THE CHEESE FLY. 313 



Descriptions. 



state appear very little different. It appears that 

 the eggs of this fly are extruded from the uterus 

 into the cavity of the abdomen, and there un- 

 dergo their first change, differing in this respect 

 from most others of the insect tribes. When, 

 the worms have attained their full size (which is 

 generally in seven or eight days) they quit their 

 food, and go in search of some loose earth, in 

 which they bury themselves and undergo their 

 metamorphosis. See plate of insects, fig. 6. 



The Hessian-fly is not quite the fourth part of 

 an inch in length. Its thorax is dark-coloured, 

 but marked longitudinally with two yellow lines. 

 The grubs are white, about two lines in length, 

 composed of ten rings, with the head pointed at 

 the end. These are lodged and nourished in the 

 very heart of the stems of wheat and rye, just 

 above the root, which by their voracity they en- 

 tirely destroy. The chrysalis is yellow, seining, 

 rather more than one line long, and coniposed 

 f rings. These animals are very destructive to 

 corn. 



The cheese- fly is very common, about the 

 tenth of an inch long, and of a dark colour, with 

 whitish wings, each marked with a black rib. 

 The larvae are the troublesome maggots found 

 in cheese, generally called, by housewives, hop- 

 pers. The maggots are surprisingly strong and 

 vigorous, and leap to a considerable distance 

 when disturbed. The maggot, when leaping, 

 erects itself on its tail, and, bending its head into 



VOL. VI. NO. 46. 2 R 



