BULLETIN OF THE BROOKLYN ENT. SOC. 7 



BIOLOGICAL NOTES 



ON SOME 



GENERA OF TENEBRIONID^E. 



BY CARL F. GISSLEK. 



How easily certain genera of Tenebrionidae become adapted not 

 only to an entirely different climate, but also to a but partially 

 imitable medium, unlike their former manner of living, is drawn 

 in the instance of Eleodes gigantea, Mann. — 



Since fully two years these beetles live in one of my breeding 

 cages. 



Gonzales, Monterey Co., Cal. where they were collected, is sit- 

 uated in a beautiful valley, 30 miles from the Pacific Ocean 



Snow is there an unknown thing : the rainy season begins in 

 February and lasts till middle of April ; the thermometer never 

 sinks below 38° Fahrenheit. — 



During the winter 1877-78 I kept the cage in a cold room and 

 put it into a warmed room in January "79. 



Every sudden change of temperature seemed to incite their 

 sexual impulse, as I noticed that they copulated less in even tem- 

 perature. They appeared to be similarly influenced on sprink- 

 ling the ground and moss on which they walk. 



The oviposition occurs during the whole year, though it sets in 

 more frequently in the later part of fall. I have not yet succeed- 

 ed in obtaining the chrysalis-stage from the 40 mm. long larvae, 

 which are casting off their skin every five or six days. 



For the same length of time I kept a single pair of Coelocnemis 

 magna, Lee, received from the same locality. 



As a peculiarity I have to mention, that the small (23 mm. long) 

 male rarely descend from the back of the larger (33 mm. long) 

 female, which is not the case with Eleodes. 



Both, male and female, possess the characteristic tibial groove 

 with silky pubescence (see Horn, Revision of U. S. Tenebri- 

 onidse p. 335) ; in the male the tibial tip is feebly thickened 

 and I may add ''slightly curved," which is also the case, though 

 less defined, with the middle and posterior tibiae in the same sex. 



This curvature, together with the broadened intercoxal process 

 of the abdomen and the "pedinoid" form of the elytral epipleurae 

 (this is lacking in Eleodes, except E. pedinoides), also the present, 

 sexual dimorphism, — all illustrate the law of adaptation to in- 

 herited conditions. 



