THE CANADIAN ENTOMOLOGIST. 143 



puparium or flax-seed state, from the resemblance which it bears in this 

 condition to a grain of flax-seed. The attention of farmers was drawn to 

 the depredations of the insect by a communication to the press, and 

 information sought as to the extent of the evil. From letters received 

 from various sections of the Province, it is evident that the insect prevails 

 over an extended area, and that the sum total of the loss entailed on the 

 agricultural community in Ontario from this cause would figure up to a 

 large sum, probably hundreds of thousands of dollars. In 1876 and 1877 

 this insect appeared in considerable force and seriously injured the wheat 

 crop in many parts of our Province, but since that time we have enjoyed 

 comparative immunity from it until now. 



The Hessian Fly belongs to the order of Diptera, or two-winged 

 insects, and is about one tenth of an inch long, with dusky transparent 

 wings fringed with fine hairs. There are two broods during the year. The 

 flies which appear in the autumn deposit their eggs from one to twenty or 

 more on a plant in the cavities between the ridges of the blades or between 

 the stalk and sheathing base near the roots of the young fall wheat. 

 These hatch in four or five days into tiny grubs, soft, smooth and shining, 

 which work their way down the leaf to the base of the sheath, about the 

 crown of the root. Here they fasten themselves head downwards to the 

 tender stalk, live upon the sap and gradually become imbedded more or 

 less in the substance of the stalk. When once located the larva moves no 

 more, but growing rapidly, soon becomes plump, and when mature is 

 about one sixth of an inch long, greenish, and semi-transparent ; before 

 long it changes to the flax-seed state, in which condition it remains 

 throughout the winter. Early in spring the flies are produced, which 

 deposit their eggs about the first or second joint of the stalk, where they 

 pass through their several stages, assuming the flax-seed state a few weeks 

 before the wheat ripens, from which the flies hatch in August and September. 



The effect of the presence of this insect in the young fall wheat is to 

 weaken the plants, which become unhealthy, turn yellow and sometimes 

 die. Often there is a gall-like swelling or enlargement of the stalk near 

 the base, in and about which the insects will be found. The unhealthy 

 plants contrast strongly with the rich green of the vigorous uninjured 

 grain. The late brood may be easily found by separating the leaf from 

 the stalk of the young wheat in October or November • the early brood, as 

 already stated, in the reclining stalks, which, when very numerous, makes 

 the wheat appear as if •' lodged" in patches. 



