ATTACKING THE FRUIT. 135 



abundance as to do much damage to the fruit-crop. In 

 Southern Illinois and in some portions of Missouri it has 

 proved destructive, but in most of the Northern United 

 States and in Canada, although common on thorn-bushes and 

 crab-apples, it seldom attacks the more valuable fruits to any 

 considerable extent. 



No. 60. The Apple Maggot. 



Trypeta pomonella Walsh. 



This is a footless maggot, shown at a, Fig. 143, tapering to 

 a point in front, and cut squarely off behind, which lives in 

 the pulp of the apple, and tunnels it with winding channels, 

 making here and there little roundish discolored excavations 

 about the size of a pea. This maggot is of a greenish-white 

 color, about one-fifth of an inch long, with a pointed head 

 and a pale-brown, flattish, rough tubercle behind it ; the 

 hinder segment has two pale-brown tubercles below. 



The pupa is of a pale yellowish-brown color, and differs 

 from the larva only in being contracted in length ; in this in- 

 stance the true pupa is enclosed within the shrunken skin of 

 the larva. When about to change, the maggot leaves the 

 apple, and, falling to the ground, burrows under the surface, 

 and there enters the pupal state, in which condition it remains 

 until the middle of the following summer, when the perfect 

 insect escapes in the form of a two-winged fly. 



The fly (6, Fig. 143) is about one-fifth of an inch long, and 

 measures, when its wings are expanded, nearly half an inch 

 across. The head and legs are rust-red, the thorax shining 

 black, more or less marked with grayish or white ; the ab- 

 domen is black, with dusky hairs, and with whitish hairs bor- 

 dering the spaces between the segments of the body. The 

 wings are whitish glassy, with dusky bands. This insect is 

 single-brooded, the fly appearing in July, when, by means of 

 a sharp ovipositor, it inserts its eggs into the substance of 

 the apple. It frequently attacks apples which have been 

 previously perforated by the codling worm, and it prefers the 



