362 Phylum Arthropoda 



watch glass was a circle of wire netting to prevent the moths from fall- 

 ing into the liquid. Black cloth was substituted for wire netting as a 

 cover for the bottles containing the foliage and the wick of absorbent 

 cotton. Since the moths of both species are very sluggish during the 

 day no difficulty was experienced in moving them from one cage to 

 another. 



Although leaves and other debris were placed in the cages of the 

 columbine borer, eggs were rarely laid anywhere but on the bottom. No 

 debris of any kind need be provided, thus making it easy to find and 

 count the eggs. Eggs of the iris borer are placed in clusters of from 2 

 to as many as 150, carefully glued down. Although females deposited 

 their eggs on dried leaves, they also pasted them on practically every- 

 thing in the cage that had a rough or crinkled surface. The females 

 evidently prefer to lay their eggs between two surfaces as clusters were 

 often placed in folds of cloth or between two pieces of paper toweling. 



Eggs were collected from the cages in the fall and placed in salve 

 boxes. These small boxes were buried in dead leaves in large cartons 

 and these in turn were kept out of doors all winter. When hatching was 

 desired in the spring the eggs were brought inside and placed on the soil 

 beside iris or columbine plants growing in pots. Larvae were hatched as 

 early as March, although outdoors they did not hatch so soon. These 

 larvae found their way to the plants and developed satisfactorily under 

 these nearly natural conditions. 



References 



For the trapping of Catocala see p. 337. 



For the trapping of Noctuidae in general see p. 364. 

 Family Arctiidae 



For the rearing of Utetheisa, Euchaetias, Hyphantria, Halysidota, and Ammalo 

 see p. 365. 



Family bombycidae 



METHODS FOR THE LABORATORY CULTURE OF THE 

 SILKWORM, BOMBYX MORI 



William Trager, Rockefeller Institute for Medical Research 



METHODS for the large scale rearing of Bombyx are readily avail- 

 able in books and government publications. I will attempt here 

 merely to describe the technique used by Dr. R. W. Glaser and those in 

 his laboratory in connection with studies on silkworm diseases. 



The silkworm eggs (which may be obtained from a dealer) are kept at 

 room temperature in groups of about 50 in small glass dishes. The larvae 

 hatch within 10 to 14 clays, and are provided with a mulberry leaf on 



