Article beginning on page 328.
Psyche 9:328-329, 1900.

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328 PSYCHE. [April, 1902
A NEW SILPHID BEETLE FROM A SIMPLE INSECT-TRAP.* BY A. LEONARD MELANDER, AUSTIN, TEX.
The curiosity of an investigating ant
may sometimes lead it to destruction.
During the month of November last,
having had occasion to use a large quan- tity of the common Texas "stinging red
ant " (Pogonomyrmex barbatus var. mole-
faciem Buckley) we selected as the easiest and quickest method of capture a novel
expedient. A number of four-ounce
bottles were sunk in the gravel nest-heap dose to the entrance, nearly to the level of the ground, and then were left opened. The ants ready to resent this disturbance immediately hurried up the little embank- ment to the open bottles and in their pre- cipitous rush fell headlong over the edge, after which they were unable to crawl
up the smooth surface of the glass.
After the first excitement the ants
largely neglected the traps but now and
then a passer-by would peer over the
edge, doubtless called there by the stricl- illation of the ants within, and losing its insecure foothold would topple over into the bottle.
In the course of our regular visits to
these automatic traps we noticed that in the early morning each bottle invariably contained one or more specimens of a
small fly that quickly effected its escape at the slightest noise.
After several
vain attempts the flies were at last secured by simply corking the bottle, and upon
--
*Contributions from the Zoological Laboratory of the University of Texas No. 28.
examination proved to be a form belong-
ing to the cave-dwelling genus Leria
(BZ@haroptera), L. $ectinuta, originally described by Dr. Loew from this state.
The propensity of this species to seek
a bottle as a substitute for a burrow
opens a new and interesting field for
collecting rnyrmecophilo~~s and cavern-
frequenting insects.
That this fly is
probably a true myrmecophile, habitually using the burrows of the agricultural ant as its domicile, is quite possible, and
even probable when we consider that
only the bottles sunk in the ant-nests
yielded specimens, though numerous
bottles had been arranged as control
experiments in the open fields close by, and moreover even if placed on the ant-
bed the bottles never contained a fly
when there were no ants within.
Aside from the Lena and the ever-
present Eleodes tyicostata, which in its capacity of scavenger is always found
scurrying over the ant-beds, another
insect was taken in great numbers.
This one; an exceedingly active litLle
Silphid beetle, is closely related to
Ptomophagz~sparasttus Leconte, another
ant-guest, which has been taken in the
Eastern States in nests of Formica.
The
present beetle belongs to the division
Catopomorphus of the genus, but dis-
tinctly differs from its relative in the approximation of the elytral strigae, and in its selection of a host of another sub- Pwht 9 328-129 tprc-1901). htlptlpsyclirnilclub or@@-328 html



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family - a biological difference that
must not be underrated.*
Although a number of the flies and
beetles were confined in the bottles with the ants for several days they rested
unharmed, evidently the closest iulimacy existing between the three. The beetles
would run about among the ants or fly
in the bottle with a quick darting move- ment, but at no time were the ants
observed to molest either of their guests. This is interesting especially in the case of the Lcria which has never before been found associating with ants, and which,
were the ants unfriendly toward it, might be supposed to have accidently used the
ant-burrow in place of some other suita- ble excavation.
Ptomophagzis iexiinus sp. 11ov.
Length 2.75-3. mm.
Form elongate oval,
Mordellid-like, slightly narrowed posteriorly ; color dark castancous, sliinin& thorax almost piceo~is. Head, thorax, and elytra uniformly, closely and finely strigose, the strigsic pro- vided with short closely-placed, uniform, golden yellow pubescence; that of the head radiating from the vertex, that of the thorax and elytra directed straight backwards. An. tennae not. reaching the hind angles of the tho- rax, the first four joints fuscons, moderately slender, the first arid second joints long, joints six to eleven broader and shorter, piceous, the eighth joint. two-thirds as long as the ninth, and not appreciably narrower. Thorax fully two-thirds as long as the width of its base, the sides gradually then quickly narrowing in front; hind angles acute, base feebly but distinctly hisinuate, the nmow hind mnrgin more or less castaneous; disc of the thorax stri~ose as nell as the sides, the strigae conforming more or less with the front
margin. The strigae of the elytra not 11-ans- verse but more or less conforming with the posterior margin : suttn'al stria well impressed nearly to the apex; sutural angles rounded in the male, but provided with a distinct angle in the female. Body beneath finely and sparsely punctate and pubescent, the lemora wholly strigose similarly to the upper surface of the body: tibia1 spurs equal, those ot the hind legs one-third the length of the 1uctatws11s.
Described from ten males, and thirteen
females, taken, as above mentioned, at
Austin, Texas. The front tarsi of the
male are flattened and broadened. The
tips of the tibiae are (imbria.te apically with short equal spines, which, as the
strigosity of the thorax is distinct, further confirm Dr. Horn's statement that these
characters arc correlated in this genus.



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