. Soc. 22:346, 378; Wickham. 1896. Proc. Davenport Acad.
Nat. Sci. 6:169; Wickham, 1896. Bull. Lab. Nat. Hist. State Univ. Iowa
3(4): 170; Hopkins. 1897. West Virginia Agric. Expt. Sta. Rept. 6:41;
Wickham. 1898, Bull. Lab. Nat. Hist. State Univ. Iowa 6(3):312; Hopkins,
1899, West Virginia Agric. Expt. Sta. Bull. 56:392. 415; Hopkins, 1899,
U, S. Dept. Agric. Div. Ent. Bull., n. s.. 21:14; Chittenden, 1899, U. S.
Dept. Agric. Div Ent. Bull. 22:56 (in part); Wickham, 1902, Bull. Lab.
Nat. Hist. State Univ. Iowa 5(3): 309; Felt, 1903, New York St. For. Comm.
Rept. 7:480 (in part); Felt. 1906, New York St. Mus., Mem. 8, 2:342
(in part).

Dendroctonus valens Leconte. 1860. Pacific R. R. E.xplor. 5(2): 59; Chapuis,
1869, Synopsis des Scoly tides, p. 35 (1873, Mem. Soc. Roy. Sci. Liege

June 14, 1963 revision of dendroctonus 11

2, 3:243); Powell, 1904, Jour. New York Ent. Soc. 12:237; Powell, 1905,
Jour. New York Ent. Soc. 13:5; Hopkins, 1905, U. S. Dept. Agric. Bur.
Ent. Bull. 56:6, 11, 17; Hopkins, 1906, Proc. Ent. Soc. Washington 7:147;
Hopkins, 1906, Proc. Ent. Soc. Washington 7:81; Swaine, 1909, New York
St. Mus. Bull. 134:100; Hopkins, 1909, U. S. Dept. Agric. Bur. Ent. Tech.
ser. 17(1):151; Hagedorn, 1910, Coleopterorum Catalogus 4:23; Hagedorn,
1910, Genera Insectorum 111:60; Hopkins, 1915, U. S. Dept. Agric. Bur.
Ent. Tech. ser. 17(2) :211 etc.; Blatchley and Leng, 1916, Rhynchophora
or weevils of N. E. America, p. 577, 654; Swaine, 1918, Dom. Canada
Dept. Agric. Ent. Br. Bull. 14(2): 63; Chamberlin, 1939, Bark and Timber
Beetles of North America, p. 167; Schedl, 1940 (1939), An. Esc. Nat. Cienc.
Biol. 1:320, 323, 339; Schedl, 1955, Zeitschr. Angew. Ent. 38:14; Cham-
berlin, 1958. Scolytoidea of the Northwest, p. 78. Biol.: Hopkins, 1902,
U. S. Dept. Agric. Div. Ent. Bull. 32:12; Gillette, 1903, Colorado Agric.
Kept. 24:118; Hopkins, 1903, Canadian Ent. 35:61; Hopkins, 1904, U. S.
Dept. Agric. Div. Ent. Bull. 48:19; Currie, 1905, U. S. Dept. Agric. Div.
Ent. Bull. 53:74; Fall, 1907, Trans. American Ent. Soc. 33:218; Burke,
1908, Proc. Ent. Soc. Washington 9:115; Hopkins, 1909, U. S. Dept.
Agric. Bur. Ent. Bull. 58:62; Hopkins, 1909, U. S. Dept. Agric. Bur. Ent.
Bull. 83(1): 153; Hopkins, 1912, U. S. Dept. Agric. Bur. Ent. Circ. 142:6;
Swaine, 1913, Ontario Ent. Soc. Kept. 43:90; Swaine, 1914, Dom. Canada
Dept. Agric. Expt. Farms. Ent. Bull., ser. 2, 17:20; Compere, 1915, Cal-
ifornia Hort. Bull. 4:574; Chamberlin, 1917, Canadian Ent. 49:323, 327;
Chamberlin. 1918, Oregon Agric. Expt. Sta. Bull. 147:9; Blackman, 1919,
Psyche 26:90; Herbert, 1919, Jour. Econ. Ent. 12:337; Hopping, 1921,
Canada Dept. Agric. Ent. Br. Circ. 15:12; Hopping, 1922, Canadian Ent.
54:129, 130, 132; Graham. 1922, Minnesota Ent. Kept. 19:15; Blackman,
1922, Mississippi Agric. Expt. Sta. Tech. Bull. 11:22, 28, 58; Felt, 1924,
Manual of Tree and Shrub Insects, p. 263; Hatch, 1924, Michigan Acad.
Sci. Pap. 6:584; Trimble, 1924, Ann. Ent. Soc. America 17:384; Craig-
head, 1927, U. S. Dept. Agric. Circ. 411:4; Peirson, 1927, Maine For. Serv.
Bull. 5:108, 121; Keen, 1928, California Dept. Nat. Res. Bull. 7:37; St.
George, 1929, U. S. Dept. Agric. Farmers Bull. 1586:4; Craighead, 1930,
U. S. Dept. Agric. Muse. Pub. 74:4; Blackman, 1931, New York St. Coll.
For., Syracuse Univ. Bull. 4(4), Tech. Pub. 36:31; Burke, 1932, California
Agric. Mo. Bull. 21:366; Walther, 1933, Jour. Econ. Ent. 26:828; Walther,
1933, Pan-Pac. Ent. 9:47; Kaston, 1936, Connecticut Agric. Expt. Sta. Bull.
387:645; Burke, 1937, Proc. Western Shade Tree Conf. 4:29; Brimley,
1938, North Carolina Dept. Agric. (Insects of North Carolina) :246;
Dodge. 1938, Minnesota Agric. Expt. Sta. Tech. Bull. 132:28; Keen, 1938,
U. S. Dept. Agric. Misc. Pub. 273:109; Beal, 1939, U. S. Dept. Agric.
Farmers Bull. 1824:12; Wheeler, 1940. California Cult. 87:636; DeLeon,
1942, U. S. Dept. Agric. Bur. Ent. PI. Quar. E-568, 4 p.; Felt and Bromley,
1942, Jour. Econ. Ent. 35:170; Evenden et. al., 1943, U. S. Dept. Agric.
Circ. 664; Parr, 1943, Jour. Forestry 41:419; Felt and Bromley, 1944,
Jour. Econ. Ent. 37:213; Beal and Massey, 1945, Duke Univ. School For.
Bull. 10:81; Leech, 1945, Canada Dept. Agric. Div. Ent. For. Ins. Surv.
Rept. 1944:66; Patterson, 1945, Univ. Washington Pub. Biol. 10:150;
Anderson, 1947. Texas For. Serv. Bull. 33:7; Bruhn, 1947, Great Basin
Nat. 8:21; Weidman nad Bobbins, 1947, Jour. Forestry 45:428, 431; Mues-
ebeck, 1950, Jour. Econ. Ent. 43:125, 131; Pearson, 1950, U. S. Dept. Agric.
Monogr. 6:154; Craighead, 1950, U. S. Dept. Agric. Misc. Pub. 657:295;
Evans and Dyer, 1951, Canada Dept. Agric. Div. Ent. For. Ins. Surv. Rept.
1950:110; Becker, 1951, Zeitschr. angew. Ent. 33:186; Lannon, 1951,
Rhode Island Dept. Agric. Cons. Rept. 16:38; Perry, 1951, Unasylva
5:161; Whiteside, 1951, U. S. Dept. Agric. Circ. 864:3; Anonymous, 1951,
U. S. Dept. Agric. Bur. Ent. PI. Quar. Ins. Pest. Surv. Sp. Sup. 4:8; Beal,
1952, Duke Univ. School For. Bull. 14:50; Hoyt, 1952, U. S. Dept. Agric.
Bur. Ent. PI. Quar. Rept. 1950-51:16; Keen, 1952, U. S. Dept. Agric. Misc.
Pub. 275:127, 142; Anonymous, 1952, U. S. Dept. Agric. Bur. Ent. PI.
Quar. Coop. Econ. Ins. Rept. l(Sup. 4):93; Becker, 1954, Zeitschr. angew.
Ent. 36:20; Knight and Wilford, 1954, U. S. Dept. Agric. Rocky Mtn. For.

The Great Basin Naturalist

78 STEPHEN L. WOOD Vol. XXIII, Nos. 1-2

Range Expt. Sta. Ins. Cond. 1953:4; Reid, 1955, Canadian Ent. 87:316,
323; Shenefelt and Benjamin, 1955, Wisconsin Agric. Ext. Circ. 500:84;
Anonymous, 1955, California For. Pest Contr. Action Comm. For. Ins.
Cond." 1954:7; Morena Noriega, 1956, Fitofilo 9(15) :23. 35; Ostmark and
Wilford, U. S. Dept. Agric. Rocky Mtn. For. Range Expt. Sta. Paper 22:6.
Dendroctonus beckeri Thatcher, 1954, Coleopterists Bull. 8:3. Biol.: Perry,
1955, Coleopterists Bull. 9:1.

This, the largest species in the genus, is very closely related to
terebrans, but is readily distinguished by the reddish brown body
color, by the smaller punctures m the lateral areas of the pronotum,
by the smaller, less abundant decli vital granules (Fig. 30) and,
in part, by the distributions (Fig. 55).

Male. — Length 5.4-9.0 mm. (average about 8), 2.3 times as long
as wide; mature body color reddish brown.

Frons irregularly convex, with a pair of lateral protubrances
about a third of distance below upper margin of eye to epistomal
margin, these protubrances separated by a broad, shallow, subcon-
cave depression; epistomal margin elevated, its surface smooth and
shining; epistomal process very broad, equaling about two-thirds
(0.60 times) the distance between eyes, its arms oblique (about 20°
from the horizontal), elevated only at inner angles of arms, the
horizontal portion about two-thirds its total width, broadly concave,
overlapping and ending just above epistomal margin and bearing
under its distal margin a dense brush of yellowish setae. Vestiture,
in addition to epistomal brush, moderately long, sparse, inconspic-
uous.

Pronotum 1.3 times as wide as long; sides weakly arcuate, al-
most subparallel, on basal two-thirds then moderately constricted
just behind the broadly, shallowly emarginate anterior margin;
surface smooth and shining, the punctures very close, rather shallow
but sharply impressed, rather small but irregular in size, not larger
laterally; an impunctate, feebly raised median line indicated on
posterior three-fourths; vestiture scanty, longer and more evident
laterally.

Elytra 2.2 times as long as pronotum; sides straight and sub-
parallel on basal two-thirds, rather broadly rounded behind; basal
margins arcuate and bearing a row of about twelve moderately
large, raised, overlapping crenulations, with several smaller sub-
marginal ones particularly on interspaces two and three; striae
weakly impressed, the punctures rather small and deep; interstriae
about one and one-half times as wide as striae and armed by abun-
dant, confused, small, transverse crenulations, each averaging about
one-third the width of an interspace, almost never more than half
as wide on posterior half of disc. Declivity moderately steep, con-
vex, with a feeble impression between first and third striae; strial
punctures slightly smaller than on disc; interstrial punctures con-
fused and finely to coarsely granulate, the largest granules forming
an indefinite median row (in a few luales only this median row
of granules appears). Vestiture moderately abundant, longer on de-

June 14, 1963 revision of dendroctonus 79

clivity, longest setae slightly exceed a distance equal to width of an
interspace.

Female. — Similar to male except a median frontal elevation evi-
dent at upper level of eyes; pronotal punctures very slightly larger;
and discal crenulations and declivital granules a little larger.

Type locality. — California (Totonicapan, Guatemala for beck-
eri). The types of both descriptions were studied. Hopkins did not
state that the type of valens is a male.

Hosts. — Pinus arizonica., chicuahuana, contorta, coulteri, ech-
inata, edulis., jeffreyi, lambertiana, lawsoni^ leiopliylla, monticola,
murrayana, oocarpa, ponderosa, pseudostrobus, radiata, resinosa,
rigida, rudis, sabiniana, sylvestris., strobijormis, strobus tenuifolia,
and virginiana, Abies concolor, Larix laricina, Picea canadensis,
excelsa, and rubens.

Distribution. — The coniferous forests of America north of Guat-
emala, except in the extreme southeastern United States.

Specimens from the following localities were examined (Fig. 55). Arizona:
Apache N. F., Chiricahua Mts., Flagstaff, Ft. Apache Indian Res., Fredonia,
Graham Mts., Grand Canyon N. P., McNary, Oak Ck. Canyon, Paradise, Portal,
Prescott, Ramsey Canyon, Rincon Mts., Santa Catalina Mts., and Williams.
California: Alder Ck., "Alpine Ck." near Lake Tahoe, Arnold, Bass Lake,
Bear Lake, Ben Lomond, Berkeley. Blancos Corral. Boulder Ck., Bray, "Burnt
Corral," "BSA Camp" at Oakland, Camp Greenley, Camp Wolfboro. Carmel.
Cedar Ridge, Chester, Cisco, Columbia, Cow Ck., Crane Valley, "Crooked
Ck.," Crystal Lake. Cummings R. S., "Dark Canyon" in San Jacinto Mts., Del
Monte, Devil's Garden, Dorrington. Dunsmuir, "Durley and Herrick Mine" in
Plumas Co., Echo Lake. Eldorado. Fallen Leaf Lake, Fresno. General Grant
N. P., Hackamore, Halls Flat on Black Mtn., Harvey Valley, Hat Creek, Hay-
fork, "Hazel Green," Herkey Ck. in San Jacinto Mts., Hobart Mills, Hope Val-
ley, Huckleberry Meadow. Huntington Lake. Idyllwild, Inverness, Jackson,
Jacumba, Jamesberg, "Jerome Mill." Julian, Junipero Serra Peak. Kelsey, Lake
Co., Lake Arrowhead, Lake Tahoe, Lake Tenaya, "Lake McKenzie," Lamoine,
Leavitt Meadows in Lassen Co., Little Yosemite, Lomo. Lone Pine. Loyalton.
"Lumgray R. S." Madrone, Manzanita Lake in Lassen N. P., Mather, Mc-
Cloud, McKenzie, Meadow Valley, Merced. Miami R. S., Milford, Millbrae,
Miller Mt. Mill Valley, "Millwood," Mineral, Modoc N, F.. Moffitt Ck.. Mono
Lake, Monterey. Mt. Hamilton. Mt. Hermon, Mt. Laguna, Mt. St. Helena,
Nevada City, New Indria, North Fork, Oakland, Old Station, Onion Valley.
Oriental, Orinda, Orinda Crossing. Pacific Grove, Palo Alto, Pebble Beach, Pied-
mont. Pinecrest. Pinehurst, "Pinogrande," Placerville, Plumas N. F.. Point
Areno, Pollock Pines, Quincy, "Quintette," Rattlesnake Ck., Riverside Co., Sac-
ramento, Salinas, San Bernardino, San Bernardino Mts., "Sand Flat." San
Francisco. San Jose, San Mateo, Santa Barbara Co.. Santa Cruz, Santa Lucia
Mts., Sequoia N. P., Shuteye, Shingle Springs, "Simpson Meadows," Sisson,
"Snowline Camp" in Eldorado Co., Solano Co.. Stanford, Stauffer, Stewarts
Point. Stirling City, "Summerdale," "Sugarloaf Mt." in Los Angeles Co.,
Tallac, Three Rivers, Timber Mt.. Truckee, Viola, Walkermine, Wawona,
"Whitaker's Forest in Tulare Co., "Willow Meadow." Willow Ranch, Yreka,
and Yuba Gap. Colorado: Bailey, Cheyenne Mt.. Estes Park, Ft. Garland,
Douglas Co., Longs Peak. Manitou Park, "Mt. McClellan." Palmer Lake,
Placer, "Powder River," Red Mt., San Isabel N. F., and Vallecito R. S. in
LaPlata Co. Idaho: Beaver Creek in Logan Canyon, Cedar Mt., Centerville,
Coeur d'Alene, Farrogot, Grangeville, Grimes Pass. Harris Ridge. Moscow,
Pioneerville, Priest River and Smiths Ferry. Illinois: "Illinois." Kansas:
"Kansas." Maine: Brunswick, Casco Bay. Limerick, Orono, Paris, Peak Island,
and Portland. Massachusetts: Cambridge, Framingham, Lynn, and Stoneham.

The Great Basin Naturalist
80 STEPHEN L. WOOD Vol. XXIII, Nos. 1-2

Michigan: Grand Island, and Marquette. Minnesota: Aitkin, Cloquet, Duluth,
Grand Rapids, Itasca Park, Olmsted, Pluninier, Roseau Co., and Two Harbors.
Montana: Helena, Missoula, and Sula. Nevada: Reno. New Hampshire: Dur-
ham, Manchester, and Webster. New Jersey: Lakehurst, Nilltown, and New-
foundland. New Mexico: "Bright Angel," Capitan, Capitan Mts., Carson N. F.,
Cloudcroft, Coolidge, "Culdridge," Ft. Wingate, Las Vegas, Lincoln N. F.,
Ruidoso, Sierra Blanca Mts., and Vermejo. New York: Hamburg, Ithaca, Syr-
acuse, and West Point. North Carolina: Asheville, Balsam, Biltmore, and
"Pink Beds." Ohio: Hocking Co. Oregon: Albany, "Anthony Ck.," Ashland,
Aspen Lake, Baker, Bourne, Clover Ck., Cold Springs, Colestine, Corvalis, Crater
Lake, Hood River, Joseph, Kerby, Klamath Lake, LaGrande, Mt. Hood, Prine-
ville, Pringle Falls, Siskiyou Mts., "Slate Ck.," Sumpter, "Sutton Ck.," and
Talent. Pennsylvania: Chambersburg, Milford, and Philadelphia. South
Dakota: Black Hills, Custer, Deadwood, Elmore, Lead, and Spearfish. Utah:
Ashley N. F., Escalante, Eureka, Kamas, Logan Canyon, Mammoth Mt., Nav-
ajo Mt., and Panguitch Lake. Virginia: Fredericksburg. Vermont: Fairlee.
Washington: Blewett Pass. Buckeye, Dayton, Easton, East Satsop River, Fair-
fax, "Grass Prairie," "Half Moon," Maiden, Metaline Falls, NewMan, North-
port, Olympia, Pullman, Satus Ck., Seattle, Skakomish River, Skakomish, and
Toppenish. West Virginia: Bretz, Cranesville, Crow, "Deckers Ck.," Hardy
Co., Kanawha Station, "Mayfield Hill," Moorefield, Morgantown, Randolph.
"Pallslow," Pendleton, Romney, "Roosevelt," and Tucker Mine. Wisconsin: Ash-
land, Bayfield, and Madison. Wyoming: "Lynn," Moskee, and Wyoming in
Albany Co. Alberta: Athabasca Falls, Ft. Chipewyan, and Waterton Lakes
N. P. British Columbia: Aspen Grove, Campbell River, Canford, Kamloops,
Little Shuswap Lake, Midday Ck., Nicola, O'Kanagan Landing, Oliver, Peach-
land, Princeton, "Spious Ck.." Summerland, Trinity Valley, Vernon, Westwold.
Northwest Territory: Ft. Smith. Nov.\ Scotia: Kentville. Ontario: Ottawa,
Prince Edward Co., Toronto, and Quitoico Pk. Quebec: Duparquet, Ft. Cou-
longe, Montreal. Saint Anne, and Saint Johns. B.\ja Californl-^: Sierra San
Pedro Marlir. Chihuahua: Cerocahui, and Chihuahua. Distrito Federal:
Mexico. Durango: El Salto. Hidalgo: Jacala. Mexico: Chalco, Ozumba Mt.,
and Tlalmanalco. Morelos: Cuernavaca. Puebla: Texmelucan. Guatemala:
Cerro Quemado, Cuchumatenes Mts., El Baul, Guatemala City, Huehuetenanto,
La Esperanza, Momostenango, Patzun, Panajachel, Quezaltenango, Totonicapan,
and Uruapan.

Geographical variation. — Specimens from the northeastern parts
of the range appear to be somewhat smaller than those from other
areas; however, this may result from the limited material at hand,
rather than actual population difference. The sexual differences of
the frons appear to be more strongly developed in series originating
in southern Mexico and Guatemala. There is also a tendency for
the egg galleries of some specimens from those areas to be elongate
and narrow; however, neither the sexual nor the gallery character
is found in a majority of the population in those areas.

Biology. — In general, this is a secondary enemy of pine and
spruce, but on occasion it attacks and kills apparently healthy trees.
It usually works in conjunction with other more aggressive species
and, consequently, comparatively little economic loss is attributed
to it.

This species may overwinter either as young or mature adults
or as partly grown larvae. There is an extreme overlapping of gen-
erations which is reflected by the fact that these insects may be seen
in flight at any month of the year during their period of activity.
In the northern parts of its range this period of activity evidently

June 14, 1963

REVISION OF DENDROCTONUS

81

is from May to October; in the southern areas the species probably
is active throughout the year.

Ordinarily stumps, injured, weakened or dying trees are selected
for attack, although in some areas apparently healthy trees are
selected. The attack usually is concentrated at or near the ground
level at the base of the tree, but in some areas it may extend six or
more feet above the level of the ground. Generally this species ar-
rives quite some time after other species have attacked a particular
tree.

The attack on any one tree ordinarily involves only a few pair
of beetles of this species. It usually begins a few inches above the
ground level then progresses above and below that point. It is not
concentrated and, in fact, may involve two or more successive gen-
erations before the host succumbs.

The egg galleries (Fig. 56) of this species are exceedingly var-
iable. The female, as with other species in the genus, constructs the
entrance tunnel. After reaching the cambium region the tunnel
extends upward for a short distance. If the amount of pitch en-
countered is excessive it may continue upward, if not, it may curve

Fig. 56. Dendroctonus valens: Egg galleries broad, shape commonly re-
sembling an inverted "J"; eggs placed in masses in grooves and packed in frass
along sides of galleries (shaded areas above) ; larvae feed in congress often
e.xcavating large tabular areas in the inner bark (larval excavations not in-
cluded).

The Great Basin Naturalist

82 STEPHEN L. WOOD Vol. XXIII, Nos. 1-2

downward into the roots. The egg gallery may be linear, slightly
wider than the length of the beetle constructing it, or it may be
branched or of a broad, irregular cave type. The linear pattern is
more common in warmer parts of the range. In southern Mexico
egg galleries exceeding 40 centimeters in length were not uncom-
mon; however, it should be mentioned that broad cave-type exca-
vations were found in the same tree with linear galleries as were
all degrees of intergradation between the extremes. Usually one side
of the gallery is expanded somewhat, either continuously or irreg-
ularly, for deposition of the eggs.

Oviposition in most areas of the United States evidently begins
in late May or early June and continues throughout the warm
months. Egg laying in northern or southern areas probably would
begin earlier or later than this. The eggs are deposited along the far
side of the expanded parts of the gallery, either loosely packed in
frass or in layers, in groups of 10 to 40 or more. They are then
covered with a more or less compact layer or partition of frass.
There are no egg niches.

According to Swaine (1914:20) the larvae hatch in about ten
days. They do not construct individual tunnels but mine in congress
in the phloem next to the cambium in a general direction away from
the egg gallery. Behind them the large flat cavity is filled by a red-
dish frass. The length of the larval period has not been determined
precisely, but probably exceeds two months; it is suspected that in
northern areas it may exceed a year. Pupal cells generally are
formed in the frass, although occasionally a larva will construct a
short individual tunnel in the phloem adjoining the common cavity
where the pupal cell is formed. In the southern parts of its distri-
bution there is one complete and at least a partial second generation
each year; in the northern areas a generation evidently may re-
quire more than one year.

Dendroctonus micans (Kugelann)
Fig. 21

Bostrichus micans Kugelann. 1794, Schneider Magazin 5:523.

Dendroctonus micans: Erichson, 1836, Archiv Naturgesch. 2(1):53; Eichhoff,
1864, Berliner Ent. Zeitschr. 8:27; Chapuis, 1869, Synopsis des Scolytides,
p. 35 (1873. Mem. Soc. Roy. Sci. Liege ser. 2, 3:243); Reitter, 1869, Verh.
naturf. Ver. Briinn 8(2) :p. ?; Lindemann, 1875, Bull. Soc. Imp. Nat. Mos-
cou 49:213, 221; Lindemann. 1879. Bull. Soc. Imp. Nat Moscou 54:73;
Verhoff, 1896, Archiv Naturgesch. 62(1): 124; Lovendal, 1898. De Danske
Barkbiller, p. 87; Barbev, 1901. Scolytides I'Europe Centrale, p. 56; Hop-
kins, 1901, U. S. Dept. Agric. Bur. Ent. Tech. ser. 17(1): 143; Hagedorn,
1910, Coleopterorum Catalogus 4:21; Hagedorn, 1910, Genera Insectorum
111:60; Reitter, 1913. Wiener Ent. Zeit. 32(Beiheft) :47; Spessivtseff,
1913, (Practical keys to the bark beetles), p. 57; Spessivtseff, 1922, Medd.
Skogsforsoksanstalt 19(6) :465; Spessivtseff. 1925, Svensk Insektfauna 3:164;
Pfeffer. 1932, Cat. Coleopt. Cechosloveniae 2:13; Schedl. 1932. in Winkler,
Cat. Coleopt. reg. palaercticae. p. 1635; Kurentzov. 1941. Bark-beetles of the
Far East, U. S. S. R.. p. 116; Balachowsky. 1949, Faune de France 50:134;
Stark, 1952, Fauna U. S. S. R., 30:184; Pfeffer, 1955, Fauna C. S. R.

June 14, 1963 revision of dendroctonus 83

(Czechoslovakia), p. 121. Biol.: Ratzeburg, 1861, Forstl. Bl. 2:64; Heyden,
1874, Jahrb. Nass. Ver. f. Naturk. 27-28:297; Eichhoff, 1880 (1881), Die
Europaischen Borkenkafer, p. 125; Ahum, 1881. Forstzoologie 3(1):262; Hen-
schel, 1885, Centralbl. f. d. g. Forsw. 11:534; Heyden, 1887, Ber. u d. 60
Vers, deutsch. Naturf. u. Aerzte, p. ?; Ahum. 1888, Zeitschr. Forst.-Jagdw.
22:242; Judeich and Nitche, 1895, Lehrbuch der mittel europaischen
Forstinsektenkunde, p. 458; Severin, 1902, Bull. Soc. Centr. forestiere
Belg. 9:72, 145; Weber, 1902, Allg. Zeitschr. Ent. 7:108; Brichet and
Sevenn. 1903. Bull. Soc. Centr. forestiere Belg. 10:244; Baudisch, 1903,
Centralbl. Forstw. 29:151; Bergmuller, 1903, Centralbl. Forstw. 29:252;
Bergmiiller, 1904, Forstl. Bl., p. 145; Quairiere, 1904, Bull. Soc. Centr.
Forestiere Belg. 11:626; Niisslin, 1905, Leitfaden der Forstinsektenkunde,
p. 175; Quairiere, 1905, Bull. Soc. Forstiere Belg. 12:183; Quievy, 1905,
Bull. Soc. Centr. Forestiere Belg. 12:334; Fuchs, 1906, Zeitschr. Forst.-
Landw., p. 291; Fonnanek, 1907, Kurovci v. Cechach a na Morave zijici,
p. 21; Pomerantzew, 1907, Ljaess, Shur. St. Petersburg 37:177; Tredl,
1907. Ent. Blatt. 3:11; Severin. 1908, BuH. Soc. Centr. Forestiere Belg.
15:1; Hopkins, 1909, U. S. Dept. Agric. Bur. Ent. Buh. 83(1):141; Koch,
1909. Zeitschr. Forst.-Landw. 7:319; Chabrier, 19—. Mem. Mus. Hist.
Nat. 6:470; Saalas. 1913, (reference ?), p. 17; Traghardt, 1916, Skogsv.
Tdjskr., p. 484; Saalas, 1917, Fichtenkafer Finnlands 2:493; Kneiff, 1923,
Mitt. Deutch. Denfrol. Ges., p. 246; Loos, 1925, Sudetendeutsche Forst.-Jag-
dztg. 25:53; Eulefeld, 1922. D. Forstz. 37:589; Koch. 1928. Bestimmungstabel-
len Ins. Fichte u. Tanne, p.?; Spessivtseff, 1931, Opredelitel Korojedov, p. 86;
Torka. 1933, Ent. Blatt. 29:120; Roubal, 1942, Katalog Coleopt. Slovenska
3:258; Bioltchev, 1934, Lesov. Mis. 3(1) :4; Pfeffer. 1943. Lesnicka prace
22:181; Karpinski, 1948, Korniky ziem Polski, p. 96; Pfeffer, 1949, Les-
nicka prace 28:151; Gohrn, 1954, Det. forstl. Forsogsv. i Danmark 21:383.

Hylesinus {Dendroctonus) micans: Ratzeburg. 1839, Die Forst-Insekten 1:217;
Kollar. 1858. Verb. Zool.-Bot. Ges. Wien 7:24; Willkomm, 1863, Thar. f.
Jahrb.' 15:249; Wahl, 1897, Zeitschr. Forst.-Jagdaw., p. 589; Eckstein, 1904,
Zeitschr. Forst.-Jagdw., p. 243; Koch, 1909, Naturw. Zeitschr. Land-Forstw.,
p. 319.

Hylesinus micans: Geitel, 1862. Verb. Harz. Forstr., p. 21, 1867, p. 13; Geb-
bers, 1872, Verb, Harz. Forstr., p. 58; Ulrici, 1873, Zehschr. Forst - Jagdw.,
p. 150; Gluck, 1876. Zeitschr. f. Forst.-Jagdw. 8:385; Pauly, 1892,
Zeitschr. Forst. - Jagdw.. p. 257. 315, 351; Metzger, 1897, Miind. forstl. Hefte,
p. 59; Obertreis. 1897, Zeitscher. Forst - Jagdw., p. 93; Schneider, 1897,

Waldungen des Rheinlandes 12:382; F , 1900, Deutsche Forst. - Zeit.

15:52; Esser. 1901, Wochenschr. Forst.. p. 286; Eckstein, 1904, Zeitschr.
Forst. - Landw., p. 243; Methner, 1935, Wochenbl. Landesb. Pomniern
2:216.

This is the only species in the genus occuring outside of the
nearctic region. It appears to have reached Eurasia in comparatively
recent times and is perhaps doubtfully distinct from the subarctic
North American punctatus. This species may be distinguished from
punctatus by the larger size and stouter form, by the flat epistomal
process, by the smaller strial punctures, by the somewhat larger
elytral crenulations, and by the distribution.

Male. — Length 6.0-8.0 mm. (average about 7), 2.33 times as
long as wide; mature body color rather uniformly dark brown.

Frons convex, protruding very slightly in center area just below
middle; epistomal margin elevated- smooth, shining; epistomal pro-
cess a fourth (0.27 times) as wide as distance between eyes, its arms
strongly oblique (about 55° from the horizontal) with margins
sharply defined but not elevated, the horizontal portion about two-

The Great Basin Naturalist

84 STEPHEN L. WOOD Vol. XXIII, Nos. 1-2

thirds its total width, flat, overlapping and ending just above
epistomal margin and bearing under its distal margin a dense brush
of yellowish setae; surface smooth and shining from vertex to epis-
toma, the punctures rather close, deep, coarse, sharp, with no indi-
cation of granules or tubercles. Vestiture fine, long, inconspicuous,
rather sparse.

Pronotum 1.4 times as wide as long, widest at base; sides weakly
arcuate and converging slightly anteriorly on basal half, then rather
abruptly narrowed to a moderate constriction just behind the broad-
ly, shallowly emarginate anterior margin; surface smooth and
shining, the punctures rather coarse, close, deep, with a few very
minute points interspersed; median line im punctate posteriorly;
vestiture moderately abundant, fine and rather short on disc, longer
and coarse laterally.

Elytra 2.5 times as long as pronotum; sides straight and sub-
parallel on basal two-thirds, rather broadly rounded behind; basal
margins arcuate and bearing a row of about twelve, moderately
large, raised, overlapping crenulations, with several smaller sub-
marginal ones particularly on interspaces two and three; striae
weakly impressed, the punctures moderately large and deep; inter-
striae slightly more than twice as wide as striae and armed by
abundant confused, small, transverse crenulations, each averaging
about one-fourth the width of an interspace, never more than a
third as wide on posterior half of disc. Declivity rather steep, con-
vex, with the sutural interspaces slightly elevated; strial punctures
almost as large as on disc; interstriae smooth, with numerous con-
fused punctures less than one-third as large as those of striae,
about a third of them minutely granulate on upper rim. Vestiture
rather long and abundant; slightly longer on declivity, longest
setae about one and one-half times as long as width of an inter-
space.

Female. — Similar to male except frons with a few minute gran-
ules between punctures (about one for each six punctures); punc-
tures of pronotum and transverse crenulations of elytra a little
larger; and declivital granules much larger.

Type locality. — Europe. The type was not studied.

Hosts. — Picea excelsea; less commonly from Abies, Larix and
Pinus.

Distribution. — The coniferous forests of northern Eurasia from
northern France to Siberia. About 150 specimens representing more
than 50 localities were examined.

Geographical variation. — Not evident in the limited material at
hand.

Biology. — This is a primary enemy of spruce forests in northern
Europe and Asia where extensive damage has been inflicted at
various times. Estimates of timber actually destroyed by this insect
are not available.

Since the habits and work of this species were not observed

June 14, 1963 revision of dendroctonus 85

during this study the following was summarized primarily from
Eichhoff (1881:125-128) and from Severin {in Hopkins, 1909:
142-146).

The winter may be passed either as adults or as partly grown
larvae. This indicates that there is an overlapping of generations
as in related species. In central Europe the dates of oviposition indi-
cate that the period of flight activity begins late in May or early
in June and continues until about August, with the principal period
of flight occurring in late June or early July.

Trees selected for attack may be either prostrate or standing;
down trees are infested only on the under surface. The lower por-
tion of the bole of standing trees may also be attacked, particularly
if the tree is in a weakened condition, although young, vigorous,
healthy trees may also be attacked during an epidemic. The pattern
of the attack is not clear from available reports, but it is assumed
that it progresses upward from the ground level.

The egg galleries tend to be vertical, although they are fre-
quently curved and irregular in shape. They may be up to 20 cm.
long, and usually are slightly wider than the beetle making the
gallery; ordinarily they have two or three areas expanded on one
side or the other. In each of these expanded areas groups of about
20 to 50 eggs are deposited and covered by or separated from the
main part of the gallery by a layer or partition of frass. J'he first
eggs are deposited in June and the last ones in September. Evidently
one female may re-emerge and construct a second or a third set of
galleries.

The larvae feed in congress, forming a large flat cavity in the
phloem next to the cambium. There are no egg niches or individual
larval mines. The larval period evidently requires at least two
months for completion; it commonly continues over winter, pupation
taking place during the early part of the following summer. Pupal
cells are formed in the frass that fills the larval excavation. There
may be one complete and a partial second generation each year.

Dendroctonus punctatus Leconte
Figs. 18, 57.

Dendroctonus punctatus Leconte, 1868, Trans. American Ent. Soc. 2:173; Le-
conte. 1876. Proc. American Philos. Soc. 15:384. 385; Schwarz. 1886. Ent.
Americana 2:56; Hopkins, 1902, Proc. Ent. Soc. Washington 5:3; Hopkins,
1909, U. S. Dept. Agric. Bur. Ent. Tech. ser. 17(1): 142; Swaine, 1909,
New York St. Mus. Bull. 134:98; Hagedorn, 1910, Coleopterorum Catalogus
4:23; Hagedorn, 1910, Genera Insectorum 111:60; Hopkins, 1915, U. S.
Dept. Agric. Bur. Ent. Tech. ser. 17 (2): 211; Blatchley and Leng, 1916,
Rhyncophora or Weevils of Eastern North America, p. 654; Swaine, 1918,
Dom. Canada Dept. Agric. Ent. Br. Bull. 14(2) :65. Biol.: Packard, 1887,
U. S. Dept. Agric. Ent. Comm. Bull. 7:177; Packard, 1890, U. S. Dept.
Agric. Ent. Comm. Kept. 5:722; Hopkins. 1899. West Virginia Agric. Expt.
Sta. Bull. 56:447; Hopkins, 1909. U. S. Dept. Agric. Bur. Ent. 83(1): 139;
Felt, 1924, Manual of Tree and Shrub Insects, p. 261.

Dendroctonus rufipennis: Dietz, 1890, Trans. American Ent. Soc. 17:28; Ham-

The Great Basin Naturalist

86 STEPHEN L. WOOD Vol. XXIII, Nos. 1-2

ilton, 1894, Trans. American Ent. Soc. 21:35; Johnson, 1897, Pennsylvania
Dept. Agric. Rept., p. 73.
Dendroctonus johanseni Swaine, 1919, Canadian Arctic Exped. Rept. 1913-1918,
3(E) :5 {new synonymy); Van Dyke, 1924, Natl. Geographic Soc. Tech.
Pap. 2(1):25; Swaine. 1933, Sci. Agric. 14(1) :29; Chamberlin, 1939, Bark
and Timber Beetles of North America, p. 165.

This species is very closely related to and perhaps doubtfully
distinct from the Eurasian micans. but may be distinguished by the
smaller size, by the more slender form, by the transversely concave
epistomal process, by the larger strial punctures, by the smaller
elytral crenulations, and by the distributions (Fig. 57). It is more
lively to be confused with murrayanae and obesus, but may be dis-
tinguished by the uniformly brown color, by the smooth, polished
frons which is deeply punctured but devoid of granules, and by the
much larger punctures of the declivital striae.

Male. — Length 5.4-6.8 mm. (average about 6), 2.41 times as
long as wide; body color uniformly brown to dark brown.

Frons convex, protruding very slightly at center just below mid-
dle; epistomal margin elevated, smooth, shining; epistomal process a
third (0.32 times) as wide as distance between eyes, its arms
strongly oblique (about 55° from the horizontal) and slightly ele-
vated, the horizontal portion about two-thirds its total width, shal-
lowly concave, overlapping and ending just above epistomal mar-
gin and bearing under its distal margin a dense brush of yellow-
ish setae; surface smooth and shining from vertex to epistoma, the
punctures rather close, deep, coarse, sharp, interspersed with a
few very minute punctures, with no indication of. granules or tu-
bercles. Vestiture fine, long, inconspicuous, rather sparse.

Pronotum 1.4 times as wide as long, widest at base; sides weakly
arcuate and converging toward the rather strong constriction just
behind the broadly, shallowly emarginate anterior margin; surface
smooth and shining, the punctures rather fine but irregular, close,
deep, with a few very minute points interspersed; median line
impunctate posteriorly; vestiture moderately abundant, fine and
rather short on disc, longer and coarse laterally.

Elytra 2.5 times as long as pronotum; sides straight and subpar-
allel on basal two-thirds, rather broadly rounded behind; basal mar-
gins arcuate and bearing a row of about twelve moderately large,
raised, overlapping crenulations, with several smaller marginal ones
particularly on interspaces two and three; striae weakly impressed,
the punctures large and rather deep; interstriae about one and one-
half times as wide as striae and armed by rather abundant con-
fused, small, transverse crenulations, each averaging about one-
fourth the width of an interspace, never more than a third as wide
on posterior half of disc. Declivity rather steep, convex, with the
sutural interspaces slightly elevated; strial punctures almost as large
as on disc; interstriae smooth, with numerous confused punctures
less than one-third as large as those of striae, about a third of them
minutely granulate on their upper rims. Vestiture rather long and

June 14. 1963 revision of dendroctonus

87

Fig. 57. Probable geographical distribution of Dendroctonus punctatus with
collection sites indicated.

abundant; slightly longer on declivity, longest setae about one and
one-half times as long as width of an interspace.

Female. — So very similar to male that the sexes are recognized
only with difficulty; female very slightly more coarsely sculptured,
particularly declivital granules very slightly larger.

Type locality. — Northern New York (Sandstone Rapids, Copper-
mine River, Northwest Territories for johanseni) . The type of
both johanseni and punctatus were studied.

Hosts. — Picea glauca, rubens. and sitchensis.

Distribution. — The northern spruce forests from Alaska to New
York and south along the mountains to West Virginia.

Specimens from the following localities were examined (Fig. 57). Alaska:
Circle, Haines Rd. (mi. 27), Rampart House, and Savonoski. New York: "N. Y."
Pennsylvania: Mt. Alto. West Virginla: Randolph Co. Alberta: Cypress
Hills, and McKenzie Highway (25th baseline). Northwest Territory: Akla-
■^ik. Ft. Smith, and Sandstone Rapids of the Coppermine River. Ontario: Fra-

The Great Basin Naturalist

88 STEPHEN L. WOOD Vol. XXIII, Nos. 1-2

ter. Yukon: Alaska Highway (mi. 1152) Carcross, Carmaks (mi. 8. Mayo Rd.),
Rampart House, Watson Lake, Whitehorse, and Wolf Ck.

Geographical variation. — Not observed in the limited material at
hand.

Biology. — This species evidently is rare in forests accessible to
economic interests; consequently, it is not presently recognized by
forest interests as an important species. Structurally and biologically
it is so similar to obesus that field observers usually do not distin-
guish it from that species.

It is known to infest the lower bole and stumps of spruce from
West Virginia to Alaska. Structurally it is almost indistinguishable
from micans and is very similar to murrayanae; therefore, it is pre-
sumed that its biology is equally similar to these species. Collectors
who took punctatus in two different areas of northern Canada and
in Alaska suspected that at least two years were required to com-
plete the life cycle in those areas; one year evidently is sufficient
in the Great Lakes area and in the eastern United States.

Dendroctonus murrayanae Hopkins
Figs. 19, 39, 58-59.

Dendroctonus shoshone Hopkins, 1902, Proc. Ent. Soc. Washington 5:3 {nomen
nudum) .

Dendroctonus rufipennis: Hopkins, 1909 (nee. Kirby, 1837), U. S. Dept. Agric.
Bur. Ent. Tech. ser. 17(1): 138; Hagedorn, 1910, Coleopterorum Catalogus ^
4:23; Hagedorn, 1910, Genera Insectorum 111:60; Blatchley and Leng,
1916, Rhyncophora or weevils of Northeastern America, p. 655; Swaine,
1918, Dom. Canada Dept. Agric. Ent. Br. Bull. 14(2) :64; Dodge, 1938,
Minnesota Agric. E.xpt. Sta. Tech. Bull. 132:28; Chamberlin, 1939, Bark
and Timber Beetles of North America, p. 152. Biol.: Hopkins, 1909, U. S.
Dept. Agric. Bur. Ent. Bull. 83(1): 136; Vitzthum. 1926, Zool. Jahrb. Abt.
Syst. Georgr. Tiere 52(5-6) :407; Watson, 1931, Canadian Ent. 63:126;
Swaine, 1933, Sci. Agric. 14:29.

Dendroctonus murrayanae Hopkins, 1909, U. S. Dept. Agric. Bur. Ent. Tech.
ser. 17(1): 140; Hagedorn, 1910, Coleopterorum Catalogus 4:22; Hagedorn,
1910, Genera Insectorum 111:60; Swaine, 1918. Dom. Canada Dept. Agric.
Ent. Br. Bull. 14(2:64); Chamberlin, 1939, Bark and Timber Beetles of
North America, p. 151, 164; Chamberlin, 1958. Scolvtoidea of the North-
west, p. 77. Biol.: Hopkins, 1909, U. S. Dept, Agric. Bur. Ent. Bull. 83(1):
138; Swaine. 1913, Ontario Ent. Soc. Rept. 43:89; Swaine, 1914, Dom.
Canada Dept. Agric. Expt. Farms Bull., ser. 2, 17:28; Hopping, 1922,
Canadian Ent. 54:130; Felt, 1924, Manual of Tree and Shrub Insects,
p. 261; Craighead, 1927. U. S. Dept. Agric. Circ. 411:9; Keen, 1938,
U. S. Dept. Agric. Misc. Pub. 273:109; Clapp, 1942, U. S. Dept. Agric.
For. Serv. Rept. 1941:31; Patterson, 1945, Univ. Washington Pub. Biol.
10:150; Watts, 1948, U. S. Dept. Agric. For. Serv. Rept. 1947:27; Raid,
1955, Canadian Ent. 87:316.

This species is very closely allied to punctatus and obesus and is
distinguished from thein with considerable difficulty. From punc-
tatus it differs by the more closely punctured, sparsely granulate
frons (Fig. 19), by the more coarsely punctured pronotum, by the
subequal size of strial and interstrial punctures of the declivity, by

June 14. 1963 revision of dendroctonus 89

the reddish brown elytra with dark brown pronotuni, and by the
hosts. From obesus it differs by the distinctly punctured, finely,
more sparsely granulate frons, by the male genitalia (Fig. 39), by
the galleries (Fig. 59), and by the hosts.

Male. — Length 5.0-7.3 mm. (average about 6). 2.3 times as long
as wide; body color dark brown, with reddish brown elytra.

Frons convex, protruding slightly on lower half; epistomal mar-
gin elevated, smooth, shining; epistomal process a third (0.32 times)
as wide as distance between eyes, its arms strongly oblique (about
55° from the horizontal) and moderately elevated, the horizontal
portion about two-thirds its total width, shallowly concave, over-
lapping and ending just above epistomal margin and bearing under
its distal margin a dense brush of yellowish setae; surface shining
from vertex to epistoma, the punctures very close, deep, coarse,
about half of them with a small rounded granule on median or
lower rim (usually). Vestiture fine, long, inconspicuous, rather
sparse.

Pronotum 1.35 times as wide as long, widest at base; sides weakly
arcuate and converging toward the rather strong constriction just
behind the broadly, shallowly emarginate anterior margin; surface
smooth and shining, the punctures rather fine, but irregular, close,
deep; median line impunctate posteriorly. Vestiture moderately
abundant, fine and rather short on disc, longer and coarse laterally.

Elytra 2.4 times as long as pronotum; sides straight and sub-
parallel on basal two-thirds, rather broadly rounded behind; basal
margins arcuate and bearing a row of about twelve moderately
large, raised, overlapping crenulations, with several submarginal
ones particularly on interspaces two and three; striae very weakly
impressed, the punctures rather large and deep, usually decreasing
in size toward base; interstriae slightly more than one and one-
half times as wide as striae and armed by rather abundant, confused,
small, transverse crenulations, each averaging about one-fourth the
width of an interspace, never more than a half as wide on posterior
half of disc. Declivity rather steep, convex, with the sutural inter-
spaces slightly elevated; striae impressed, the punctures half as
large as on disc, usually three times as large as those of interspaces
(except in a few examples having unusually large interstrial punc-
tures); interstriae almost smooth, subshining, the punctures rather
abundant, confused (very irregularly three-ranked), the median
series very finely granulate on upper rims, Vestiture rather long
and abundant; slightly longer on declivity, longest setae about one
and one-half times as long as width of an interspace.

Female. — Very similar to male except arms of epistomal process
less strongly elevated, and declivital granules distinctly larger.

Type locality. — Keystone. Wyoming. The type was studied.

Hosts. — Pinus banksianna, corttorta and strobus.

Distribution. — The Great Lakes area to Alberta, then south to
Utah and Colorado.

90

STEPHEN L. WOOD

The Great Basin Naturalist

Vol. XXIII, Nos. 1-2

Specimens from the following localities were examined. Colorado: Jeffer-
son, Kenosha Pass, and Wheeler Basin. Idaho: Targhee N. F. Michigan:
Grand Island, and Whitefish Point. Minnesota: International Falls. Montana:
Wisdom. Utah: Logan Canyon and Wolf Ck. Pass. Wyoming: Bighorn Basin,
Dubois, "Homestake," Keystone, Saratoga, and Shoshone N. F. Alberta: Banff,
Cypress Hills. Edmonton, Hillsdale, Jasper N. P., and Lake Louise. British
Columbia: Stanley, and Wycliff. Manitoba: Clear Lake Trail in Riding Mts.
Ontario: Black Sturgeon Lake, and Frater.

Fig. 58. Possible geographical distribution of Dendroctonus murrayanae
with collection sites indicated.

Geographical variation. — Specimens from the Great Lakes area
average about 6.1 mm., those from the western half of the distribu-
tion about 5.7 mm. Those from the west also tend to have the pro-
notal punctures and the punctures of the declivital striae and inter-
striae very slightly larger. These differences are not sufficiently
consistent, however, to warrant the recognition of distinct geo-
graphic races. It is possible that the apparent geographical differ-
ences are invalid, since one short series from Manitoba and another
from Black Sturgeon Lake, Ontario, are intermediate in these char-
acters and tend to obliterate any geographical distinctiveness.

Biology. — Ordinarily this is not an aggressive species, although
available data indicate that it has contributed to bark beetle epi-
demics more commonly than published data would suggest and that

June 14, 1963 revision of dendroctonus 91

it has killed healthy, vigorous Lodgepole pine. Because of the close
superficial resemblance to obesus some losses actually caused by
this species have been attributed to the destructive spruce beetle
which supposedly infested Lodgepole pine. In all cases where speci-
mens were preserved for study the "spruce" beetles infesting Lodge-
pole pine actually were this species.

The overwintering young and old adults and larvae in all stages
of development become active when subcortical spring tempera-
tures become sufficiently high, probably about 45° to 50°F. Flight
activity probably does not begin before June at the high altitudes in
Utah where Lodgepole pine grows. The earliest attacks observed
during this study were found in the second week of July. Because
of overlapping generations it is suspected that attacks probably con-
tinue from late June to early September.

Stumps, windfalls, overmature or weakened trees larger than
about eight inches D. B. H. are selected for attack by this species:
Trees dying from the attacks of ponderosae apparently provide a
favorite breeding place for this species. In standing trees the attack
seldom extends higher than about two feet above the level of the
ground; in addition, it usually extends downward into the roots.
In prostrate trees the lower side of the bole is preferred.

The attack evidently begins at or near the ground level at one
side of the tree and progresses upward, downward, or around
the tree from that point. At times two or more successive genera-
tions may be involved in progressively girdling a living tree. Ordin-
arily only a few pairs of beetles are involved in the attack on a par-
ticular tree.

The egg galleries (Fig. 69) are irregularly vertical, slightly wid-
er than the beetle making them, with two or three irregular but
shallow expanded areas along one or both sides; often short branch
galleries may also be present. The galleries observed during this
study averaged about 12 cm. in length; the longest ones were 20
cm. in length; they were constructed entirely by the female. As
with other species they were excavated "in the phloem in contact
with the cambium. In a number of instances it was observed that
the female excavated the complete egg gallery before the male ap-
peared; evidently this is not a normal habit. In such instances there
were no eggs or larvae in the gallery. When the male was present
the lower part of the gallery was packed with frass thereby closing
the entrance hole. Copulation was observed twice; in both instances
it occurred near the middle of the gallery in one of the expanded
areas.

In the Wasatch National Forest in Utah eggs were found during
1960 from July 12 to September 9; it was not determined whether
or not these were the first or last eggs of the season. The eggs are
deposited in the expanded areas in groups of about 20 to 50 or
more. A more or less loose covering or partition of frass separates
them from the main parts of the egg gallery. In the galleries ob-
served, from one to three such groups occurred in each gallery.

The Great Basin Naturalist

92

STEPHEN L. WOOD Vol. XXIII, Nos. 1-2

^/^M

Fig. 59. Dendroctonus murrayanae: Egg gallery longitudinal, short, rather
irregular; eggs deposited in irregular masses in egg grooves and packed in
frass (left) ; larvae mine in congress, transversely through the second instar,
then longitudinally as much as several feet. Characteristically islands of un-
excavated bark remain at the angle where the larval mines turn.

Hatching time varied considerably with the season, but probably
averaged about ten days in the galleries studied. There were no
individual egg niches in any of the galleries. Evidently a female
may re-emerge to construct a second set of galleries; this is sup-
ported by the fact that in September about a fourth of the galleries
studied contained only the female, there were no adults present
in an additional fourth.

The larvae feed in congress in a general transverse direction
away from the egg gallery (Fig. 59). About six to ten centimeters
from the egg gallery the excavated area turns either upward or
downward and continues in that direction for an additional 20 to
30 cm. or more. It is characteristic of this species that just before

June 14, 1963 revision of dendroctonus 93

or just after the vertical turn is made a few small groups of larvae
become separated from the main body of larvae and mine indepen-
dently for short distances before rejoining them. This leaves irreg-
ular islands of unexcavated phloem in the general cavity. When
near maturity several of the larvae may construct short indepen-
dent mines where pupation occurs; however, most of the pupal
cells occur in the frass of the principal larval excavation. It appeared
that the eggs laid in early July were represented by third and
fourth instar larvae in September and probably did not mature
until the following June; eggs laid in September evidently matured
the following July. Evidently there may be one complete and a
partial second generation each year in Utah. In the northern parts
of the distribution it is possible that less than one complete genera-
tion occurs each year.

Dendroctonus obesus (Mannerheim)
Figs. 20, 40, 60-61.

Hylurgus obesus Mannerheim, 1843, Bull. Soc. Imp. Nat. Moscou 16:296; Man-
nerheim, 1852, Bull. Soc. Imp. Nat. Moscou 25:356; Mannerheim, 1853,
Bull. Soc. Imp. Nat. Moscou 26:238.

Dendroctonus obesus: Leconte, 1868, Trans. American Ent. Soc. 2:173; Cha-
puis, 1869, Synopsis des Scolytides, p. 35 (1873, Mem. Soc. Roy. Sci. Liege,
ser. 2,3:243); Provancher, 1877, Fauna Ent. Canada 1:573; Provancher,
1878, Fauna Ent. Canada 5(Add. et Cor.): 13; Schwarz, 1900, Proc. Wash-
ington Acad. Sci. 2:537; Hopkins, 1902, Proc. Ent. Soc. Washington 5:3;
Hopkins, 1909, U. S. Dept. Agric. Bur. Ent. Tech. ser. 17(1): 135; Swaine,
1909, New York St. Mus. Bull. 134:97; Hagedorn, 1910, Catalogus Coleop-
torum 4:22; Hagedorn, 1910, Genera Insectorum 111:60; Swaine, 1918,
Dom. Canada Dept. Agric. Ent. Br. Bull. 14(2) :66; Chamberlin. 1939,
Bark and Timber Beetles of North America, p. 151, 164; Chamberlin, 1958,
Scolytoidea of the Northwest, p. 77. Biol.: Packard, 1877, U. S. Geol. Surv.
Kept. 1875:589 (1877, Amer. Nat. 7:22); Hamilton, 1894, Trans. Amer-
ican Ent. Soc. 21:35; Hopkins, 1899, U. S. Dept. Agric. Div. Ent. 21:15,
21; Hopkins, 1902, U. S. Dept. Agric. Div. Ent. Bull. 37:22; Hopkins,
1903. Canadian Ent. 35:60; Hopkins, 1909, U. S. Dept. Agric. Bur. Ent.
83(1): 132; Swaine, 1914, Dom. Canada Dept. Agric. Expt. Farms Bull. 7:33;
Hewitt, 1915, Canadian Ent. Kept. 1915:30; Chrystal, 1915, Quebec Soc.
Protec. PL Kept. 7:73; Chrystal, 1916, Agric. Gaz. Canada 3:796; Chrys-
tal, 1916, Proc. Ent. Soc. British Columbia 9:65; Chrystal, 1917, Canadian
Ent. Kept. 1915:44; Hopping, 1921, Canada Dept. Agric. Ent. Circ. 15:10;
Hopping, 1922, Canadian Ent. 54:131; Felt, 1924. Manual of Tree and
Shrub Insects, p. 260; Van Dyke, 1924, Natl. Geographic Soc. Tech. Pap.
2:25; Patterson, 1945, Univ. Washington Pub. Biol. 10:150; Armand, 1947,
U. S. Dept. Agric. Bur. Ent. PI. Quar. Kept. 1946-47:34; Anderson, 1947,
U. S. Dept. Agric. Kept., sec. F., 1947:140; Anonymous, 1947, U. S. Dept.
Agric. Bur. Ent. PI. Quar. Ins. Cond. 1946:19; Anonymous, 1949, U. S.
Dept. Agric. Bur. Ent. PI. Quar. Ins. Cond. 1948:20; Richmond and King-
horn, 1951, Forest Chron. 27:31.

Hylurgus rufipennis Kirby, 1837, in Richardson, Fauna Boreali Americana
4:195 {new synonymy); Mannerheim, 1853, Bull. Soc. Imp. Nat. Moscou
26:238; Peck, 1876, Trans. Albany Inst. 8:283, 301; Peck, 1879, New York
St. Mus. Nat. Hist. Rept. 28:32; Packard, 1890, U. S. Dept. Agric. Ent.
Comm. Rept. 5:814; Hough, 1882, Report on Forestry Submitted to Con-
gress by the Commission of Agriculture, pt. 8:259.

Dendroctonus rufipennis: Leconte, 1868, Trans. American Ent. Soc. 2:173;
Leconte, 1876, Proc. American Philos. Soc. 15:384, 385; Provancher, 1877,

The Great Basin Naturalist

94 STEPHEN L. WOOD Vol. XXIII, Nos. 1-2

Fauna Ent. Canada 1:573; Provancher, 1878, Fauna Ent. Canada 5 (Add.
et Cor,): 13, 14; Leconte, 1878, U. S. Geol. Geogr. Surv. Bull. 4:469;
Schwarz. 1886. Ent. Americana 2:56; Dietz. 1890, Trans. American Ent.
Soc. 17:28; Hopkins, 1898, U. S. Dept. Agric. Div. Ent. Bull. 17:69; Chit-
tenden, 1898, U. S. Dept. Agric. Div. Ent. Bull. 18:96; Smith, 1899, New
Jersey St. Bd. Agric. Kept. 27(Suppl.):364; Hopkins, 1899, West Virginia
Agric. E.xpt. Sta. Bull. 56:349; Hopkins, 1899, Proc. Ent. Soc. Washington
4:343; Chittenden, 1899, U. S. Dept. Agric. Div. For. Bull. 22:56; Smith,
1900, Cat. Ins. New Jersey, p. 364; Hopkins, 1905, U. S. Dept. Agric. Bur.
Ent. Bull. 56:6; Felt, 1906. New York St. Mus., Mem. 8, 2:753; Tredl,

1907, Ent. Blatt. 11:6. Biol.: Litner, 1885. New York St. Ent. Kept. 2:54;
Fletcher, 1887, Kept. Minist. Agric, Append., Ent. Kept., p. 39, 40; Pack-
ard. 1887, U. S. Dept. Agric. Ent. Comm. 7:177; Packard, 1890, U. S.
Dept. Agric. Ent. Comm. Kept. 5:721; Johnson, 1897, Pennsylvania Agric.
Kept., p. 73; Harvey. 1898. Maine Agric. Expt. Sta. Kept. 13:176; Weed
and Fiske, 1898, U. S. Dept. Agric. Div. Ent. Bull. 17:67; Howard, 1898,
U. S. Dept. Agric. Div. Ent. Bull. 10:97; Hopkins, 1899, West Virginia
Agric. Expt. Sta. Bull. 54:197, etc.; Johnson, 1901, Ent. News 12:92;
Wickham, 1902, Bull. Lab. Nat. Hist. St. Univ. Iowa 5:309.

Dendroctonus similis Leconte. 1860, Pacific R. R. Explor. 5 (2): 59; Leconte,

1868, Trans. American Ent. Soc. 2:173.
Polygraphus rufipennis: Packard, 1890, U. S. Dept. Agric. Ent. Comm. Rept.

5:721.
Dendroctonus {Polygraphus) rufipennis: Gary, 1900, The Forester 6(3): 52.
Dendroctonus piceaperda Hopkins, 1901, U. S. Dept. Agric. Div. Ent. Bull.

28:16 {new synonymy); Hopkins, 1902, Proc. Ent. Soc. Washington 5:3;

Hopkins, 1902, U. S. Dept. Agric. Div. Ent. Bull. 32:21; Hopkins, 1902,

U. S. Dept. Agric. Div. Ent. Bull. 37:22; Hopkins, 1903, U. S. Dept.

Agric. Yearbook 1902:266, 270, 281; Hopkins, 1904, U. S. Dept. Agric. Div.

Ent. Bull. 48:26; Hopkins, 1905, U. S. Dept. Agric. Yearbook 1904:266;

Hopkins, 1905, U. S. Dept. Agric. Bur. Ent. Bull. 56:10, 11; Currie, 1905,

U. S. Dept. Agric. Bur. Ent. 53:82; Felt, 1905, New York St. Mus., Mem.

8, 1:6; Felt, 1906, New York St. Mus., Mem. 8.2:338, 379, 693; Burke,

1906. Proc. Ent. Soc. Washington 8:4, 5; Hopkins, 1906, Proc. Ent. Soc.

Washington 8:5; Fall and Cockerell, 1907, Trans. American Ent. Soc.

33:218; Hopkins, 1907, U. S. Dept. Agric. Yearbook 1906:515; Hopkins,

1908, U. S. Dept. Agric. Yearbook 1907:160; Hopkins, 1909, U. S. Dept.
Agric. Bur. Ent. Tech. ser. 17(1): 126; Hopkins, 1909, U. S. Dept. Agric.
Bur. Ent. Bull. 58:58, 75; Hopkins, 1909, U. S. Dept. Agric. Bur. Ent.
Bull. 83(1):114; Swaine, 1909, New York St. Mus. Bull. 134:97; Hopkins,
1910. U. S. Dept. Agric. Bur. Ent. Circ. 125:2; Hagedorn, 1910, Coleop-
terorum Catalogus 4:22; Hagedorn. 1910 Genera Insectorum 111:60;
Blatchley and Leng, 1916, Rhynchophora or weevils of North Eastern
America, p. 653; Murphy, 1917, U. S. Dept. Agric. Bull. 544:27; Swaine,
1918. Dom. Canada Dept. Agric. Ent. Br. Bull. 14(2) :62, 66; Brues, 1920,
Insects and Human Welfare, p. 70; Peirson, 1923, Maine For. Serv. Bull.
1:25; Craighead, 1924, Dom. Canada Dept. Agric. Ent. Br. Bull. 25:39;
Felt, 1924, Manual of Tree and Shrub Insects, p. 258; Swaine, 1924, Can-
ada Dept. Agric. Pam. 48, 19 p.; Swaine, 1924, Pulp and Paper Mag.
22:567; Boutin, 1926, Nat Canadien 53:7; Craighead, 1927. U. S. Dept.
Agric. Circ. 411:10; Peirson, 1927, Maine For. Sei-v. Bull. 5:118; Watson,
1928. Sci. Agric. 8:613; Craighead, 1930, U. S. Dept. Agric. Misc. Pub.
74:4; Swaine. 1930, Canada Dept. Agric. Div. For. Ins. Sp. Circ, 2 p.;
Swaine, 1931. Canada Dept. Agric. Div. For. Ins. Sp. Circ, 4 p.; Balch,
1931, Forest Chron. 7:66; Peirson, 1932, Field Book of Destructive Forest
Insects, ed. 2, p. 7; Balch, 1932, Nova Scotia Dept. Lands For. Rept.
1931:52; Balch. 1933. Nova Scotia Dept. Lands For. Rept. 1932:48; Swaine,
1933, Forest Chron. 9(4): 12; Swaine. 1933, Sci. Agric. 14:14, 23; Twinn,
1933. Ontario Ent. Soc. Rept. 64:74; Twinn, 1934, Ontario Ent. Soc. Rept.
65:123; Balch, 1934, Pulp and Paper Mag. 35:680; Gobeil, 1935, Quebec
Soc. Prot. PI. Rept. 27:60; Dunn, 1936, Ontario Ent. Soc. Rept. 66:9; Nash,

June 14, 1963 revision of dendroctonus 95

1937, Massachusetts For. Pk. Assoc. Tree Pest Leaf. 14, 4 p.; Seavey, 1937,
Maine For. Conim. Bien. Kept. 21:69; Dodge, 1938, Minnesota Agric. Expt.
Sta. Tech. Bull. 132:27; Gobeil. 1938, Quebec Min. Terr. For. Serv. Ent.
Bull. 2, 16 p.; Osborne, 1938. New York St. Conserv. Dept. Kept. 27:111;
Chamberlin, 1939, Bark and Timber Beetles of North America, p. 164; Sea-
vey, 1939, Maine For. Comm. Bien. Kept. 22:71; Gobeil, 1939, Nat. Can-
adien 66:71; Mclntyre, 1939, Jour. Forestry 37:879; Nash, 1940, Massa-
chusetts For. Pk. Assoc. Imp. Tree Pests 1940:70; Gobeil, 1941, Jour. For-
estry 39:632; Gobeil, 1941, Pulp and Paper Mag. 42:730; Brown, 1941,
Canada Dept. Agric. Div. Ent. For. Ins. Surv. Kept. 1940:8; Kendall,
1941, Maine For. Comm. Kept. 23:52; Balch, 1942, Nova Scotia Dept.
Lands For. Kept. 1941:37; Balch, 1942, Jour. Forestry 40:621; Balch, 1942,
Pulp and Pap. Mag. 43:900; Brown, 1943, Canada Dept. Agric. Div. Ent.
For. Ins. Serv. Kept. 1942:6; Kendall, 1943, Maine For. Comm. Kept.
24:38; Parr, 1943, Jour. Forestry 41:420; Twinn, 1943, Canada Dept.
Agric. Ins. Pest Kev. 21:8; Twinn, 1943, Ontario Ent. Soc. Kept. 73:70;
Atwood. 1944, Canada Dept. Agric. Div. Ent. For. Ins. Serv. Kept. 1943:37;
Balch and Hawboldt, 1944, Nova Scotia Dept. Lands For. Kept. 1943:51;
Hawboldt, 1944, Canada Dept. Agric. Div. Ent. For. Ins. Serv. Kept. 1943:6;
Atwood, 1945, Canada Dept. Agric. Div. Ent. For. Ins. Serv. Kept. 1944:8;
Harrison, 1945, Nova Scotia Dept. Lands For. Kept. 1944:36; Keeks, 1945,
Canada Dept. Agric. Div. Ent. For. Ins. Surv. Kept. 1944:6; Keeks, 1946,
Canada Dept. Agric. Div. Ent. For. Ins. Surv. Kept. 1945:10; Keeks, 1946,
Canada Dept. Agric. Ins. Pest. Kev. 24:26; Levesque, 1946, For. Quebecoise
11:529; DeGryse, 1947, For. Ent. Canada, p. 4; Hawboldt, 1947, Nova
Scotia Dept. Lands For. Kept. 1945-46:36; Kennedy, 1947, Ontario Koy.
Comm. For. Kept. 1947:117; Hawbolt, 1948, Nova Scotia Dept. Lands For.
Kept. 1947:39; Keeks, 1948, Canada Dept. Agric. Div. Ent. For. Ins. Surv.
Kept. 1947:14; Keeks, 1949, Canada Dept. Agric. Div. Ent. For. Ins. Surv.
Kept. 1948:15; Hopkins, 1950. New York St. Conserv. Dept. Kept. 39:85;
Hopkins, 1951, New Yoi'k St. Conserv. Dept. Kept. 40:102; Anonymous,
1951, U. S. Dept. Agric. Bur. Ent. PL Quar. Ins. Pest Surv. Sp. Sup. 4:8;
Reeks, 1953, Canada Dept. Agric. For. Ins. Surv. Kept. 1952:11; Shenefelt
and Benjamin, 1955, Wisconsin Agric. Ext. Circ. 500:64; Marquis, 1956,
U. S. Dept. Agric. N. E. For. Expt. Sta. Kept. 1955:10. 110; Price, 1956,
U. S. Dept. Agric. Kocky Mtn. For. Kange Expt. Sta. Kept. 1955:27;
Forbes, 1956, Canada Dept. Agric. For. Ins. Surv. Kept. 1955:18; Forbes,
1957. Canada Dept. Agric. For. Ins. Surv. Kept. 1956:16.

Dendroctonus californicus Hopkins, 1902, Proc. Ent. Soc. Washington 5:3
{nomen nudum).

Dendroctonus dietzi Hopkins, 1902, Proc. Ent. Soc. Washington 5:3 {nomen
nudum) .

Dendroctonus wickhami Hopkins. 1902, Proc. Ent. Soc. Washington 5:3 {nomen
nudum) .

Dendroctonus piceaperda var, engelmanni Fall, 1907, Trans. American Ent. Soc.
33:218 {nomen nudum).

Dendroctonus engelmanni Hopkins, 1909, U. S. Dept. Agric. Bur. Ent. Tech.
ser. 17(1): 130 {new synonymy); Hagedorn, 1910, Coleopterorum Catalogus
4:20; Hagedorn, 1910, Genera Insectorum 111:60; Swaine. 1918, Dom.
Canada Dept. Agric. Ent. Br. Bull. 14(2) :65; Chamberlin, 1939, Bark and
Timber Beetles of North America, p. 151. 161; Chamberlin, 1958, Scoly-
toidea of the Northwest, p. 75. Biol.: Hopkins, 1908, U. S. Dept. Agric.
Yearbook 1907:161; Hopkins, 1909, U. S. Dept. Agric. Bur. Ent. Bull.
58:59; Hopkins, 1909, U. S. Dept. Agric. Bur. Ent. Bull. 83(1):126; Hop-
kins, 1909, U. S. Dept. Agric. Yearbook 1908:574; Hopkins, 1910, U. S.
Dept. Agric. Bur. Ent. Circ. 125:2; Hopkins, 1912, U. S. Dept. Agric. Bur.
Ent. Circ. 142:6; Craighead, 1927. U. S. Dept. Agric. Circ. 411:10; Keen,
1939. U. S. Dept. Agric. Misc. Pub. 273:126; Craighead and Brown, 1945,
U. S. Dept. Agric Bur. Ent. PI. Quar. E-649:4; Patterson, 1945, Univ.
Washington Pub. Biol. 10:149; Spencer, 1945, Green Thumb 2(1):9;
Wygant, 1945, U. S. Dept. Agric. Bur. Ent. PI. Quar. Ins. Pest Surv.

The Great Basin Naturalist

96 STEPHEN L. WOOD Vol. XXIII, Nos. 1-2

1944:14; Annand, 1945, U. S. Dept. Agric. Bur. Ent. PI. Quar. Kept.
1944:20, 33; Annand, 1946, U. S. Dept. Agric. Bur. Ent. PI. Quar. Kept.
1945:30; Bloch, 1946, Timberman 48(2): 102; Anderson, 1947, U. S. Dept.
Agric. Sec. Kept. 1946:140, 147; Annand, 1947, U. S. Dept. Agric. Bur.
Ent. PI. Quar. Kept. 1946:34; Massey, 1947, Rocky Mtn. Conf. Ent. Kept.
18:6; Anonymous, 1948, U. S. Dept. Agric. Bur. Ent. PI. Quar. Ins. Pest
Sui-v. 1947:17; Anonymous, 1949, U. S. Dept. Agric. Bur. Ent. PL Quar.
Ins. Pest Surv. 1948:19; Annand, 1949, U. S. Dept. Agric. Bur. Ent. PI.
Quar. Kept. 1948:10; Corhart, 1949, American For. 55 (3): 14, 41; Wygant,
1949, U. S. Dept. Agric. Yearbook 1948:417; Bloch, 1950, Green Thumb
7(10):24; Bloch, 1950, Timberman 51(11):78, 80, 82, 84; Gardiner, 1950,
Canada Min. Agric. Kept. 1949:105; Kenney, 1950, British Columbia Dept.
Lands For. For. Serv. Kept. 1949:73; MacKay, 1950, Canada Dept. Agric.
Div. Ent. For. Ins. Surv. Kept. 1949:114, 120; Mielke, 1950, Jour. For-
estry 48:882; Nelson, 1950, Jour. Forestry 48:182; Watts, 1950, U. S.
Dept. Agric. For. Serv. Kept. 1949:11, 40, 54; Anonymous, 1950, U. S.
Dept. Agric. Bur. Ent. PL Quar. Ins. Pest Surv. 1949:25; Beal, 1951, Proc.
West. For. Conserv. Assoc. 41:58; Bloch, 1951, Green Thumb 8:22; Prater,
1951, American For. 57(6): 18; Ross and Jones, 1951, Canada Dept. Agric.
Div. Ent. For. Ins. Surv. 1950:114, 121, 123; Sun, 1951, Proc. N. Cent.
Sts. Br. American Assoc. Econ. Ent. 6:58; Anonymous, 1951, U. S. Dept.
Agric. Bur. Ent. PL Quar. Ins. Pest Surv. Sp. Sup. 4:4; Anonymous, 1951,
U. S. Dept. Agric. Bur. Ent. PL Quar. Ins. Pest Surv. 1950:23; Anony-
mous, 1951, U. S. Dept. Agric. Bur. Ent. PL Quar. Coop. Econ. Ins. Sp.
Rept. 4:88; Anonymous, 1952, Timberman 53(12): 96, 98, 100, 103; Even-
den, 1953, Proc. Northw. Wood Prod. Clinic 8:56; Hoyt, 1953, U. S. Dept.
Agric. Bur. Ent. PL Quar. Rept. 1951-52:68; Massey, Chishol, and Wy-
gant, 1953, Jour. Econ. Ent. 46:951; Morse, 1953, Proc. Northw. Wood
Prod. Clinic 8:56; Rettig. 1953, Proc. West. For. Conserv. Assoc. 43:50;
Sommers, 1953, British Columbia Dept. Lands For. For. Serv. Rept. 1952:60;
Yeager, 1953, Trans. N. Amer. Wildlife Conf. 18:596; Fitzgerald, 1954,
American For. 60(1) :24; Hoyt, 1954, U. S. Dept. Agric. Bur. Ent. PL
Quar. Rept. 1952-53:20; Knight and Wilford, 1954, U. S. Dept. Agric.
Rocky Mtn. For. Range Expt. Sta. Ins. Cond. 1953:2; Massey et al., 1953,
Jour. Econ. Ent. 46:951; Massey and Wygant, 1954, U. S. Dept. Agric.
Circ. 944, 35 p.; Nelson, 1954, Jour. Forestry 52:503; Schaeffer, 1954,
Jour. Forestry 52:860; Vaux, 1954, Jour. Forestry 52:506; Bailey, 1955, U. S.
Dept. Agric. Inteiintn. For. Range Expt. Sta. Rept. 1954:40; Davidson,
1955, Mycologia 47:58; Love, 1955, Trans. American Geophys. Union
36:113; Price, 1955, U. S. Dept. Agric. Rocky Mtn. For. Range Expt. Sta.
Rept. 1954:13, 17; Smith, 1955, Jour. Forestry 53:208; Thomson, 1955, Proc.
British Columbia Ent. Soc. 51:45; Anonymous, 1955, U. S. Dept. Agric.
For. Serv. Imp. For. Ins. 1954:5, 7, 9; Anonymous, 1955, U. S. Dept. Agric.
Pacific Northw. For. Range Expt. Sta. Ins. Surv. 1954:26, 37, 39, 41, 43, 45;
Anonymous, 1956, U. S. Dept. Agric. Pacific Northw. For. Range E.xpt. Sta.
Ins. Surv. 1955:31, 40, 44, 46, 49; Knight, 1956, U. S. Dept. Agric. Rocky
Mtn. For. Range Expt. Sta. Pap. 25, 12 p.; Ostmark and Wilford, 1956, U. S.
Dept. Agric. Rocky Mtn. For. Range Expt. Sta. Pap. 22:2, 13; Price, 1956,
U. S. Dept. Agric. Rocky Mtn. For. Range Expt. Sta. Rept. 1955:21;
Yasinski, 1956, U. S. Dept. Agric. Rocky Mtn. For. Range Expt. Sta. Pap.
23:2; Bailey, 1957, U. S. Dept. Agric. Intermtn. For. Range Expt. Sta.
Rept. 1956:31, 37; Brown, 1957, Canada Dept. Agric. For. Ins. Surv. Rept.
1956:74; Knight, 1957, Bull. Ent. Soc. America 3(3) :27; Nagel, 1957,
Jour. Forestry 55:894; Price, 1957, U. S. Dept. Agric. Rocky Mtn. For.
Range Expt. Sta. Rept. 1956:81, 84, 86, 89, 92, 99; Whiteside, 1957, U. S.
Dept. Agric. Pacific Northw. For. Range Expt. Sta. For. Ins. Cond. 1956:17,
34, 38, 40.
Dendroctonus borealis Hopkins, 1909. U. S. Dept. Agric. Bur. Ent.. Tech. ser.
17(1): 133 {new synonymy); Hagedorn, 1910, Coleopterorum Catalogus
4:20; Hagedorn, 1910, Genera Insectorum 111:60; Swaine, 1918, Dom.
Canada Dept. Agric. Ent. Br. Bull. 14(2):61, 66; Chamberlin, 1939, Bark
and Timber Beetles of North Anl'erica, p. 151, 163; Chamberlin, 1958,

June 14, 1963 revision of dendroctonus 97

Scolytoidea of the Northwest, p. 68, 76. Biol.: Hopkins, 1909, U. S. Dept.
Agric. Bur. Ent. Bull. 83(1): 132; Hewitt, 1917, Dom. Canada Dept.
Agric. Ent. Br. Bept. 1916:35, 37, 40; Hopping, 1921, Dom. Canada Dept.
Agric. Circ. 15:10; Hopping, 1922, Canadian Ent. 54:131; Felt, 1924,
Manual of Tree and Shrub Insects, p. 260; Van Dyke, 1924, Natl. Geogr.
Soc. Tech. Pap. 2(1):25; Twinn, 1934, Ontario Ent. Soc. Bept. 65:123;
MacKay, 1948, Canada Dept. Agric. For. Ins. Surv. Bept. 1947:93; Mac-
Kay, 1949, Canada Dept. Agric. For. Ins. Surv. Bept. 1948:114; Evans, 1950,
Canada Dept. Agric. For. Ins. Sui-v. Bept. 1949:107; Evans and Dyer, 1951,
Canada Dept. Agric. For. Ins. Surv. Bept. 1950:110; McGuffin and Beid,
1952, Canada Dept. Agric. For. Ins. Serv. Bept. 1951:98; Anonymous,
1952, U. S. Dept. Agric. Bur. Ent. PI. Quar. Coop. Econ. Ins. Bept. Sp.
Bept. 4:94; Brown, 1955, Canada Dept. Agric. For. Ins. Surv. Bept. 1954:104.

This species is very closely allied to murrayanae but is distin-
guished with difficulty by the more coarsely, closely granulate frons
(Fig. 20), by the very distinctive male genitalia (Fig 40), by the
galleries (Fig. 61), and by the hosts.

Male. — Length 4.4-7.0 mm. (average about 5.5), 2.3 times as
long as wide; mature body color very dark brown with reddish
brown elytra, old adults usually uniformly black.

Frons convex, protruding slightly on lower half; epistomal mar-
gin elevated, smooth, shining; epistomal process a third (0.35 times)
as wide as distance between eyes, its arms rather strongly oblique
(about 45° from the horizontal) and moderately elevated, the hor-
izontal portion almost two-thirds its total width, shallowly con-
cave, overlapping and ending just above epistomal margin and
bearing under its distal margin a dense brush of yellowish setae;
surface shining, the punctures very close, deep, rather fine, largely
obliterated in central area by fine, abundant granules, at least one
or two granules for each puncture in central area, less numerous
in surrounding areas. Vestiture fine, long, inconspicuous, rather
sparse.

Pronotum 1.4 times as wide as long, widest at base; sides weakly
arcuate and converging toward the rather strong constriction just
behind the broadly, shallowly emarginate anterior margin; surface
smooth and shining, the punctures rather fine but irregular in size,
close, deep; median line impunctate posteriorly. Vestiture moder-
ately abundant, fine and rather short on disc, longer and coarse
laterally.

Elytra 2.4 times as long as pronotum; sides straight and sub-
parallel on basal two-thirds, rather broadly rounded behind; basal
margins arcuate and bearing a row of about twelve moderately
large, raised, overlapping crenulations, with several smaller submar-
ginal ones particularly on interspaces two and three; striae very
weakly impressed, the punctures rather large and shallow, usually
decreasing slightly in size toward base; interstriae slightly more
than one and one-half times as wide as striae and armed by rather
abundant confused, small, transverse crenulations, each averaging
about one-fourth the width of an interspace, never more than a
third as wide on posterior half of disc. Declivity rather steep, con-

The Great Basin Naturalist

98 STEPHEN L. WOOD Vol. XXIII, Nos. 1-2

vex, with the sutural interspaces shghtly elevated; striae usually
not impressed, the punctures minute, subequal in size to and often
confused with those of interspaces; interstriae almost smooth, sub-
shining, the punctures rather numerous, confused, the median series
on each interspace very minutely granulate on upper rims. Vesti-
ture rather long and abundant; slightly longer on declivity, longest
setae about one and one-half times as long as width of an inter-
space.

Female. — Very similar to male except arms of epistomal process
less strongly elevated, and declivital striae usually weakly impressed
with the interstrial granules rather large and usually pointed.

Type locality. — Sitka Island, Alaska (Boreal North America for
rufipennis; Oregon for similis; Camp Caribou, Maine, for picea-
perda; Eagle, Alaska, for borealis; and Capitan, New Mexico, for
engelmanni) . All six types were studied.

Hosts.— AW species of Picea within its range.

Distribution. — The spruce forests of North America from Alaska
to Nova Scotia, south to Pennsylvania in the east and to the Mex-
ican border in Arizona and New Mexico in the west.

Specimens from the following localities were examined (Fig. 60) Alaska:
Chichagof Isl., Circle, Eagle, Eklutna, Ft. Yukon, Homer, Juneau, Kenai Pen-
insula, Klutina Lake, Matanuska, Nutzotin Mts., Ruby, St. James Bay, Sav-
onoski, Seward, Skaway, Tanana, and Yakutat. Arizon.\: Chiricahua Mts., San
Francisco Peak. California: Crescent City. Colorado: Argentine Pass, Boulder, {
Clyde, Ft. Collins, Glenwood Springs, Gore Pass, Gunnison, Hahns Peak, Holy
Cross Mtn., Leadville, "Leavenworth Valley," Meeker, New Castle, Ouray Peak,
Pingree Pk., Rabbit Ears Pass. San Isabel N. F.. Silver Plume, Steamboat
Springs, "Twinn Sisters," and White River N. F. Idaho: Beaver Ck. of Logan
Canyon, Collins, and Lieber Ck, in Coeur d'Alene N. F. Maine: Beaver Pond,
Camp Caribou. Cupsuptic, and "Meadows." Michigan: Grand Island, Isle
Royal, Marquette, and Munising. New Hampshire: Colebrook, West Stewarts-
town, and Wonalancet. Minnesota: Itasco St. Pk., and International Falls.
New Mexico: Capitan Mts., Cloudcroft, Las Vegas, Pecos Wilderness Area. San-
dia Mts., Santa Fe Basin, and Sierra Blanca Mts. New York; Pleasant Lake.
Oregon: Batterson, Cannon Beach, Cascade Head Expt. For., Coos Bay, Gold
Lake, "Highland Mine," Hood River Meadows, Joseph, Marshfield. "Mt. Mis-
ery," Mt. Ashland, Santiam Pass, and Tolgate. Pennsylvanias Ricketts. South
Dakota: Black Hills N. F., and Spearfish Canyon. Utah: Alta, Ashley N. F.,
Cedar Breaks N. M., Ephraim, Escalante, LaSal Mts., Logan Canyon, Lost Lake, '
Panguitch, Paradise Pk., Parowan Canyon, and Wolf Ck. Pass. Washington:
Aberdeen, Easton, Fairfax, Hoquiam, Lake Wenatchee, Metaline Falls, Morse
Ck., Mt. Rainier, Neah Bay, Parkway, Sappho, "Tieton R. S.," Wenatchee
Lake, White Pass. White River, Winthrop, and Yakima. Alberta: Babine Lake,
Banff, Calgary, Cypress Hills, Edmonton, Exshaw, Harlech, Jasper N. P., Kan-
anskis For. Sta., Lake Athabasca, Lake Louise. Lesser Slave Lake, Nordagg,
and Smoky Lake. British Columbia: Aspen Grove. Babine Lake, Bloom Ck.
Valley, Boundary Lake, Creighton Valley, Emerald Lake, Glacier, Lorna, Lower
Post, Lumberton, Lumby, Ootsa Lake, "Paxton Valley," Priest River, Princeton,
Queen Charlotte Islands, Salmo, "Seymour Ck.," Stanley, Trinity Valley, Van-
couver, Vernon, Vermilion Summit on Banff Rd., Victoria, Ymir, and Yoho
N. P. Manitoba: Churchill, "Northern Manitoba," and Riding Mt. N. P.
New Brunswick: Nictor Lake and Fredericton. Sask.\tchewan: "Northern
Saskatchewan." Northwest Territory: Aklavik, Coppeiinine River, Ft. Nor-
man, Ft. Smith, and Yellowknife. Nova Scotia: Cape Breton Isl., and St.

June 14, 1963 revision of dendroctonus

99

Fig. 60. Probable geographical distribution of Dendroctonus obesus with
collection sites indicated.

Peters. Ontario: Black Sturgeon Lake, Egg Lake in Algonquin Pk., Frater,
Hearst, "Nighthawk Lake," North Bay, "Remi Lake," and Timmins. Quebec:
Anticosti Isl., Cascapedia, Duparquet, and Gaspe Peninsula. Yukon: Teslin
and Whitehorse.

Geographical variation. — Specimens from the eastern part of the
distribution average about 0.2 mm. smaller than those from the
west. A higher percentage of western specimens, particularly from
Sitka spruce in British Columbia, are black in color (38 per cent);
only an occasional eastern specimen was black. Whether this was
due to the age of specimens at the time of collection, to climatic
or other environmental factors, or to genetic factors is uncertain.

Biology. — This is the most destructive of the spruce inhabiting
bark beetles. It is responsible for killing an estimated average of
approximately one-third to one-half billion board feet of standing
spruce timber each year. It is also reported to have inflicted sub-
stantial losses to Lodgepole Pine (Massey and Wygant, 1954:1),
but this was not substantiated by an examination of the beetles
collected from the infested pine trees (cf. murrayanae) .

The Great Basin Naturalist
100 STEPHEN L. WOOD Vol. XXIII, Nos. 1-2

The spruce beetle may overwinter in any stage of development,
but adults and half grown larvae predominate. Activity evidently
begins in May when subcortical daytime temperatures reach about
45° to 50°F. The period of flight activity evidently begins late in
May and continues until October, with two distinct seasonal peaks.
The first of these is in June, and the second in late July to early
September. Local climatic conditions or peculiarities of a particular
season may accelerate or delay these peak periods a week or two and
may also have a bearing on which of the two flight periods is
greater. The first flight includes overwintered parent and young
adults, the second primarily consists of beetles that mature from
overwintered larvae.

Under endemic conditions the trees selected for attack consist of
windfalls or other prostrate dying green trees or of overmature or
weakened standing trees larger than about eight inches D.B.H. Dur-
ing an epidemic almost any spruce tree in the stand may be selected
regardless of size or vigor. The attack usually begins on the lower
third of the bole, except for the first two or three feet above the
ground. It ordinarily progresses to include the upper bole and
stump later in the season when the second flight occurs, if popula-
tions are not excessive. In prostrate trees only the lower half next
to the ground is attacked. The upper bole smaller than eight inches
in diameter and limbs generally are not subject to attack by this
species. The attack is slow and continuous, without any sudden or
concerted swarming of the beetles; its duration may vary from a
few days to many months, depending on the population density of
beetles in the area, upon the resistance of the host, or upon climatic
or other ecological factors peculiar to the season or locality. The
number of attacks per square foot of bark surface may be as high
as 24. but averages between six and nine; the density of the at-
tacks evidently is greater at the base of the tree and gradually de-
creases upward (Massey and Wygant, 1954:13).

The egg galleries (Fig. 61) are constructed by the female beetle
mostly in the phloem tissues, but they engrave the wood more deep-
ly than other species of Dendroctonus: the thinness of spruce bark
may have some bearing on this habit. The egg galleries are vertical,
almost straight, ordinarily with the lower one or two centimeters
next to the entrance hole hooked diagonally to either the right or
left. The average length of 13 cm. and the maximum length of 23
cm. for egg galleries observed during this study, made in 1960, in
the Wasatch National Forest of Utah, agrees with that reported by
Massey and Wygant (1954:13). The egg galleries are slightly wider
than the width of the beetle making them and, in addition, there
usually is an egg groove along the side next to the cambium about
one or two millimeters deep. Ventilation tunnels are placed at ir-
regular intervals, but are not always present.

Oviposition evidently begins less than a week after the attack;
there is some question as to its duration because most of the beetles
re-emerge to construct a second or third set of galleries. Massey

June 14, 1963 revision of dendroctonus

101

Fig. 61. Dendroctonus obesus: Egg gallery longitudinal, rather short; eggs
deposited in irregular single or double rows in grooves (occasionally in individ-
ual niches as shown at upper left) : larval mines usually independent through
first instar, usually communal during second and sometimes third instars,
usually independent but frequently crossing one another through final stages.

and Wygant (1954:15) reported a maximum of 144 eggs in one
gallery; they also reported that there was an average of 20.5 eggs
per inch of gallery (excluding the diagonal first inch). In the
present study it was found that the number of eggs per inch of
gallery where eggs occurred was equal to that found by Massey and
Wygant, but this rate of deposition was seldom maintained for
more than a third the length of the gallery. The largest number
of eggs counted in one gallery during this study was 53 in an area
where a small epidemic was beginning on the Wasatch National
Forest.

There is considerable variation in the way eggs are deposited.
In some galleries all or part of the eggs are placed individually in
separate niches. These niches may be lengthened sufficiently to
accommodate two or more eggs, or extended into elongate grooves
as much as eight centimeters in length. The niches, or the more typ-

The Great Ba^in Naturalist
102 STEPHEN L. WOOD Vol. XXIII, NoS. 1-2

ical grooves, ordinarily are placed alternately on the sides of the egg
tunnel in contact with the cambium. Ordinarily, individual niches
are formed when the gallery enters a moderately unfavorable en-
vironment. Each egg or group of eggs is covered by a layer or
partition of frass that separates them from the main gallery.

Following oviposition the gallery may be extended a short dis-
tance in an irregular feeding tunnel. When both parents are repre-
sented separate feeding tunnels may give the gallery a characteristic
Y-shaped ending. Evidently most of the beetles re-emerge to form a
second or third set of galleries.

At the high altitudes where this species occurs in Colorado incu-
bation is thought to require three to four weeks (Massey and Wy-
gant, 1954:16); it probably takes much less time in Pacific Coast
areas where suitable hosts enable this species to live at or near sea
level. The newly hatched larvae feed in the phloem in contact with
the cambium, either individually or in groups, in a general direc-
tion at right angles away from the egg gallery. Ordinarily commun-
al feeding is the rule during the second instar (Fig. 61). When
about one-third grown all larvae form separate feeding tunnels that
wind throughout the phloem frequently crossing one another. Some
larvae that hatch from the first eggs deposited in June may become
callow adults by October, however most of them overwinter as lar-
vae and complete their development the following spring. Pupal
cells are formed at the ends of the larval mines or in frass of a
previously excavated area, either next to the cambium or entirely
in the bark. The pupal period in the late spring or early summer
may be completed in about 10 to 15 days (Massey and Wygant,
1954:17), however completion of this stage may take several months
if pupation begins in the late fall and continues through the win-
ter. A normal life cycle evidently requires from one to two years.

The low temperatures which prevail throughout much of the
year in many areas where this species occurs may have a profound
effect on the length of the life cycle of this insect. Collectors who
took it in the McKenzie River area in northern Canada and in
northcentral Alaska estimated that at least two years were required
for larval development. The most remarkable adjustment this
species has made to survive low temperatures, however, was re-
ported by Massey and Wygant (1954:8) from studies conducted in
Colorado. Many of the beetles emerged from, brood galleries and
went to the bases of trees, ordinarily a brood tree, where they re-
entered the host at or near the ground level. Here they passed the
winter in feeding tunnels, then re-emerged in June or July to begin
a new attack. It was estimated that about half of the beetles passed
the winter in the same spot where they became adults; the remain-
ing half included those beetles with the special overwintering habit.
This hibernation habit has not been reported from other parts of
the distribution of this species, nor has it been reported for any
other species of Dendroctonus; almost certainly it is not restricted
to the Colorado area, nor to this one species.

June 14, 1963 revision of dendroctonus 103

Dendroctonus simplex Leconte
Figs. 22, 41, 62.

Dendroctonus simplex Leconte, 1868, Trans. American Ent. Soc. 2:173; Leconte,
1876, Proc. American Philos. Soc. 15:384, 385; Provancher, 1878, Fauna
Ent. Canada 5 (Add. et Cor.): 13, 14; Schwarz, 1886, Ent. Americana 2:56;
Schwarz, 1888, Ins. Life 1:162; Dietz, 1890, Trans. American Ent. Soc.
17:28, 31; Hopkins, 1898, U. S. Dept. Agric. Div. Ent Bull. 17:69; Hopkins,
1899, Proc. Ent. Soc. Washington 4:343; Hopkins, 1909, U. S. Dept.
Agric. Bur. Ent. Tech. ser. 17(1): 117; Swaine, 1909, New York St. Mus.
Bull. 134:99; Hagedorn, 1910, Coleopterorum Catalogus 4:23; Hagedom,
1910, Genera Insectorum 111:60; Blatchley and Leng, 1916, Rhyncho-
phora or weevils of Eastern America, p. 653; Swaine, 1918, Dom. Canada
Dept. Agric. Ent. Br. Bull. 14(2): 62; Chamberlin, 1939, Bark and Tim-
ber Beetles of North America, p. 152, 162. BioL.: Packard, 1887, U. S.
Dept. Agric. Ent. Comm. Bull. 7:177; Packard, 1890, U. S. Dept. Agric.
Ent. Comm. Kept. 5:722; Harrington, 1891, Canadian Ent. 23:27; Hop-
kins, 1898, Proc. Soc. Prom. Agric. Sci. 19:104; Hopkins, 1899, West Vir-
ginia Agric. Expt. Sta. Bull. 56:392, 394; Felt, 1906, New York St. Mus.,
Mem. 8, 2:752; Fall and Cockerell, 1907, Trans. American Ent. Soc. 33:218;
Hopkins, 1907, U. S. Dept. Agric Yearbook 1906:515; Hopkins, 1909,
U. S. Dept. Agric. Bur. Ent. Bull. 83(1): 103; Swaine, 1913, Ontario Ent.
Soc. Kept. 43:89; Hewitt, 1917, Canada Dept. Agric. Ent. Br. Kept. 1916:36;
Blackman and Stage, 1918, New York St. Coll. For., Syracuse Univ. 4(4),
Tech. Pub. 10:39; Felt, 1924, Manual of Tree and Shrub Insects, p. 261;
Peirson, 1929, Maine or. Serv. Bull. 5:79; Simpson, 1929, Canadian Ent.
61:274; Prebble, 1933, Canadian Ent. 65:145; Dodge, 1938, Minnesota
Agric. Expt. Sta. Tech. Bull. 132:27; Weber, 1942, Minnesota Dept.
Conserv. . Statis Kept. 1941:79; McGuffin and Barker, 1947, Canada Dept.
Agric. For. Ins. Surv. Kept. 1946:57; Anonymous, 1955, U. S. Dept.
Agric. For. Serv. Imp. For. Ins. 1954:18.

The only species closely allied to this species is pseudotsugae
from which simplex is distinguished by the much smaller size,
by the less strongly protubrant, smoother but more coarsely punc-
tured frons (Fig. 22), by the more coarsely punctured pronotum,
by the larger punctures on the declivital interspaces, and by the
distribution (Fig. 62).

Male. — Length 3.4-5.0 mm. (average about 4.2), 2.4 times as
long as wide; mature body color dark brown, elytra often wdth a
reddish cast.

Frons broadly convex, protruding somewhat on lower half, the
inflated area arising abruptly just above the smooth, elevated rim
of epistomal margin; epistomal process less than a third (0.30 times)
as wide as distance between eyes, its arms very strongly oblique
(about 80° from the horizontal) and usually not elevated, the hori-
zontal portion about three-fourths its total width, flat, overlapping
and apparently flush with epistomal margin (actually ending just
above the slightly extended margin) and bearing under its distal
margin a dense brush of yellowish setae; surface shining, smooth,
wdth rather coarse, deep, very close punctures and a very few min-
ute granules. Vestiture sparse, rather short, fine, inconspicuous.

Pronotum 1.4 times as wide as long; widest at base, sides weakly
arcuate and converging toward the rather strong constriction just

The Great Basin Naturalist
104 STEPHEN L. WOOD Vol. XXIII, NoS. 1-2

behind the broadly, shallowly emarginate anterior margin; surface
smooth and shining, the punctures rather coarse, irregular in size,
close, deep; median line narrowly impunctate posteriorly. Vesti-
ture moderately abundant, fine and rather short on disc, longer and
coarse laterally.

Elytra 2.5 times as long as pronotum; sides straight and sub-
parallel on basal two-thirds, rather broadly rounded behind; basal
margins arcuate and bearing a row of about ten rather large, raised,
overlapping crenulations, with several smaller submarginal ones
particularly on interspaces two and three; striae weakly impressed,
the punctures rather large and deep, usually decreasing slightly
in size toward base; interstriae less than one and one-half times as
wide as striae and armed by an irregular row of transverse crenula-
tions, each averaging about one-third the width of an interspace, a
few half as wdde on posterior half of disc, a few fine punctures
interspersed with crenulations. Declivity rather steep, convex, with
sutural interspace very strongly elevated and interspace two weakly
impressed; striae rather deeply, narrowly impressed, the punctures
greatly reduced; interstrial punctures rather coarse, numerous and
confused on one, uniseriate on two and three; none of the punc-
tures granulate. Vestiture rather coarse, slightly longer on declivity,
the longest setae equal in length to about one and one-half times
the width of an interspace.

Female. — Very similar to male except declivital interspaces with
minute confused punctures and each with a median row of coarse,
somewhat pointed tubercles, the tubercles spaced by a distance
slightly less than width of an interspace.

Type locality. — Canada. The type was studied.

Hosts. — Larix laricina.

Distribution. — The eastern United States and Canada north of
West Virginia west to northern British Columbia and Alaska.

Specimens from the following localities were examined (Fig. 62). Alaska:
College, Fairbanks, and McGrath. Maine: Cupsuptic. Michigan: East Lans-
ing, Grand Island, Grand Ledge, Mackinac Isl., Marquette, Munising, Port
Huron, and Seney. Minnesota: Carlton Co., Hennepin Co., Itasca St. Pk.,
Lake Itasca. Mille Lacs Co., Pine River, and St. Paul. New Hampshire: Pitts-
burg, and West Stewartstown. New York: Erie Co. West Virginia: Cranesville.
Alberta: Bilby, Edmonton, Mitsue, and Smith. British Columbia: Wildmare
Ck. New Brunswick: Fredericton, and Nictor Lake. Newfoundland: "New-
foundland." Nova Scotia: Sydney. Ontario: Deili, Pine Springs, and Wooler.
Quebec: Gaspe, Natashquan, and Ungara Bay.

Geographical variation. — Not evident in the material at hand.

Biology. — This species prefers dying or injured trees, and con-
sequently, is not generally regarded as ha\^ing major economic im-
portance. However, it is known to have successfully attacked and
killed healthy mature larch trees.

This species was not observed during this study; all comments
which follow are based on Hopkins (1909b: 103-106), Simpson

June 14, 1963

REVISION OF DENDROCTONUS

105

Fig. 62. Probable distribution of Dendroctonus spp. with collection sites
indicated: 1, pseudotsugae (circles); 2. simplex (triangles).

(1929:274-279) and Prebble (1933:146). The galleries illustrated
by Hopkins for this species are used as the basis for the qualified
description of the galleries below. Since the placement of eggs in
his figure lack detail, since the system appears to resemble that of
the very closely related pseudotsugae, and because of the general
phyletic position of simplex in the genus, it is presumed that egg
grooves, not niches as illustrated, would normally be constructed
by this species.

The principal overwintering stage is the young adult in the
brood gallery, although it is not uncommoii for some larvae to
overwinter. Flight activity begins early in May and continues at a
relatively low level until late August; the period of greatest activity
apparently is from the last week of May to the second week of
June. Adult beetles may re-emerge to construct a second or third
set of galleries during the season, but none of their progeny leave
the brood tree until the following spring.

Trees selected for attack include windfalls, snow breaks, stumps
or other weakened or severely damaged material. The exact pattern

The Great Basm Natuialist
106 STEPHEN L. WOOD Vol. XXIII, Xos. 1-2

of the attack and details of the galleries and habits have not been
reported.

Hopkins (1909b: 103) indicated that the galleries are vertical
and slightly sinuate. Evidently they average about 20 to 25 cm. in
in length. The eggs are deposited in groups of three to six or more,
presumably in grooves rather than in individual niches. The larvae
mine individually in continual contact with the cambium away
from the egg gallery and without crossing one another. Evidently
the larval mine increases only slightly through the first and second
instars then expands suddenly into an irregularly oval feeding area
where the last two larval instars, pupation and hibernation occur.

Oviposition ordinarily begins about the last week of May. The
eggs hatch in about 11 days (Prebble, 1933:146) and complete lar-
val development in approximately 27 days; about seven days are
required for the pupal stage during the early summer months.
Simpson found young adults in the first set of galleries completed
during the season by August 1 ; in the second set of galleries young
adults were present by September 17; larvae produced in the third
set of galleries formed by these same parent adults passed the
winter as larvae. The young adults produced in the first and second
sets of galleries overwintered in those galleries and emerged the
following May and early June. The overwintered larvae from the
third set of galleries matured in June and emerged during July.

Dendroctonus pseudotsugae Hopkins

Figs. 23, 42, 62-63.

Dendroctonus similis: Leconte. 1876, Proc. American Philos. Soc. 15:385 (in
part); Leconte, 1878. Bull. U. S. Geol. Geogr. Sur\'. 4:469; Packard, 1887,
U. S. Dept. Agric. Ent. Comm. Bull. 7:177; Packard, 1890. U. S. Dept.
Agric. Ent. Comm. Kept. 5:722; Dietz, 1890. Trans. American Ent. Soc.
17:30; Hopkins, 1899, West Virginia Agric. Expt. Sta. Bull. 56:392; Hop-
kins, 1899, U. S. Dept. Agric. Div. Ent. 21:10, 11, 21, 22, 26; Wickham,
1902, Bull. Lab. Nat. Hist. St. Univ. Iowa 5:310; Fall, 1907. Trans. Am-
erican Ent. Soc. 33:218.

Dendroctonus pseudotsugae Hopkins. 1901, Proc. Soc. Prom. Agric. Sci. 22:67
(nomen nudum):, Hopkins. 1903. Canadian Ent. 35:60; Hopkins. 1904.
U. S. Dept. Agric. Div. Ent. Bull. 48:19, 45 (nomen nudum): Hopkins,
1905, U. S. Dept. Agnc. Bur. Ent. Bull. 56:10. 11; Hopkins, 1906. Proc.
Ent. Soc. Washington 8:4; Hopkins. 1909. U. S. Dept. Agric. Bur. Ent.
Tech. ser. 17(1): 121; Hagedorn. 1910. Coleopterorum Catalogus 4:22;
Hagedorn, 1910, Genera Insectorum 111:60; Swaine. 1918. Dom. Canada
Dept. Agric. Ent. Br. Bull. 14(2) :62; Chamberlin. 1939. Bark and Timber
Beetles of North America, p. 150. 159; Chamberlin. 1958. Scolytoidea of
the Northwest, p. 73. Biol.: Swaine. 1914. Dom. Canada Dept. Agric. Ent.
Br. Bull. 7:28; Brunner. 1915. U. S. Dept. Agric. Bull. 255:5; Chamber-
lin, 1917. Canadian Ent. 49:324; Chamberlin. 1918. Oregon Agric. Expt. Sta.
Bull. 147:17; Hopping. 1921. Dom. Canada Dept. Agric. Circ. 15:10; Hop-
ping, 1922. Canadian Ent. 54:131; Gibson. 1923. Canada Dept. Agric. Ent.
Br. Kept. 1919-20:16; Felt. 1924. Manual of Tree and Shrub Insects, p. 258;
Hofmann, 1924, U. S. Dept. Agric. Bull. 1200:53; Caverhill. 1925. British
Columbia Dept. Lands For. Kept. 1924:E-17; Craighead. 1927. U. S. Dept.
Agric. Circ. 411:11; Craighead. 1930. U, S. Dept. Agric. Misc. Pub. 74:5;
Craighead, 1931. Jour. Forestry 31:1016; Hopping. 1932. Timberman

June 14. 1963 revision of dendroctonus 107

33(7) :61; Bedard. 1933. Jour. Econ. Ent. 26:1128; Beal, 1935, Timber-
man 37(2): 14; Furniss. 1936. Timberman 37(3) :21; Furniss. 1937, Tim-
berman 39(2): 11; Bedard. 1937. Washington St. Coll. Res. Studies 5:103;
Hopping, 1939. in Mulholland. Forest Resources of British Columbia, p. 62;
Keen. 1938. U. S. Dept. Agric. Misc. Pub. 273:119; Beal. 1939, Rocky Mtn,
Conf. Ent. Rept. 15:6; Furniss, 1941, U. S. Dept. Agric. For, Serv. Fire
Contr. Notes 5:211; Hopping, 1942. Canadian Ent. 74:205; Kimmev and
Furniss, 1943, U. S. Dept. Agric. Tech. Bull. 851:20; Patterson. 1945, Univ.
Washington Pub. Biol. 10:149; Hopping, 1947, Canadian Ent. 79:150;
Leech, 1947, Canada Dept. Agric. For. Ins. Surv. Rept. 1946:80; Leech,
1947, Canada Dept. Agric. Ins. Pest Rev. 25:63; Anonvmous, 1947, Calif-
ornia Dept. Nat. Res. Div. For. For. Ins. Cond. 1946:10; Mahaffay, 1948.
American For. 54:64, 80; Anonjmous, 1948, LT. S. Dept. Agric. Bur. Ent.
PL Quar. Ins. Pest Surv. 1947:17; MacKay. 1948, Canada Dept. Agric.
For. Ins. Surv. Rept. 197:94; MacKay, 1949, Canada Dept. Agric. For. Ins.
Surv. Rept. 1948:114; Bedard, 1950, U. S. Dept. Agric. Circ. 817, 10 p.;
Evans, 1950. Canada Dept. Agric. For. Ins. Surv. Rept. 1949:106; MacKay,
1950, Canada Dept. Agric. For. Ins. Surv. Rept. 1949:114, 120; Anony-
mous, 1950. U. S. Dept. Agric. Bur. Ent. PI. Quar. Ins. Pest Surv. 1949:26;
Anonymous, 1950, U. S. Dept. Agric. Pacific Northw. For. Range Expt.
Sta. Rept. 1949:52; Beal, 1951, Proc. West. For. Conserv. Assoc. 41:58;
Evans and Dyer, 1951, Canada Dept. Agric. For. Ins. Surv. Rept. 1950:110;
Kenney, 1951, British Columbia Dept. Lands For. For. Serv. Rept. 1950:63;
Richmond and Kinghorn, 1951, For. Chron. 27:31; Ross and Jones, 1951,
Canada Dept. Agric. For. Ins. Surv. Rept. 1950:114; Anonymous, 1951,
U. S. Dept. Agric. Bur. Ent. PI. Quar. Ins. Pest Surv. Sp. Sup. 4:7;
Anonymous, 1951, U. S. Dept. Agric. Bur. Ent. PI Quar. Ins. Pest Surv.
1950:25; Evans and Dver. 1952. Canada Dept. Agric. For. Ins. Surv. Rept.
1951:108; Graham, 1952. British Columbia Lumberm. 36(7): 52; Anony-
mous, 1952, U. S. Dept. Agric. Bur. Ent. PI. Quar. Coop. Econ. Ins. Rept.
l(Sp. Rept.):92; Evans and Dyer, 1953, Canada Dept. Agric. For. Ins.
Surv. Rept. 1952:130; Richmond. 1953. British Columbia Dept. Lands
For. For. Serv. Rept. 1952:86; Richmond. 1953, British Columbia Lumberm.
37(5) :42, 90, 92; Ross and Jones, 1953, Canada Dept, Agric. For. Ins.
Surv. Rept. 1952:133; Wright, 1953, Proc. West. For. Conserv. Assoc.
43:153; Anonymous, 1953. U. S. Dept, Agric. Portland For. Ins, Lab. Rept.
1952:30; Evans and Silver. 1954. Canada Dept. Agric. For. Ins. Surv. Rept.
1953:139; Glascock, 1954. Proc. West, For. Conserv. Assoc. 44:45; Hoyt,

1954, U. S. Dept. Agric. Bur. Ent. PI. Quar. Rept, 1952-53:21; Knight and
Wilford, 1954. U. S. Dept. Agric. Rocky Mtn. For. Range Expt. Sta. Ins.
Cond. Rept. 1953:4; Orr, 1954, U. S. Dept. Agric. Intermtn. For. Range
Expt. Sta. Ins. Cond. Rept. 1953:1: Ross, 1954. Canada Dept. Agric. For.
Ins. Surv. Rept. 1953:142; Bailey, 1955, U. S. Dept. Agric. Intermtn. For.
Range Expt. Sta. Rept. 1954:41; Cornelius, 1955, Jour. Forestry 53:711;
Cornelius, 1955. Proc. West. For. Conserv. Assoc. 45:50; Cowlin. 1955,
U. S. Dept. Agric, Pacific Northw. For. Range Expt. Sta. Rept. 1954:31.
37; Evenden and Wright. 1955, U. S. Dept. Agric. For. Serv. For. Pest
Leaf. 5, 4 p.; Fang and Allen, 1955. Jour. Econ. Ent. 48:79; Kinghorn,

1955, Jour. Econ. Ent. 48:501. 503; Silver and Ross. 1955, Canada Dept,
Agric. For. Ins. Surv. Rept. 1954:117; Spaur, 1955, Oregon St. Bd. For. Bien.
Rept. St. For. 1952-54:42; Anonymous, 1955, California For. Pest Contr.
Act. Comm, For. Ins. Cond. 1954:6, 8; Anonymous, 1955, U. S. Dept.
Agric. For. Serv. Imp. For. Ins. 1954:2, 4. 7, 10; Anonymous, 1955, U. S.
Dept. Agric. Pacific Northw. For. Range Expt. Sta. For. Ins. Sui-v. 1954:23;
Anonymous. 1956. U. S. Dept. Agric. Pacific Northw. For, Range Expt,
Sta. For. Ins. Surv. 1955:27, 40; Bailev, 1956. L^. S, Dept, Agric, Intermtn.
For. Range Expt. Sta. Rept. 1956:29, 32; Chapman and Wilson, 1956, Jour.
Econ. Ent 49:427; Cowlin, 1956, U. S. Dept. Agric. Pacific Northw. For.
Range Expt, Sta. Rept. 1955:34, 37; Gardiner. 1956, Canada Min. Agric.
Rept. 1954-55:17; Hagenstein and Furniss. 1956, Proc. Soc. Amer, For.
1955:167; LeJeune. 1956. British Columbia Dept. Lands For. For. Serv.
Rept. 1955:80; McArdle. 1956, U. S. Dept. Agric. For. Serv. Rept. 1955:12;

The Great Basin Naturalist
108 STEPHEN L. WOOD Vol. XXIII, Xos. 1-2

Lu and Bollen, 1956. Proc. Soc. Amer. Bact. 56:35; Ostmark and Wilford,
1956, U. S. Dept. Agnc. Rocky Mtn. For. Range Expt. Sta. Pap. 22:5. 13;
Phipps, 1956. Oregon St. Bd. For. Bien. Rept. St. For. 1954-56:29; Price,
1956, U. S. Dept. Agric. Rocky Mtn. For. Range Expt. Sta. Rept. 1955:21;
Rudinsky and Vite, 1956, For. Sci. 2:258; Silver and Ross. 1956. Canada
Dept. Agric. For. Ins. Surv. Rept. 1955:93; Walters. 1956. Canada Dept.
Agric. Pub. 975, 11 p.; Yasinski. 1956, U. S. Dept. Agric. Rocky Mtn. For.
Range Expt. Sta. Pap. 23:1, 3; Cowlin, 1957, U. S. Dept. Agric. Pacific
Northw. For. Range Expt. Sta. Rept. 1956:25; Gibson. 1957. Jour. Econ.
Ent. 50:266; Kahn, 1957. Canadian Jour. Zool. 35:519; Lu. 1957. For. Sci.
3:336; Price, 1957, U. S. Dept. Agric. Rocky Mtn. For. Range Expt. Sta.
Rept. 1956:81. 84. 86; Silver and Ross. 1957. Canada Dept. Agric. For. Ins.
Surv. Rept. 1956:81. 86; Vite and Rudinsky, 1957, For. Sci. 3:156;
Whiteside, 1957, U. S. Dept. Agric. Pacific Northw. For. Range Expt. Sta.
For. Ins. Cond. 1956:2. 5, 31. 43; Atkins and Chapman. 1957. Canadian
Ent. 89:80.

This species is very closely allied to simplex, but may be distin-
guished by the larger size, by the more strongly protubrant. more
finely punctured, subgranulate. irregular surface of the frons (Fig.
23). by the more finely punctured pronotum. by the finer punc-
tures of the declivital interspaces, and by the distribution (Fig. 62).

Male. — Length 4.4-7.0 mm. (average about 5.5), 2.3 times as
long as wide; body color very dark brown, with reddish brown
elytra.

Frons broadly convex, protruding rather strongly on lower half,
inflated area arising abruptly just above smooth, elevated rim of
epistomal margin; epistomal process about a fourth (0.24 times)
as wide as distance between eyes, its arms very strongly oblique
(about 80° from the horizontal) and usually not elevated, the hori-
zontal portion about three-fourths its total width, flat, overlapping
and apparently flush with or exceeding epistomal margin and
bearing under its distal margin a dense brush of yellowish setae;
surface irregular, rather finely, closely punctured and becoming
granulate on lower half. Vestiture sparse, rather short, fine incon-
spicuous.

Pronotum 1.4 times as wide as long, widest at base; sides weakly
arcuate and converging toward the strong constriction just behind
the broadly, shallowly emarginate anterior margin; surface smooth
and shining, the punctures rather small, irregular in size, close,
deep; median line narrowly impunctate posteriorly (usually); ves-
titure moderately abundant, fine and rather short on disc, longer
and coarse laterally.

Elytra 2.5 times as long as pronotum; sides straight and sub-
parallel on basal two-thirds, rather broadly rounded behind; basal
margins arcuate and bearing a row of about ten rather large, raised,
overlapping crenulations- with several smaller submarginal ones
particularly on interspaces two and three; striae weakly impressed,
the punctures rather large and moderately deep, usually decreas-
ing slightly in size toward base; interstriae about one and one-half
times as wide as striae and armed by abundant, confused, trans-
verse crenulations, each averaging almost half the width of an inter-

June 14, 1963 revision of dendroctonus 109

space, a fe^\ two-thirds as wide on posterior half of disc. Declivity
rather steep, convex, with sutural interspace very strongly elevated
and interspace two weakly impressed; striae rather deeply impress-
ed, the punctures half as large as on disc; interstrial punctures
rather fine, abundant and confused on one and three, almost uni-
seriate on two; none of the punctures granulate. Vestiture rather
coarse, slightly longer on declivity- the longest setae equal in length
to about one and one-half times the width of an interspace.

Female.— Very similar to male except declivital interspaces with
smaller punctures and each with a median row of very coarse,
somewhat pointed tubercles, the tubercles spaced by a distance slight-
ly less than width of an interspace.

Type locality. — Grants Pass, Oregon. The type was studied.

Hosts. — Pseudotsuga taxifolia, P. macrocarpa, and less commonly
from Larix occidentalis and Tsuga heterophylla.

Distribution. — Western United States, Alberta and British Col-
umbia.

Specimens from the following localities were examined (Fig. 62). Arizona:
Chiricahua Mts., Flagstaff, San Francisco Mts.. and Santa Catalina Mts. Calif-
ornia: Alameda Co., Alma, Bean Ck., Big Basin, Boulder Ck.. Callahan, Camp
Meeker, Chester, Coulterville, Dead Horse Summit in Siskiyou Co.. Fieldbrook.
Foresthill, Gaberville, Green Point. Guerneville, Hackamore, Half Moon Bay,
Happy Camp in Siskiyou Co., Honda, Laguinitas, La Honda, Lights Ck.. Mc-
Cloud, Meadow Valley, Moffat Ck. in Siskiyou Co., Mohawk, Palo Alto, Placer-
ville. Point Reyes, Quincy, Santa Cruz, Trinity Co., Upper Lake in Lake Co.,
Wrights, and Yellow Ck. Color.'^dg: Colorado Springs, Ft. Garland. Gunnison
N. F., Moffat, Pagosa Springs, Palmer Lake, San Isabel N. F., San Juan N. F.,
and Saguache. Idaho: Beaver Canyon in Nez Perce Co., Beaver Ck. in Logan
Canyon, Henry's Lake, Kooskia, Kootenai, Pioneerville. Priest River, Sandpoint,
Smiths Ferry, and Stites. Montana: Apgar. Belton, Bozeman, Columbia Falls,
Fish Ck. Station, Kalispell, Lake McDonald, Middle Ck. in Gallatin Co., and
Ovando. New Mexico: Capitan, Cloudcroft, Santa Fe, Tres Ritos, and Vermejo
Pk. Oregon: Ashland, Clover Ck.. Cold Springs, Corvallis, Detroit, Dixie Pass,
Elk Ck., Forest Grove. Grants Pass. Hood River, Jewell, Klamath N. F., Mac-
Donald Forest, Mary's Peak, Mistletoe, Mt. Angel. Myrtle Point, Newport,
Oregon Caves, Otis, Philomath, Pinehurst. Portland, St. Helens. Salmon River,
Santiam N. F., Siskiyou Mts., Sumpter, Tillamook, Tiller, and Waldo. Utah:
Cache N. F., Logan Canyon, Panguitch, Parowan Canyon. Provo Canyon, and
Sanford Canyon. Washington: Ashford, Buckeye, Curlew, Des Moines. Easton.
Fairfax, Grays Harbor City, Hoodsport, Hoquiam, Kent, Keyport, La Grande,
Longmire, Meredith, Metaline Falls. Monroe, Mt. Rainier N. P., North Bend,
Northport, Orting, Payallup, Port Angeles, Port Williams, Pullman, Quinalt.
Sappho, Satsop, Seattle. Shelton, Stimson Ck. in Mason Co., and Vancouver.
Alberta: Waterton. British Columbia: Australian, Babine Lake, Barriere,
Bestwick, Boston Bar, Britain River, Buttle Lake, Campbell River. Canim Lake,
Cowichan Lake, Cumberland, Fernie, Eraser River Valley. Grant Lake. Hamil-
ton Lake, Kamloops, Kettle River Valley, Lac LaHache, Lillooet River Valley.
Lumby, Macalister, Merritt, Ninipkish Valley, Okanagan Lake. Prince George,
Quesnel, Seymour Narrows, Soda Ck., Trinity Valley. Upper Campbell Lake.
Vancouver, Vernon, West Kettle River Valley, Williams Lake, Windermere
Lake, and Wogs Lake.

Geographical variation.— Not evident in the material at hand.
Biology. — This is a primary insect enemy of Douglas Fir. Al-
though estimates of damage inflicted by it are not available for

The Great Basm Naturalist
110 STEPHEN L. WOOD Vol. XXIII. Nos. 1-2

all regions where it occurs, it probably is responsible for an aver-
age annual loss ni excess of a half billion board feet of timber.

The winter is passed chiefly as young adults, although some
larvae and parent adults also overwinter successfully. Flight activ-
ity may begin as earl}- as the first of April and evidently continues
at least until early September. Two principal periods of flight ac-
tivity occur, the first during May or June is composed of over-
wintered young adults, the second during July or August is com-
posed of beetles that overwintered as larvae and of parent adults
re-emerging from their first set of galleries. The exact timing of
each principal flight period may vary from locality to locality with
altitude, latitude, exposure- peculiarities of a particular season, or
other local ecological factors.

Ordinarily the material selected for attack includes stumps,
windfalls, broken logs, or other injured or prostrate trees larger
than eight inches in diameter. However, when populations are high
or when assisted by draught, healthy, vigorous standing timber ma}'
be selected. The attack on a standing tree usually begins in the
upper midbole area and progresses upward and downward from that
point. In prostrate material, at least when the bark is relatively
thick, the beetles attack the sides and upper surfaces as well as the
lower. The attack is slow and continuous, without any sudden or
concerted swarming of the beetles. Its duration is variable, evidently
depending on the population density of beetles in the area- upon
resistance of the host, or upon local climatic or other local ecolog-
ical factors. It may be completed in a few days or it may continue
for more than a year and involve two or possibly more successive
generations.

The egg galleries (Fig. 63) are constructed almost entirely in the
inner bark; the}' are in continual contact with the cambium and
may very lightly score or at least stain the wood. They are straight
or nearly so. and parallel the grain of the wood.

The initial attack is made by the female beetle in a crevice of
the bark. Soon after beginning the attack she is joined by a male
who takes over the function of removing frass from the entrance
hole. Mating evidently occurs within a few hours after the cambium
is reached. After the gallery has been extended several centimeters
the male may pack the lower areas with frass thereby closing the
entrance hole, or he may leave the gallery in search of another fe-
male. Most of the galleries are from about 12 to 30 cm. in length,
but are known to exceed 90 cm. As with other species, ventilation
tunnels are placed at irregular intervals, or they may be entirely
absent. The maximum number of ventilation tunnels counted in
more than a hundred galleries measured during this study was four;
about 80 percent of the galleries had two ventilation tunnels.

Oviposition may begin within two or three days after the attack;
according to Vite and Rudinsky (1957:157) the first eggs, under
controlled laboratory conditions, may appear within 36 hours after
the attack begins. Eggs evidently may be found throughout the

June 14. 1963

REVISION OF DENDROCTONUS

111

Fig. 63. Dendroctonus pseudotsugae: Egg galleries longitudinal, straight;
eggs deposited in grooves, each oriented with its long axis perpendicular to egg
gallery; larval mines usually independent, almost never cross, but may join
one another during final stages of development.

period of summer activity until about early September. According
to Chamberlin (1918:20) one female may produce as many as 160
eggs in one gallery; the maximum number counted during this
study was 102 in a gallery only partly complete.

Eggs are deposited in grooves about two to four millimeters deep
along the sides of the gallery, near but not necessarily touching the
cambium. The grooves are placed alternately on the sides, without
overlapping or without more than a few millimeters between the
end of the groove on one side and the beginning of the next on the
other side. The grooves vary considerably in length, they range from
less than one to more than eight centimeters. The eggs are deposited

The Great Basin Naturalist
112 STEPHEN L. WOOD Vol. XXIII, Nos. 1-2

in a single row in contact with one another and oriented with the
long axis perpendicular to the egg gallery and more or less parallel
to the cambium. It is presumed that the larvae emerge from the
egg at the end farthest from the egg gallery. This habit of orienting
the eggs is peculiar in the genus among the species observed per-
sonally during this study, and presumably is associated with the
fact that the larvae construct independent mines, rather than work-
ing in congress as with other species that deposit masses of eggs
in common grooves. The eggs are held in position by a rather thick
layer or partition of coarse, fibrous frass that separates them from
the egg gallery. Following the period of oviposition most of the fe-
males re-emerge to construct a second set of galleries.

The period of incubation varies considerably with various fac-
tors, particularly temperature. Vite and Rudinsky (1957:161) found,
under controlled conditions, that it ranged from about 6 to 28 days.
Under field conditions estimates of the incubation period range
from 8 to 24 days. Under controlled conditions, Vite and Rudinsky
(1957:161) found that larval development required about 19 to 72
days and the pupal period about 5 to 18 days. The larvae construct
individual mines more or less perpendicular to the egg gallery and
are in continual contact with the cambium area. They increase
gradually in diameter and tend to fan out somewhat as they pro-
gress. Unless crowding occurs they normally do not cross one an-
other. Near the end of larval development a pupal chamber may
be cleared in the cambium area at the end of the larval mine, or
the larva may bore out into the bark for a variable distance before
pupating. The young adults overwinter in the brood galleries and
emerge the followdng spring. Larvae that develop from eggs depos-
ited in the fall may not mature before the onset of cold weather
and, therefore, pass the winter as larvae. These larvae mature early
in the following summer and may emerge in July or August, or,
evidently, they may overwinter in the brood galleries (Bedard,
1950:9). There is one complete generation and possibly a partial
second generation each year.

Material Examined

Although an exact count was not kept during this study, it is
estimated that the number of specimens examined exceeded the fol-
lowing figures: brevicomis-, 2000; frontalis, 400; parallelocollis, 500;
adjunctus, 500; ponder osae. 2000; aztecus, 26; terebrans, 200;
valens, 2000; micans, 150; punctatus. 200; murrayanae, 400; obesus,
5000; simplex, 300; and pseudotsugae , 2000. The distribution maps
and records treated in the discussion of each species indicate where
these species were collected.

The holotypes of species studied include: brevicomis Leconte,
barberi Hopkins, frontalis Zimmerman, arizonicus Hopkins, mexi-
canus Hopkins, approximatus Dietz. convexifrons Hopkins, pon-
derosae Hopkins, monticolae Hopkins, jeffreyi Hopkins, aztecus

June 14, 1963 revision of dendroctonus 113

Wood, valens Leconte, beckeri Thatcher, punctatus Leconte, johan-
seni Swaine, murrayanae tlopkins, {Hylurgus) obesiis Mannerheim,
piceaperda Hopkins, engelmanni . Hopkins, borealis Hopkins, similis
Leconte, simplex Leconte, and pseudotsugae Hopkins. In addition,
the types of adjunctus Blandford and of rufipennis Kirby were com-
pared to my specimens by Dr. R. T. Thompson at the British Mus-
eum of Natural History. The types of parallelocollis Chapuis, tere-
brans Olivier, and of micans Kugelann were not examined; speci-
mens of parallelocollis that were compared to the type for Hopkins
were studied, however. Because micans is the only European species
in the genus there was no problem with its identity.

Biological studies of the various species were conducted by my-
self in the following localities: brevicomis at Flagstaff, Prescott and
Williams, Arizona, Dixie N. F., Salina and Ashley N. F., Utah,
Plumas N. F. and Lassen N. F., California, and near Sisters, Ore-
gon; frontalis at Prescott, Arizona; parallelocollis at Dixie N. F.,
Salina and Sanford Canyon, Utah, Prescott and Williams, Arizona,
and Texmelucan, Puebla (Mexico); adjunctus, Dixie N. F., Sanford
Canyon, and Panguitch, Utah, and Prescott, Arizona; ponderosae,
Logan Canyon, Ashley N. F., Wasatch N. F., Salina, Panguitch,
Sanford Canyon, La Sal Mts.. and Dixie N. F., Utah, Flagstaff,
Arizona, Fallen Leaf Lake, Lassen N. F., and Tahoe N. F., Califor-
nia, and Ochoco N. F., Oregon; aztecus, Coapala, Sinaloa (Mexico);
terebrans, Kingsland, Georgia; valens, Logan Canyon, Ashley N. F..
and Panguitch Lake, Utah, Lassen N. F., and Yreka, California;
murrayanae, Logan Canyon, and Wasatch N. F., Utah; obesus,
Santa Fe Ski Basin, New Mexico, Logan Canyon, Wasatch N. F.,
Ashley N. F., Dixie N.F., Utah, Gold Lake and Cascade Head Expt.
For., Oregon; and pseudotsugae, Logan Canyon, and Sanford Can-
yon, Utah, Siskiyou Co., California, and Mary's Peak, Oregon.

The hosts and localities included in this study are restricted to
those recorded for specimens examined during the study. When lo-
calities were not known to me and could not be located on avail-
able maps, the locality designation was placed in quotation marks.
The scientific name of Douglas fir used here is Pseudotsuga tazifolia,
as employed by R. J. Preston (1961, North American Trees, p. 63).
not P. menziesii as currently employed in the checklist.

References to the vast quantity of literature treating Dendroc-
tonus species is listed in the synonymies and is thought to be fairly
complete to 1958 for all species except micans. About two-thirds to
three-fourths of the articles listed were examined; mechanical prob-
lems made it impossible to examine all sources or to locate and re-
view all recent articles. The disadvantages in this approach are ob-
vious; undoubtedly some injustices and errors have resulted. Be-
cause no real taxonomic problem involved the European micans,
an extensive effort to locate references to this species was not made.
In treating the biologies of all species it was arbitrarily decided that
when three principal authors who included original data in their
reports agreed on a particular point, that point was considered as

The Great Basin Naturalist
114 STEPHEN L. WOOD Vol. XXIII, NoS. 1-2

common knowledge, if it more or less agreed with my observations,
and literature citations were not included. In a few instances where
contradictory data were presented, all pertinent articles were studied
and a decision was made as to the accuracy of the report.

Acknowledgement

The contributions and cooperation of numerous individuals and
organizations have made possible the completion of this study. The
writer is indebted to M. L. Prebble, Forest Entomology and Path-
ology Branch. Canada Department of Forestry, for providing in 1955
the initial stimulus and encouragement to undertake a revision of
this difficult and important genus of forest insects. Appreciation is
also expressed to the U. S. National Museum, to the Museum of
Comparative Zoology, to the Museum Zoologicum Univesitatis (Hel-
sinki), to the Canadian National Collection of Insects, to the Portland
(Oregon), Berkeley (California), and Albuquerque (New Mexico)
regional laboratories of the Forest Service, U. S. Department of
Agriculture, to the University of California (Berkeley) and to the
Oregon State University for making available facilities and/or spec-
imens for this study. Special thanks are also due to J. B. Thomas
(Sault Ste. Marie), George R. Hopping (Calgary), and D. A. Ross
(Vernon), Forest Entomology and Pathology Laboratories, Canada
Department of Forestry, for special notes and specimens; to R. W.
Stark and David L. Wood. Department of Entomology and Parasit-
ology, University of California (Berkeley), and to R. L. Furniss.
Forest Service, U. S. Department of Agriculture, for council and
direction in arranging field studies and especially for their kindness
in reviewing the manuscript of this paper. Of the many forest ran-
gers and entomologists contacted for direction and advice in locat-
ing local infestations, special mention should be made for the kind-
ness and special assistance of Vern P. Yerkes, Cascade Head Exper-
imental Forest (Otis, Oregon). Sincere thanks are also expressed to
Donald E. Bright, Jr., to Jay B. Karren, and to Howard P. Shurtleff
for the many weeks they spent gathering biological data throughout
the western United States from 1960 to 1962, for this project.
Appreciation is also expressed to the National Science Foundation
for the financial aid necessary to conduct the field work that
was so vital to this study.

Literature Cited

Beal, J. A. 1939. The Black Hills beetle, a serious enemy of
Rocky Mountain pines. U. S. Dept. Agric. Farmers' Bull. 1824,
22 p.

Bedard, W. D. 1950. The Douglas-fir beetle. U. S. Dept. Agric.
Circ. 817, 10 p.

Blackman, M. W. 1922. Mississippi bark beetles. Mississippi
Agric. Expt. Sta. Tech. Bull. 11, 130 p., 18 pis.

June 14, 1963 revision of dendroctonus 115

Blackman, M. W. 1931. The Black Hills beetle. Bull New York
St. Coll. For., Syracuse Univ. 4(4), Tech. Pub. 36, 97 p.

Blandford, W. F. H. 1895-1905. Family Scolytidae. Biologia Cen-
trali-Americana, Coleoptera 4(6): 81-298.

Chaniberlin, W. J. 1918. Bark-beetles infesting the Douglas fir.
Oregon Agric. Expt. Sta. Bull. 147. 40 p.

Chapuis, F. 1869. Snyopsis des Scoly tides. Desoer: Liege. (Pre-
print of: 1873. Synopsis des Scolytides. Mem. Soc. Roy. Sci.
Liege, ser. 3,2:213-269.)

Craighead, F. C, J. M. Miller, J. C. Evenden, and F. P. Keen.
1931. Control work against bark beetles in western forests and
an appraisal of its results. Jour. Forestry 29(7): 1001-1018.

Dietz, W. G. 1890. Notes on the species of Dendroctonus of Bor-
eal America. Trans. American Ent. Soc. 17:27-32.

Dixon, J. C. and E. A. Osgood. 1961. Southern pine beetle, a re-
view of present knowledge. U. S. Dept. Agric. For. Serv. S. E.
For. Expt. Sta. Pap. 128, 34 p.

Eichhoff, W. 1864. Ueber die Mundtheile und die Fiihlerbildung
der europaischen Xylophagi sens, strict. Berliner Ent. Zeitschr.
8:17-46.

Eichhoff, W. 1878. Ueber die Borkenkafer-Gattungen Hylurgus
Latr. und Blastophagus Eichh. Stettiner Ent. Ztg. 39:399-400.

Eichhoff, W. 1881. Die europaichen Borkenkafer. Springer: Ber-
lin. 315 p.

Erichson, W. F. 1836. Systematische Auseinandersetzung der
familie der Borkenkafer (Bostrichidae). Archiv Naturgesch.
2(l):45-65.

Evenden, J. C, W. D. Bedard and G. R. Strubble. 1943. The
Mountain pine beetle, an important enemy of western pines.
U. S. Dept. Agric. Circ. 664, 25 p.

Fabricius, J. C. 1801. Systema Eleutheratorum secundum or-,
denes, genera, species, adjectis synonymis, locis, observation-
ibus, descriptionibus 2:384-395.

Fronk, W. D. 1947. The Southern pine beetle, its life history.
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Hopkins, A. D. 1909a. Contributions toward a monograph of the
scolytid beetles. I. The genus Dendroctonus. U. S. Dept. Agric.
Bur. Ent. Tech. ser. 17(1): 1-164.

Hopkins, A. D. 1909b. Practical information of the scoiy+.J beg.
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Dendroctonus. U. S. Dept. Agric. Bur. Enl. cull. 83(1): 1-169.

Hopkins, A. D. 1915. Contributions toward a monograph of scoly-
tid beetles. II. Preliminary classification of the superfamily
Scolytoidea. U. S. Dept. Agric. Tech. ser. 17(2) : 165-232.

Larcordaire, T. 1866. Familie LXIII. Scolytides. Histoire Natu-
relle des Coleopteres 7:349-398.

Latrielle. P. A. 1802. Histoire naturelle, generale et particuliere
des crustaces et des insects 3, 467 p. Paris.

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Leconte, J. L. 1860. Report on insects collected on the survey.
Reports of Explorations and Surveys for a Railroad Route from
the Mississippi River to the Pacific Ocean 9(1): 1-72, 2 pis.

Leconte, J. L. 1868. Appendix to Zimmermann's synopsis of the
Scolytidae of America north of Mexico. Trans. American Ent.
Soc. 2:150-178.

Leconte, J. L. 1878. Family IX. Scolytidae. In J. L. Leconte and
G. H. Horn, The Rhynchophora of America north of Mexico.
Proc. American Philos. Soc. 15:341-391.

Massey C. L. and N. D. Wygant. 1954. Biology and control of
the Engelmann spruce beetle in Colorado. U. S. Dept. Agric.
For. Serv. Circ. 944, 35 -p.

Miller, J. M. and F. P. Keen. 1960. Biology and control of the
western pine beetle. U. S. Department of Agriculture: Wash-
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Prebble, M. L. 1933. The larval development of three bark
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Simpson. L. J. 1929. The biology of Canadian bark beetles. Can-
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Swaine, J. M. 1914. Forest insect conditions in British Columbia.
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Swaine, J. M. 1919. The Coleoptera collected by the Canadian
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Thatcher, T. O. 1954. A new species of Dendroctonus from Guat-
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Vite. J. P. and J. A. Rudinsky. 1957. Contribution toward a
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Westwood, J. O. 1838. Family Scolytidae. In Synopsis of the
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Green and Longmans: London.

Wood, S. L. 1957. Ambrosia beetles of the tribe Xyloterini (Col-
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Wood, S. L. 1961. An alternative proposal to the suggested val-
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INDEX

Page

Abstract 1

Introduction 2

History 2

Discussion of morphological characters 4

Discussion of biology 10

Infraspecific variation 20

Phylogeny 23

Genus Dendroctonus Erichson 24

Key to the species of Dendroctonus 26

Dendroctonus brevicomis Leconte 29

Dendroctonus frontalis Zimmerman 39

Dendroctonus parallelocollis Chapuis 46

Dendroctonus adjunctus Blandford 51

Dendroctonus ponderosae Hopkins 57

Dendroctonus aztecus Wood 69

Dendroctonus terebrans (Olivier) 71

Dendroctonus valens Leconte 76

Dendroctonus micans (Kugelann) 82

Dendroctonus punctatus Leconte 85

Dendroctonus murrayanae Hopkins 88

Dendroctonus obesus (Mannerheim) 93

Dendroctonus simplex Leconte 103

Dendroctonus pseudotsugae Hopkins 106

Material examined ■- 112

Acknowledgement 114

Literature cited 114

117

fU^

Great Basin

AUb 1 6 !h86

UNIVERSITY
Volume XXm December 16, 1963 Nos. 3-4

TABLE OF CONTENTS

A Survey of the Herpetofauna of the Death Valley Area.

By Frederick B. Turner and Roland H. Wauer 119

The Systematics of Crotaphytus Wislizeni, the Leopard
Lizards. Paul; I. Illustrated. By Wibner W. Tanner and
Benjamin H. Banta 129

New Lacebugs from the Eastern Hemisphere. Illustrated.
By Carl J. Drake 149

Undescribed Species of Nearctic Tipulidae (Diptera). By

Charles P. Alexander 159

Scissor-Tailed Flycatcher in Death Valley, California. By
Roland H. Wauer 165

New Distributional and Host Data for the Tick Dermacentor
hunteri Bishopp. By Elias P. Brinton and Glen M.
Kohls L 166

A New Species of Craniotus (Coleoptera: Tenebrionidae) .

Illustrated. By Vasco M. Tanner 167

Index 171

4

Published by
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UNIVERSITY

The Great Basin Naturalist

Published at Provo, Utah by
Brigham Young University

Volume XXIII December 16. 1963 Nos. 3-4

A SURVEY OF THE HERPETOFAUNA OF THE
DEATH VALLEY AREA

Frederick B. Turner and Roland H. Wauer'

Since the report of the Death Valley Expedition of 1891
(Stejneger, 1893), there have been only incidental notes on the
herpetofauna of the Death Valley area of eastern California.
Specimens were collected by Grinnell and Dixon in 1917 and 1920;
and Joseph Slevin of the California Academy of Sciences collected
in the Panamint Mountains in the early 1930's. At about the
same time. Klauber prepared a tentative list of amphibians and
reptiles known from the area (unpublished). Death Valley Na-
tional Monument was established in 1933 and during 1939 and
1940. Park Naturahst Wilbur Doudan collected specimens for the
National Park collection. During the late 1940's Stebbins made
several collecting trips to the area. During the winters of 1953-54
and 1954-55. Frederick B. Turner collected for the National Park
Service, and Roland H. Wauer collected specimens during his five
years residency from 1957 through 1962.

The writers have drawn on field notes of Joseph Grinnell,
Joseph Dixon, Robert C. Stebbins, Richard G. Zweifel, Robert
Glaser and data available in the files of the Death Valley National
Monument. We wish to thank Matt Ryan, Ralph and Florence
Welles. Warren Hill and Dick Davis for additional data. Records
are included from the American Museum of Natural History, the
University of California Museum of Vertebrate Zoology and the
California Academy of Sciences.

The Area

The arid valleys and mountain ranges of Inyo County. Calif-
ornia, are physiographically a part of the Great Basin Desert.
However, the Death Valley area is characterized by higher temper-
atures and less rainfall than most of the Great Basin, so there is a
strong affinity with the Mojave Desert. The area is roughly that
of Death Valley National Monument, which includes small sections

1. Laboratory of Nuclear Medicine and Radiation Biology. University of California. Los .\ngeles;
and U. S. National Park Service. Zion National Park. Utah.

119

The Great Basin Naturalist
120 FREDERICK TURNER & ROLAND WAUER Vol. XXIII, Nos. 3-4

of Nye and Esmeralda Counties, Nevada; and San Bernardino
County, California. The Panamint Range forms the western edge
of Death Valley and rises to a height of 11,049 feet at the summit
of Telescope Peak. The Panamint crest is nowhere below 4500
feet and four distinct zonal formations exist. The Amargosa Range
forms the eastern edge of Death Valley and exists wholly within
the Lower Sonoran Life Zone, except for an area in the Grapevine
Mountains where a pinon-juniper association is present between
5500 and 6700 feet elevation. The valley itself is an elongated fault
basin, of which 550 square miles lie below sea-level. It extends for
140 miles from Ubehebe Crater, south to Saratoga Springs. The
lowest point is near Badwater, - 282 feet.

Habitats

From the floor of Death Valley Telescope Peak rises over
11,330 feet from the salt pan of Death Valley. The huge dry lake
bed is "a chemical desert not fit to sustain life" (Wauer, 1962).
Surrounding the salt pan is a line of phreatophytes (deeply rooted
plants) which separates the salt flats from the gravels of the
alluvial fans. Only where the fans dip very steeply into the playa
itself is there a distinct demarcation between the salt and gravels.
Iodine bush {Allenrolfea occidentalis) grows in isolated bunches
nearest the salts, and saltgrass {Distichlis stricta) and arrowweed
{Pluchea sericea) occur next. The dominant species of this zone is
honey mesquite {Prosopis juliflora). Mesquite occurs in large
stands at Coyote Well, north and south of Bennett Well, on the
Furnace Creek fan, south of Salt Creek, and in Mesquite Valley.
Sacatone grass (Sporobolus airoides) and desert holly (Atriplex
hymenelytra) occur next and mingle with creosote bush {Larrea
divaricata) .

Fresh water occurs at only a few places on the valley floor.
Potable water flows from Mesquite Springs along an irrigation
ditch for almost a quarter-mile. Furnace Creek Ranch offers many
irrigation ditches and open ponds and a wide range of exotic plants
such as tamarisk (Tamarix) and date palms (Phoenix). Tule
Spring and Eagle Borax Works are along the western edge of Death
Valley amid the line of phreatophytes. A pool of stagnant water
persists at Tule Spring and perennial pools of water exist at Eagle
Borax Works. Perennial pools also exist at Coyote Well and along
the Amargosa riverbed which flows north down the center of Death
Valley. Saratoga Springs is a large oasis in the southern end of the
valley where a two-acre lake occurs.

In the north-central portion of the valley there are twenty-five
square miles of sand dunes. Mesquite and saltgrass occur in isolated
stands throughout the dunes. Arrowweed grows along the southern
end of the sands and continues south to a brackish stream called
Salt Creek. This flow reaches the center of the valley in late spring
and is completely dry during the summer. Sand dunes also exist
just south of Saratoga Springs.

Dec. 16, 1963 herpetofauna of death valley 121

The alluvial fans extend from the salt pans as much as twelve
miles, or as little as twenty or thirty feet, before reaching the
mouths of canyons. In the Amargosa Range the canyons and washes
begin almost immediately above the salt pan. The gravels of the
larger fans, such as those from Cottonwood, Emigrant, Monarch,
Blackwater, Titus, Furnace Creek, Hanaupah and Johnson Canyons,
cover many hundreds of square miles. Creosote bush is dominant
here, but desert holly, fourwinged saltbrush {Atriplex canescens),
bursage (Franseria dumosa), honey sweet {Tidestromia oblongi-
jolia), and brittlebush {Encelia farinosa) are usually present.

The rocky canyons support a more diverse plant growth than
the previously mentioned areas. Here, again, is creosote bush,
greenmolly (Kochia americana), cliffrose {Cowania mexicana),
globemallow {Sphaeralcea eremicola), rabbitbrush {Chrysotham-
n'us), and desert fir {Peucephytlum schotti) . Vegetation also grows
along the canyon walls, such as stingbush (Eucnide urens) and
Death Valley sage {Salvia funerea) . Because of the restricted flow
of occasional large amounts of water, the canyons tend to be well
scoured and support few large shrubs except along the edges. The
main channels, or washes, are a jumble of rocky debris.

A line of springs occur through the Panamint Range between
3500 and 4500 feet elevation. Heavy growths of wallow (Saliz),
rabbitbrush and Baccharis. and in a few places cottonwood {Popu-
lus fremonti). are the dominants. Desert grape (Viiis girdiana)
grows in abundance in Hanaupah and Cottonwood Canyons.

Large open sage flats occur directly below the pinon-juniper
woodlands. Examples of this habitat are Greenwater, Amargosa,
and Butte Valleys; and Old Crump, Wildrose, Rabbit ,and Harris-
burg Flats. Vegetation consists primarily of shadscale {Atriplex con-
fertifolia), cliffrose, blackbrush {Coleogyne ramosissima) , bladder-
sage (Salazaria mexicana), big sagebrush {Artemisia tridentata)
and cottonthorn (Tetradymia spinosa) .

The pinon-juniper woodlands of the Panamint and Grapevine
Mountains occur between about 5500 feet and 8000 feet elevation.
Juniper {Juniperus osteosperma) and pinon {Pirtus monophylla)
dominate the zone. Less dominant forms are desert sage {Salvia
carnosa). big sagebrush and cottonthorn. At the upper limits of
the pinon-juniper zone is mountain mahogany {Cercocarpus ledifol-
ius) . The woodlands, constituting the Upper Sonoran Life Zone,
give way to a transition zone dominated by limber pine {Pinus
flexilis), water birch {Betula frontalis), currant {Ribes cereum)
and service berry {Amelanchier alnifolia). Above 10,000 feet, in
the Boreal Zone, bristlecone pine {P. aristata) is dominant.

The Herptofauna

Three species of amphibians and thirty-five species of reptiles
have been reported on good evidence.

The Valley Floor: The desert oases support small populations
of amphibians and reptiles. Red-spotted toads {Bufo punctatus) are

The Great Basin Natiiralist
122 FREDERICK TURNER & ROL.'VND WAUER Vol. XXIII. Nos. 3-4

-a

p K

C "5

u

List of Species and Races

Is

'0>

en

cc 0.

Is

inon-

rans..
oreal

>fo

<fa

Uc/D

C/Dfa

0^^ HCQ

Amphibians

Bufo punctatus

X

X

Hyla regilla

X

X

Rana catesbeiana

X

Reptiles

Gopherus agassizi

X

X

Coleonyx v. variegatus

X

X

X

Dipsosaurus d. dorsalis

X

X

X

Crotaphytus collaris baileyi

X

X

Crotaphytus w. wislizeni

X

X

X

Sauromalus o. obesus

X

X

X

Callisaurus draconoides

gabbi

X

X

X

X

Uma notata scoparia

X

Sceloporus magister

X

X

X

Sceloporus occidentalis

biseriatus

X

X

X

X

Sceloporus graciosus gracilis

X X

Uta stansburiana stejnegeri

X

X

X

X

X

X

Uta graciosa

X

Phrynosoma platyrhinos

calidiarum

X

X

X

Gerrhonotus panamintinus

X

X

Xantusia vigilis

X

X

X

Cnemidophorus t. tigris

X

X

X

X

X

Eumeces gilberti

Leptotyphlops h. humilis

X

X

X

rubricaudatus

X

X

Lichanura roseofusca gracia

X

Masticophis flagellus piceus

X

X

X

X

X

Masticophis t. taeniatus

X

X

Salvadora h. hexalepis

X

X

X

Phyllorhynchus decurtatus

perkinsi

X

X

Arizona elegans

X

Pituophis catenifer deserticola

X

X

X

X

Lampropeltis getulus

californiae

X

X

Rhinocheilus lecontei clarus

X

X

Sonera semiannulata isozona

X

X

X

Sonora semiannulata linearis

X

Chionactis o. occipitalis

X

X

Trimorphodon vandenburghi

X

Hypsiglena torquata

deserticola

X

X

X

Tantilla utahensis

X

Crotalus mitchelli stephensi

X

X

X

X

X

Crotalus c. cerastes

X

X

X

Table 1. Distribution of the amphibians and reptiles of the Death Valley area,
Inyo County. California.

Dec. 16, 1963 herpetofauna of death valley 123

found at Saratoga Springs, Eagle Borax Works, Furnace Creek
Ranch and Inn. and Cow Creek. There are isolated groups in Fur-
nace Creek Wash and in all of the Texas Spring drainages (Turner,
1959a). Toads also occur around the canyon springs in the Lower
Sonoran Life Zone. Records exist from Johnson. Hanaupah. Emi-
grant and Cottonwood Springs. The Pacific tree frog {Hyla regilla)
has a similar range, but is found in the valley at Saratoga Springs
and near Scotty's Castle only. The bullfrog (Rana catesbeiana)
exists at Furnace Creek Ranch and Inn where it was introduced
about 1920.

The most common reptile of the valley oases is the side-
blotched lizard {Uta stansburiana) . It is present throughout the
year except during the coldest days, and has been found several
feet onto the salt pan, probably in search of insects and spiders that
occur in this unproductive area. Uta have been found throughout
the Lower Sonoran Life Zone. The banded gecko {Coleonyx varie-
gatus) occurs about the desert oases also, but is nocturnal. One was
collected at 4000 feet in Wildrose Canyon.

The worm snake (Leptotyphlops humilis) has been found
from below sea-level to about 4000 feet. The most common snake
of the valley oases is the desert whipsnake {Masticophis jlagel-
lum). It occurs about the mesquite and tamarisk growths at Fur-
nace Creek Ranch. Eagle Borax Works. Mesquite Spring and Stove
Pipe Wells Hotel, and frequents the washes and canyons and the
open sage flats below the pinon-juniper association. The only other
reptile occasionally found at the valley oases is the sidewinder
{Crotalus cerastes), which prefers the low alluvial fans and washes
but rarely is found at the oases such as Furnace Creek Ranch and
Eagle Borax Works. Records exist throughout the lower half of the
Lower Sonoran Life Zone.

The sand dunes of Death Valley afford another habitat. The
fringe-toed lizard {JJma notata) and long-tailed uta {Uta graciosa)
have been found in the dunes south of Saratoga Springs (Norris,
1958). The dunes located in the central portion of Death Valley
are inhabited by banded geckos, gridiron-tailed lizards {Callisaurus
draconoides), side-blotched lizards and sidewinders.

WTierever mesquite is prevalent there occurs an additional
group of reptiles. Here is the crested lizard (Dipsosaurus dorsalis),
whicn ranges up into the low canyons and washes where mesquite
exists. The whiptail lizard {Cnemidophorus tigris) also occurs in
mesquite thickets, and is present in the low canyons and washes in
the Lower Sonoran Life Zone. Other species found in the mesquite
thickets are the banded gecko, the side-blotched lizard, the desert
whipsnake and the sidewinder.

The Alluvial Fans: Of the reptiles discussed so far, all but
Uma and Uta occupy alluvial fans above the valley floor. Other
species exist where the gravel and creosote bush habitat persists.
The desert tortoise {Gopherus agassizi) has been found from 1500

The Great Basin Naturalist
124 FREDERICK TURNER & ROL.\ND WAUER Vol. XXIIL Nos. 3-4

to 3500 feet elevation and is never common. It is sometimes found
on the open fans and washes and even on the sage flats. Both col-
lared lizards (Crotaphytus coUaris) and chuckwallas {Sauromalus
obesus) occur where tlie fans are sprinkled with large boulders.
The chuckwalla often is found below sea-level where the fans meet
the salt pans (e.g., below Sheep, Willow Creek and Johnson Can-
yons). There are no records from the Upper Sonoran Life Zone.

The carnivorous leopard lizard {Crotaphytus wislizeni) occurs
from below sea-level into the canyons and washes, and even into
the pinon-juniper woodland. The horned lizard [Phrynosoma platy-
rhinos) is rarely found at lower elevations, but prefers the upper
slopes amid creosote bush. In similar areas the patch-nosed snake
{Salvadora hexalepis). the leaf-nosed snake {Phyllorhynchus decur-
tatus), the gopher snake {Pituophis catenifer), the ground snake,
Sonora semiannulata) . Mitchell's rattlesnake {Crotalus mitchelli)
and the sidewinder occur. Patch-nosed snakes are not common, but
a few records exist from the upper alluvial fans and canyons to
about 4500 feet. The gopher snake frequents the same zones, but
is more common and often occurs around canyon springs. Mitchell's
rattlesnake frequents alluvial fans but rarely is found below sea-
level. It has been collected at Mahogany Flat (8200 ft.) so it can be
expected throughout the Low^er and Upper Sonoran Life Zones.

The Canyons and Washes: Most of the species already dis-
cussed range into canyons and washes. In fact, twenty-seven species
of reptiles have been reported here. Twelve species, not so far men-
tioned, are found in this habitat. The spiny lizard (Sceloporus
magister) has been found in the upper canyons of the Lower Sonor-
an Life Zone such as Cottonwood and Emigrant Canyons; and also
on the higher flats below the pinon-juniper woodland and in the for-
est itself. Records exist from 3900 to 7000 feet elevation. The range
of the western fence lizard [Sceloporus occidentalis) is very sim-
ilar. The alligator lizard {Gerrhonotus panamintinus) w^as first re-
ported by Stebbins (1958 )in Surprise Canyon. The night lizard
{Xantusia vigilis) has been collected in Monarch Canyon, near
Dante's View, and among pinon pines to 9360 feet in the Panamint
Mountains (Turner, 1959c).

The desert boa {Lichanura roseofusca) has been found in
Hanaupah and Emigrant Canyons (Turner. 1959b). A striped whip-
snake [Masticophis taeniatus) was taken at Willow Creek (5400
feet) in 1891. and another found near Hunter Spring in the pinon
forest. The California king snake (Lampropcltis getulus) prefers
open canyons above 3900 feet. Records exist from Johnson and Wild-
rose Canyons; and for the sage flats such as Wildrose and Harris-
burg Flats. Other species found in this habitat are the long-nosed
snake (Rhinocheilus lecontei). the shovel- nosed snake {Chionactis
occipitalis), the lyre snake (Trimorphodon vandenburghi), the
night snake {Hypsiglena torquata). and the black-headed snake
(Tantilla utahensis) . The latter has been found in Surprise Canyon
only.

Dec. 16. 1963 herpetofauna of death valley 125

The Canyon Springs: The red-spotted toad and the Pacific tree
frog have been found here, as well as the western fence lizard, the
desert whipsnake. the night snake, and Mitchell's rattlesnake. Gil-
bert's skink [Eumeces gilberti) is common among the grapevines
in tianaupah and Johnson Canyons (Rodgers and Fitch. 1947) and
has also been recorded on Harrisburg Flat.

The Sage Flats-. Most of the individuals found in the canyons
and washes also occur in this vegetation type.

The Pinon-J uniper Woodlands: Ihe species occurring in this
habitat have already been discussed.

The Transition and Boreal Life Zones: The sagebrush lizard
and the night lizard are the only two species knowTi to occur
above the pinon-juniper woodlands. The sagebrush lizard has been
found above 10,000 feet, and Xantusia has been collected at 9360
feet in the Panamint Mountains.

List of Selected Records

The following is a selected list of reptiles that have not been
previously reported from the Death Valley area, or that have been
recorded on few occasions.

1. Western Worm Snake. Leptotyphlops h. hunulis. This species
was first reported by Klauber (1931) from Bennett Well, but since
then additional individuals have been reported from below sea-level
to 4000 feet at Wildrose. In April of 1960, during the reconstruction
of Bennett, Shorty's and Gravel Wells, much of the planking was
removed and replaced. Several blind snakes were found at each site,
but a large aggregation of several dozen snakes was uncovered at
Shorty's Well. They were situated beneath the board planking some
four feet below the surface of the ground. A few individuals were
collected and identified by Wauer.

2. Desert Leaf-nosed Snake. Phydlorhynchus decurtatus perkinsi.
This species was first collected by Slevin near Mesquite Spring in
April of 1935. It has since been found in Emigrant and Goler Can-
yons and recently Wauer collected a specimen at the edge of the
salt pan (- 150 feet) in Mav of 1961. The temperature at 8:30 p.m.
was 85° F.

3. California King Snake. Lampropeltis getulus californiae. This
species has been found to be fairly common throughout the Pana-
mint Range, but there are no localities from the Amargosa Range,
east of Death Valley. Specimens were taken at Towne Pass, Wild-
rose and Johnson Canyons, and on Harrisburg Flat.

4. Desert Long-nosed Snake. Rhinocheilus lecontei clarus. The
first specimen from the area was taken by Robert Glaser on Towne
Pass. April 11. 1954. Wauer collected a specimen on Harrisburg
Flat on June 23. 1962. The temperature at 3500 feet was 75° F.

5. Ground Snake. Sonora semiannulata. Two races have been re-
corded. The more abundant is 5. .s. isozona. the most common noc-

The Great Basin Naturalist
126 FREDERICK TURNER & ROLAND WAUER Vol. XXIII, NoS. 3-4

tuinal snake in the area. Specimens have been taken from 2500
to 5200 feet elevation, in both the Panamint and Amargosa Ranges.

5. s. linearis was collected in Wildrose Canyon on July 5, 1954,
and identified by Klauber.

6. Mojave Shovel-nosed Snake. Chionactis o. occipitalis. This
species was first collected by Arnold Applegarth in Furnace Creek
Wash in March of 1954. Additional species have been taken in
Goler Canyon, at Ballarat and at Ryan. The race intergrades with
talpina along its northern limits which is the area immediately east
of the Ainargosa Range.

7. California Lyre Snake. Trimorphodon vandenburghi. A single
specimen was collected by Wauer on Daylight Pass at 10 p.m. on
June 26, 1962. It was taken at 4300 feet in a creosote bush habitat.
The temperature was 78° F. On July 1, 1962, Warren Hill found
a road kill in Furnace Creek Wash at 1500 feet elevation. The two
locations are about 15 miles apart in the Amargosa Range. Both
specimens represent easternmost records for the species. The Day-
light Pass specimen was taken only I/2 mile from the Nevada line.
Both Schmidt (1953) and Stebbins (1954) show the range for this
species as extending east from the California coast to the Argus
Mountains. These records, then, increase the known range of this
species by about 100 miles to the east.

Discussion

In general, the reptilian fauna of the Death Valley area in-
cludes a few widely distributed forms, (e.g., Callisaurus, Uta,
Cnemidophorus tigris, Masticophis flagellum, and Crotalus cerastes),
which present a fairly continuous distribution at lower elevations,
except for the alkaline desert. However, many species exhibit
disjunct patterns of distribution, the spottiness inversely propor-
tional to the adaptive versatility of the species involved. Some of
these latter forms are isolated on islands of suitable habitat afford-
ed by the mountain ranges on each side of the valley (Miller,
1940; Stebbins, 1958). There is little known about the distribution
of such forms. The Amargosa Range has had only slight study.
The Panamint Range has been more intensively worked. The faun-
istic diversity of the Panamints, as opposed to the Amargosa Range,
is due to this factor and to the fact that the latter is more uniform
ecologically. In spite of numerous explorations of the Panamints,
Stebbins (1958) has recently described a new Gerrhonotus from
Surprise Canyon. Further work is apt to be comparably rewarding.

In view of the relatively high degree of endemism exhibited
by Death Valley's plants, one might expect comparable differenti-
ation among the fauna. The Death Valley area is the type locality
for several insects and a half-dozen vertebrates. A concentration of
type localities may or may not be indicative of conditions favoring
the establishment of races and/or species. Here it probably is. In
the case of populations occupying isolated montane areas, where the

Dec. 16, 1963 herpetofauna of death valley 127

duration of isolation may be inferred fairly accurately (i.e., from
the Pleistocene recession of surrounding bodies of water), a compari-
son of such isolates may throw light on the rate at which morpho-
logical differences may become established. It is, of course, impor-
tant to know that presumably disjunct populations are indeed
genetically isolated.

We may also look ahead to future modifications of the desert
areas of southeastern California, which will be subjected to con-
tinued exploitation in coming years. The encroachments are al-
ready of dismaying extent. While Death Valley National Monu-
ment is set aside as a preserve, the area has had large in-holdings
and provisions for multiple use by individuals and mining con-
cerns. Extensive records compiled now may be useful in evaluating
the impact of heavier visitor use, or of construction and mining
activity. Even since 1920, we may infer from Grinnell's notes that
the area around Furnace Creek Ranch has been markedly changed.
Although there has been no intention of maintaining this area un-
der natural conditions, it serves as an example of how the original
reptilian fauna has been impoverished. Grinnell recorded Cro-
taphytus collaris^ Phrynosoma, Dipsosaurus, Cnemidophorus, Cal-
lisaurus and Uta, but only Uta remains in large numbers.

While the geographic limits of reptilian distributions are im-
posed by broad climatic regimes, the most difficult problems in-
volve an explanation of the discontinuities within such overall
ranges. The occurrence of some species is clearly linked with some
attribute of the physical environment. An excellent example is
afforded by the species of the genus Uma, which has been nicely
treated by Norris (1958). Here one limiting factor is an appropriate
substrate within the broad climatic limits suitable for the species.
Certain otherwise suitable sand deposits are not occupied because
of a lack of pathways for dispersal. Usually such problems are not
so easily resolved. Klauber (1939) discussed data on the activity
and distribution of snakes accumulated after some 100,000 miles of
driving in southeastern California, commenting on time of day and
year, temperature, moonlight, irrigation and habitat as factors in-
fluencing activity and distribution of snakes. Even after this, Klau-
ber could not draw unequivocal conclusions as to the causal rela-
tions between the distribution of snakes and their environment.

Sometimes the distribution of a reptile coincides closely with
that of a plant species, which is considered as an "indicator" for
a particular widespread climatic regime. Yet the concordance is
never perfect. There are places where the "indicator" occurs and
not the reptile; and vice versa. For example, Stebbins (1948) has
discussed the distribution of Xantusia vigilis and various species of
Yucca. These cases, at best, merely tell us that the tolerance range
of the animal is roughly comparable to that of the plant, and there
is no indication of what limiting factors may operate within the
range of the reptile, or upon what stage of the life cycle the limi-
tation is imposed. Around Death Valley, chuckwallas occur only

Tile Great Basin Naturalist
128 FREDERICK TURNER & ROLAND WAUER Vol. XXIII, NOS. 3-4

in areas wdth large rocks or where there are sizable crevices in the
walls of rocky canyons. The influence of vegetation, either as a
direct source of food for herbivorous lizards, or as food for arthro-
pods which are in turn eaten by carnivorous forms, has not been
investigated. Nor do we know how interspecific competition for
suitable shelter and basking sites, or possibly food, may influence
distribution.

Literature Cited

Klauber, L. M. 1931. Notes on the worm snakes of the south-
west, with descriptions of two new subspecies. Trans, of the San
Diego Soc. of Natural History No. 23:333-352.

. 1939. Studies of reptile life in the arid southwest. Bull.

Zool. Soc. San Diego No. 14:1-100.

Miller, Alden H. 1940. A Transition island in the Mohave
desert. Condor 42 (3): 161-163.

Norris, Kenneth. 1958. The evolution and systematics of the
iguanid genus Uma and its relation to the evolution of other
North American desert reptiles. Bull Amer. Nat. Hist. 114:251-
326.

Rodgers, Thomas L. and Henry S. Fitch. 1947. Variation in the
skinks (Reptilia: Lacertilia) of the skiltonianus group. Univ.
Cahf. Publ Zool. 48 (4): 169-220.

Schmidt, Karl P. 1953. A checklist of North American am-
phibians and reptiles. Amer. Soc. of Ichthyologists and Her-
petologists. 280 pp.

Stebbins, Robert C. 1948. New distributional records for Xantusia
vigilis with observations on its habitat. Amer. Midi. Nat. 39
(1):96-101.

. 1954. Amphibians and reptiles of western North Ameri-
ca. McGraw-Hill: New York. 528 pp.

1958. A new alligator lizard from the Panamint Moun-

tains, Inyo County, California. Amer. Mus. Nov. 1883:1-27.

Stejneger, L. 1893. Annotated list of reptiles and batrachians
collected by the Death Valley Expedition in 1891, with de-
scriptions of new species. North Amer. Fauna No. 7:159-228.

Turner, Frederick B. 1959a. Some features of the ecology of
Bufo punctatus in Death Valley, California. Ecology 40(2):
175-181.

. 1959b. New localities for Lichanura roseofusca gracia

in Inyo County. California. Copeia 1959 (2): 172.

1959c. Xantusia v. vigilis in Death Valley National

Monument. Copeia 1959(2) : 172-173.
Wauer, Roland H. 1962. A survey of the birds of Death Valley.
Condor 64 (3): 220-233.

THE SYSTEMATICS OF CROTAPHYTUS WISLIZENI,
THE LEOPARD LIZARDS

PART I

A REDESCRIPl ION OF CROTAPHYTUS WISLIZENI

WISLIZENI Baird and Girard,

AND A DESCRIPIION OF A NEW SUBSPECIES FROM THE

UPPER COLORADO RIVER BASIN^

Wilmer W. Tanner and Benjamin H. Banta*

One group of North American iguanid lizards to receive slight
consideration for systematic studies has been the leopard lizard,
Crotaphytus wislizeni. This species has a wide distribution occur-
ring in most of the arid and semi-arid basins of western North
America, i.e.. Great Basin, Upper Colorado River Basin [Painted
Desert]. Mojave Desert, San Joaquin Valley of central California,
Colorado Desert, Sonora Desert, Chihuahua Desert, peninsular, and
to a limited extent, insular Baja California. Throughout this ex-
tensive area, populations of C. wislizeni occur on the brushy low
lands of the valleys, low foothills, and alluvial fans, seldom being
found at elevations exceeding 6000 feet above sea level. In con-
trast to Crotaphytus collaris, the collared lizard, C. wislizeni is not
restricted to rocky rough areas, but occurs where the soils are
sandy or of loose gravel. Perhaps the densest populations are found
in areas where rodent burrows have provided numerous holes for
escape as well as underground tunnels used for shelter (aestivation
and hibernation) and perhaps nesting.

We have been amazed that such a large, attractive lizard
should escape the attention of systematic herpetologists for so long
a time. Since April 1852, when Baird and Girard published the
original description, not a single major study has been published
on this species. Stejneger (1893) discussed the question of wislizeni
and silus, but was apparently limited by insufficient material. Cope
(1900), with the same material available as Stejneger, concluded by
placing silus as a subspecies of wislizeni. Van Denburgh (1922),
with additional material from the San Joaquin Valley, was able to
describe the juvenile color pattern of silus, but did not attack the
major problem associated with the variable adult patterns of other
populations. Smith (1946) recognized the need to determine if
silus is a valid species or a subspecies of wislizeni. His retention
of silus as a subpecies of wislizeni, following the check list of
Stejneger and Barbour (1943), left the problem essentially as it
had been for many years.

1. Partial support for this study was provided by a grant from the Johnson Fund of the
American Philosophical Society and from the Atomic Energy Commission Grant number AT
(11-1) 819.

• Bnghani Young University, Provo, Utah, and Colorado College, Colorado Springs, Colorado.

129

The Great Basin Naturalist
130 WILMER TANNER & BENJAMIN BANTA Vol. XXIII, NOS. 3-4

This study originated out of an extension of recent efforts
which included this species in the Great Basin (Banta, 1963) and
the Upper Colorado River Basin (Tanner. 1963). During our in-
dependent studies, opportunities were afforded each of us to make
comparisons of the wislizeni populations from the Great Basin and
adjacent areas to the south and east. Resulting from these studies
were the independent realizations of the existence of a distinct
population of leopard lizards in the Upper Colorado River Basin of
eastern Utah and the adjacent states to the east and south, as well
as the need to re-define Crotaphytus wislizeni wislizeni.

Crotaphytus wislizeni was originally described by Baird and
Girard in April 1852 with the type locality listed as "near Santa
Fe, New Mexico." Since then the following names have been
proposed: C. gambeli Baird and Girard, 1852, type locality, "Calif-
ornia"; C. fasciatus Hallowell, 1852, type locality, "Jornada del
Muerte, New Mexico"-; C. copeii Yarrow, 1882, type locality,
La Paz, Baja California Sur, Mexico; C. silus Stejneger, 1890, type
locality, Fresno. California; C. fasciatus Mocquard, 1899, type
locality. La Palmas. Baja California, Mexico.

Included in the synonomy of Crotaphytus wislizeni of Cope
(1900:225) is "Leisosaurus hallowellii Aug. Dumeril, vol. 8, 1856,
p. 533, note 1." We are unable to determine the reason for this
inclusion by Cope. We have checked the Dumeril report and find
that the name Leiosaurus haUowelU was proposed as another name
for L. fasciatus, and although there were discussions of the similari-
ties and differences between Leiosaurus and Crotaphytus, nowhere
did he synonymize Crotaphytus with Leiosaurus. Guibe (1954:50)
also lists Leiosaurus fasciatus Dumeril and Bibron, 1837, Erpet.
Gen.. IV, p. 244, but does not mention L. hallowelli.

Baird (1858:253). in the original description of Crotaphytus
reticulatus, states that it (reticulatus) is "more closely related to
Crotaphytus collaris than to Crotaphytus (Gambelia) wislizeni."
These same words were repeated by Baird in 1959.^ The use of
Gambelia as a genus rather than as a subgenus for the leopard
lizard was first applied by Smith in 1946. However, this was not
widely accepted and Schmidt (1953:117) retained all species in
the genus Crotaphytus. Robison and Tanner (1962) after examin-
ing the skeleton and the muscles of the pectoral girdle, throat, and
head of C. collaris, C. reticulatus and C. wislizeni, were also opposed
to the raising of Gambelia to full generic status. They found that
many of the morphological differences existing between collaris
and wislizeni are intermediate in reticulatus thus indicating a
strong genetic, and. consequently, generic relationship between
these three species. Although we believe that Baird's arrangement
(i.e., Gambelia as a subgenus of Crotaphytus to include the leopard

1. Eacli of the above names. uisli:rni. gnuifx'U. aiiti fnsrialtis. were clesirilied in the same
volume of the same journal (Proceedings. Arademy of National Sciences of Philadelphia, vol 6,
on pages 69 (April), 126 (August'l. 207 (December), respectively.

5. Smith 11946:159} cites Baird i 1857:7) as the original description of Gambelia.

Dec. 16, 1963 systematics of leopard lizards 131

lizards) should stand, further comparative consideration may be
fruitful; we can not, however, pursue it further in this account.

The mutual and almost simultaneous recognition of this prob-
lem prompted us to unite our efforts toward an eventual major re-
vision of this species complex. A start was made by comparing
samples from the Great Basin with samples from the Upper Colo-
rado River Basin and these in turn with samples from populations
to the south. Such preliminary studies provided data which sug-
gested a greater degree of variation in this species than has been
previously indicated.

We are not yet prepared to present data covering all segments
of the leopard lizard species complex. However, we have seen and
examined most of the types (except Crotaphytus (fasciatus) fascio-
latus Mocquard in the Paris Museum), particularly those types
which effect our deliberations concerning populations occurring out-
side of Baja California. Within the United States, four subspecies
of Crotaphytus wisUzeni seem certain, but before we can determine
the designations for the western populations certain nomenclatural
problems must be resolved.

We have found that those populations occurring in the Rio
Grande Valley of New Mexico and the Upper Colorado River Basin
of Utah and Colorado present no major nomenclatural problems, and
since both are very distinct, only these two populations wall be
considered in this report.

Acknowledgments. Some aspects of this study were begun
by the junior author during the tenure of a grant from the National
Science Foundation to the Department of Amphibians and Rep-
tiles, California Academy of Sciences (CAS). The examination
of type specimens was facilitated by a grant from the Johnson Fund
of the American Philosophical Society. The type and many para-
types of C. IV. punctatus now deposited in the collections at Brig-
ham Young University, (BYU). were obtained during field work
conducted by the senior author with support of Atomic Energy
Commission, Grant AT(11-1 )-819. We are indebted to Dr. Alan E.
Leviton for the photograph of the type specimen C. fasciatus, fig.
2, and to Mr. Maurice Giles of the California Academy of Sciences
for the photographs comprising figs. 1, and 3 through 5.

For assistance offered to examine material, we wish to thank
Dr. Richard G. Zweifel, American Museum of Natural History
(AMNH); Dr. James Bohlke, Mr. Roger Conant, and Mr. Edmond
V. Malnate. Academy of Natural Sciences of Philadelphia (ANSP);
Dr. Doris M. Cochran, United States National Museum (USNM);
Mr. Neil Richmond and Dr. M. Graham Netting, Carnegie
Museum of Pittsburgh (CM); Dr. Robert F. Inger. Chicago Natural
History Museum (CNHM); Dr. George S. Myers. Division of Sys-
tematic Biology, Stanford University (SU); Mr. Robert G. Crippen
and Dr. Robert C. Stebbins, Museum of Vertebrate Zoology, Uni-
versity of California at Berkeley (MVZ); Dr. Laurence M. Klau-
ber, San Diego Natural History Museum (SDNHM); Dr. Alan

The Great Basin Naturalist
132 WILMER TANNER & BENJAMIN BANTA Vol. XXIII. NoS. 3-4

E. Leviton, California Academy of Sciences (CAS); Dr. James R.
Dixon, New Mexico State University (NMSU); and Dr. Frederick
A. Shannon (FAS), Wickenburg, Arizona.

Genus Crotaphytus Holbrook

Subgenus Gambelia Baird

Crotaphytus wislizeni wislizeni Baird and Girard

Rio Grande Valley Leopard Lizard
(Figures 1 - 2)

Crotaphytus wislizenii Baird and Girard, 1852, Proceedings, Aca-
demy of Natural Sciences of Philadelphia, 6:69,^ type locality, near
Santa Fe, New Mexico; Baird and Girard, 1852, in Stansbury:
340-341, pi. 3.

Crotaphytus fasciatus Hallowell, 1852: 207-8.
Gambelia wislizeni wislizeni Smith, 1946:159.
Gambelia wislizenii wislizenii Cochran. 1961:105.
Crotaphytus wislizeni wislizeni (new combination) Schmidt, 1953:
117.

Type. USNM 2685. (See Remarks).

Range. Throughout the Rio Grande Valley of western Texas,
northwestern Coahuila, northeastern Chihuahua, and central New
Mexico, northwest to near the Utah-Arizona line, west through
central and southern Arizona and northern Sonora to the Colo-
rado River.

Diagnosis. Distinguished from all other C. wislizeni by several
rows of large dark brown dorsal and lateral spots, each with a
circle of white dots at or near the outer margin. In adults the
light cross bands have faded or have developed into a series of small
dots, often included as a part of the circular margin of the spots.
The two median rows of brown spots are large, only one spot be-
between the dorsal cross bands and romid to ovoidal in shape. Post-
mentals usually four but ranging from two to six.

Description of Subspecies. Scales on the body and head
smooth, not imbricate; 30 to 50 dorsal, and all ventral scale rows
enlarged; lateral scales small, beadlike; basal tail scales smooth,
but becoming keeled and spined posteriorly; scales on dorsum
of head only slightly enlarged and platelike; supralabials 12
(14.1) 16 ^; infralabials 11 (13.85) 16; dorsals (parietal to base of
tail) 179 (196.84) 223; scales at midbody 149 (167.8) 185; ven-
trals 90 (101.04) 117; femoral pores 18 (20.61) 25, each pore en-

4. Cnpe (190n. p. 255 cites the article in volume (i nf the PixxreHings of the .\cademy of
Natural Sciences of Philadelphia as the original description. However, beginning with the first
edition of the check list of North American aniphibans and reptiles by Stejneger and Barbour
(1917) and continuing through all their editions (1923, 1933. 1939. 19431 the description in the
Stansbury report is credited as the orgLnal. Smith and Taylor (1950), Schmidt (1953) and
Cochran (1961) continued this erroneous usage. See discussion under Remarks.

5. Minmium range (.mean m parentheses) maximum range.

Dec. 16, 1963 system atics of leopard lizards

133

tered posteriorly by one to three small scales; usually four post-
mentals, 2 (4.25) 6; gulars small and beadlike.

Head distinct, 22-30 mm. long (base of skull to snout) and
15-20 mm. wide; total length up to 400 mm.; snout to vent lengths
40 (recent hatchling) to 125 mm. in large adult; tail long. 65 to 70
per cent of total length; longest toe in adults (snout-vent of 100
mm. or more) 30 to 40 mm.

The color pattern consists of a juvenile and an adult phase. Both
are distinct although variable, and will therefore be described
separately.

Juvenile Pattern. A series of 7 to 9 well defined cream
or white transverse bars occur in parallel sequence extending from
the nape to the base of the tail; these bars may be straight, zigzag,
or broken medially; dorsolaterally and laterally there are two series
of white spots, often appearing as short bars, parallel or alternate

Figure 1. Crotaphytus wislizeni wislizeni showing the diagnostic dorsal pattern
reproduced from plate 31 of Baird (1859). These drawings were listed as based
on United States National Museum specimen 2685 by Baird (1859, p. 7) col-
lected from "Sonora" by "Col. J. D. Graham, U. S. A." The caption from Baird
(p. 35) states. "Plate XXXI. Figs. 1-8. - Crotaphylus (sic.) wislizenii, B. & G.
No. 2685. - Fig. 1, animal; fig. 2, head from above; fig. 3, head from the side;
fig. 4, inferior surface of body; fig. 5, a fore finger from the side; fig. 6, a
hind toe from the side; fig. 7, dorsal scales; fig. 8, a femoral pore. All
magnified, except figs. 1 and 4."

The Great Basin Naturalist
134 WILMER TANNER & BENJAMIN BANTA Vol. XXIII, NoS. 3-4

with dorsal bars; tail and hind legs also with white bars; white
body bars one half to one millimeter long and encompassing 3 to 4
scales in a row; between the transverse bars, and lateral to mid-
dorsal line, round brown spots form two rows of 7 to 9 spots on
body; lateral spots of irregular size and position; dorsal spots oc-
cupy approximately one half of distance between transverse bars.
On the posterior margins of white bars, two small dark half cir-
cular spots develop immediately anterior to large median spots be-
coming proportionately smaller in older juveniles and adults; in
specimens ranging from 50 - 55 mm. in snout-vent length, a light
circle forms around dark median spots; this light circle develops
into a circular band of light dots in older lizards. The first ade-
quate description of the juvenile pattern was provided by Ruthven
(1907:516).

Adult Pattern. Transverse bars between nape and base
of tail reduced in width to form narrow stripes, 1 to 2 scales across,
or obliterated, usually irregular and confused with other light mark-
ings; dorsomedial dark spots large, usually occupying at midbody
more than half of distance between transverse bars; usually four
rows of smaller lateral spots, and one or two small spots between
large medial spots and anterior transverse bar. Around each of
spots, medial and usually in the first two or three lateral rows of
spots, a conspicuous circle of small white dots (2 to 4 scales in each
dot) occur at or near the outer edge; head and tail spots not so
encircled; transverse white bars often forming a portion of dotted
circles and tending to become more obscure. Ground color grayish
brown, light to medium brown or dark brown; ground color vari-
able, reflecting age and population differences.

Specimens Examined. A total of 96 as follows: ARIZONA:
Cochise County. 0.9 miles Southwest of Portal (MVZ) 67023);
31 miles Southwest of Portal (MVZ 6707;). Gila County. Gila
River (USNM 22130). Maricopa County-. 2 miles Southwest of
Morristown (FAS 6701); 0.75 miles north of Morristown (FAS
6748); Paradise Valley (CAS 17238); 1.5 miles Southwest of Wick-
enburg (FAS 1355, 1496 and 7502); 3.5 miles Southwest of Wicken-
burg (FAS 1456); 9 miles West of, 4 miles North of Wickenburg
(FAS 12314); Divide, 11 miles West of Wickenburg (FAS 12772);
Winter's Well, 15 miles Northwest of Palo Verde (USNM 1474-5).
Mohave County. Dolan's Spring (MVZ 16020); 0.5 miles West of
Hackberry (FAS 7359-61); 7.6 miles north of Wickieup (FAS
16023). Pima County. Santa Catalina Mountains (CAS 34320); 9
miles south of Ago (FAS 4849); Tucson (USNM 17180. 19698.
FAS 276); Turner's Tanks (USNM 60106); no specific locality
(USNM 61378). Yavapai County. 10 miles northeast of Aguila
(FAS 3008. 15612 and 15614); 9.8 miles northwest of Congress
(FAS 11590); 6 miles northwest of Wickenburg (FAS 3442).
Yuma County. Papago Wells (CAS 34204-8); Yuma (CAS 33486
and 33490).

Dec. 16, 1963 systematics of leopard lizards

135

NEW MEXICO: Bernalillo County: Albuquerque (SU 11798-
11801; USN.M 37961, 38054, 58304-5). Dona Ana County: Las
Cruces (USNM 22267, NMSU 1489 and R-9); College Ranch near
Mexico (NMSU R-3 and R-63); Red Lake, 41 miles north of Las
Cruces (NMSU 271-2); 7 miles north of Hwy. 80 (NMSU, 1488);
5.5 miles north of Radium Springs (NMSU 2047); 1.4 miles west
of Intersection Hwy 359 (NMSU 1487). Hidalgo County: Hachita
USNM 45067 and 45105); 27 miles north of Rodeo (MVZ
67164). Luna County: 0.5 miles east of Columbus (CNHM
51771); Deming (USNM 44956). Santa Fe County: near Santa Fe
(USNM type and 8475). Valencia County: near Grants (SU
5043-4); Laguna (USNM 4274).

TEXAS: El Paso County: El Paso (CAS 74036). Hudspeth
County: Ft. Hancock (USNM 20668); 7 miles southwest of Mc-
Nary (NMSU 2070). Reeve County: 20 miles east of Toyahvale
(USNM 32843-4); Pecos River (USNM 5064).

MEXICO: Chihuahua: 1 mile south of Ahumada (USNM
104738-40); 6 miles southwest of Rancho Maria (USNM 10471);
Rancho Maria, Near Progresso (USNM 104741-50); Santa Maria
(CNHM 1639); Lake Santa Maria (USNM 47414); no specific
locality (USNM 58036). Sonora: 5 miles northeast of Libertad
(CM 4810); northwestern Sonora (USNM 2685 and 431830);
Tiburon Island, Gulf of Cahfornia (SU 17049-50; USNM 64464).

ovIfiN^ ?■ P°^^^^ V^w of type specimen of Crotaphytus fasciatus (USNM)
^/6b) showing Its dorsal pattern identical to Crotaphytus wislizeni wislizeni.

The Great Basin Naturalist
136 WILMER TANNER & BENJAMIN BANTA Vol. XXIII, NOS. 3-4

Remarks: The original description of this species first ap-
peared as a short prehminary note in April, 1852, and is quoted in
its entirety as follows:

'VROTAPHYTUS WISLIZENII, B. and G. — Head pro-
portionally narrow and elongated; cephalic plates and scales on the
back very small; yellowish, brown, spotted all over wdth small
patches of deeper brown or black. Caught near Santa Fe, by Dr.
Wislizenius (sic); specimens of the same species sent in by Lieut.
Col. L. D. Graham, collected between San Antonio and El Paso
del Norte."

At the beginning of the article containing this description is
the following statement: "Full description and figures of these
species will shortly appear in Capt. Stansbury's Report to Congress
on the great (sic.) Salt Lake (Utah)." As previously stated. Cope
(1900:255) was obviously correct in assigning the original de-
scription to the April 1852 Proceedings article. The more detailed
account in the Stansbury report followed several months later.

The description in the Stansbury Report (1852:340) is general
and basically concerned with body proportions and color pattern
differences between C. collaris and C. wislizeni. Although one of
the basic dorsal color pattern differences in wislizeni is not includ-
ed in the original description, Baird (1859, plate 31) does show the
circle of white spots surrounding each of the large brown spots.
This is based upon a specimen from "Sonora," Mexico, (see figure
1 which we have designated as the lectotype). This character was
later recognized, in part at least, and reported in the description of
Crotaphytus gambeli by Baird and Girard in August 1852:126 as
follows: "The general distribution of color is the same as in C.
wislizenii; the only difference consists in the absence of the small
yellowish white dots spread all over the body of the latter species.
The transverse yellowish markings appear also to be more con-
spicuous."

There is a question as to whether or not the designation of
USNM 2770 is correct. Cochran (1961:105) was apparently aware
of this problem as she quoted the following from the "original de-
scription:" "Figured specimen caught near Santa Fe. New Mexico,
by Dr. Wislizenus." This is a misquote, and should correctly read,
"Caught near Santa Fe, by Dr. Wislizenius." Dr. Wislizenus' name
was misspelled in the original description and the misspelling was
not listed on the "Errata in Vol. VI" of the Proceedings of the
Philadelphia Academy. In the more detailed description that ap-
peared later in the Stansbury Report, the name was spelled correct-
ly stating. "The specimen which we have figured was caught near
Santa Fe. by Dr. Wislizenus, during the Mexican War." The
holotype of Crotaphytus wislizeni is listed bv Yarrow (1882:53);
Cope, (1900:258); Smith and Taylor (1950:^94); Cochran (1961:
105) as USNM 2770, collected at "Colorado" by H. Baldwin Moll-
hausen, no date given. Mollhausen was one of two naturalists (the
other being Dr. C B. R. Kennerly) attached to the survey of the

Dec. 16, 1963 system atics of leopard lizards

137

Pacific Railroad Route, under the command of Lt. A. W. Whipple
in 1853-1854, (after C. wislizeni was described). Yarrow (1882:53)
apparently was the first to designate holotypes for the United States
National Museum collections and the designation of USNM 2770
as the type must be attributed to him.

The type mentioned, but not designated by Baird and Girard,
as obtained by Dr. Wislizenus has presumably been destroyed, ac-
cording to a recent letter from Dr. Doris M. Cochran. This animal
must have been collected around the end of June or early July
of 1846. We have checked Wislizenus' account (1848) of his

Figure 3. Dorsal view of the adult pattern of Crotaphytus wislizeni wislizeni

based upon a specimen from Cochise County, Arizona.

journey across New Mexico, Texas, and Chihuahua, and were un-
able to find any reference to the specific collection of any reptiles,
let alone of a leopard lizard. Since no type specimens were desig-
nated in the original and subsequent descriptions, and since the
allusion to the specimen obtained by Mollhausen is an obvious
error, we must of necessity designate another type specimen. In
the original description Baird and Girard stated, "specimens of the
same species sent in by Lieut. Col. J. D. Graham, collected between
San Antonio and El Paso del Norte." Baird (1859, plate 31) was

The Great Basin Naturalist
138 WILMER TAXXER & BEXJAMIN BAXTA Vol. XXIII. NoS. 3-4

the first one to actually show the dorsal color pattern of C. w.
wislizeni based upon USXM 2685 from "Sonora" obtained by
"Col. J. D. Graham. U.S. A/' Because this specimen is still avail-
able in the collections of the United States National Museum and
owing to the fact that specimens from "between San Antonio and
El Paso del X'orte" obtained by Colonel Graham were mentioned
in the original description, we take the liberty of designating
USXM 2685 as the holotype for C. wislizeni wislizeni. This is ne-
cessitated by the fact that the allusion to the specimen obtained by
Mollhausen, USXM 2770 as the t]v-pe, is an ob\-ious error.

We are aware of the problems involved in specifically desig-
nating localities listed by the early survey reports. Areas included
in Sonora. Utah, etc., do not have the same boundaries today. It is
common knowledge that the names of many areas have been
changed with the advance of histor\' and what was once alluded to
as "Sonora" in the 1850"s may now be portions of Xew Mexico,
Arizona, Chihuahua or Sonora. Although the state of Sonora.
Mexico, as it is now constituted, is included in the range of Crota-
phytus w. wislizeni. it is questionable that any of the tv'pe series
used by Baird and Girard were actually collected in Sonora as
recognized todav.

Other studies Van Denburgh. 1922. pi. 8: Smith 1946. p. 160,
pi. 30 y have shown the color pattern as described above, but seem-
ingly have not recognized its significance. Ruthven (1907. p. 516)
perhaps came closest to describing the pattern of the circle of
white dots around the darker and larger spots in specimens of
Crotaphytus wislizeni wislizeni from Alamogordo. X'ew Mexico,
and Tucson. Arizona, than any previous author. f^Fig. 3).

Crotaphytus wislizeni punctatus. new subspecies

Small Spotted Leopard Lizard

(Figures 4-5)

Type. An adult female. BYU 20928. taken in the Yellow Cat
mining District approximately 10 miles south of L'.S. Highway
50-6, Grand County, Utah, by Wilmer W. Tanner on 28 June 1961.

Paratypes. COLORADO: Mesa County-. Grand Junction
(USXM 44793-5 . UTAH: Emery County: approximatelv 15
miles northwest of Hanks\-ille ^BYU 16497 and 20931-3); Green
River (CAS 38376 ;: 25 miles northwest of Hanks%-ille ^BYU 14913; ;
5 miles west of Temple Mountain Junction (BYU 20934-9; CAS
92466-9 and 93358;. Garfield County: Star Spring rBYU 12846);
one mile east of Star Spring ^BYU 11742 and 12187): mouth of
North Wash ^BYU 12558): Trachyte Creek at Junction of Utah
Highwav 95 BYU 12614-17;: six miles south of Wa^-ne-Garfield
countv line on L'tah Highwav 95 (BYU 12685). Grand County: 10
miles "south of Cisco (BYC 12857. 12859-600): Castle Vallev ^BYU
12853): Moab ^BYU 11363j: Arches National Monument (BYU
9040-1. 10243 and CM 20765-6. CXTJM 62810): Yellow Cat Mine

Dec. 16, 1963 systematics of leopard lizards

139

(BYU 20610 and 20920-30); Thompson (CAS 38217-34, 41131,
41133-5); Elgin (CAS 3834'3A) ; Kane County. Hall Cave (BYU 122,
924-8); 15 miles northwest of Hole-in-the-Rock (BYU 11271); Lone
Rock (BYU 11325. 12008 and 14981); Willow Spring tank (BYU
114); Catstare Canyon (BYU 11347-8. 11329-30, 11378-81, 12186,
and 12873); Crossing of the Fathers (BYU 14912). San Juan Coun-
ty. Bluff (BYU 482); Navajo Mountain Trading Post (BYU 12554);
Green Water Spring (BYU 16751); Montezuma Creek (BYU 16797-
8); Copper Canyon, 3 miles north of old mine (MVZ 21792).
Wayne Cow^O': 'Hanksville (BYU 8396-7).

Other Materlal. ARIZONA: Coconino County. W^ahweap
Creek (MVZ 21793); one mile west of Glen Canyon Dam (BYU
18920); 16 miles west of Marble Canyon Bridge^ (MVZ 16383);
Marble Canyon (BYU 556); Tuba City (BYU 555 and MVZ 8663).
Navajo County: Joseph City (BYU 12782-3). UTAH: San Juan
County: two miles above mouth of Nokai Creek (CNHM 37419).
Sevier County: two miles south of Joseph (MVZ 49711-2). Wash-
ington County: Ivans (BYU 6801); Saint George (BYU 515 and
1635).

Diagnosis. Similar in habits to other adjacent populations
of Crotaphytus wislizeni but distinct in having a dorsal color pat-

. . V •- "Taj * ■•-''' »

V

Figure 4. A. Dorsal view of holotype of Crotaphytus wislizeni punctatus
(BYU20928). B. Ventral view of holotype.

The Great Basin Naturalist
140 WILMER TANNER & BENJAMIN BANTA Vol. XXIII, NOS. 3-4

tern of numerous, small, round brown spots on a background of
light brownish gray and with the transverse bars reduced to nar-
row or faint lines in adults. In contrast to some populations occur-
ring in the Great Basin and Baja California to the west and south-
west, to all C. w. wislizeni in Arizona, New Mexico and northern
mainland Mexico, the dorsal brown spots are not encircled by
white or cream colored spots at or near their margins. Only a
limited degree of dorsal pattern polymorphism seems to occur.
(see fig. 5). Furthermore, C. w. punctatus is distinct from all other
subspecies in having an increase in posttnentals from 4 to 6. (see
fig. 6).

Description of Type. An adult female, snout vent 104.5,
total length 309.5 mm., tail into total length .6624; orbit to ros-
tral 8.3; orbit to ear 9.2; dorsal scales (occipital scale to base of
tail) 212; ventrals 102, noticeably larger than laterals and dorsals;
scales around middle of body 175; middorsal rows only slightly en-
larged, beadlike; supralabials 17-18; infralabials 15-16; femoral
pores 22-23; one to three usually two. small scales contacting pores
posteriorly; dorsal head scales from rostral to occiput 22; post-
mentals 4 right side, 3 left side, 7 total; scales on anterior half
of tail smooth, posteriorly keeled but not spinous. Head scales
smooth and platelike, some raised medially, none imbricate; gular
scales elongate anteriorly, becoming rounded and beadlike before
and at the gular fold; ventrals enlarged, imbricate and in approxi-
mately 35 longitudinal rows.

Head distinct, 24.8 mm. long, 20.5 wide; body slightly flatten-
ed, wider than high; longest toe 20.0 mm. Color pattern consist-
ing of a series of nine transverse bars from neck to base of tail,
greatly faded, not distinct anteriorly; dorsal and lateral spots small,
involving 7 to 16 scales; 10 to 12 spots on one side between two
transverse bars; lateral spots smallest, tail with two dorsal and two
lateral rows of spots, larger than body spots and becoming pro-
gressively larger posteriorly until they fuse to form black and white
rings; gular region marked with seven parallel dark stripes extend-
ing from labials to near gular fold where they terminate; dorsum
of hind legs spotted and colored as body; front legs with gray body
color but wdthout spots; body ground color gray (see remarks);
brown spots distinct.

Range. Upper Colorado River Basin in Utah from Uintah
County through Emery to Kane and Washington counties on the
west and south; southeast through western Colorado to northwest-
em New Mexico and west along the northern edge of Arizona
(north of the Little Colorado and the Colorado River at least to
Toroweap in Mohave County) .

Remarks. The dorsal pattern in the subspecies of C. wislizeni
appears to have four important variables in the adults: (1) the
general background color; (2) number and size of dorsal dark

Dec. 16, 1963 system atics of leopard lizards

141

spots; (3) the size of the dorsal transverse bars; and (4) the pre-
sence or absence of other dorsal markings such as the fine light
dots surrounding the brown spots in C. w. wislizeni.

Based upon the tliree subspecies now recognized the following
remarks are appropriate. The background color is lightest in C. w.
punctatus and darkest in C. w. silus. In the latter the scales are
mostly dark brown or tending toward black, but in C. w. wislizeni
there are lighter shades and a tendency for the base of each scale
(not included in a brown spot) and the skin between scales, to be
much lighter than the crown. In C. w. punctatus, this is carried
still further in some specimens with only the top of each scale pig-
mented. This produces a blending or fusion of the basal white and

»«
•^

C
^

^^

Figure 5. The limited range of dorsal pattern polymorphism of Crotaphytus
wislizeni punctatus as indicated by a portion of the paratypic series from
Thompson, Grand County, Utah.

the dark dot on the crown of each scale into a gray or brownish
ground color. This factor, in addition to (or combined with) the
size of the dorsal spots, determines in a general way whether the
lizard will have a dark (silus) or light (punctatus) appearance.
The light colored appearance of other segments of the Upper Colo-
rado River herpetofauna was first commented upon by Van Den-
burg (1922).

The number of spots is perhaps not as variable as their size,
although in punctatus the spots are not only smaller but also more
numerous than in wislizeni. A comparison of wislizeni with speci-
mens from Nevada and California, including silus, indicates that

142

The Great Basin Naturalist
WILMER TANNER & BENJAMIN BANTA Vol. XXIII, NoS. 3-4

60-
55 —
50—
45—

15 —
10—
5—

25-

>20—

4 5 6 7
NUMBER OF POSTMENTALS

PUNCTATUS

AVG. 4.15

2 3 4 5 6
NUMBER OF POSTMENTALS

Figure 6. Histograms showing the numbers of postmentals in A.. C. w. wislizeni
and B, C. W . punctatus.

the size of spots rather than the number of spots is the variable.
This is also generally true for the transverse bars, with silus having
wide distinct bars and the eastern subspecies, punctatus and wis-
lizeni, narrow, faint (even to forming a discontinuous series of
dots), to a complete absence of the bars in old adults.

Perhaps the most ornate character in the dorsal pattern is the
development of the circle of white dots around the dark rust brown
spots. (Those having this character well developed, are. in our
opinion, one of temperate North America's most attractive and
beautiful lizards). This character is present in C. w. wislizeni as
we have defined it and has been observed in specimens from
northern Baja California (San Andreas), southern California and
extreme south and eastern Nevada. It may, therefore, be necessary
to extend the range of C. w. wislizeni to these areas as additional
material indicates more adequately the extent of the actual geo-
graphic ranges.

Specimens of C. w. punctatus from central Sevier County,
Utah, represent the only known records outside of the Colorado

Dec. 16, 1963 systematics of leopard lizards 143

River Basin. Their occurrence here is not surprising for it is known
that other reptile species (e.g., Sceloporiis undulatus elongatus)
have penetrated the eastern margins of the Great Basin, presumably
through Salina Canyon.

Specimens seen from Washington County, Utah, are also
punctatus; however, a few specimens from the western part and
north along the Nevada line to Iron County show traces of the
white dots (see Van Denburgh 1922b, plate 8). There is also a
reduction in the postmentals with four being most common.

Intergradation between C. iv. punctatus and C. w. wisUzeni
also appears to occur in central Coconino County, Arizona. Speci-
mens from the Tuba City-Cameron area show faint but definite
tracings of the white circle of dots around the dark spots, but have
six postmentals and small spots and are considered to be closer to
C. w. punctatus.

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NEW LACEBUGS FROM THE EASTERN HEMISPHERE

Carl J. Drake'

The present paper describes six new species, two from the
Phihppines, two from Rhodesia, one from Jordan, and one from the
Ivory Coast. Unless recorded otherwise, beneath the description,
the types are in the Drake Collection (USNM). The author desires
to express his sincere appreciation to Miss Liza Biganzoli, Wash-
ington, D.C. for the fine illustrations.

Cysteochila pelates, new sp.
Figure 1

Small, oblong, brown with head black and cephalic spines
testaceous; body beneath with abdomen dark brown and thoracic
sterna blackish. Legs reddish brown with tibiae testaceous. An-
tennae with segments I and II brown. III testaceous, IV swollen
apically and mostly dark fuscous. Length 2.75 mm., width 0.80 mm.

Head very short, armed with five short spines; labium reach-
ing middle of mesosternum, sulcus open behind. Antenna slender,
indistinctly pilose, measurements: segment I, 0.11 mm.; II, 0.10
mm.; Ill, 0.70 mm.; IV, 0.20 mm. Pronotum moderately convex,
coarsely punctate, tricarinate. All carinae raised and non-areolate;
median carina percurrent; lateral pair concealed in front of middle
of disc by reflexed paranota, divergent posteriorly behind pronotal
disc; collar slightly raised at middle so as to form a small tectiform
hood; paranotum totally reflexed, covering anterior part of lateral
carinae, six areolae deep in wddest part; posterior triangular pro-
jection finely areolate.

Metathoracic scent glands with ostiole and ostiolar sulcus on
each metapleuron, the sulcus nearly vertical. Legs short, wdth
femora slightly swollen, indistinctly pubescent. Elytra scarcely
wider and only a little longer than abdomen, finely areolate, with
sutural area on same horizontal plane as discoidal area; costal area
absent; subcostal area narrow, vertical, biseriate; discoidal area
large, acutely angulate at base and apex, five areolae deep opposite
apex of hind projection of pronotum, acutely angulate at base and
apex; sutural areas overlapping with apices jointly rounded. Hind
wings as long as abdomen.

HoLOTYPE, macropterous d , Aquaba, Jordan, 3.V.1963, on
Acacia segal Del., collected by Dr. Hans Eckerlein. One paratype
cf, same data as type, in Eckerlein Collection. The holotype is
illustrated.

The small form, closely reticulated dorsal surface, and obsolete
costal areas separate this little species from its congeners.

1. Smithsonian Institution, Washington, D. C.

149

150

The Great Basin Naturalist
CARL J. DRAKE Vol. XXIII, Nos. 3-4

Fig. 1. Cysteochila pelates, new sp.

Cysteochila apheles, new sp.
Figure 2

Small, oblong, whitish testaceous with head dark brown; pro-
notal disc, posterior half of paranota, apex of backward projection
of pronotum, median carina on pronotal disc, crossband on elytra
(including most of discoidal area), apical part of costal area, and
entire sutural area brownish fuscous; bucculae brown with hind
margin testaceous; body beneath reddish brown. Sternal laminae

Dec. 16, 1963

EASTERN HEMISPHERE LACEBUGS

151

of rostral sulcus testaceous, rostrum brownish. Antennae brown,
with third segment brownish testaceous. Legs with coxae, tro-
chanters, and basal three-fourths of femora reddish brown, the
apices of femora and tibiae testaceous. Hind wings clouded with
fuscous. Length 2.50 mm.; width (elytra) 0.90 mm.

Head very short, armed with five testaceous spines, anterior
three spines porrect and hind pair appressed; eyes large, dark fus-
cous; bucculae wide, areolate. closed in front. Antenna slender,
moderately clothed with extremely short golden pubescence,

Fig. 2. Cysteochila apheles, new sp.

The Great Basin Naturalist

152 CARL J. DRAKE Vol. XXIII, Nos. 3-4

measurements: segment I, 0.11 mm.; II, 0.10 mm.; Ill, 0.64 mm.;
IV, 0.32 mm. Rostrum extending to base of mesosternum; laminae
of sulcus uniseriate; channel narrow, parallel on prosternum.
slightly wider and feebly divergent on mesoternum, much wider
and cordate on metasternum, closed behind. Ostiole and ostiolar
canal present on each metapleuron, channel almost vertical, the
sides elevated.

Pronotum moderately convex, punctate, areolate on backward
projection, tricarinate; median carina slightly more raised than
lateral pair, slightly higher, arched and clearly uniseriate on
pronotal disc; lateral carinae barely concealed by reflexed paranota
on pronotal disc, divergent posteriorly on triangular process. Hood
small, low, extending backwards between calli. slightly produced in
front; paranota very large, reflexed, feebly elevated opposite
humeral angle. Legs moderately long; femora little swollen,
sparsely clothed with short golden pubescence.

Elytra not much wider and scarcely longer than abdomen;
sutural areas overlapping each other with apices jointly rounded
in repose; costal area moderately wide, composed of two rows of
serially arranged areolae; subcostal area slightly narrower than
costal area, biseriate, gently sloping downwards; discoidal area
large, two thirds as long as elytra, acutely angulate at base and
apex, widest just behind middle, there five or six areolae deep.
Hypocostal ridge uniseriate, areolae small.

IIoLOTYPE, macropterous cT, San Jose, Mindora, Philippine Is-
lands, C. F.Baker.

Closely allied to the species described below, but easily
separated from it by the pale testaceous color and prominent
fuscous markings, longer antennae, and arched median carina on
pronotal disc. The holotype is illustrated.

Cysteochila aei, new sp.
Figure 3

Small, oblong, reddish brown with basal part of costal area up
to and then beyond median crossband to clouded apex brownish
testaceous; body beneath brown, shiny. Legs brow^i with tibiae
browaiish testaceous. Antenna brown with third segment brownish
testaceous and fourth fuscous. Length 2.50 mm.; wddth 0.95 mm.

Head very short, armed with five brown spines, anterior
three spines porrect. hind pair appressed; eyes large, dark fuscous;
bucculae very wdde. areolate, closed in front. Rostrrmi extending
to end of mesosternum, rostral laminae badly broken. Antenna
slender, rather sparsely clothed with inconspicuous, golden pubes-
cence, measurements: segment I, 0.10 mm.; II, 0.09 mm.; Ill, 0.75
mm.; IV. 0.34 mm. Ostiole and ostiolar channel of scent glands
present on each metapleuron. Legs slender, femora slightly swollen.

Pronotum moderately convex, punctate, tricarinate; median
carina more elevated on pronotal disc, there distinctly uniseriate,

Dec. 16, 1963 eastern hemisphere lacebugs

153

Fig. 3 Cysteochila aei, new sp.

areolae becoming indistinct on backward projection of pronotum;
lateral carinae concealed on pronotal disc by reflexed paranota, in-
distinctly areolate, slightly divergent posteriorly on triangular pro-
cess; paranota very large, reflexed, just covering lateral carinae
feebly elevated adjacent to humeral angles. Elytra with sutural
areas overlapping each other with apices overlapping and jointly
rounded in repose; costal area moderately wide, composed of two
rows of areolae; subcostal area shghtly narrower than costal area;
nearly vertical, biserate; discoidal area large, extending beyond mid-

The Great Basin Naturalist

154 CARL J. DRAKE Vol. XXIII. Nos. 3-4

die of elytron, acutely angulate at base and apex, widest behind
middle, there five or six areolae deep; sutural area on same hori-
zontal level as discoidal area. Hind wings not as long as fore pair,
densely clouded with fuscous.

HoLOTYPE, macropterous cf, Montalban, Luzon, Philippine Is-
lands, C. F. Baker.

The largely brown dorsal surface, brown femora, tectiform
hood, and less elevated median carina on pronotal disc, separate
this species from C. apheles.

Cysteochila epelys, new sp.
Figure 4

Oblong, wide, pale brown with head, hood, pronotum (except
hind projection), rear half of each paranotum, pronotal carinae,
median and subapical crossbands of elytra blackish fuscous; body
beneath brown with mesosternum black; sternal laminae of rostral
sulcus brownish testaceous. Legs with basal three-fourths of femora
reddish brown, tips of femora, tarsi and most of tibiae flavotesta-
ceous. Antenna with segments I and II dark brown. III brownish, IV
dark fuscous. Length, (S and ? 4.20 mm.; width d" 1.25 mm.; 9
1.35 mm.

Head short, armed with five short testaceous spines; bucculae
areolate. closed in front. Antenna moderately long, slender, incon-
spicuously clothed with short golden pubescence, measurements:
segement I, 0.15 mm.; II, 0.10 mm.; Ill, 0.90 mm.; IV, 0.38 mm.
Labium brown, reaching to metasternum; sulcal laminae wide,
uniseriate, parallel on mesosternum, more widely separated and
cordate on metasternum, open behind.

Pronotum wide, moderately convex, coarsely pitted, tricarinate,
each carina uniseriate; median carina more elevated than lateral
pair, highest on pronotal disc; lateral carinae divergent posteriorly,
concealed on pronotal disc by reflexed paranota; hood moderately
large, inflated, somewhat pyriform, produced backwards behind
calli on anterior part of pronotal disc; paranotimi very large, re-
flexed, resting on lateral carina, three rows of cells deep in upright
part and seven or eight in reflexed part; thoracic scent glands with
ostiole and sulcus on each metapleuron, sulcus vertical with sides
raised.

Elytra a little wider and longer than abdomen, sutural areas
overlapping each other in repose; costal area wide, composed of
two rows of moderately large areolae, the areolae clear except in
crossbands; subcostal area narrow, vertical, composed of two rows
of small, rounded areolae; discoidal area large, five-eighths as long
as elytron, four or five cells deep in widest part, acutely angulate
at base and apex; sutural area large, on same level as discoidal
area, with areolae fairly large and subequal in size to those in dis-
coidal area. Hind wings clouded with dark fuscous.

HoLOTYPE, macropterous cf, Abijan, Ivory Coast, French West

Dec. 16, 1963 eastern hemisphere lacebugs

155

Fig. 4. Cysteochila eyplys, new sp.

Africa. Jan. 1962, E. Laborve, in Paris Museum (fig. 4). Allotype,
macropterous 9, same data as type, Drake Collection (USNM).
The broad form, shape of hood, and coloration distinguish
epelys from its congeners described here.

Cysteochila cybele, new sp.

Oblong, rather broad, brown, without markings on reticulated
surface; head blackish with dorsal spines testaceous; body beneath
brown with mestosternum blackish. Antennae brown with fourth
segment swollen and mostly black. Legs yellowish brown with fe-

The Great Basin Naturalist

156 CARL J. DRAKE Vol. XXIII, Nos. 3-4

mora tending to be darker. Length 3.10-3.25 mm., width (middle of
elytra) 1.62 mm. Female usually slightly broader and more
obovate than male.

Head very short, armed with five long spines, anterior spines
porrect, basal pair recumbent; bucculae wide, areolate, closed in
front. Rostrum extending to base of mesosternum; laminae of
rostral sulcus uniseriate, with sulcus narrow and sides parallel on
mesosternum, wider and cordate on metasternum, ends of laminae
forming a v-shaped opening behind. Antenna slender, indistinctly
pubescent, fourth segment subclavate, measurements: segment I,
0.12 mm.; II, 0.10 mm.; Ill, 0.72 mm.; IV, 0.25 mm. Legs rather
short, indistinctly pubescent, femora only slightly swollen.

Pronotum broad, moderately swollen, rugulosely punctate,
tricarinate. all carinae raised, distinct, and non-areolate; median
carina percurrent; lateral pair completely concealed on pronotal
disc by reflexed paranota, divergent posteriorly on backward ex-
tension; hood very small, testiform, feebly projected forward at
middle; paranotum large, totally reflexed, extending inward slight-
ly farther than lateral carina, moderately clothed on lateral sides
by fine grayish hairs. Ostiole and ostiolar canal of metathoracic
scent glands very distinct on each metapleuron, with channel ver-
tical and sides raised.

Elytra wide, with sutural areas overlapping each other so that
their apices lie jointly rounded at rest, not much longer than
abdomen; costal area moderately wide, composed of one to almost
two complete rows of areolae, usually with outer row complete
and a partial inner row in basal third of area; subcostal area
mostly biseriate, nearly vertical, not as wide as costal area; dis-
coidal area large, almost three-fourths as long as elytron, with
areolae somewhat irregular and confused in arrangement, seven
or eight cells deep in widest part just behind middle; sutural area
large, on same horizontal level as discoidal area, areolae slightly
larger than those in discoidal area. Hind wings slightly shorter
than front pair, clouded with fuscous.

HoLOTYPE, cT and allotype, 9 , both macropterous, 30 miles
northeast of Kapar Mpashi, Northern Rhodesia, 9.V.1956, C. N.
Smithers. Paratypes: 9 specimens with same data as type.

The broader form, solid brown color, wider and hairy sides of
pronotum distinguish this species from its congeners described
herein. The costal area varies slightly in width and ranges all the
way from one to two full rows of areolae.

Leptopharsa ralla, new sp.

Very elongate, moderately widening posteriorly, widest across
apices of elytra, brownish testaceous with head, eyes and calli dark
fuscous; antennae testaceous with fourth segment almost entirely
blackish fuscous; legs testaceous with tips of tarsi blackish. Body
beneath brownish fuscous with rostral laminae whitish testaceous.

Dec. 16 1963 eastern hemisphere lacebugs

157

Length 3.70 mm.; width 0.75 mm. (pronotum) and 1.09 mm.
(across apices of elytra).

Head very short, slightly produced in front of eyes, armed
with five testaceous spines; three frontal spines short, tubercular;
hind pair long, appressed, extending forward to front margm of
eyes; bucculae wide, areolate, closed in front. Labium moderately
long,' testaceous, extending to base of mesostemum; rostral lammae

Fig. 5. Stephanitis subfasciata Horvath.

The Great Basin Naturalist

158 CARL J. DRAKE Vol. XXIII, Nos. 3-4

uniseriate, closed at base, the areolae moderately large. Antenna
very long, about five-sevenths as long as entire insect, measure-
ments: segment I, 0.32 mm.; II, 0.11 mm.; Ill, 0.80 mm.; IV, 0.38
mm. Ostiole and ostiolar canal of metathoracic scent glands present
on each metapleuron.

Protonum moderately convex, punctate, tricarinate; lateral
carinae slightly raised, slightly divergent anteriorly, indistinctly
areolate; median carina slightly more raised than lateral pair, per-
current, areolae a little larger and clearly visible in front of middle
of pronotal disc, the cells between calli fairly large; collar raised,
composed of two rows of areolae, without any indication of pronotal
hood; paranotum moderately wide, wider in front than behind,
composed of a single row of areolae; posterior process of pronotum
long, triangular, blunt at apex. Legs very long, slender; femora
not swollen.

Elytra narrow, very little wider but much longer than ab-
domen; costal area composed of one row of fairly large areolae;
subcostal area narrow, nearly vertical, mostly biseriate; discoidal
area elongate, acutely angulate at base and apex, widest near middle,
there four areolae deep, not quite reaching middle of elytron, sutural
areas large, overlapping each other. Hind wings extending a little
beyond apex of abdomen, not as long as elytra.

HoLOTYPE, macropterous d", Chirinda Forest, South Rhodesia,
6-8. VIII. 1957, C. N. Smithers. The elongate form, very long legs,
and very long antennae separate this species from African mem-
bers of the genus. The antennae are five-sevenths as long as the
entire length of the body.

Stephanitis subfasciata Horvath
Figure 5

Stephanitis subfasciata Horvath 1912, Ann. Mus. Nat. Hun-
garici, vol. 10, pp. 320, 325.

This species was originally described from China (Macao) and
Formosa (Takao). We have specimens from the iy^Q localities
(det. Horvath) plus other material from Java, Larat Island, Hong
Kong, and China (Foochow). The specimens from Larat have the
veinlets of hood and dorsal surface mostly reddish brown instead
of pale testaceous. A specimen from Larat is illustrated.

UNDESCRIBED SPECIES OF NEARCTIC TIPULIDAE
(DIPTERA). III.

Charles P. Alexander^

At this time I am characterizing various species of the genus
Tipula Linnaeus, derived from several sources, as follows: Two
species from California, discovered during the progress of a survey
of the cave fauna under the leadership of Mr. Richard E. Graham,
in collaboration with Dr. Willis J. Gertsch and Mr. R. de Saussure;
two further species from Maine and Newfoundland, taken by Mr.
David L. Carson and Dr. A. E. Brower; and a further very interest-
ing crane fly discovered by Mr. James Baker in the Steens Moun-
tains, Oregon. The disposition of the type specimens and further
acknowledgements are indicated in the text.

Tipula {Trichotipula) gertschi, n.sp.

General coloration of mesonotum dark brown, praescutum with
four obscure brownish yellow stripes; antennae of male relatively
long, flagellum dark brown; claws of male simple; wings faintly
darkened, stigma darker brown; macrotrichia in outer fourth of
cell /?5; no stigmal trichia; abdominal tergites dark brown, bases
restrictedly more yellowish; male hypopygium with tergal lobes
entirely without blackened spicules, ninth sternite with two pencils
of long black setae, inner dististyle with lower beak blackened.

Male. Length about 8 mm.; wing 9 mm.; antenna about 3.9
mm.

Female. Length about 12 mm.; wing 11.5 mm.

Frontal prolongation of head short and stout, the nasus vir-
tually lacking; dorsum brownish yellow, sides brownish black,
midventral area pale; palpi dark brown, terminal segment elongate,
brownish yellow. Antennae of male relatively long; scape and
pedicel slightly paler than the dark brown flagellum; flagellar
segments subcylindrical, the basal enlargements feebly indicated,
verticils shorter than the segments; terminal segment very small,
globular, about one-third the verticils. Head medium brown.

Pronotum obscure yellow, scutum restrictedly patterned with
pale brown. Mesonotal praescutum brown with four obscure
brownish yellow stripes, the intermediate pair slightly broader than
the dark median interspace, the latter narrowed to a point behind,
very narrow in the type; posterior sclerites of notum dark brown,
with vague indications of a capillary median paler vitta extending
from suture to abdomen. Pleura brown, dorsopleural membrane
whitened. Halteres infuscated, base of stem narrowly yellowed.
Legs with coxae pale brown basally, apices restrictedly paler; tro-

1 . Amherst, Massachusetts.

159

The Great Basin Naturalist
160 CHARLES P. ALEXANDER Vol. XXIII, NOS. 3-4

chanters yellow; remainder of legs medium brown; claws simple.
Wings faintly darkened; stigma oval, darker brown; restricted
obliterative areas before stigma and across base of cell 1st M2; pale
longitudinal lines in cell \st A and outer end of /?; veins light
brown. Macrotrichia in outer fourth of cell R; no stigmal trichia;
medial veins chiefly glabrous, trichia present on most of Mj, outer
end of M, and in cases at tip of M,s. Venation: Rs shorter than
m-cu-^ petiole of cell Mi about one-half longer than m.

Abdominal tergites dark brown, proximal ends restrictedly
more yellowed; sternites light brown, their posterior borders nar-
rowly yellowed. Male hypopygium with posterior border of ter-
gite having a broad U-shaped emargination to form relatively nar-
row obtuse lobes, margins of the latter entirely without spicules or
spinoid setae, as in other species, having numerous very small and
delicate setae only. Ninth stemite on either side with a brush or
stout pencil of about twenty long black setae. Outer dististyle
about twice as long as broad, widest before midlength. setae long
but relatively sparse. Inner dististyle with beak long and narrow,
tip obtuse; lower beak and margin blackened, sclerotized; outer
surface of basal half with numerous erect yellow setae. Aedeagus
very long and stout, as common in the subgenus.

Habitat. California (Calaveras County).

HoLOTYPE, alcoholic cf. Buckeye Cace, September 4, 1961
(W. J. Gertsch); No. 1976. Allotype, $, Cave of the Catacombs,
September 1, 1961 (R. E. Graham); No. 1893, in Alexander Collec-
tion. Type in American Museum of Natural History.

Named in honor of the collector. Dr. Willis J. Gertsch, dis-
tinguished student of the Arachnida. The fly is readily told from
other generally similar species by having the tergal lobes of the
male hypopygium entirely without spicules and in the long setal
pencils on the ninth sternite. The most similar such species is
Tipula {Trichotipula) cazieri Alexander, with other regional allies
including T. [T .) furialis Alexander and T. (T.) sayloriana Alex-
ander.

Tipula (Yamatotipula) carsoni, n.sp.

Size small (wing of male about 11 mm.); mesonotum gray,
praescutum with four narrow brownish gray stripes that are nar-
rowly margined with brown, pleura light gray, dorsopleural mem-
brane yellow; antennae of male relatively long, flagellum black;
wings weakly infuscated, prearrular and costal fields more yel-
lowed; abdominal tergite yellow, with two broad dark browTi
longitudinal stripes; male hypopygium with the tergite produced
into two flattened blades that are separated by a linear split, each
blade on its inner and apical parts with slender spinoid setae;
inner dististyle with beak large, outer margin strongly crenulated
or scalloped; outer basal lobe a long narrow flattened blade, the
apex truncate; gonapophysis a small slender blade.

Dec. 16, 1963 new nearctic tipulidae 161

Male. Length about 9.5-10 mm.; wing 10.5-11.2 mm.; an-
tenna about 4.2 - 4.3 mm.

Frontal prolongation of head yellowed, light gray pruinose
above at base, nasus elongate; palpi with basal segment brown, re-
mainder brownish black. Antennae with scape and pedicel ob-
scure yellow; first flagellar segment elongate, brownish yellow,
remainder of flagellum black, in the paratype, the extreme tips of
the more proximal segments yellowed, outer segments uniformly
blackened; segments feebly incised, much longer than the verticils.
Head in front whitened, brownish gray behind, with indications of
a darker median line; vertical tubercle small; setae of vertex
short, black, of occiput longer, yellow.

Pronotum brownish gray, paler laterally. Mesonotal praes-
cutum with humeral and lateral borders gray, disk with four nar-
row brownish gray stripes that are narrowly margined with
brown, interspaces pale brown; scutum light gray, each lobe with
two darker brown areas; scutellum brown, posterior border more
yellowed; mediotergite light gray, posterior border narrowly dark-
er; pleurotergite grayish brown, dorsal katapleurotergite clearer
gray. Pleura light gray; dorsopleural membrane yellow. Halteres
with stem brownish yellow, knob dark brown. Legs with coxae light
gray; trochanters yellow; femora and tibiae brownish yellow, tips
narrowly brownish black; tarsi passing into black. Wings weakly
infuscated. prearcular field and cells C and Sc more yellowed, es-
pecially the latter; stigma brown, proximal end paling to yellow;
a very restricted brown cloud over anterior cord; small obliter-
ative areas before stigma and across base of cell 1st M,>, the latter
extending into apex of cell /?; veins brown, more yellowish brown
in the brightened areas. Venation: /?,, relatively long; cell 1st M2
small; cell M , deep, its petiole in cases to twice m.

Abdominal tergites with the restricted median ground yellow,
with two broad dark brown sublateral longitudinal stripes, lateral
margins paler yellow; sternites yellow; subterminal segments
darkened to form a narrow ring; outer end of ninth segment, with
the appendages yellowed. Male hypopygium with the tergite pro-
duced into two flattened blades, separated by a linear split, the
apical and mesal parts of each blade with slender black spinoid
setae. Outer dististyle unusually small, long-oval, with yellow
setae; inner style much larger, the large beak yellow, gently arcu-
ated, apex obtuse; outer margin crenulated or scalloped, forming
about four lobes, with a strong pale seta in the notch of each
crenulation, these gradually decreasing in size outwardly; face of
beak conspicuously reticulated, wdth pale setae; outer basal lobe
a long narrow flattened blade, apex truncate, the upper angle
slightly produced. Phallosome with gonapophyses appearing as
small slender flattened blades .

Habitat. Newfoundland, Maine.

HoLOTYPE, d", Aspen Brook Rest Camp, Newfoundland, 300

The Great Basin Naturalist
162 CHARLES P. ALEXANDER Vol. XXIIL NoS. 3-4

feet, in swampy area along small lateral rills of brook at camp, July
17, 1961 (D. L, Carson). Paratype, cT- Rangeley, Franklin Co.,
Maine, July 21, 1961 (A. E. Brower).

I take great pleasure in naming this fly for Mr. David L, Car-
son, companion on collecting trips to Alaska and Newfoundland,
who has aided greatly in making known the crane flies of these
areas. It most resembles species such as Tipula {Yamatotipula)
aprilina Alexander, T. (Y .) dejecta Walker, and T. (Y .) sulphur ea
Doane, differing from all in the structure of the male hypopygium,
particularly the tergite and dististyles.

Tipula (Platytipula) perhirtipes, n.sp.

Closely allied to Tipula {Platytipula) cunctans Say; legs stout,
very conspicuously hairy, including all segments from the femora
through the third tarsal segment.

Female. Length about 17 mm.; wing 14 mm.; antenna about
3.1 mm.

Frontal prolongation of head light gray, clearer dorsally;
nasus elongate; palpi brown, terminal segment short, black. An-
tennae with scape and pedicel light brown; proximal four seg-
ments of flagellum brownish yellow, their bases vaguely darker,
outer segments passing into black; terminal segment small, sub-
globular. Head gray, vertex strongly infuscated.

Pronotum gray. Mesonotal praescutum gray, with three
brown stripes; scutum gray, lobes patterned with brown; scutellum
gray, darkened medially, parascutella and postnotum light gray, f
Pleura whitish gray, dorsopleural region yellowed. Halteres dark
brown. Legs of female relatively short and stout; coxae whitish
gray; trochanters yellow; femora and tibiae brownish yellow, tips
narrowly blackened, more extensive on forelegs; tarsi passing into
black; legs conspicuously hairy, with unusually long and abund-
ant erect setae, including all segments with the exception of coxae
and outer two tarsal segments. Wings brownish yellow, cells C
and Sc dark brown, stigma yellow^ed; veins dark brown. Veins un-
usually glabrous, beyond cord wdth only two or three on vein
/?4 + ■;. Venation: Cell 1st M. relatively short, less than twice the
petiole of cell M^.

Abdomen obscure brownish yellow, patterned wdth darker,
most evident as an interrupted median tergal stripe on proximal
five segments, less evident elsewhere.

Habitat. Maine (Kennebec County).

HoLOTYPE, 9 , Vassalboro. in bog. September 30, 1961 (A. E.
Brower).

Tipula (Lunatipula) grahamina, n.sp.

Mesonotal praescutum with five dark stripes, the lateral pair
broad, intermediate three narrow, separated by delicate yellow
lines; no nasus; femora brownish yellow, tips narrowly dark brown,
claws simple, wings pale brown, stigma darker, whitened obliter-

Dec. 16, 1963 new nearctic tipulidae 163

ative areas before stigma and in cells R, 1st M^ and M.^; male
hypopygium with posterior border of tergite broadly emarginate,
with a low median lobe at base of notch; aedeagus and apophyses
generally similar in shape, appearing as slender blades; eighth
sternite with posterior margin simple, the midregion with about
20 moderately long setae.

Male. Length about 13-17 mm.; wing 12.5-17 mm.; antenna
about 4.5-6.5 mm.

Frontal prolongation of head light brown, subequal to remain-
der of head; nasus lacking; palpi brown, terminal segment paler
outwardly. Antennae with scape and pedicel yellow, flagellum
brown, their segments shorter than the verticils. Head brown.

Pronotum brown. Mesonotal praescutum with broad sublateral
brown stripes the median region with three narrow brown lines
that are separated by equally narrow yellow vittae; scutal lobes
dark brown, median area paler; scutellum brown, paler apically,
with a vague darker central area; postnotum brown, lateral mar-
gins of mediotergite more yellowed, pleurotergite brownish yellow.
Pleura chiefly dark brown; dorso-pleural region pale yellow. Hal-
teres with stem pale, knob dark brown. Legs with fore and middle
coxae yellow, restrictedly darkened at bases, posterior coxae more
uniformly brown; trochanters yellow; femora brownish yellow, tips
narrowly dark brown; tibiae and tarsi yellowdsh brown, terminal
segment blackened; claws small, simple. Wings pale brown, stigma
darker, cell Sc yellowed; white obliterative areas before stigma,
outer end of cell R and bases of cells IstMo and M,; veins light
brown. Venation: Rs about one-half longer than m-cu; petiole of
cell Ml about one-half longer than m.

Abdominal tergites brownish yellow, laterally with large
brown spots; basal sternites more uniformly light yellow, outer seg-
ments and hypopygium dark brown. Male hypopygium with the
tergite transverse, posterior border with a broad U-shaped emargin-
ation, with a small secondary median notch, beneath which is a
low truncate sclerotized lobe; lateral lobes narrowly obtuse, mar-
gins virtually glabrous. Outer dististyle dilated outwardly, apex
obliquely truncate, surface and margins with abundant setae,
some very long; inner dististyle with beak narrowly obtuse, lower
beak broadly so; posterior crest produced; outer basal lobe broad
and conspicuous, tip obtuse. Phallosome with both the aedeagus and
apophyses appearing as slender blades, narrowed to acute points, the
former longer. Eighth sternite with posteriorrnargin simple, without
lateral lobes or armature; median region membranous, with about
20 moderately long setae.

Habitat. California (Plumas and Shasta Counties).

Holotype, alcoholic d", Kloppenberg Cave. Plumas County,
September 19, 1959 (R. E. Graham). Paratypes, alcoholic d ,
Hall City Cave, Plumas County, August 1959 (R. de Saussure) ;
No. 1285; alcoholic cT, Samwel Cave, Shasta County, June 15,

The Great Basin Naturalist
164 CHARLES P. ALEXANDER Vol. XXIII, Nos. 3-4

1959 (R. E. Graham); No. 1162. in Alexander Collection. Type in
American Museimi of Natural History.

This interesting crane-fly is named for Mr. Richard E. Gra-
ham, Department of Mammalogy, American Museum of Natural
History, who is conducting the present survey of the fauna of Calif-
ornia caves. In the lack of a nasus and pattern of the mesonotal
praescutum, the species agrees with Tipula {Luuatipula) usitata
Doane, differing in further coloration and in all hypopygial de-
tails. T. (L.) biunca Doane likewise lacks the nasus but differs
more decisively in hypopygial structure.

Tipula (Lunatipula) productisterna, n.sp.

Belongs to the unicincta group; mesonotal praescutum with
three gray stripes, the interspaces brown, the intermediate pair
more clearly so; antennae short, flagellum black; halteres yellowed,
base of knob infuscated. legs brownish yellow, tips of femora and
tibiae darkened, tarsi black, claws long-spined; wings strongly
yellowish brown, scarcel}^ patterned; abdomen yellow, tergites
trivittate with dark brown, outer segments darker brownish yellow;
male hypopygium with tergal lobes only slightly produced, round-
ed; ninth sternite produced into two long fingerlike lobes that are
directed inwardly; outer basal lobe of inner dististyle long and
fingerlike; phallosome with symmetrical apophyses; eighth sternite
large and sheathing, outer lateral angles bearing a single powerful
fasciculate bristle; median region of emargination with a glabrous
depressed-flattened pale plate that is produced into two divergent
blades.

Male. Length about 16 mm.; wdng 17 mm.; antenna about
3.4 mm.

Frontal prolongation of head buffy yellow. Antennae rela-
tively short; scape and pedicel yellow, flagellum black; flagellar
segments very feebly incised, only slightly exceeding their longest
verticils. Head brownish yellow, clearer yellow medially behind.

Pronotal scutum light brown, scutellum light yellow, clearer
medially. Mesonotal praescutum with three brownish gray stripes,
the interspaces clearer brown, best-indicated as long narrow lines
on either side of the median stripe; posterior sclerites of notum
brownish gray, central region of scutum narrowlv yellowed. Pleura
brownish gray; dorsopleural membrane light yellow. Halteres yel-
lowed, including most of the knob, the base of latter infuscated.
Legs with foi'e coxae infuscated. the remaining pairs and all tro-
chanters more yellowed; femora and tibiae brownish yellow, tips
narrowly darkened; tarsi black, claws long-spined. Wings strongly
yellowish brown, darker on costal region, more yellowed on
proximal half, stigma darker bro\\'n; obliterative areas conspicuous,
yellowish white, crossing cell 1st M ■ into the adjoining cells; veins
light brown. Venation: Rs long, more than three times R2 + ?.;
petiole of cell AU shorter than m; distal section of Cw, strongly
decurved at margin.

Dec. 16, 1963 new nearctic tipulidae 165

Abdomen yellowed, tergites trivittate with dark brown, the
stripes narrowly interrupted by pale posterior borders, lateral
margins broadly pale; outer segments, including the large hypopy-
gium. darker brownish yellow. Male hypopygium with the tergite
transverse, lateral lobes irregularly rounded, only slightly produced,
median region completely divided. Ninth sternite on either side
conspicuously produced into a fingerlike lobe, broad-based, bent
inwardly; a further more ventral elongate lobe, its outer margin
and apex with abundant short yellow setae. Outer dististyle a
small oval blade on margin of the large inner style, this with the
beak short-triangular; outer basal lobe narrowed into a fingerlike
pale lobule. Phallosome symmetrical, the gonapophyses moderately
large, spinelike, darkened, gradually narrowed into acute points.
Eighth sternite large and sheathing, outer angles each with a single
powerful fasciculate bristle; median region of emargination with a
depressed-flattened pale plate, its outer margin produced into two
divergent blades, separated by a U-shaped notch.

Habitat. Oregon (Harney County).

HoLOTYPE, cf, Fish Lake Steens Mountains, 7,200 feet July
14, 1962 (James Baker).

This interesting fly was taken by my long time friend James
Baker, of Baker, Oregon, to whom I am indebted for many Tipu-
lidae over the past several years. Other regional members of the
unicincta group that have the tergal lobes only slightly produced
include Tipula {Lunatipula) mormon Alexander and T. (L.)
rabiosa Alexander, both of which have the hypopygial structure
quite different, especially in the lack of the long fingerlike lobes
of the ninth sternite as found in the present fly. Other species of
Tipula with somewhat comparable elongate digitiform lobes have
these on the basistyle rather than on the ninth sternite.

NOTE

SCISSOR-TAILED FLYCATCHER IN DeATH VaLLEY, CALIFORNIA

On May 3, 1962, the writer observed and collected a male scissor-tailed
flycatcher Muscivora jorticata at Furnace Creek Ranch in Death Valley, Inyo
County, California. It was observed "fly-catching" among the mesquite growth
whcih surrounds the "Ranch." This species increases the avian population of
the below-sea-level region of Death Valley to 233 species (Wauer, Condor,
64:220-233). It is also the northeastern most record for the species in California
and the first for the western portion of the Great Basin; along the eastern
edge of the Sierra Nevada.

Roland H. Wauer, Zion National Park, March 20, 1963.

NEW DISTRIBUTIONAL AND HOST DATA
FOR THE TICK DERMACENTOR HUNTERI BISHOPP

Elias P. Brintoni and Glen M. Kohls2

Published records indicate that the tick Dermacentor hunteri
Bishopp has been collected from the bighorn sheep, Ovis canadensis,
in Arizona (Bishopp, 1912; Cooley, 1938; Russo, 1956), Mexico
(Cooley. 1938), and Nevada (Allen, 1962) and from the mule deer,
Odocoileus hemionus, in Arizona (Russo, 1956). New distributional
and host data from this little-known tick are presented below.

In April 1952, Miss Grace Grant, a student at Brigham Young
University, collected a male tick of this species at the upper
reaches of Beaver Dam Slope in southwestern Washington County,
Utah. This locality is about five files due west of the Cliff Service
Station on on Highway 91, between the Station and Terry's Ranch
on Beaver Dam Wash. Apparently the tick was removed from the
clothing since the collection data recorded it from man without any
information that it was attached to the skin. On November 26 and
27, 1955, Dr. W. L. Jellison of the Rocky Mountain Laboratory
removed two ticks, a male and a female, from his clothing while
collecting mammals in the same general area. On June 22, 1961,
Dr. D Elden Beck of Brigham Young University collected a female
specimen from a cottontail rabbit, Sylvilagus nuttallii grangeri,
taken in the upper part of Snow's Canyon, about seven miles north
of St. George, Washington County, Utah.

In November and December 1962, Dr. Charles G. Hansen sent
to the Brigham Young University Zoology and Entomology Dept.
351 males and 86 females of Dermacentor hunteri collected from
bighorn sheep in the Desert Bighorn Sheep Reserve near Las
Vegas, Nevada, and in January 1963 he sent 2 males and a female
taken from a mule deer in the same area. This deer was also in-
fested with the winter tick, D. albipictus (Packard).

References

Allen, R. W. 1962. Parasitism in Bighorn Sheep on the Desert
Game Range in Nevada. The Desert Bighorn Council Trans-
actions (1962). Published annually (Las Vegas, Nevada). P. O.
Box 440, Las Vegas, Nevada.

Bishopp. F. C. 1912. A New Species of Dermacentor and notes
on other North American Ixodidae. Proc. Biological Society of
Washington. 25: 29-37.

Cooley, R. A. 1938. The Genera Dermacentor and Otocentor in
the United States, with studies in variation. National Institute
of Health Bulletin No. 171, 89 pp.

Russo, J. P. 1956. The Desert Bighorn Sheep in Arizona. Wild-
life Bulletin No. 1 Arizona Game and Fish Department. 153
pp. illus.

1 . Brigham Young University. Piovo. Utah.

2. Rocky Mountain Laboratory, National Inistitute of Allergy and Infectious Diseases. U. S.
Public Health Service, Hamilton, Montana.

166

A NEW SPECIES OF CRANIOTUS (COLEOPTERA:
TENEBRIONIDAE)

Vasco M. Tanner^

Within the last few years some intensive collecting in the south-
western part of the Great Basin, Arizona and northern Mexico has
resulted in the accumulation of a large and interesting series of
tenebrionid species. This study has to do with the description of
the second known species of the rare genus Craniotus.

In 1851 John L. Leconte described a new genus and species-
of Tentryiinae from a unique which was collected on the Colorado
Desert of California. Leconte evidently proposed the name Craniotus
because of the "horn-like" projections at the sides of the head an-
terior to the eyes. Other characteristics of the genus are: Clypeus
round, shield shaped, intermediate lobe of the epistoma truncate,
jaws bifid at tip; eyes almost transverse; antennae slender, third
joint much elongated, the eleventh segment small and attached to
the apex of the tenth which is much broadened; body convex, cov-
ered with fine setae; prothorax slender and round; sides wide with-
out margins; scutellum elongate; epipleurae narrow and evident on
the posterior part of the elytra; metathoracic coxae widely separated;
femora and tibiae long, slender; tarsi with long hairs above and
stiff spines beneath.

George Horn'^ observed that this "genus may be readily distin-
guished from all others of the tribe (Gnathosiini) by the very
prominent triangular lateral lobes of the head. The epipleurae and
the elytra are connate without trace of suture."

Col. Casey believed this singular genus was most closely allied
to the old world Adesmiini; also that it resembles the American
Edrotes in many respects. He comments as follows: "In Adesmia the
eyes are much more finely faceted the head and mandibles are
almost similar, except that the front is not dilated at the sides and
the mentum not emarginate at base, and the eleventh antennal joint
is free, though very small. The coxae and metasternum are almost
exactly as in Craniotus, but the posterior are still more widely sepa-
rated, almost globular in form and approach the sides of the body
very closely."

Specimens of Adesmia have not been seen by the writer, but
several species of the genra Edrotes and Triorophus have been
studied and comparisons made with Craniotus. There are some ex-
ternal body resemblances of Craniotus with the above mentioned
genera, but there is no agreement in the genitalia structures. If

1. Contribution No. 183 from the Dept. of Zoology and Entomology, Brigham Young Univer-
sity. Provo, Utah. Paratype specimens, of this study, were collected by field workers of the Brigham
Young University under the Atomic Energy Commission Contract AT (11-1) 786.

2. Leconte. John L., Description of new species of Coleoptera from California, Annals Lye.
N.H.N.Y. Vol. v. pp. 125-216, pi. 1851.

3. Horn, George H,, Revision of the Tenebrionidae of America, North of Mexico. Trans. Am.
Phil. Society. Vol. XIV, Pt. 11.

167

168

VASCO M. TANNER

The Great Basin Naturalist

Vol. XXIII, Nos. 3-4

Fig. 1 Dorsal view of the female of C. blaisdelli. Fig. 2 Elytral pattern
of C. pubescens. Fig. 3 Ventral view of genitalia of C. blaisdelli. Fig. 4
Lateral view of C blaisdelli.

other characters than those used by early workers are considered in
making decisions as to relationships of genera, tribes and subfamilies,
we will need to abandon Col. Casey's conclusions in the light of
present morphological findings. The writer has long contended,
1927^, that more attention must be paid to the internal as well as
the external morphology of the beetles. Blaisdell's work on the geni-
talia of the Tenebrionidae has added materially to the value of his
studies of this family. In 1934'' he commented as follows on the
necessity of shifting Craniotus to the subfamily Asidinae: "The
study of the genitalia of the Tenebrionidae indicates very definitely

4. Tanner. Vasco M. 1927.. .\ Prelinunaiy Study of the Genitalia of Female Coleoptera.
Trans. Ani. Ento. Soc. Vol. LIII, 5-50. 14 plates.

5. Frank E. Blaisdell, Sr., 1934. Studies in the Genus Aurhmobius (Coleoptera: Tenebrionidae).
Trans. Am. Ento. Soc. LX. 223-264. Plates XVI, XVII, and XVIII.

Dec. 16, 1963 new species of craniotus 169

that changes should be made in the taxonomic sequences of sub-
families and tribes. . . . The Craniotini possess genitalia wholly
Asidine in character and should precede the Asidini in our lists."
Again Blaisdell. 1939'', contends that: "The Asidinae possess distinc-
tive primary sexual characters, the typical characters are described
above and figured in Plate V. The species Craniotus pubescens
Leconte heretofore placed after Edratini and before Zopherini in
our lists, belongs to the subfamily Asidinae, Tribe Craniotini. Its
genital characters being distinctly of the type found in that subfam-
ily. The author has reported this fact in a previous publication."

Not only do species of Craniotus agree in general with the
female genitalia structures of the Asidinae, but there is also an
agreement in the type of antennae, mentum, eyes, and position of
the closed coxal cavities. I am, therefore, of the opinion that in this
instance the female genitalia (fig. 3-4) of C. blaisdelli as well as
external body characters are more closely related to Asidini than
Edrotini and that Craniotus and species should be placed in the tribe
Craniotini in the subfamily Asidinae.

Craniotus blaisdelli Tanner, n. sp.
Figs. 1-4

Form robust, two times as long as wide. Color deep black, luster
dull to slightly shining.

Head small in size, projections at the sides of the head anterior
to the eyes extend beyond one third the width of the head; frons de-
pressed between the projections and the clypeal area; clypeus slightly
emarginate; epistoma punctures discrete, small, irregular, each bear-
ing a short black seta. Eyes transverse, not emarginate, larger dor-
sally. Antennae slender, third joint as long as the fourth and fifth
combined, in length not extending to the pronotal base; the eleventh
segment small, attached to apex of tenth.

Pronotum about one-sixth wider than long, sides without mar-
gins, disk convex, anterior angles acute, surface with irregularly
placed papilliform structure, each bearing a decumbent brownish
colored seta. Base broadly truncate, scutellum elongate.

Elytra one third longer than wide, base equal to that of the
pronotum; humeri obsolete, sides broadly arcuate, disk moderately
convex; arcuately precipitous at apex; surface devoid of striae; small
punctures from which arise short stiff black setae; luster dull to
more or less shining, connate, the suture, however, is distinct. Epi-
pleurae without a trace of a suture.

Legs long, especially the tibiae of the metathoracic legs; coxa
closed and widely separated. First and second abdominal sternites
about equal, in width, punctured and with black short erect setae.

Genitalia of the female, figs. 3-4, of the elongate type, rather

6. Frank E. Blaisdell, Sr., 1939. Studies in the Relationships of the Subfamilies and Tribes of
the Tenebrionidae, Based on the Primary Genital Characters also descriptions of new species.
(Coleoptera.) Trans. Am. Ento. Soc. LXV, 43-60, Plates IV and V.

The Great Basin Naturalist
170 VASCO M. TANNER Vol. XXIII, NoS. 3-4

heavily sclerotized valvifer; coxite small, black, with obscure stylus;
ninth segment membranous, acting as a sheath for the retracted
genital organ. The female genitalia of Pelecyphorus semilaevis is an
elongate type similar in structure to C. blaisdelli.

Measurements: length 10-13 mm; width 5-6 mm.

Type: Female, collected in Inyo Mountains, California, April
18, 1949 by Owen Bryant.

Paratypes: 1- ? , collected by field workers of the Brigham
Young University, Nevada test site Ecology Project, 12.5 miles
N.N.E. of Mercury, Nevada, in the Larrea-Franseria Community,
Nov. 1961; l-d" collected 9.3 miles west of Mercury in the Larrea-
Franseria Community, Dec. 1961; 1-2 collected 32.5 miles north of
Mercury in a Coleogyne Community, Nov. 1960.

Type and paratypes are in the author's collection at Brigham
Young University. One paratype deposited in the entomological col-
lection of the California Academy of Sciences at San Francisco.

I am pleased to dedicate this species to the memory of Dr. Frank
E. Blaisdell, Sr., one of this country's most renown authorities en
the Tenebrionidae.

Remark: — Craniotus blaisdelli is a larger species than pube-
scens. The elytral covering of blaisdelli consists of sparse, short black
setae, devoid of striae and with a more or less dull luster yet wrth a
shining surface. The elytra of pubescens, fig. 2, has three rather
distinct lines or areas on either side of the suture which are covered
with brownish decumbent thickly placed setae. These areas are sep-
arated by small spaces devoid of setae. The head and thorax of
pubescens is also thickly covered with brownish decumbent setae.
The prothorax is more round and convex with numerous deep
punctures.

INDEX 10 VOLUME XXIII

The new genera and species described in this volume appear in bold
face type in this index.

Alexander, Charles P., Article by,

159.
A New Species of Craniotus (Cole-

optera: Tenebrionidae) Illustrat-
ed, 167.
A Revision of the Bark Beetle

Genus Dendroctonus Erichson

(Coleoptera: Scolytidae) Illus-
trated, 1.
A Survey of the Herpetofauna of

the Death Valley Area, 119.
Banta, Benjamin, See Tanner,

W. W., 129.
Brinton, Elias P., Article by, 166.
Craniotus blaisdelli, 169.
Crotaphytus Holbrook, 132.

wislizeni punotatus, 138.

w. wislizeni Baird and Girard,

132.
Cysteochila aei, 152.

apheles, 150.

cybele, 155.

epelys, 154.

pelates, 149.
Dendroctonus Erichson, 24.
Dendroctonus adjunctus Blandford,

51.

aztecus, 69.

brevicomis Leconte, 29.

frontalis Zimmerman, 39.

micans (Kigelann), 82.

murrayanae Hopkins, 88.

obesus (Mannerheim), 93.

parallelocollis Chapuis, 46.

ponderosae Hopkins, 57.

pseudotsugae Hopkins, 106.

punctatus Leconte, 85.

simplex Leconte, 103.

terebrans (Olivier). 71.

valens Lecortte, 76.
Dermacentor hunteri Bishopp, 166.
Drake, Carl J., Article by, 149.
Gambelia Baird, 132.
Kohls, Glen M., see Brinton, E. P.,

166.

Key to the Species of Dendroc-
tonus, 26.

Leptopharsa ralla, 156.

New Distributional and Host Data
for the Tick Dermacentor hunt-
eri Bishopp, 166.

New Lacebugs from the Eastern

Hemisphere, Illusti'ated, 149.
Scissor-tailed Flycatcher, 165.

Stephanitis subfasciata Horvath,
158.

The Systematics of Crotaphytus

wislizeni, the Leopard Lizards

Part I, Illustrated, 129.
Tanner, Vasco M., Article by, 167.
Tanner, Wilmer W., Article by, 129.
Tipula (Lunatipula) grahamina,

162.

(Lunatipula) piioduetisterna, 164.

(Platytipula) perhirtipes, 162.

(Trichotipula) gertsclii, 159.

( Yamatotipula) carsoni, 160.
Turner, Frederick B., Article by,

119.
Undescribed Species of Nearctic

Tipulidae (Diptera), 159.
Wauer, Roland H., see Turner,

F. B., 119.
Wood, Stephen L., Article by, 1.

171

3 2044 072 231

Date Due