HESSIAN FLY 255 



in early summer and mature in midsummer, tlie larvae issuing 

 from the clover heads and pupating in the ground anfl the 

 second brood appearing later in the summer and depositing 

 eggs which produce the second generation of larvae which 

 develop in the later blooming clover. These hit the crop 

 of clover grown for seed. They mature with the late autumn 

 and either maggots or the mature puparia would be found 

 during the winter time and the larvse particularly which are 

 caught before they have completed their growth may be 

 included in clover seed. The fully de\^eIoped larvae pass 

 into the pupa stage at the surface of the ground. It is 

 doubtful if the midge can be transported from one place to 

 another by means of the clover seed. Just how it is intro- 

 ducefl into remote districts is uncertain. Its means of loco- 

 motion is by its own flight. It is pretty generally dispersed 

 throughout the portion of the country where clover is now 

 grown. The means of treatment would lie more in the 

 direction of cutting the clover at the time to cut short the 

 growth of the larvae — a little earlier cutting of the clover, 

 catching the larvae before they have issued from the clover 

 heads. 



Hessian Fly (Mayetiola destructor). — The Hessian fly is 

 the most destructive of the family. It is an introduced 

 species and was first described from materials. in this country 

 in 1820, It probably originated where wheat did. It was 

 never described scientifically until by Say. It had been 

 known as a destructive insect earlier than 1820 anrl the 

 name was given to it about the time of the Revolution, when 

 the Hessian soldiers were in this country, either because the 

 insect was thought to have been introduced by them or as 

 an obnoxious name. The name was adopted over the entire 

 English-speaking world. The evidence that it is an old- 

 world species is from its food plants and that it spreads 

 from one centre. There are a number of other evidences. 

 Its natural food plants seem to be limited to wheat, rye, and 

 barley, though there is a question as to barley. It was 

 proved by a Frenchman that it does not occur on oats. At 

 one time it was thought to breed in various grasses, but later 



