526 



INSECTS AT HOME. 



If a 'stung' caterpillar be carefully dissected, so that the skin 

 is removed from the body, the space between tlie digestive 

 organs and the skin, wliich ouglit to be occupied by a layer 

 of fat, is found to be literally stuffed witli the tiny wliite 

 grubs of the ^licrogaster. 



The fatty substance on which these larvae feed is intended 



1. Microgaster glomei-atiis. 2. Mj-mar pulchelhis. 3. Tcleas elatior. 4. Cleonvmus ma- 

 cnlipeniiis. a. Tele.is, antenna, female. b. Do., antenna, male. c. Microgaster, larva 

 in caterpillar of cabbage-butterfly. d. Microgaster alvearius, cocoons. 



as material from which the future butterfly is to be evolved. 

 But, as it is almost entirely consumed by these internal foes, 

 the insect seldom has sufficient streno'th to effect its chanoe 

 into the pupa — much less into the butterfly. Just in propor- 

 tion as the fat decreases, the Ichneumon larvas increase, so that 

 to the eye the caterpillar looks quite plump and liealtli}^, when 

 it is in reality absolutely emaciated. Yet the presence of these 



