THE HESSIAN FLY. 



IS 



Having thus touched briefly upon its general history, I pro- 

 ceed to describe the structure and habits of this fly, called in 

 science, very aptly, Cecidomyia destructor, and we have the advan- 

 tage of Mr. Meade's examination of British- bred specimens, as 

 recorded in the ''Entomologist." The perfect insect has the 

 head and eyes black and hairy, the antennse are rather long and 



brownish, the proboscis small and pink, the 

 thorax black, with two red streaks running 

 from the neck to the base of the wings, the 



IV-r^^'^j^'^'^^F-^ abdomen reddish brown, with regular black 

 J / H 1 \ spots, which coalesce m some specimens, 

 the legs pink, sprinkled with blackish hairs, 

 the wings, transparent as usual, are also 

 hairy. In the male flies the wings are 

 .longer and appear of a reddish tinge, and 

 the legs are paler, but the females, on the 

 whole, are the larger, and they seem to be 

 more abundant than the males. The number 

 of eggs laid by each female has been vari- 

 ously stated between ten and fifty ; probably 

 the smaller estimate is nearer to the average, if the size of the egg is 

 correctly reported. Like the larva of all flies, the maggot of the 

 Hessian fly is legless, but it has just below the head a curious 

 process or appendage, which the American observers call the 

 " breastbone." It is found in several species of Cecidomyia ; the 

 use is not known positively, but no doubt this in some way aids 

 the larva in acquiring its food, the mouth-organs being somewhat 

 feeble. This maggot is oval and glossy, with the head not very 

 discernible ; its skin dotted over by a number of tiny tubercles, in 

 colour white or greyish. To the chrysalis or pupa the name of 

 flax-seed is familiarly applied, from its likeness to that object. 

 This, however, is really the cast-off integument of the maggot, 

 forming a puparium, in which the true pupa lies to await its 

 transformation to a fly. This puparium is brown, spindle-shaped, 

 flattened, and each end is bluntly pointed. This pupa stage is of 

 special importance, for the puparia are hidden in the stalks of the 

 cereal, solitary often, sometimes two or three together, and it is by 

 this agency the species travel from one district or country to 

 another, as the flies themselves do not take long journeys. 



