THE GENUS CALOSOMA. 



29 



caterpillars per pair. The writers believe that the average would be 

 slightly lower than this if more experiments had been conducted, 

 especially if some of the females did not oviposit. In two of the 

 experiments the beetles fed unusually late and the records were 

 started somewhat earlier than the normal time of activity in New 

 England. The average feeding period of this species about Wash- 

 ington, D. C, is probably from May 15 to Sept. 1 or 15, and in New 

 England from June 1 to Sept. 15. 



From a lot of larvae that hatched September 23, 1909, two pairs of 

 adults issued from cavities at the bottom of jars between November 

 16 and 21, and immediately came to the surface in search of food. 

 The beetles were kept in jars of earth in the laboratory at a tem- 

 perature of about 72° F., during the day. Various living insects 

 were offered for food and none of them was refused. The feeding 

 records are given in Table 3. 



Table 3. — Feeding records of two pairs of young adults of Calosoma scrutator, fall of 



1909. 



Pair 



No. 



Insects eaten. 



Num- 

 ber. 



Pair 

 No. 



Insects eaten. 



Num- 

 ber. 



2857 





i 4 



12 



29 



1 



31 



2558 



Full-grown Pontia rapse caterpillars . . 

 Full-grown Tenebrio molitor larvae 



Total 



22 





Full-grown Carpocapsa pomonella 



23 





Full-grown Pontia rapae larva? 



P. rapx pupa 







Full-grown Tenebrio molitor larvae . - . 

 Total 







77 



45 











i Females. 



On December 15 all the beetles buried themselves in the earth for 

 hibernation and the jars were transferred to the laboratory cellar 

 where they remained until the following spring. In this experiment 

 the beetles came to the surface and fed as soon as they entered the 

 adult stage. Adults of C. sycophanta seldom do this, but remain in 

 the pupal cavity until the following spring. In feeding, the beetles 

 showed no preference for the species mentioned in Table 3. These 

 were supplied because they could be most easily secured. 



This record was obtained Under laboratory conditions and would 

 not apply under natural conditions in New England. It indicates 

 that late fall emergence of the beetles may take place in the southern 

 range. 



REPRODUCTION. 



The largest number of eggs deposited in a single season by one 

 female was 396. Records were kept of five pairs that reproduced in 

 1909 to show the number of eggs deposited daily by each female. 

 These records are given in Table 4. 



