54 



CALOSOMA SYCOPHAXTA. 



Table XI. — Feeding records of 4 pairs of old Calosoma beetles. 1910. 



Pah- No. 



Emerged 

 from 



hiberna- 

 tion. 



Ceased 

 feeding. 



Male 



Female 



Sixth-stage caterpillars 

 consumed. 



died. died. 



Tent. 



SS : ™*- 



4808 



May 25 

 ...do 



July 20 July 25 July 12 

 .do July 24 



102 

 95 



*>04 1 s 306 



4809 



194 | 3*>89 



4810 



Mat 26 



June 3 



i July 7 - Tulv 11 



237 3 294 



4811 





2 July 5 i J-Q 



179 3393 













1 Added male Xo. 4811. 2 Record discontinued. 3 Females laid eggs. 



Table XII. — Feeding records of Calosoma beetles, 1910. 



Tair Xo. 



Emerged 

 from 



hiberna- 

 tion. 



Ceased 

 feeding. 



Female 

 died. 



Sixth-stage caterpillars con- 

 sumed. 



Tent. 



Gipsy, 

 moth. 



Salt 

 marsh. 



Total. 



Old males, youns: females: 



4812...'. May 26 



July 18 

 Aug. 9 



Aug. 2 

 July 18 





110 

 87 



104 

 105 



106 

 97 



357 

 125 



4 



°16 







188 



Young males, old females: 



4814 June 3 



Aug. 3 



1401 

 2 230 

















Female laid eggs. 



2 Female laid eggs: did not hatch. 



These tables show, on the average, that the old Calosoma beetles 

 consume more food than young ones. This is undoubtedly due to 

 the greater reproduction which is common with the former. 



The average for the old beetles was 328 caterpillars and for the 

 young beetles 239, while the average for all the pairs given in Tables 

 X, XI, and XII is 272 caterpillars. This is a fair average, as nearly 

 as can be determined, of the number of caterpillars that the Calosoma 

 beetles will actually destroy. In the field probably the number would 

 be increased, as feeding under natural conditions would undoubtedly 

 stimulate activity and appetite. 



In addition to the large number of experiments that has been 

 carried on to determine the amount of food that will be eaten by 

 Calosoma beetles that emerge from hibernation at the normal time, 

 several series were conducted with beetles that were taken from 

 hibernation in March, April, and May. These beetles did not become 

 active and begin feeding for a considerable time after the cages were 

 removed to a warm room in the laboratory, but as small caterpillars 

 of various species, particularly brown-tail moth larvae that were 

 being fed in the laboratory, were used for food, large numbers were 

 destroyed before midsummer. Most of these caterpillars were small 

 and as soon as the Calosoma beetles became active large numbers 

 were required to satisfy their hunger. 



The average number of small brown-tail moth caterpillars eaten 

 by 3 pairs of Calosoma beetles removed April 9, 1908, was about 



