EFFECTS ON THE HIGHER INVERTEBRATES 63 



in 11 days of starvation; another lost 70 per cent in 17 days; while a larger 

 Papilio podalirius lived only ten days with loss of 29 per cent. The loss 

 of the corresponding pupae is much less, being only 7.8 per cent for the Hylo- 

 pkila in 30 days. The loss is relatively greatest in the latter part of the fasting 

 period for the pupae, but in the earlier part for the imago. Kellner ('87) noted a 

 slight prolongation of the larval stage in underfed silkworms (Bombyx mori). 

 Kellogg and Bell ('03) found that underfeeding the larvae in this species causes 

 dwarfing of the moths, the effect being decreasingly evident in the second and 

 third generations. They further ('04) noted that starvation of the larva one to 

 four days does not affect the time of metamorphosis, or the size or fertility of 

 the moth. Starvation of four to seven days, however, reduces the last inter- 

 moulting stage, resulting in a normal (though smaller) cocoon and moth. Death 

 occurs if the larva is starved eight days or more. The cocoon loses about four 

 per cent of its weight on the first day. The pupa loses slightly but steadily 

 during the pupal period (2-10 days), with total loss of about 14 per cent. 

 In the Tent caterpillar (Clisiacampa) and the Mourning-cloak butterfly 

 (Euvanessa antiopa) the loss is steady but greater, amounting to 35 and 65 

 per cent, respectively. Kopec ('24) during intermittent starvation of the larvae 

 of the moth, Lymnantria dispar L., found a considerable prolongation of the 

 larval life with a slight abbreviation of the pupal period. The body weight 

 is decreased and the adipose tissue exhausted. Kopec ('24a) further noted that 

 when the female moths derived from starved caterpillars are mated with normal 

 males, the eggs laid are reduced in number but apparently develop normally. 

 The spermatozoa of the male moths from starved caterpillars appear normal, 

 and are capable of fertilizing normal eggs, but the resultant larvae show a 

 higher mortality and the pupae appear dwarfed. Thus inanition is more injuri- 

 ous to the male than to the female. 



As to the effects of inanition upon the sex of butterflies, Treat ('73) found 

 a larger proportion of males resulting from underfeeding the larvae of Papilio 

 asterias, Vanessa antiopa, and Dryocampa rubicunda. Poulton ('93) found no 

 evidence to indicate that the sex in Smerinthus populi can be determined by 

 external conditions. "It may be admitted that the larger female larvae 

 require more food, chiefly to prepare for the amount of material to be stored up 

 in the ova. It would not therefore be at all surprising if the female larvae were 

 starved before the males when a minimum food was supplied." Cuenot ('99) 

 cited the negative results of Riley, Bessels, Briggs, Andrews and Fletcher in 

 starvation experiments on butterfly larvae. Kellogg and Bell ('04) likewise 

 obtained no evidence that underfeeding the silkworm larvae produces an excess 

 of males, although they ('03) found fertility greatly reduced. Kopec ('24a) 

 obtained similar results. 



In the underfed silkworm larvae, Kellogg and Bell ('03) also found great 

 individual variation in the resistance to inanition. The time required for 

 metamorphosis is abnormally prolonged, usually with five moults instead of 

 four, and the silk-production is greatly reduced. Pictet ('05, '05a) also found 

 in malnourished butterflies a prolongation of the larval period, with shortening of 

 the pupa period. There is also an imperfect pigmentation of the imago, which 



