INSECT N0TI&5. 275 



Test with Lot of 8 ground-beetles. 



May 13. They were given 8 negro bugs (Connie! cena puli- 

 caria) and one Cosmopepla carnifex. May 18, 3 negro bugs 

 and the C. carnifex had been eaten. A crushed live negro bug 

 offered them was devoured at once. They showed hesitation 

 in attacking live ones. Their jaws seemed to find little pur- 

 chase when they tried. Four beetles were observed to bite at 

 the same negro bug, but their jaws slipped off every time with- 

 out harm to the bug. 



May 18. A sowbug which had been with them for 5 days 

 was still alive and unharmed. 



May 18. They were given an unbroken cecropia pupa, which 

 they soon punctured at the abdominal rings and gorged as 

 much as their bodies would hold. 

 Test with lot 23 ground-beetles. 



May 10. They ate on this date 3 cut worms (a little less 

 than 1 inch long), 2 tarnished plant-bugs and 1 wounded sow- 

 bug. 



May 11-12. They devoured 5 unwounded sowbugs and 1 

 Cosmopepla carnifex. 



May 13. They disposed of the half of a beetle S erica ves- 

 pertina that was cut for them. 



May 15. They were offered small eggs but remained indif- 

 ferent to those that were broken for them as well as the whole 

 ones. 



These ground-beetles seem a little shy about attacking their 

 prey, but when the first pair of jaws have pierced the chitinous 

 skin the other beetles gather about and there is soon nothing 

 left of the soft parts of the victim. If a morsel is small enough 

 a beetle grabs it and runs, often with several beetles after him. 

 At the body of an insect too large to be dragged much they pile 

 up one above another devouring the prey, or if others crowd 

 them away they bite viciously at one another for a place. They 

 nip at one another between the thorax and abdomen or pinch 

 each others' legs. One beetle had one of his legs bitten off 

 between the femur and tibia by another who was trying to drag 

 him away from a cutworm. 

 Test zvith the rove-beetles or Staphylinids. 



These beetles ate tarnished plant-bugs, negro bugs (C. puli- 

 caria), Cosmopepla carnifex and cutworms. Three Staphy- 



