THE LEPIDOPTERIST 71 



without producing a moth. In the Saturnids the oc- 

 currence seems not to be rare, as I remember having 

 had a larvae of S. pavonia L., which also pupated with- 

 out having made a cocoon. This also happens some- 

 times when the adult larvae has been disturbed in the 

 spinning act ; when interrupted in spinning the larvae 

 usually starts spinning again, but sometimes it seems 

 unable to do so. Whether such abnormal pupae ever 

 hatch is not known to me. 



Concerning cases of abnormal oviposition ; it seems 

 that the odor of the food-plants attracts the female 

 and stimulates its laying instincts, but errors are fre- 

 quent, and the eggs are often attached to objects or 

 plants near the food-plant, as I observed in having 

 Plusia clirysitis ovipositing in a cage on nettle, but 

 also occasionally on the walls of the cage. To induce 

 Noctuidae to oviposit, it is recommended to put the 

 leaves of the food-plant into the box^ but the eggs 

 will not necessarily be deposited on the plant. In 

 1915, Dr. Glaser brought me a caterpillar of 

 Colias philodice, to which an egg of this species had 

 been attached, another case of error in oviposition. 

 If eggs are deposited in wrong places, the 

 larvae will, of course, perish unless they succeed in 

 eventually reaching their food plant. If eggs of 

 the Gipsy moth, for instance, have been laid on a 

 house-wall, there is small chance for the young cater- 

 pillars to reach some tree near by^ but many of them 

 will soon be exhausted and perish. There is no 

 reason to assume that the young larvae of Papilio 

 usterias would have been able to feed on wafer ash, 

 just because an e^gg has been laid on this plant ex- 

 ceptionally. I think it most likely that the asterias 

 female was just about to deposit an egg on the car- 

 rots, etc., when it was disturbed or chased away ; the 

 egg was then placed on the nearest plant which the 

 butterfly found on its way. 



It would be interesting to cover some of these 

 plants with a screen or netting and observe whether 

 the Papilio will deposit eggs on the outside when un- 

 able to reach the plants themselves. 



