Saturniidae 359 



emergence end may be modified so that the moth cannot later escape 

 from the cocoon. 



Care of the Cocoons. The cocoons are best kept out-of-doors in woven 

 wire or screen cages if they are to overwinter. Otherwise the pupae are 

 injured or killed by a shortage of moisture, and without exposure to cold 

 do not usually come out of hibernation satisfactorily. Refrigeration is 

 possible in keeping the pupae over winter. On one occasion the writer 

 kept thirteen hundred cocoons in a refrigerator room where the humidity 

 was high and the temperature held constantly at the freezing point. 

 Ninety-eight per cent of emergence occurred the following spring, mostly 

 during a brief period of about two weeks. Refrigeration at about 42 ° F., 

 however, sometimes proves highly fatal to the pupae, and should be 

 avoided. Apparently this temperature is too high for complete 

 dormancy and too low to sustain development. 



Reference 

 For the rearing of Hemileuca, Automeris, Tropaea lima, and Callosamia see p. 365. 



BREEDING LYMANTRIID AND SATURNIID MOTHS* 



William Trager, Rockefeller Institute for Medical Research 



EGGS and pupae of lymantriid and saturniid moths may be readily 

 obtained from professional collectors. 

 Eggs are placed for hatching in small covered glass dishes (diam. 7 

 cm., volume 150 cc). The newly hatched larvae are kept on twigs of 

 food plant placed in the same dishes, the dishes being inverted over pieces 

 of blotting paper to absorb excess moisture and facilitate removal of the 

 excreta. The larvae are transferred to fresh leaves as often as the old 

 leaves dry out. In transferring, they are gently shaken off the old leaves 

 on to the fresh ones and are handled as little as possible, and then only 

 with a soft brush. Larvae which cling tightly to their substrate, and those 

 about to molt, should be put on fresh food together with the leaf to 

 which they are attached. After the first molt the caterpillars are put 

 in larger containers and it is well to put them in wire gauze cages as soon 

 as they are large enough to be unable to escape through the mesh. The 

 larvae may also be kept outdoors on growing plants surrounded by suit- 

 able cages. When kept indoors, the trouble of providing a constant 

 supply of fresh food may be somewhat reduced by placing twigs of the 

 food plant in a bottle of water with the opening plugged with cotton to 

 prevent the caterpillars from crawling in and drowning. Leaves supplied 

 in this way must be changed at least every other day. As the larvae get 



♦Abstracted from "Die Zucht der Lymantriidae und Saturniidae'' by K. Pariser in 

 "Methodik der wissenschaftlichen Biologie," T. Peterfi, Verl. Julius Springer, Berlin, 

 1928, Bd. II, S. 290-300. 



