INSECTS. 131 



which are laid by tte mother on the substances that are to serve 

 for the food of her young. 



The far-famed Hessian fly and the wheat-fly of Europe, and of 

 this country, are small gnats or midges, and belong to the family 

 called CECIDOMYIADJS, or gall-gnats. The insects of this family are 

 very numerous, and most of them, in the maggot state, live in galls 

 or unnatural enlargements of the stems, leaves, and buds of plants, 

 caused by the punctures of the winged insects in laying their eggs. 

 The Hessian fly, wheat-fly, and some others differ from the ma- 

 jority in not producing such alterations in plants. The proboscis of 

 these insects is very short, and does not contain the piercing bris- 

 tles found in the long proboscis of the biting gnats and musquitos. 

 Their antennae are long, composed of many little, bead-like joints, 

 which are larger in the males than in the other sex ; and each joint 

 is suiTOunded with short hairs. Their eyes are kidney-shaped. 

 Their legs are rather long and very slender. Their wings have 

 only two, three, or four veins in them, and are fringed with little 

 hairs around the edges ; when not in use, they are generally carried 

 flat on the back. The hind-body of the females often ends with a 

 retractile, conical tube, wherewith they deposit their eggs. Their 

 young are little, footless maggots, tapering at each end, and gene- 

 rally of a deep yellow or orange color. They live on the juices of 

 plants, and undergo their transformations either in these plants, or 

 in the ground. 



The Hessian fly was scientifically described by Mr. Say, in 1817, 

 under the name of Ceddomyia destructor. It obtained its common 

 name from a supposition that it was brought to this country, in 

 some straw, by the Hessian troops under the command of Sir Wil- 

 liam Howe in the war of the Revolution. 



The head and thorax of this fly are black. The hind-body is 

 tawny, and covered with fine grayish hairs. The wings are black- 

 ish, but are more or less tinged with yellow at the base, where also 

 they are very narrow ; they are fringed with short hairs, and are 

 rounded at the end. The body measures about one tenth of an 

 inch in length, and the wings expand one quarter of an inch, or 

 more. It is a true Cetidomyia, differing from JLasioptera in the 

 shortness of the first joint of its feet, aifd in the greater length of 

 its antennae, the bead-like swellings whereof are also most distant 

 from each other. Two broods or generations are brought to ma- 

 turity in the course of a year, and the flies appear in the spring and 

 autumn, but rather earlier in the Southern and Middle States than 



