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Psyche 4:123-129, 1883.

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PSYCHE.
ON THE LIFE-HISTORIES AND IMMATURE STAGES OF THREE E UMOL PIN/.
RY STEPHEN ALFRED FORBES, NORMAL, ILLINOIS. [ With Plate i .]
The three species to which this paper
is devoted ( Colaspis hwnnea Fab.,
Pana aferrima Oliv., and Scelodonfa
ftibescens Mels.) , live underground in
the larval stage, and feed upon the roots of the strawberry (Fragaria, vesca L.) . The larvae of all three often occur
in the same localities and situations ;
they are extremely similar in general
appearance, two of them (Paria and
.Sce/od&zta) being, indeed, almost in-
distinguishable ; and their food-plants
and food-habits are identical. They have consequently not been discriminated
heretofore, even where they have been
collected in considerable numbers and
studied with some care ; and their
life-histories, as far as made out, have very naturally fallen into some confii-
sion.
The following account is based upon
almost continuous observation of one of
the species, upon breeding experiments
y ith all three, and upon numerous col-
lections of all, made from August 1882
to December 1883, mostly in southern
Illinois. where all are abundant in
strawberry fields.
COIASPIS BRUNNEA Fab.
Literature.
The firht undoubted reference to an
immature stage of this beetle, which I
have found. is in the 3rd report of the
state entomologist of Missouri (C. V.
Riley), for 1871, 13. 81-84, in which the larva is described and figured, and record is made of the fact that it feeds upon
the roots of the strawberry. A brief
outline of its life-histoly is also given, but in terms to show that it was not at
that time distinguished from the larva
of Scelodon fa.
In his report as state entomologist for
the following year, p. 34, Mr. Riley
again described this larva from numer-
ous specimens, and figured the dorsal
and ventral aspects of the head, a sepa- rate mandible, and one of the ventral
segments. The description given of the
mandible and of the anal segments, and
the figure of the former, do not apply
exactly to the larva of Colas-$& and it
is possible that the specimens upon
which this second description was based
belonged to one of the other species.
In the American entomologist for
ISSO, v. 3, p. 243, Mr. Riley repeats
his original figures of the Colasfis larva ; and this form has since been mentioned
frequently in various economic publica-
tions, but without any further additions to oily knowledge, either of its characters or of its history. The pupa has remain-
ed hitherto unknown.
Description.
Larva. (PI. I, figs. 7-8.) This spe-
cies is 3 to 4 mm. long by one-half that width, white throughout, except the




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124 PSYCHE. (January-February is$-
head and the first segment, which are a
pale, yellowish brown. The first seg-
melilt is leathery and smooth above, and as Iong as the two following together;
but each of the remaining eleven seg-
ments is marked 011 the back by about
three transverse dorsal folds, which ter- minate on the skies in large, low eleva- tions, pointed-ovate in form (the pointed ends being upwards), one to each seg-
ment of the body except the first and
the last.
The first spiracle is liirger than the
remaining eight, arid placed between the first ancl second,thoracic segments. The others are situated at the lower eiscis of the ovate elevations mentioned above,
and just within a tortuous longitudinal
groove, which separates these elevations from a series of proiniiient tubercles
which extend along the sides, one tuber- cle to each segment. Still beneath the
first mentioned row of tubercles is ail- other longitudinal groove, and a second
series of tubercles ; and these again ;ire separated from the transverse ventral
.
ridges by still another irregular longi- tudinal groove. Finally. the ends of
these ventral ridges tire cut off oblique- ly by a. series of grooves, each extend- ing from before backwards and inwards,
thus forming n fourth series of eleva-
tions. on a line with the legs.
In CoZasjIs, the elevations of this
last series have the form of thick,
fleshy tubercles which project down-
ward beyond the general ventral surface. each bearing about ten hairs of varying
lengths, the three or four longest of
which are longer and stouter than any
others on the larva. The hairs on the
ventral ridges between these tubercles
form an unbroken row. They are about
nine in number, alternately longer arid
shorter, with very many short ones inter- mingled; the longest being about as
long as the corresponding segments.
The twelfth ventral segment (fig. 7E)
is deeply and widely einarginate pos-
teriorly, divided, in fact, into * two
triangular plates, between which the
unusually developed thirteenth segment
appears. These lateral plates are fringed with spines on the posterior two-thirds
of their inner margin. The thirteenth
or anal segment is likewise longitudi-
nally divided beneath.
These two segments taken together
are about one and a half times the length of the pre'ceding one; and their dorsal
arches are likewise relatively elongate, being scarcely, if at all, shorter than
the next segment in advance,
The legs are about as long its the tho-
racic segments to which they are at-
tached. and are white, with the excep-
tion of the claws, which are dark brown
at the tips. They are provided with a
few slender white hairs, which become
shorter and more spine-like toward the
end of the leg.
The head is smooth. somewhat flat-
tened in front, with a few slender, scat- tered hairs. The clypens is trapezoidal, and the anterior edge ,of the labrum
(fig. 7D) is convex. The antennae
(fig. 7A) are situated just outside the
bases of the mandibles. They are mi-
nute white, four-jointed, the two basal
joints short and quadrate, the second




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January-February 1884.1 PSYCHE. 125
and third together as long as the first. The outer distal angle of the third joint is continued as a cylindrical process,
which reaches to the end of the joint
following.
The mandibles (fig. 7C) are rather
narrow (the
width being about two-
thii-d-s the length), strongly curved,
comparatively broad, and obtuse at tip.
where they are ernarginate, or some-
times trifid.
Each bears two long, slen-
der hairs at its outer base.
The cardinal and basal pieces of the
maxilla (fig. 7Bc) are not clearly dis-
tinct ; the maxillary lobe is stout, round- ed at the tip, and convex internally,
with about ten spines, of varying
strength,
along the inner margin, the
two basal ones being very strong, and
about half the length of the lobe. This
last extends only a little beyond the
second joint of the palpus. The palpi
(fig- 7Bd) are prominent and four-
jointed, the third joint longest, about
equal to the first and second together.
und the fourth slender and cylindrical.
The labium (fig. 7Bb) is thick and
quadrate, without distinct palpigerous
tubercle, and bears on its under surface two slender, cylindric;il, unarticulate
palpi (fig. 7Ba), which are about as
long as the third joint of the maxilla,
and taper slightly distally.
Pupa. The pupa is 3.5 mm. long
by 2.5 mm. wide; white, except the
eyes and the mandibles, which show
through the outer envelop red or black.
The front of the head is set with a
few long, stout hairs, articulated upon
slender, conical tubercles ; and three
similar rows of hairs appear upon the
thorax, one near the anterior border,
another near the posterior, and a third
intermediate. Six other liairs occur
upon the scutellum, and a row of about
six or eight borders each one of the
abdominal segments above.
The anterior inferior angle of the tibio- femoral articulation of each leg bears a stout, curved hook, that on the first pair of legs being very small. Eii~h of these articulations is likewise armed with two long hairs borne upon slender, conical
tubercles. The sheaths of the antennae
are tuberculate externally,
r 7
1 he posterior segments of the abdo-
men are peculiarly armed. The last
(fig. 7F) terminates in two simple,
incurved hooks, and bears in front of
these a pair of stout lateral spines,
projecting directly outwards ; while a
similar but smaller pair of backward-
projecting spines is borne by the penul- timate. .
'The imago is said by Dr. Fitch to
appear in the latter part of June, con-
tinuing t111-011gh the month of July.
Mr.
Riley. in hi5 third Missouri report. says that pupation commences in June, the
beetles appearing in that month and con- tinning to issue from the gro~iild until fall Larvae of this species were first seen
me in southern Illinois on 19 May, at
which time they were about half-grown.
On 28 June, full-grown larvae and ima-
gos were found in the earth, in straw-
berry fields, the iimagos having, of
course, just transformed. Adults again
occurred in the earth on 9 July, but by
18 July all had emerged. -As early as




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126 PSYCHE. [ Jftnnt~v-Ftbnuiry 4%.
4 July the? appeared in stubble fields, paring the characters of the larva, as and were found from the beginning in
described by Prof. Cook, with those
sweeping- the leaves of the strawberry,
supposed to disthgiiish Colaspis,
where they continued common until i
Prof. Cook's article, in a revised form, , August. They were also taken in vine-
was also published by the State agri- -
yards, feeding upon the leaves bf grapes, cultural society of Michigan, in its re- on I I July.
port for the year ending August 3ist,
Careful and repeated search in all 1880, p. 373. Another account of the situations suited to their development larva, with some additional notes upon failed to discover either larvae or pupae its habits, was given b$ the present wri-- again during the year; and I have no ter in the Transactions of the State hor- doubt that the species is single-brooded, ticultural society of Illinois, for 1883, and think that it completes its trans-
p. 199, and again, in the following year, formations, under ordinary circumstan- in a paper on Insects affecting the ces, by I August. ' strawberry, published in the Transac- Numerous collections made in Octo-
tions of the Mississippi valley horticul- her, November and December, through-
tural society for 1883, p. 77 and aldo
out the region where these beetles ap- issued as a separate pamphlet- This peared abundantly earlier in the yew, description was somewhat fuller thw failed to discover a single specimen any preceding, and was illustrated by a among the thousands of hibernating in- figure of the larva made from a camera- sects encountered; and I am of the lucida drawing, but still insufficient to opinion that this species hibernates distinguish it clearly from the larva bf rarefy, if ever, as an imago, bat believe Colaspis, and applying equally well that it deposits its eggs in late summer or either to Paria or ,to Sceludonta. autumn, probably in the earth about
strawberry roots, Description.
. Larva. Agreeing closely in size,
'*RIA 'liv. ('I. 3 fig. 7 4. ) for^ nppearallce with the Literature.
larva of Cvlaspis, this species may be
The larva of this chrysomelid was
distinguished by the following details : first noticed in 1880, in an article by The brown hairs of the ventral ridges Prof. A. J. Cook, of Michigan, printed are few and short, all shorter, in fact, originally in several western agricultu- than the corresponding segments. The ral journals, andmlater in the report of ends of these segments are cut off by the Michigan sLite horticultural society oblique grooves, and have the form of for that year, p. 293'. This newspaper
triangular tubercles, with their apices
description was republished in the inwards ; but these are not raised at a11 American entomologist- - for October above the general ventral surface. Each 1880, v. 3, p. 242 243, mid a few re-
of them bears from five 'to seven hairs, marks were added by Mr. Riley, corn-
of which about three are longer than




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January-February 1834.1 PSYCHE. 127
the others. The hairs of the median
portion of the ridge are separated into
two groups by a narrow, median, naked
strip. The vent is surrounded by a cir-
clet of ten short hairs. All the hairs of the last four segments are longer and
stouter than those preceding ; and those of the dorsal surfaces of these segments are likewise more numerous
The dor-
sal arches of the last two abdominal
rings are broken into four prominent
tubercles, which are sometimes slightly
blackened, and bear especially strong
spinous hairs.
The eyes are represented by a small
cluster of a varying number of pigment
specks, situated at less than the length of the antenna above its base.
The antennae are three-jointed, very
short, not twice as long as wide, the
length of the basal joint being just about its width. The cylindrical process of
the penultimate joint is segmented off,
forming an apparent accessory article
beside the terminal one. The cly-
peus is about as long as the labrum ;
and upon the middle of the upper sur-
face of the latter are four long hairs,
arranged transversely ; and at the infe- rior edge of the posterior surface are
eight strong hooks or spines, pro-
jecting inwards and backwards. The
maxillary palpi are strong and thick,
the two basal joints being broader than
long, the third about as long as wide,
and the fourth ovate. The tip of the
third joint extends scarcely beyond the
end of the blade of the maxilla. The
latter is not longer than broad, andiis
armed with about ten stout, blunt spines at its inner margin.
The general form of the mandibles
(fig. 6B), seen from above, is triangu-
lar, the length being scarcely greater
than the width
at their base.
The tip,
seen from beneath, is obtuse and more
or less conspicuously emasginate, often
decidedly lobed, in whic1-1 case the lobes are equal. It is never trifid, and never acute. Occasionally this bilobate char-
*acter of the mandibles is indicated by a longitudinal groove, which scarcely ren- ders the tip en~iirginate.
The anal segment of this larva is used
as a proleg, the grub looping along on a smooth surface after the manner of a
phalaenid larva.
Pupa. The pupa may be distin-
guished by differences in the armature
of the posterior segments of the abdo-
men, especially the last (fig. 6A). This terminates in a pair of brown, chitinous hooks, which curve dorsally, instead of
inwards as in Colas$is, each being fur-
nished with a strong, erect tooth or
spine arising from the 11pper side of the bsise. From the middle of the concave
margin of each hook springs a long
slender hair. The spines in front of
these anal hooks proiect directly back-
wards. This pupa is further distin-
pislied from that of Colas$is by the
absence of spines up011 the anterior infe- rior angle of the tibio-femoral articula- tion of the first and second pairs of legs. Last April the adult beetles were
found not uncommonly in strawberry
fields in southern Illinois, 11aving evi- dently lately emerged from their winter




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quarters ; but the most careful search of fields infested by root-worms yielded no Pa~ia larvae. On 18 May, the adults
were again obtained in considerable
numbers, by sweeping the foliage of
strawberries ; and 011 15 June a few were seen in the ground about the roots of
the plants. On 20 July, larvae and pu-
pae of this species were found among the strawberry roots, adults also occurring' on the foliage ; and on 26 July all stages were sent me from I~nsing-, Michigan.
From I to 10 August, larvae, pupae
and imagos were collected in southern II- linois. 011 11 August, the larvae and
pupae were noticeably less common than
before, but the images were now more
abundant on the leaves, and several were taken from cavities in the earth. Some
larvae and pupae taken from the ground
on I August, were kept in earth (after
careful study of tlie living- specimens for subsequent identification) until they
transformed, one beetle emerging on I I
August.
On 24 August, the earth was ex-
amined and three more adults were
found. These were the last iin mature
examples seen, only scattering adults
occurring in our collections during Sep- tember, October, and November. On
8 December they were taken in ahnn-
dance under leaves and rubbish on the
pound, hibernating in tlie strawberry
fields.
Evidently, here we get no glimpse of
a second brood, either early 01- late. but find the beetles wintering as mature in- sects, probably laying their eggs in the ground in June, the adults appearing-
again late in July and in August.
[ January-February 1884.
SCELODONTA PUBESCENS Mels.
(PI. I, fig. 2.)
The -larva and pupa of this species
have hitherto remained unknown.
Description.
Larva.
The description of the larva
of Paria afewi?na, given above, will
answer for this species also, point by
point, with the exception of characters
drawn from the mandibles (fig. 5C).
The tips of these are us~ially entire, and rather obtuse, although rarely irregular- ly lobed, or trifid, the central lobe being then much the most prominent. The
inner edge of the mandible is excavated
.
on the distal third, like that of Paria. Pupa. (PI. I , fig. 3.) The pupa
of this species is indistinguishable from that of Pariq except by the fact that the terminal hooks of the abdomen (fig. 5
A) are smaller, more slender, destitute
of the basal spine and of the hair spring- ingfrom the convex margin.
Life-Histo?;~.
My first specimens of the larva of this
species were obtained in August 1882,
two half-grown individuals and one
adult beetle occurring in a small collec- tion of insects made at that time in
southern Illinois. On I I September,
large and small larvae were found de-
vouring strawberry roots, and a single
adult was obtained by sweeping- in the
field. On g November, full-grown lar-
vae were abundant. all having gone into
winter quarters in oval cavities in the
earth. They occurred at various depths,
from 2.5 to 10 cm.. and often at con-