20 



CALOSOMA SYCOPHANTA. 



METHODS OF REARING PREDACEOTJS BEETLES. 



Late in July, 1907, several beetles which were received in ship- 

 ments from Europe were placed in jars with earth, one pair in each, 

 and fed with caterpillars daily until they refused food, and entered 

 the ground for hibernation. The earth was examined for eggs at 

 the time new food was added, but only one pair reproduced. It was 

 necessary to remove carefully the caterpillars that had been killed 

 by the beetles each day, to keep the jars from becoming foul and to 

 prevent the development of certain mites (Tyrogly pints sp.) which 

 feed on decomposing animal matter, after which they attack the 

 beetles and their larvae, causing serious injury and sometimes death. 



Fig. 11.— Outdoor insectary used for rearing Calosoma beetles. | original. I 



When eggs were found the beetles were transferred to another jar, 

 which was given the same number as the one originally assigned, the 

 first jar being kept under observation for larvae. 



The number of larvae that hatch is usually taken as the index of 

 the number of eggs deposited. It is impracticable to remove the eggs 

 from the earth to make accurate counts, as they are easily injured 

 in handling. 



Several of the larvae that hatched in August, 1907, were fed in 

 separate jelly glasses containing a small quantity of earth, and later 

 they were transferred to cages out of doors, to enter the pupal stage. 

 A few pupated in earth in large jars, and some of these were placed in 



