MAINE AGRICULTURAL EXPERIMENT STATION. 59 



in length and bulge a little in thickness, the skin at the same 

 time growing tougher and slightly darker. The insect is known 

 in this form as the pupa, and rests in this stage all winter. 

 With the return of summer a second transformation takes place 

 when the tough skin which has covered the pupa all winter is 

 broken open by the adult insect (a fly with dark bands on its 

 wings) which has developed inside the pupal case. This mature 

 fly spends its life laying eggs in the flesh of young apples, thus 

 starting a new generation of apple maggots. 



The maggot, pupa, and adult fly are shown in the accompany- 

 ing illustration, enlarged about 3 times. (Fig. 24). 



Maggot. Fly. Pupa. 



Fig. 24. 



The apple maggot enlarged 3 times. 



PREVENTIVE MEASURES. 



As pointed out here, it is useless to try to poison the growing 

 maggots as they are within and protected by the apple. It is 

 also evident that if the maggots contained in windfalls and 

 picked fruit are destroyed one year there will be no trouble to 

 fear from them the next. Of course it is highly improbable 

 that even by the greatest vigilance, every maggot could be thus 

 destroyed. But when it is considered that each maggot left to 

 its own devices has a chance of becoming a fly capable of lay- 

 ing at least three hundred eggs, and that each maggot unde- 

 stroyed this year may mean three or four hundred next year, 

 the importance of killing as many as possible is evident. If the 

 apple maggots, as do many insects, all developed about the 

 same time, the problem would be much simpler, but as full 

 grown maggots are found in apples from before the middle of 

 August until into the winter, the watch for them must extend 

 over several months. 



