Collecting and Preserving Insects 



gauze, are frequently used to advantage in this work, and glass 

 jars — from the small test-tube to the large morphine bottles and 

 fruit jars and up to the large battery jars — all may be used in 

 rearing different kinds of insects. The large, so-called Riley 

 breeding cage, shown at Figure 256, is a good one, especially if 



Fig. 257. — Comstock improved base for breeding cage. (After Riley.) 



it is used with the improved base invented by Professor Com- 

 stock, shown at Figure 257. Some very good breeding jars are 

 sold by the dealers in entomological supplies, but most workers 

 prefer to construct their own cages. 



All earth used in rearing insects in the cages or in the bottles 

 should be sterilized and sifted. This is necessary in order to 

 destroy disease germs, in order subsequently to regulate the 

 amount of moisture, and in order to destroy predaceous mites 

 and other insects which might be the cause of damage or con- 

 fusior . In my office we prepare earth readily and in bulk in a 

 galvanized iron oven 2% xi^xi foot. The cover is roof- 

 shaped, and lifts off by a central handle. There is a circular 

 orifice in this cover to emit steam and facilitate drying. The oven 

 stands on legs and is heated by a single gas jet from a Bunsen 

 burner placed beneath. After tv/o hours' heating the moisture 

 becomes dissipated, and the earth becomes dry and is readily 

 sifted. It is then passed through a sieve, and is in proper condi- 

 tion to use either in large boxes for underground insects or in the 

 ordinary breeding jars and cages. 



397 



