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 " {Pogo/wmyrmex harbatus var. mok- 

 faciens 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 

 close 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 strid- 

 ulation 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. 2S. 



examination proved to be a form belong- 

 ing to the cave-dwelling genus Lena 

 {B/ep/mrop/era), L. pcctinaia, 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 myrmecophilous 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 nnt- 

 bed the bottles never contained a fly 

 when there were no ants within. 



Aside from the Lcria and the ever- 

 present Eleodcs tricostata, which in its 

 capacity of scavenger is always found 

 scuriying over the ant-beds, another 

 insect was taken in great numbers. 

 This one. an exceedingly active little 

 Silphid beetle, is closely related to 

 Ptomophagus parasitus 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- 



