Insects Injurious to the Fruit of the Apple 



^905 



weather. If the fniit is ripening and if the weather is warm, the larvse 

 may become fuUy developed within two weeks after hatching from the eggs; 

 while on the other hand if the fruit is hard and green and if the weather 



Fig. 106. — Apples infested by apple maggots, cut open in order to show decaying 



interior 



is cold, the maggots do not mature so quickly, and the time of emergence 

 from the apples may be deferred for months. A case is on record where in 

 January maggots were observed leaving the apples in storage. The presence 

 of maggots in the fruit usually hastens decay and causes the apples to drop 

 to the ground. When the larva becomes full-grown, it leaves the fruit 

 by a small ragged exit-hole in the skin, burrows an inch or so into the 

 ground, and its skin contracts and hardens to fonii a tough leathery 

 protective covering known as a 

 puparium (Fig. 107), which some- 

 what resembles a grain of wheat. 

 Within this puparium a series of 

 remarkable changes takes place, in 

 which the organs of the larva are 

 broken down and made over into 

 those of the adult, or fly. By the 

 end of the second day the true pupa 

 is formed within this protective 

 covering, and the head, legs, and 

 wings of the fly become apparent. 

 In this stage the insect spends the 

 winter, and the following spring the fly emerges through a circular spHt at 



the head end of the pupariimi. In New York, however, during the 

 120 



Fig. 107. — Puparium of apple maggot, 

 enlarged. Natural size shown in upper 

 right-hand corner ■ 



