56 



CALOSOMA SYCOPHANTA. 



with the exception of the few days from June 19 to June 26, when 

 caterpillars from other and unsprayed localities were used. One 

 male Calosoma died July 18 and a female died on July 29. The other 

 beetles went into hibernation at the normal time. The experiment 

 indicates that neither of the beetles that died was injured by the food 

 supply. It is probably true that most of the caterpillars taken from 

 the sprayed area had no great amount of poisoned leafage in their 

 bodies, otherwise they would have died. Under natural field condi- 

 tions Calosoma beetles of this species may migrate from sprayed 

 areas, either immediately after spraying or as soon as caterpillars 

 commence to show the effects of the poison, as the caterpillar food 

 supply is greatly reduced and the beetles naturally seek localities 

 where caterpillars are plentiful. 



Experiment in Feeding Calosoma Beetles on Beefsteak. 



Calosoma beetles that were placed in cold storage August 15, 1908, 

 were removed in March and May, 1909, and as the supply of gipsy 

 moth caterpillars was very limited at that time they were furnished 

 with beefsteak for food. In each case the beetles fed on it for about 

 a week, but selected caterpillars in preference whenever they were 

 available. At the end of a week they seemed to become tired of 

 steak and seldom fed on it. These observations show that tins spe- 

 cies will probably eat raw meat to a limited extent if forced to do 

 so by hunger, but that caterpillars are always preferred and selected 

 for food whenever they can be found. 



Starvation Experiments with Calosoma Beetles. 



May 26, 1910, 2 pairs of young Calosoma beetles that were pupse 

 in the fall of 1909 and 2 pairs of old Calosoma beetles that were 

 received from Europe in the summer of 1909, and hibernated in cages 

 in the laboratory yard, were placed in jars of earth, 1 pair in each, as 

 soon as they came out of hibernation, to determine how long they 

 could live without food. 



Table XIII. — Starvation experiment to determine the length of time the adult Calosoma 

 sycophanta can live without food. 



Calosoma sycophanta. 



Date 

 emerged 



from 

 hiberna- 

 tion. 



Date 

 male 

 died. 



Length of time . Date 

 male lived with- , female 

 out food. died. 



Length of time 

 female lived 

 without food. 



Young pair. 



Do 



Old pair 



Do 



1910. 

 May 26 



..do 



..do 



..do 



1910. 

 June 26 

 June 29 

 July 17 

 June 30 



1910. 



1 month July 9 



1 month 3 days ! July 5 



1 month 21 days... June 26 

 1 month 4 days , 0) 



1 month 13 days. 

 1 month 9 days. 

 1 month. 

 P) 



1 This female, after living without food for 1 month and 21 days, was offered several full-grown gipsy 

 moth caterpillars July 17, ~and ate 2 in 10 minutes. The next day a male was added, copulation was 

 attempted several times, but without satisfactory results. The female died July 30 without depositing 

 eggs. During the 12 days the pair were in the jar 33 sixth-stage gipsy moth caterpillars were eaten. 



