8 



siderable extent in Ontario. My attention was first called to it this season during the last 

 week in July, when the grain was ripening. On visiting the wheat fields in the vicinity 

 of London, I found the insect very prevalent, and in some instances I believe the injury 

 to the crop must have been fully twenty per cent. The affected stalks were lying on 

 the ground, and the grain in the heads imperfectly developed ; on pulling these they 

 would often break at the point where the insect had been at work, that is, about the 

 base of the first or second joint. On examining the affected stalks, the insect was found 

 to be in what is known as the 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 Prov- 

 ince, 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 gra- 

 dually 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 effects 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 vigor- 

 ous 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. 



Various measures have been recommended for the destruction of this insect. Some 

 have advised the immediate threshing of the wheat and the burning of the straw ; but 

 since most of the insects are left in the stubble this would be labour lost. Tearing up 

 the stubble with a cultivator immediately after harvest, and raking it into heaps and 

 burning it, is another suggestion ; but this involves much labour at a time when the 

 farmer is extremely busy, and during the process many of the insects would necessarily 

 be shaken out of the stalks and escape. Burning the stubble in the field where prac- 

 ticable is a much wiser course ; but it must be borne in mind that this process involves 

 the destruction of the friendly parasites which feed upon the enemy, as well as the 

 enemy itself. In my address to you two years ago, I expressed the opinion that we 

 were almost wholly indebted for such immunity as we enjoy from destructive insects to 

 the insect parasites which destroy them. Subsequent experience has confirmed this 

 view, and any measure which involves the destruction of these useful friends should he 

 adopted with caution. I am happy to state that from specimens reared within the past 

 few days, I find that a large proportion of the Hessian Fly is being destroyed by para- 

 sites this season. Late sowing has been much recommended, and the results seem to 



