PREDACEOUS COLEOPTERA. 383 



fifteen days before the second was put in, destroyed thirty- 

 one caterpillars and three pupae ; and, after the other beetle 

 was put in with it, the two destroyed fifty gypsy moth 

 caterpillars and one Sphinx drupiferarum caterpillar before 

 July 24, when the first beetle died. The remaining beetle 

 destroyed four gypsy moth caterpillars, one sphinx cater- 

 pillar and one male gypsy moth between July 24 and July 

 30. Another Calosoma scrutator was then put into the cage, 

 and August 5, when they were placed out of doors, they had 

 killed eight caterpillars, three pupae and two female moths. 



Two specimens of Calosoma frigidum (Plate 53, Fig. 

 1) , male and female, were put into a cage together at the in- 

 sectary, June 28, and supplied with gypsy moth caterpillars. 

 This species is much smaller and more active than C. scru- 

 tator. They are not so clumsy, but are able to seize the 

 caterpillars and destroy them while on a vertical surface, as 

 on the trunk of a tree. July 27, one of these beetles died, 

 and the other was removed to be used by the artist. Dur- 

 ing this time they killed ninety-two gypsy moth caterpillars, 

 three pupae and one female moth. 



Three other individuals of this species were put into a 

 cage in the insectary, July 21, and supplied with gypsy 

 moth caterpillars. One of the beetles died the second day, 

 and on August 5 the other two were placed in an outside 

 cage. During the fifteen days that these beetles were fed 

 in the insectary they killed thirty-nine gypsy moth cater- 

 pillars, two pupae, two sphinx caterpillars and one cut- 

 worm. 



Calosoma calidum. Three specimens of this beetle were 

 placed in a cage July 12, and supplied with gypsy moth 

 Caterpillars. July 19, twenty-three caterpillars had been 

 killed, and another beetle was put into the cage. July 27, 

 one of the beetles died, the four having killed thirty-four cat- 

 erpillars and one pupa since July 19. Fifteen gypsy moth 

 caterpillars, four pupse, eight cut-worms and two Sphinx 

 drupiferarum caterpillars were killed between July 27 and 

 August 5. 



One specimen of Carabus serratus was supplied with 

 gypsy moth caterpillars, and killed five before it died. 



