42 



CALOSOMA SYCOPHANTA. 



for each individual larva provides an excellent way of handling them, 

 but when large numbers are to be reared for field liberation it is 

 desirable to adopt some method that will save as much time as pos- 

 sible and at the same time insure the development of most of the 

 specimens. Owing to the cannibalistic habits of the Calosoma larvae 

 in all stages it is necessary to furnish large quantities of food if many 

 are to be fed in the same container. If these conditions are main- 

 tained a considerable number of the larvae can be fed in the same jar 

 or cage until after the second molt. 



Early in August, 1908, 5 newly hatched larvae were placed in a 

 Fiske tray (fig. 17) without earth. They fed in this tray and molted 



twice before showing 

 any inclination to 

 attack each other. 

 After this time 3 of 

 the larvae were killed 

 by their comrades 

 and as similar experi- 

 ments gave the same 

 result it is apparent 

 that they can not be 

 kept longer in close 

 quarters. 



Another experi- 

 ment was tried using 

 a large Fiske tray 5 

 feet long and 2 feet 

 wide. Ten Calosoma 

 larvae 2 days old were 

 placed in it with food 

 and a quantity of 

 leaves. Eight larvae 

 passed through the 

 first molt success- 

 fully, 6 through the second — these were left in the tray — and at the 

 time of the final examination only 1 remained. Apparently some of 

 them grew faster and killed the others while searching for food. 



In another test where 5 small larvae were placed in a small Fiske 

 tray and were removed after they had molted once, all survived. 



The facts thus obtained have been made use of in rearing larvae for 

 field liberation. Ten to fifteen Calosoma larvae were placed in a large 

 battery jar containing earth, and plenty of food was supplied. The 

 larvae were removed usually after molting once, but in some cases they 



Fig. 17.— A "Fiske tray" for feeding gipsy moth caterpillars. Asec- 

 tion at the top has been sawn out and bent back to show the 

 tanglefooted band which prevents the caterpillars from escaping. 

 (Original ) 



