PREDACEOUS BEETLES. 103 



the opinion, however, that they would not fly upward, but 

 simply extend their wings to lessen the velocity of the fall. 



Calosoma scrutator (Fab.) has been found to be fully a,s 

 active, particularly as regards climbing, as frigidum, and, 

 on account of its greater size and strength, is a more for- 

 midable enemy to caterpillar life. The amount of good done 

 does not depend entirely on the number of larvae which the 

 beetles actually eat, as when food is plenty they kill or 

 mutilate a great many which they make no pretence of eat- 

 ing, as is shown by the following statement. Mr. Harry 

 Vinton, while working in a colony of the gypsy moth in 

 Saugus, during June, 1897, saw a C.frigidum kill or wound 

 seven of the caterpillars on a tree trunk and then disappear 

 among the brush. All the larvte were so badly disabled that 

 they could not recover. 



The representatives of this genus are found principally in 

 the spring and early summer, and after laying their eggs 

 probably remain in the ground. This has been found to be 

 the case with the beetles kept in confinement in cages. After 

 midsummer the food supply is usually less plentiful, and 

 these beetles probably do not feed on vegetable matter dur- 

 ing the latter part of the season, as do some other Carabids. 

 Harpalus caliginosus (Fab.), for example, was taken Sep- 

 tember 23, feeding on the flower-heads of the ragweed (Am- 

 brosia artemisioefolia), one of our most common garden 

 weeds.* Professor Forbes, in his studv of the food of 



*/ 



Carabidse, found, from dissecting three C. scrutator and nine 

 C. caUdum, that only food of animal origin was present in 

 the stomachs. He also emphasizes the fact that the mouth 

 parts of this genus are adapted for animal rather than vege- 

 table feeding.f 



*The Calosomas, aside from being able to hibernate as ima- 

 goes, can also live an almost incredible length of time without 

 taking food. The following notes may be of interest in this 

 connection. A single female of Calosoma ivillcoxi~Lec., kept 

 in confinement, ate nothing from June 30 to August 18 ; 



7 ~ o 



several specimens of C. frigidum, confined in a breeding 



* This observation corroborates those of Wm. Trelease ("American Entomolo- 

 gist," 1880, p. 251) and Wm. A. Buckhout (ibid., p. 277). 

 t Bulletin Illinois State Laboratory of Natural History, Nos. 3 and 6, 1883. 



