22 



BULLETIN 417, U. S. DEPARTMENT OF AGRICULTURE. 



Daily records were kept of one pair of adults in 1909 from July 1 

 to August 23, when the male died. The female died July 26. The 

 latter was received from Washington, D. C, May 18, and fed greedily 

 upon raw beef until May 25. Caterpillars of Malacosoma americana 

 were then supplied until July 1, and large numbers were consumed. 

 One hundred and twenty-six sixth-stage Porthetria dispar caterpillars 

 were consumed from July 1 to August 23. 



In 1911 two pairs of adults were received from Washington, D. C, 

 June 4, and placed in jars. Their feeding records are shown in 

 Table 1. 



Table 1. — Feeding records of two pairs of Calosoma externum, 1911. 



Pair 



No. 



Received 



and 



record 



started. 



Ceased 

 feeding. 



Females 

 died or 

 entered 



hiberna- 

 tion. 



Fifth and sixth stage caterpillars 

 consumed. 



Malaco- 

 soma 



ameri- 

 cana. 



Por- 

 thetria 

 dispar. 



Estig- 

 mene 

 acraea. 



Total. 



5061 

 5062 



June 4 

 ...do 



July 7 

 Aug. 172 



July 7i 

 Aug. 173 



52 

 40 



77 

 153 





129 

 220 



27 



1 Female died; record closed. 



2 Record closed because of scarcity of food. 



s Original female died July 5; another added on same date. 



The usual custom is to discontinue feeding records when the female 

 dies, but with No. 5062 another female was added on the same date 

 and the record continued as long as food was available. The record 

 was stopped August 17, but the pair was not transferred to a hiber- 

 nation cage until August 26. Neither of the females included in Table 

 1 reproduced in 1911, which partly accounts for the comparatively 

 small amount of food consumed, namely 129 and 220 caterpillars, 

 respectively. 



One pair of adults (No. 5097) fed in 1912. The female emerged 

 from hibernation May 27 and died August 3 ; the male died July 24. 

 One hundred and one full-grown caterpillars of M. americana, M. 

 disstria, and P. dispar were consumed during the time and the female 

 deposited eggs during the season. 



The records at hand would indicate that the capacity of this species 

 for consuming food is somewhat less than has been found with some 

 other species of the genus. The records of C. externum secured are, 

 however, rather incomplete, and more caterpillars would have been 

 destroyed under natural conditions. 



REPRODUCTION. 



During the season of 1909 one pair of beetles reproduced very 

 sparingly. The male was received June 7 and placed with the female 

 on that date. On June 27 eggs were found in the jar, and on July 1 

 the pair were noted in copulation and again eggs were seen. They 

 were scattered through the earth in the jar, but only two hatched, 

 and no larvae were reared. 



During 1911 several beetles were received from Washington, D. C, 

 in June and July, but no reproduction resulted that } 7 ear. The 

 beetles entered hibernation in the fall and lived to emerge in the 



