Papers on cereal and forage insects

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Title:
Papers on cereal and forage insects
Series Title:
Bulletin / U.S. Dept. of Agriculture, Bureau of Entomology ;
Physical Description:
7 v. : ill. ; 23 cm.
Language:
English
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United States -- Bureau of Entomology
Publisher:
U.S. Dept. of Agriculture, Bureau of Entomology
Place of Publication:
Washington, D.C
Publication Date:

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Subjects / Keywords:
Forage plants -- Diseases and pests   ( lcsh )
Grain -- Diseases and pests   ( lcsh )
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federal government publication   ( marcgt )
bibliography   ( marcgt )
non-fiction   ( marcgt )

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Bibliography:
Includes bibliographical references and index.

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Source Institution:
University of Florida
Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
aleph - 029637351
oclc - 22577538
Classification:
lcc - SB818 .B85 no.95, 1913
System ID:
AA00018926:00004

Full Text






U. S. DEPARTMENT OF AGRICULTURE,

BUREAU OF ENTOMOLOGY-BULLETIl No. 95, Part V.
L 0. HOWARD. Entomologt and Chief of Bureau.



PAPERS ON CEREAL AND FORAGE INSECTS.


THE FALSE WIREWORMS OF THE


PACIFIC NORTHWEST.


BY


JAMES A. JIYSLOP,
Agent and Expert, Cereal an 4 ..I. Aa ",Investigations.
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WASHINGTON:
GOVERNMENT PRINTING OFFICE.
1912.


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B UREA U OF ENTOMOLOG Y. ;
L. 0. HowARD, Entomologist and Chief of Bureau. i!
C. L. MARLArF,. Entomologist *and Acting Chief in Absence of Chief. 1 l
R. S. CLIrrON, Executive Assistant. |
W. F. TASTET, Chief Clerk.
F. H. CHTrFENDEN, in diarge of truck crop and stored product insect investiga.on...
A. D. HopKrNs, in charge offorest insect investigations.
W. D. HUNTER, in charge of southern field crop insect investigations.
F. M. WEBSTER, in charge of cereal and forage insect investigations.
A. L. QUAINTANCE, in charge of deciduous fruit insect investigations.
E. F. PaLumps, in charge of bee culture.
D. M. ROGERS, in charge of preventing spread of moths, field work.
Roma P. CURaiE, in charge of editorial work.
MABEL COLCORD, in charge of library.
CEREAL AND FORAGE INSECT INVESTIGATIONS.
'.:: ":EEEE l















F. M. WEBSTER, in charge.i
GEo. I. REEVES, W. J. PHILLPS, C. N.-AINSLIE, E. 0. G. KELLY, T. D. UnBAs
HARRY S. SMITH, GEO. G. AINSaLE, J. A. HYSLOP, W. R. WALTON, J. T. MON|
J. J. DAVIS, T. H. PARKS, R. A. VICKERY, V. L. WILDERMUTH, E. G. S~ii
HERBERT T. OSBORN, PiIP LUGINBILL, C. W. CREEL, E. J. VOSLER, B. NR I
SON, VERNON KING, entomological assistants.
NETTLE S. KLOPFER, ELLEN DASHIELL, preparators.
MIRIAM WELLES REEVES, collaborator.


















CONTENTS.


Introduction........................................
Historical...........................................
Distribution........................................
The work in the Big Bend region of Washington .......
Descriptions..........................................
Eleodes letcheri vandykei Blaisd......................
The egg......................................
The larva ....................................
The pupa.....................................
The adult.....................................
Eleodes pimelioides Mann........................
The egg.......................................
The larva................................. ...
The pupa.....................................
The adult.....................................
Food substances.....................................
Seasonal histnes ory -----------------------.......................................-
Seasonal history-------- - - - - - -


Natural enemies and parasites........................... ..
Remedial and preventive measures...................






ILLUSTRATIONS.


FIG. 22. False wireworm, Eleodes letcheri vandykei: Adults in characteristic
attitudes ....................... ....................................
23. False wireworm, Eleodes letcheri vandykei: Egg........................
24. False wireworm, Eleodes letcheri vandykei: Larva and details.........
25. False wireworm, Eleodes letcheri vandykei: Pupa, dorsal and ventral as-
pects ......... ..................................................
26. False wireworm, Eleodes letcheri vandykei: Adult....................
27. False wireworm, Eleodes pimelioides: Adult, details of larva..........
III


Page.
73
73
75
76
78
78
78
78
79
80
80
80
80
81
81
82
83
84
86


Page.

73
78
79

79
80
81


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D. A., D .B'. EBul. 95, Part W C. F. 1. 1., .April 22, 1912.

* PAPERS ON CEREALrAND) FORAGE INSECTS.
: .. 4 *.
4

THE FALSE WIREWORMS OF THE PACIFIC NORTHWEST.
",. "I i ,! .1
S' 'By JAMES A. HYSLOP,
S" 'Agent and Expert, Cereal and Forage Insert Investigations.

INTRODUCTION.
Up to within the past five years, except for a few scattering notices,
the species of Eleodes have been considered of only incidental, if of
any, economic importance. The Tenebrionidae, to which this genus
belongs, are sometimes saprophagous, feeding on dead vegetable
matter in the soil, and occasionally on dead animal tissue as well
as on stored grain and other food products.
Superficially the larvae resemble the true wireworms elateridd
larvae), and on account of this resemblance and the similarity of their
I'










FIG. 22.-The false wirewon.', Eleodes letcheri vandykei: Adults in characteristic attitudes. Some-
what enlarged. (Original.)

depredations in the, grain fields the two are often confused. On
closer examination, however, Eleodes larvae can be easily recognized;
the antennae are rather long and very conspicuously clavate, the
body is not flattened, and the forelegs are long and stout. These
larvae can move with great rapidity as compared with true wireworms
The confusion of Eleodes with the true wireworms is unfortunate,
as the preventive and remedial measures for the two pests are quite
distinct, what is efficient treatment in one case being quite useless
in the other.
HISTORICAL.
Among the earliest references to the economic importance of these
beetles in this country is a note by Prof. LIawrence Bruner,' in which
the species Eleodes tricostata Say -is recorded as attacking cabbage
SBul. 26 (old series), Div. Ent., U. S. Dept. Agr., pp. 11- 12, 1892.






74 PAPERS ON CEREAL AND FORAGE INSECTS.

plants at Lincoln, Nebr., doing even more damage than the
worms. It was also said to have attacked other garden cropli
these are not definitely recorded.. II
In 1895 Prof. C. V. Piper published an article in the Northw
Horticulturalist in which he refers to Eleodes larvae attacking gpfi
crops. -I
In 1898 Mr. Theo. Pergande 1 notes having received from McIi
son, Kans., two larvae of a tenebrionid with the statement that t
do serious damage to wheat in Salina County, Kans., by attack
the grain when it becomes softened, destroying the germ. FromMa,
of these larvae an adult was reared which proved to be Eleodes _A-
lis Say. In the autumn of 191-1 Mr. E. 0. G. Kelly, of this oflia
found the wheat in southern Kansas attacked by an Eleodes lam
which may prove to belong to this latter species, i:.
In 1908 Mr. Myron Swenk,2 assistant State entomologist i
Nebraska, reported Eleodes opaca Say as doing very serious dame
to wheat in Nebraska, in some instances 60 per cent of the us
having been destroyed.
The larvae were first found by the author in enormous numbers i
May, 1909, in a wheat field south of Pullman, Wash. The field *i
entirely ruined and had to be reseeded, though these depredation
were not entirely due to the Eleodes, as a true wireworm, the larv
of Corymbites inflatus Say, was also very numerous.
On May 12 several adult Eleodes pimelioides Mann. were found i
a depth of about 4 inches below the surface in the field above i
tioned, and more were found under boards and rubbish about ._
fields. Many larvae were placed in flowerpot rearing cages i*
-wheat as food, and on July 3 a pupa was found in one of these cag"
On July 20 an adult Eleodes pimelioides emerged. Later examinat
of several collections very clearly indicates that this species is far U
more predominant in the Palouse country.
Other species known to occur in this region are Eleodes obscure Si
var. sulcipennis Mann., Eleodes hispilabris Say var. lkvis Blai
Eleodes extricata Say, Eleodes manni Blaisd., Eleodes humeralia ,t
Eleodes schwarzii Blaisd., and Eleodes nigrina Lee. |I
In the spring of 1909, on examining an oat field at Govan, Wa.
that had been almost completely destroyed, many tenebrionid la
Eleodes letcheri Blaisd. var. vandykei Blaisd., were found crawl
over the surface of the field. They had evidently been forc.dj
leave the ground by a heavy rain which fell the day before. ,
digging in this field many more larvae were found about ready i
pupate. *=!
In the spring of 1910 the adults were found in enormous nh A.
on the roadsides in the Big Bend region and in the middle of::i::


Bureau of Entomology Notes, No. 8186.


2 Journ. Econ. Ent., vol. 2, p. 332,190.





P' FALSE WIREWORMS OF PACIFIC NORTHWEST. 75
Summer they were found under the grain shocks in large numbers..
In this region the species in enormous preponderance is Eleodea
letcheri vandylcei. Eleodes pimelioides, Eleodes nigrina, Eleodes his-
pilabris var. lavis, and Eleodes obscura var. sulcipennis also occur;
the first one rarely, the last three quite commonly.
The results of three seasons' work in the Pacific Northwest demon-
strate quite conclusively that the false wireworms are among the
most destructive insects to recently planted wheat and corn in this
region. They rank second only to the true wireworms elateridd
larvae).
False wireworms are native and not introduced forms; the climatic
conditions of the country are, therefore, ideal for their existence.
The converting of enormous areas of the scantily verdured sage-
brush prairie into wheat ranches has afforded them a new and
increased food supply and the destruction of the sage hen, badger,
and horned toad has removed their normal foes.

DISTRIBUTION.
The genus Eleodes, to which the beetles treated in this paper
belong, is very closely confined to the Upper and Lower Sonoran
Zones. These beetles do not fly and are therefore more restricted
in their distribution than insects which have a more active means of
dissemination. The mass of the species occur in the Southwest,
while several occur in the arid and semiarid regions of California,
Oregon, Washington, and Idaho. A few species extend into the
Carolinian Zone in Kansas, Nebraska, and Iowa, Eleodes tricostata
having been collected as far east as Independence, Iowa.
Eleodes pime/ioides, however, seems to be an exception to this
general rule, and is very nearly confined to the northwestern por-
tion of the Transition Zone, only occasionally being found in the
Sonoran where this zone merges into the Transition. Specimens
have been collected in the very humid coastal region of Washington,
as well as in semiarid regions of this State, of Idaho, and of Oregon; in
the Rocky Mountains at Helena, Mont., as well as at very nearly sea
level on Vancouver Island. The species is predominant in the semi-
arid Transition of Washington and Idaho, the region commonly
known as the Palouse country. The southernmost records of this
species are Lake County, Cal.; Elko, Nev.; Wasatch, Utah; and
Garland, Colo. It extends east to the middle of Colorado and north
to Vancouver, British'Columbia.
Eleodes letcheri vandykei has been collected at The Dalles, Oreg., by
Messrs. Hubbard and Schwarz. Dr. E. C. Van Dyke has taken this
K species in Modoc County, Cal., and we have found it to be the pre-
dominant species in the Big Bend region of Washington. All of
i these localities are well within the Upper Sonoran Zone.






PAPERS ON CEREAL AND FORAGE INSECTS.


Eleodes opaca is apparently confined to the Plains region easto
the Rocky Mountains, specimens having been collected in centni
and eastern Colorado, western Kansas and Oklahoma, north
Texas, all of Nebraska, and southern and eastern South Dakota,,::
Eleodes suturalis occurs over about the same region as E. o0U
with its variety texana Lee. extending southward into New M '7
and southern Texas. "I
THE WORK IN THE BIG BEND REGION -OF WASHINGTON. .i

On May 28, 1909, an oat field at Govan, Wash., was examin...
This field had been almost completely destroyed by true wireworws
besides these, many larvae of Eleodes letcheri vandykcei were found t|i
the surface of the ground, evidently forced out by the unusually late,
heavy rains of the preceding day. These latter were by far too fet!
in numbers to have destroyed the oats. Bluebirds (Sialia mexwzia
occidentalis) were noticed feeding in the fields in large numbers Oft|
the exposed Eleodes larvae. Many of the larvae were also found .iii
the ground at a depth of from 3 to 5 inches, in small spherical cells,
wherein they lay in a curled position. These were considerably!
softer and paler colored than those found in an active condition".
The work in 1910 started early in April when the false wireworms
were to be found scatteringly throughout the grain fields, the graim
having just sprouted. K
Adults were first observed in 1911 on April 17, the day being
quite hot, but the weather up to this time having been very cool"
The beetles were to be seen at about 3 o'clock in the afternoon Hin
great numbers along all the roadsides, where they were either awk:4
wardly hurrying over the ground or nibbling at the foliage of thiK
very young Polygonum littorale, which is very abundant in thi
region. I
Adults of the larger species, Eleodes obscura sulcipennis, we
usually to be found in or about the burrows of the ground squirr4
(Citellus townsendi) and the badger, 4i
When disturbed, the species of Eleodes have the ludicrous habitll
standing still and elevating the abdomen so that the long axis of t
body approaches the perpendicular instead of the nearly horizQ(n
position it normally maintains while walking or at rest. The 6
beetles to the right in figure 22 are in this attitude. Thus they...
remain motionless for several minutes and finally, if they are
further disturbed, they walk off. If one places the finger near
insect, an oily liquid is excreted from the anal aperture; which .
down over the elytra and abdomen. This liquid is pale yell6iVu
color and makes a dark-brown stain; it has a very characters& ^
strong, astringent, and offensive odor, and is evidently protective ,"
.-B


76





FALSE WIREWORMS OF PACIFIC NORTHWEST


function. Mr. Carl F. Gissler I describes this secretion and the
glands from which it is secreted.
Many pairs were in coitu on the 17th of April, and on the 21st a
female that was confined in a pill box laid four eggs. Between the
21st and 23d, when the female died, she laid 10 more eggs, which,
however, failed to incubate. Females dissected in the laboratory
were found to contain from 92 to 199 eggs. The eggs were found
to lie on the ventral side of the abdomen and to extend upward
and over part of the viscera, filling all the interstices about the
alimentary canal. The eggs were so crowded in the abdomen that
they were quite distorted. Anteriorly the eggs were smaller and
were fastened to the anterior abdominal sclerite by fine filaments.
The mating season lasted about two weeks, but the adults were in
evidence throughout May and June. Well-grown larvae were also
to be found at this time. Many of the adults in the rearing cages, as
well as two individuals observed in the field, were seen to burrow into
the ground. This is accomplished by digging with the front tibie,
which are expanded and armed with spines for the purpose, the tarsi
being folded back out of the way. The loose dirt is conveyed'back-
ward by the middle legs and piled up behind the beetle by the hind
legs. When about one-fourth of an inch of dirt has accumulated the
beetle backs out of the hole, pushing the earth out with the abdomen,
the hind legs assisting in this process by keeping the earth piled be-
hind the abdomen. On examining these butrircws two or three eggs
were found in each. The burrows are filled with earth after the
beetles come out and are from 4 to 8 inches deep.
Rearing cages were established by sinking barrels to the surface
level, filling them with eartj, and fitting vertically onto the top a
galvanized-iron cylinder 10 inches in height and the diameter of the
inside of the barrel top, the open upper end being covered with wire
mosquito bar, with an introduction hole made in the wire screen and
corked.
On April 20 about 30 pairs of mated Eleodes letcheri varndyk'ei were
placed in this cage, which had previously been seeded wNith wheat
and planted to Polygon.num littorale.
By June 25 the beetles were all dead in the cage, probably due to
abnormal conditions as well as age, thinugh no living beetles could
be found in the fields at that time. Small larvae 4 to 5 mm. (about
three-sixteenths inch) in length were then to be found in the cage.
On examining the cage on November 14 the larvae were found to
be about 14 mm. (nine-sixteenths inch) in length and at about a depth
of 12 to 24 inches below the surface. The soil in the rearing cage "
was as dry as powder to a depth of nearly 2 feet, but the desiccation
did not seem to affect the larvae.
'Psyche, vol. 2, no. 58, 1879, p. 209.
243350-Bull. 95, pt 5-12-2


77





PAPERS ON CEREAL AND FORAGE INSECTS.


July 4, 1911, the cage was again examined and the larva we
found to be about 1 j inches long. From early in July to the nQ60:x
of August it became necessary to be away from Govan, where .
experiment was in progress. On returning, August 16, the root o
was examined and two adults found about 6 inches below the surfate:pj,
They were hard and had evidently emerged some days before this
date. When the boards which had been placed over the barrel t."...
protect it during the winter were removed in the spring, a nuimbei'j|
of adults was found that had hibernated under this shelter. On thi
above date and at a depth of about 20 inches a very young fiels 4
wireworm (3.5 mm. long) was found; it was pure white and had-.:i.:!
evidently but very recently hatched. This larva was undoubteWd:f.r
the young of one of these accidentally introduced beetles.
The soil at this time was dry to a depth of 4 inches. On June 25 I
pupa was found in the field, placed in a pill box with dirt, and on the "I.
30th an adult Eleodes letcheri vandykei emerged. In the fields, wh i.ew'I.
a farmer was plowing his summer-fallow-and it may be remarkedii ,
that this is exceptionally late for working the summer-fallow in thi s
country-pupae were found turned out by the plow. A little flock ..:::':
of Brewer's blackbirds (Euphagus cyanocephalus) were walking in the ..
furrow a few yards behind the plow and picking up the upturned :
insects...:
From the middle of July until the grain is harvested adults are to ..i
be found in large numbers under the grain shocks and bundles as they .
stand in the field, and also under grain sacks. Most of the beetles.i,
are quite soft early in the season, but later become hard.

DESCRIPTIONS.
'~ .* -"iriii
Eleodes letcheri vandykei Blaisd. ,

The egg (fig. 23).-The egg is bluntly oval in longitudinal section and circularincrs ;:jJ
section; it measures 1.1 mm. in length and 0.62 mm. in diameter; it is of a pure gm **
tening white color and absolutely without sculpturing. Ovarian eggs measured 1.17.'
mm. in length and 0.74 mm. in diameter. j
The larva (fig. 24).-Elongate, subcylindrical, COen h
vex dorsally, flattened ventrally. Yellowish, venti.
'" *.".".':....' p surface paler, anterior and posterior margins of first:
= *" thoracic and posterior margins of succeeding segmun, ..|j
brown; head slightly brown, edge of mandibles bWk ..
base of mandibles brown; claws, spines on legs, aniltd.
-aa caudal segment dark brown; antenna pale yelow."
FIo. 23.-False wireworm, Eleodes Anterior and posterior margins of first and pos-tior:;
letcheri vandykei: Egg. Greatly margins of succeeding segments with striate .maxgin.
enlarged. (Original.) bands; band on anterior margin of first Begmat'|
broad er and more coarsely striate. Caudal segment scutelliform, flattened domailfY.i
and c, wvex ventrally, bearing 18 stout spines on its margin--4 on each laterat 'at"
gin and 10 on terminal margin; a slight space equal to that occupied by one e .
separates the lateral from the terminal spines. Several long hairs and a basal rw:
. ...ii


78





FALSE WIREWORMS OF PACIFIC NORTHWEST. 79"

of short hairs on caudal segment. Head subquadrate, very convex, distance from
S base to labrum equal to one-half width
of head, sides converging anteriorly, i
posterior angles rounded; two stout hairs
on lateral dorsal, surface; two oblong -
black eye-spots on lateral anterior part,
a large one at base of antennae, and a .
smaller one posterior and dorsad of this.
t Suture arising at base of each mandible 1
flexed laterally and converging posteri- ,-. .
orly to unite with the median suture at a
distance from base of head equal to one- /
fourth distance from base to labrum;
mouthparts usually directed ventrally. ,
Labrum large, basal joint trapeziform,
terminal joint rounded, bearing several L
hairs on margin, both joints margined
anteriorly. Mandibles large, visible from j
above. Labium not covering mandibles,
ligula broader than palpifer; labial palpi
cylindrical, two-jointed, second joint
papilliform; mentum larger than palpifer,
submentum larger than mentum, all ... ..
quadrangular and narrower at base than '
at anterior margin. Maxillse larger than
labium, stipes directed laterally; palpifer '
elongate and directed antero-medially; \
maxillary palpi at about middle of
palpifer, three-jointed, first and second
joints about equal in length, first stouter,
third papilliform. Thoracic legs stout; a M
tird papilliorn.e thoa c ic leg thout; FIG. 24. -False wireworm, Eleodes leocheri vandykei.
first pair longer than width of thorax, a, Larva, dorsal aspect; b, head, dorsil aspect;
second and third pairs one-third shorter; c, head, ventral aspect; d, caudal segment, dorsal
S first pair very heavy, terminal hook as aspect, a, Much enlarged; b, c, d, more enlarged.
Long as fourth joint, second joint bearing (Original.)
2 stout short spines on inner distal margin, third joint bearing 3 marginal spines
Sand fourth joint bearing 4 such spines.
The pupa (fig. 25).-Length 11 mm.,
width 5.3 mm., arcuate dorsally, flat-
Stened to slightly concave ventrally.
S i Entirely white when first pupated but
Si eyes soon become black followed by
I. tips of mandibles; just prior to emerging
Sthe elytra and dorsum of thorax become
i black. Head pressed to the prosternum.
," 1 -. Pronotum very broad and protruding
'B i& anterior to the head, making the latter
Invisible from above. Mesonotum very
:: narrow and scutelliform, with indistinct
S' transverse sulcus slightly anterior to mid-
a die. Metanotum sagittiform, about as
iF. G. 25.-False wireworm, Eleode letcheri vandykdi: broad at anterior margin as mesonotum.
S a, Pupa, ventral aspect; b, same, dorsal aspect. At the base of each elytron and of each
Much enlarged. (Original.) secondary wing pad is a rounded swell-
ihg. Seven abdominal plates visible dorsally. Between dorsal and pleural abdominal





80


PAPERS ON CEREAL AND FORAGE INSECTS.


plates is a distinct depression forming a submarginal groove. The caudal
bears a pair of posteriorly directed spines near posterior margin dorsally and a p .i .
median anal lobes ventrally. Head, legs, and antennae free. Antennse .......
behind first and second pairs of legs and over wing pads. Elytra folded vYeoh.
over the posterior. Ie g .
.y~~Eyes conspicuous.ado-ru""
margin of abdominal
jments bearing maT
tubercles. Body 1wi i
FGhair or bristles. .. or b. i i..i
The adult' (fig. 26).-ME,#
or less shining, elytr ptW
pubescent. Antennm |, |
the third joint scaxcely: am
long as the next two coi.4
bined, fourth joint a mm. I
..... "haraclonger than the fifth, ii
Slater slightly longer i
the sixth, the latter and ..
seventh equal. .u... .....o h
Pronotum usually wid$
at the middle, frequenwA
widest just in front of .40e
middle. H 4
Ely tra irregularly *ad.
quite densely muricawrI
punctate, very minutely f,,J
on the dorsumr, coarer CaW niM
the sides and apex; ;
each puncture arises a rattlw.1
short, stiff, curved, imdonn.
spicuous and semirecuaA.:
bent seta. These are nht'ii.
evident on the inflend::
sides. K
FiG. 26.-False wireworm, Eleodes letcheri vandykei: Adult, dorsal Ole"chuu4Y
aspect. Much enlarged. (Original.) Otherwise as in rbt.9
but a little more robust.-....
Measurements.-Males: Length, 14.5-16 mm.; width, 5-6.5 mm. Females: Length,*:':
15-16 mm.; width, 7.5 mm.
Genital characters as in letcheri.

Eleodes pim.elioides Mann. i
The egg.-Oval in longitudinal section and circular in cross-section; 1.34 mmt. "
length and 0.85 mm. in diameter; pure glistening white; without sculpturing oaf. h
pI
kind. 7
The larva.-Elongate, cylindrical, convex dorsally, flattened ventrally. Yellow$%:
first thoracic and eighth abdominal segments brownish, ventral surface paler, ar
and posterior margins of first thoracic and posterior margins and anterior subm".g"a4
areas of succeeding segments brown, a distinct pale median vitta; head brow 4
posteriorly, edge of the mandibles black, base of the mandibles brownish; claw
spines on legs, and caudal segment brown; antennae brownish. Anterior iazrgi 4i
first thoracic segment excavated, posterior margins on all segments except Co.
'The description of the adult given herewith is taken from "A Monographic Revision of the JCO)W
tera, belonging to the Tenebrionide Tribe Eleodlini, Inhabiting the United States, Lower 081h( 4
and Adjacent Islands," by Frank E. Blaisdekl, Sr. Bu]. 63, U. S. Nat. Mus., p. 136, 1909.





FALSE WUIBWQOR3MS OF PACIFIC NORTHWEST.


81


F depressed, faintly striate. Caudal segment sciitelliform, slightly convex dorsally,
margined laterally, tip curved slightly upward, bearing 18 acute spines on margin-
S 4 groups of 2 spines each on each lateral margin and 2 spines at tip. A number of
hairs on dorsal surface and many on ventral surface. Head suhquadrate, very convex,
sides converging anteriorly, posterior angles rounded, 2 hairs on lateral dorsal and
several hairs on ventral surface; 2 black eye spots on lateral anterior part of head, a
large oblong one at the base of antennae, and a smaller square one posterior and dorsal
of this. Suture arising at the base of each mandible flexed laterally and conv urging
posteriorly to unite with median suture near base of the head. Basal joint of labrum
trapeziform, terminal joint rounded, trilobed, hairs on margin. Mandibles large,
visible from above. Ligula broader than pilpifer. labial palpi cylindrical, 2-jointed,
second joint papilliform, mentum larger than palpifer, submentum larger than men-


FIG. 27.-Falss wireworm, Eleodes pimelioides: a, Adult, dorsal aspect; b, caudal segment of larva, dorsal
aspect; c, caudal segment of larva, lateral aspect, a, Much enlarged; b, c, more enlarged. (Original.)
turn. Legs 4-jointed. Second joint of anterior legs with 2 short stout spines on inner
anterior margin; third joint of anterior legs with 3 longer spines on inner margin, and
fourth joint with 3 still longer, stout spines; 2 spines on inner side and 1 spine on outer
side of base of claw.
The pupa.-The pupa of this species is very similar to that of Eleodes letcheri van-
dykei, from which it can be distinguished, however, by a pair of rather stout spines at
the apex of the secondary -wing pads.
The adult (Fig. 27).'-The following description is from page 384 Dr. Blaisdell's
monograph previously mentioned in this paper:
Moderately robust, ovate, feebly shining to opaque, about twice as long as wide;
prothorax more or less strongly constricted at base, densely rugoso-punctate; elytra
I Originally described in Bul. Soc. Nat. Mosoou, vol. 16, p. 274,1843.






82 PAPERS ON CERAL AND FORAGE INSECTS.

sculptured with small tubercles, which may be rounded or reclinate and ianin0t
piliferous. Head densely punctate, antenna somewhat slender, ninth j ....!e
gulo-orbicular to transversely oval, tenth more or less transversely oval. "
Pronotum subcordate to transversely suboval, widest near the middle, a .o|m
scarcely a half wider than long; sides evenly and quite strongly arcuate to ibas"l.il
enth, or subangulate at middle, rounded in front and quite rapidly conveugiuq'ill
teriorly and sinuate at basal fourth, thence in each instance quite straight a=4:i:...
allel to the basal angles; base equal to the length or in some males shorter thaw:....
length; apical angles obtuse, frequently not in the least rounded, at other time
or less so.
Elytra quite broadly oval to subquadrate, widest at or behind the middle, a o
to a third longer than wide; disc more or less deplanate on the dorsum, strongly, 11"
ately, and vertically declivous posteriorly; surface densely tuberculate, tubem,..
apparently arranged in rows on th3 dorsum or irregular throughout; each bears a v
short, black seta near the apex; when arranged in rows there are very small mui .....
punctures scattered sparsely and irregularly between, always less distinct along
suture centrally; the tubercles are more or less rounded an4 shining, the in-eed
between more or less opaque. Otherwise as in cordata. A|
Male.-First two joints of the protarsi with tuft of yellowish pubescence near
beneath; that of the second joint is rather small; tuft on the first joint of the mesota"!..
quite small. Tufts somewhat long and truncate at tips. Otherwise as in cordata. 3|
Female.-First joint of the anterior tarsi distinctly thickened at tip beneath. O ,0t.%lii'
erwise as in cordata. 's
Measurements.-Males: Length, 12-14.5 mm.; width, 6-7 mm. Females: Length,
13-15.2 mm.; width, 6.5-8 mm...... I
Genital characters, male.-As in cordata.
Female.-Genital segment triangular, surface quite plain and slightly setose." ii
Valvula.-Dorsal plate oblong, feeble or scarcely narrowed apically, slightly explain-
ate externally; apical margin nearly transverse to feebly oblique, inwardly not dfri i
fined from the surface of the apex, angle obtuse and more or less feebly rounded.
Ventrolateral surfaces.-Submarginal groove distinct and well defined beneath tue .W:
expanded external border of the dorsal plate. Otherwise as in cordata. "
.......:..ii~iil
FOOD SUBSTANCES.. :i

False wireworms are known to feed on the seed of wheat, oats, .i
and corn, on the tubers of potato, on the fleshy roots of sugar beet,
and on several garden crops, as well as on a variety of. dead organic
matter.
If several larvae are placed in a small rearing cage with insuf-i
ficient food they invariably prey upon one another until there i.::
but a single survivor. Mr Swenk1 observed that in cages' whaLtj|
larvae died of a disease their more fortunate survivors ate the dosS
individuals.
The adult beetles have been observed feeding on the seed 4
wheat and corn, on the leaves of corn, on Polygonum littorale and otb !
weed leaves, and on decaying vegetable matter. An adult beetle w'W
kept alive for several months in our laboratory. It was fed."'
wheat and occasionally drank from a piece of wet cotton. '
Journ. Econ. Ent., vol. 2, p. 336,1909. *.





FALSE WIREWORMS OF PACIFIC NORTHWEST.


SEASONAL HISTORY.
The following life history was worked out for Eleodes letcheri
vandykcei at Govan, in the Big Bend region of Washington, and unless
otherwise indicated the data refer to this species.
The adults emerge from hibernation in the early spring, about
.the middle of April, and after feeding for a short time on the leaves
of various weeds, principally Polygonum littorale, mate and start
oviposition. The eggs are deposited a few at a time in the ground,
the adult female burrowing down through the soft dust to the moist
soil below, usually to a depth of from 2 to 4 inches. The average
number of eggs laid by one female is probably about 150. Five
specimens of female Eleodes letcheri vandykei that were collected on
April 30, 1911, were dissected and found to contain 199, 138, 161,
157, and 92 eggs, respectively. Most of these eggs were full-sized
and probably mature, though one female contained 45 eggs and
another 91 eggs which were about one-third full size. A female
Eleodes pimelioides, collected May 1, 1911, at Pullman, Wash., was
found to contain 167 eggs and 2 females of Eleodes nigrina collected
late in April contained 96 and 58 eggs, respectively.
The eggs hatch in about 18 days, the recently emerged larva
being cream-white, but rapidly assuming the normal amber-yellow
color.
The larva feed throughout the ensuing summer, usually on decay-
ing vegetable matter, hibernate, and resume feeding as soon as
the soil becomes warm enough the following spring, but this time
disastrously to the spring-sown grain. In June the larva trans-
form to pupe, and early in July the newly emerged adults commence
to appear. They are quite soft on first emerging and take two or
three days to become thoroughly hardened. These adults feed during
the remainder of the summer, congregating in large numbers under
the grain sacks, shocks, and any convenient shelter. They eat a
small amount of grain and other vegetable matter and go into hiber-
nation without mating. In the spring they resume activity and
mate, thus completing the life cycle. They hibernate under boards,
in squirrel holes, and in the ground. Prof. W. T. Shaw, of the Wash-
ington State College, in digging out burrows of a ground squirrel
(Citellus columbianus), found specimens at a depth of 6 feet below
the surface in the burrows. I have dug out the hibernating beetles
at a depth of about 6 inches in the soil in wheat fields and also in
barrel root-cages.
Larve of Eleodes suturalis were received by Mr. Theo. Pergande1
on October 26, 1898, from McPherson, Kans. These pupated before
May 19 and adults emerged May 30. From this note it would seem
that Eleodes suturalis varies from Eleodes letcheri vandykcei in its life
SBureau of Entomology Notes, No. 8186.


83






84 PAPERS ON CEfEAL AND )oRAGEI IkSttT, e*
... .. .., .. .
history, hibernating as mature larve o" pupa and transfo*.
adults much earlier in the season than the latter. :.. ;
The adults of the species. herein treated seem normn1lly tQ
one season, but Dr. F. E. Blaisdellrecords.keeping adults .........
dentipes in confinement for over four years. ,...
.. :,,,, *iijli~jlJ
NATURAL EfNE S AND PArAgITrS. ....
'" .* .. ., ,,/r;' :.;
The hard chitinous integument, together with the offentte in4
tions, of these beetles render them almost *immune to atta*'f%
birds. Several western vesper sparrows (Pocetes gmaiis u
fias), two horned larks (Otocoris alpestris var.), a lkinlld....'....
(Oxyechus vocferus), a "billy" owl (Speotyto cunicularia ..
and a Brewer's blackbird (Euphdgus cyanocephalus) were shot 'whlbi<
feeding in the grain fields and the stomach contents exam eidig
these failed to show any evidence that the birds had fed on a %th
E le o d e s n I 1 II
Of the domesticated birds, chickens and ducks eat adult Egles6Hi
in large numbers. Twenty-five beetles were fed to one hen' a,'ita
were eaten very greedily. Young turkeys would not eat thM& J:|
insects. They would seize the beetle and immediately drop it"W d :
shake the head violently as though they disliked the taste, nA."
after two or three similar experiences would learn to recognize thjbeha:
insects and would not touch them. '
A large number of these beetles were fed to confined pheaa t :"
and though the conditions were very abnormal, the results mayh"i.)
suggestive. Reeves pheasant (Phasianus reevesi) anid the silflh,?
pheasant (Genneus -nychthemerus) ate the beetles freely, while thiii&
golden pheasant (Chrysolophus pictus) and the Lady Amherst p13hea-li
ant (Uhrysolophus amherst,) refused even to notice the beeite.,
However, these birds seemed quite annoyed by our presence, ak# I
might have eaten the beetles had they not been frightened. .Nos
Chinese pheasants (Phasianus torquatus) were available, so we wea
not say whether or not these birds would be of any value as enemitM *al!
of E leodes. K:.
From several sources we were informed that the sage hen (enfit H
cercus urophasianus) feeds largely on these beetles, the crop at atin !
being gorged with the black chitinous fragments. In the record o:i(l
the Bureau of Biological Survey of this department the f0llowg110
birds are listed as feeding more or less extensively on adult Eleod ti
California shrike (Lanius ludovicianus gambeli), road-runner (Geococcyx caulfbrM.|
nus), Lewis's woodpecker (Asynde&s*us lewisi), western crow (Corvus bracmhvsWq
heasperis), bronzed grackle (Quiscalus quiscula zmeus), red-headed woodpecker Cb
nerpes erythrocephalus), curve-billed thrasher (Toxostoma curvirostre), hairy
pecker (Dryobates villosus var.), western mocking bird (Mimus polyglottoa ..O ..;
terus), western robin (Planesticus migratorius propinquus), the field plover (g..B.
longicauda), the mallard (Anas platyrhynchos), and the baldpate (Mareca ame'indii)




FALSE WIREWORMS OF PACIFIC NORTHWEST. 85

.i Dr. Blaisdell1 refers to the ground owl (Speotyto cunicularia
Iiypogsa) as one of their enemies, and further states that the butcher
S 4ird impales them on thorns.
[ .It is very generally known among the farmers of the wheat regions
S of the Pacific Northwest that the Brewer's blackbirds (Euphagus
c yanocephalus) follow the plow and eat the "white worms" (Eleodes
S pupm) when the summer-fallow is being worked. The birds are to
S be seen walking in the furrows and flying away with their beaks
S filled with the soft white pupae.
* The western bluebirds (Sialia mexicana occidentalis) were seen at
Ii" Cvan, Wash., in large flocks feeding on the larvae which had been
Driven to the surface by an unusually heavy rain.
The stomachs of several horned toads (Phrynoso-ma douglasii
d ouglasii) were examined and found to contain fragments of Eleodes
S larvae, but several of these toads kept in captivity refused to eat
the adult beetles, though they would feed voraciously on other
S beetles. These little horned toads, or, as they are locally known,
S sand toads, are without doubt one of the most valuable animals in
; the western dry-farming regions. In the Southwest a larger species
(Phrynosoma cornutum), with long stout spines on the head, sup-
plants the former species. These toads move very rapidly and eat
S enormous numbers of insects. The garden toad (Bufo sp.) is re-
corded in the files of the Bureau of Biological Survey as feeding on
Eleodes. Dr. Blaisdell 2 gives the skunk as a natural enemy of
these beetles.
In the files of the Bureau of Entomology there is a note (No. 8186)
by Mr. Theo. Pergande, wherein he records having received two
Slarvae from McPherson, Kans. These pupated, and later one of
these pupae was killed by an ant (Tetramorium cispjitum).
Another of Mr. Pergande's notes records receiving an adult of
f Eleodes suturalis from Mr. C. E. Ward, of Belvidere, Nebr. This
I beetle was placed in a cigar box, and on examining the box on the
S following morning a large number of larvae were noticed crawling
I about. These larvae later spun cocoons around the edge of the box
S and were believed to be microgasterid parasites that had issued
I from the beetle. The adult parasites were later determined as
S Perilitus n. sp., and these are preserved in the National Museum
I collections.
S "The author found an adult beetle with the abdomen nearly filled
S by a nematode worm, but lost the specimen, making further deter-
mination impossible. Mr. Myron Swenk' records a disease, prob-
ably caused by bacteria or a fungus, that attacks the larvae. The
|Bul. 63, U. S. Nat. Mus., p. 29, 1909.
Loc. cit., p. 29.
PL',: Proc. Ent. Soc. Wash.,-vol. 2, pp. 211, 219, 1S92.
..Jour. Econ. Ent., vol. 2, p. 335, 1909.







first symptom of this disease is a small red spot on one of
segments, usually on the first thoracic or the terminal
segment. This spot enlarges, finally encircling the body, and-"A
a very short time the insect succumbs. This disease was
lent as to interfere with much of Mr. Swenk's experimental
REMEDIAL AND PREVENTIVE MEASURES.
If a field is well stocked with false wireworms at the time wbq.
is sown, remedial measures are of little avail, as was demonstrl"
by our experiments carried out in the Big Bend country of W
ington. The insects are well adapted to the present agdicu1tI
practices of the spring-wheat growers in the Pacific NorthwI
Here the plowing of summer-fallow land is commenced as ea*|
possible in the spring, which in the average season is id April. Th
who can spare teams and men often commence while the see gi
the crop in other fields is in progress. The most progressive farvi
then disk their fallow land in June so that this will be well fiahi
when haying commences. :*
By slightly modifying this procedure an enormous numbwa:..
these beetles would be destroyed. Instead of plowing eail
the spring and disking in summer, reverse the process. DisI
early as the land can be worked and the apparatus is avaiU
which will usually be in April. This will conserve the moisture fI
as well as plowing. Then plow as late as possible; if the land has 1
well disked and the men and horses can be spared, it is well to d.
this plowing to late July and early August. At this time the ht
are in the pupal, or, as they are commonly called, "white-worj
stage. They can not move through the ground as can the atk
larvae, but can merely squirm when irritated. The plowing, Iwh
should be deep to be effective, turns out great numbers of th
pupe, and they are either eaten by birds or killed by the burit
sun. Many more are destroyed by being crushed or suffocated I
the broken pupal cells. Aside from killing many Eleodes pup .
this practice of late plowing the summer-fallow would greatly aid i
weed eradication. The early disking would not bury the weed se.
to retard germination; all the seed would develop; then the late pl0
ing would destroy the entire crop of weeds. If the weeds start.V
early, a second disring may be necessary, as weeds very ra .
deprive the soil of its moisture. .
Concerted effort and very thorough work are absolutely essential I
render this treatment appreciably effectual. The cooperation of
the farmers over a considerable area is advised, as the adult beefi
walk rapidly and will readily reinfest a well-treated ranch, comingI
from an adjoining, poorly worked field or pasture.




FALSE WIREWORMS OF PACIFIC NORTHWEST.


S This treatment is by no means advocated for those farmers who
find it impossible to disk their summer-fallow, as leaving the land
rt untouched until July would cause all the accumulated winter's
i moisture to evaporate, and the plowing would simply be stirring the
.. dust and be of no value whatever.
I In the spring of 1910 a series of experiments was carried out at
I: Wilbur, Wash., to determine the value of certain substances alleged
i to be useful as poisons or repellents against elaterid larva. Eleodes
alarve were also quite numerous in the fields where these experiments
w were carried out; hence mention of the results, though relating prin-
cipally to another insect, may not be out of place here.
Seed in bulk was treated with the following substances: Lead arse-
nate, at the rate of two-thirds of a pound per bushel of seed, dissolved
Sin water; strychnine sulphate, at the rate of two-thirds of an ounce
per busheL-of seed, dissolved in water; coal tar applied until seed
was all coated, then sanded until dry. The substances were stirred
into the grain thoroughly with a wooden paddle and then allowed to
dry several days.
The experiments were sown in strips with a wheat seeder 11
feet wide and one-half of a mile long. Untreated check strips were
planted between each treated plat.
Just after sprouting the percentage of damage done by insects
Swas estimated by counting the damaged and undamaged seed in
Several areas of 1 square yard each in each plat. The results were
entirely negative as all the plats, including the checks, were about
equally attacked.
S These treatments, even had they been found efficient, would have
Seen impracticable from an economic standpoint. The poisons were
too expensive and the application too expensive and laborious, and,
Sin addition, the coal-tair treatment, even after drying several days,
Sso- clogged the seed cups on the seeder as to cause very uneven dis-
Stribution of seed.

I?
"i,:
i: ., "


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