METHODS OF REARING BEETLES. 



21 



a cellar during the winter, and young beetles were recovered in the 

 spring. Other pupae were removed from the jars and placed in out- 

 of-doors cages. It was necessary to construct an artificial chamber 

 in the earth in which to place each pupa, and this was done success- 

 fully in a few cases. A better plan is to allow the larva to make its 

 pupal cell and not to permit the earth to be disturbed until the fol- 

 lowing spring. 



The method above described of rearing these beetles was so satis- 

 factory that in the spring of 1908 an attempt was made to rear larvae 

 for liberation in field colonies. By holding some of the shipments of 

 beetles that arrived late in the summer of 1907 and placing them in 

 large hibernation cages it was possible to have a stock of breeders 

 ready for use as soon as desired in the spring. 



Fra. 12.— Jars of earth containing eggs of Catatonia sycophanta. They have been placed in the sun 

 to hasten hatching. (Original.) 



The result of the work for the year was the rearing for colonization 

 of 2,300 larvae. During the following year this line of work was con- 

 tinued and 6,100 additional larvae were placed in field colonies, and 

 in 1910 6,380 were reared and liberated. When larvae are being 

 reared for liberation in field colonies it is desirable to hasten their 

 development as much as possible. They are given an abundance of 

 food and the jars containing eggs (fig. 12) are placed in the sun on 

 cool days to accelerate hatching. The method of liberating larval 

 colonies enables the species to become established over a much wider 

 range and also gives it a better chance of surviving, owing to the vary- 

 ing conditions and locations in which it can be placed. 



