174 EXPERIMENTAL FARMS 
2-3 EDWARD VIL, A. 1903 
and other causes are suggested to account for the destruction of the plants, which is 
frequently considerable. Mr. Criddle, of Aweme, is of the opinion that many of the 
reports concerning cutworm injury in the wheat 
fields through that part of Manitoba where he 
is, should really refer to Hessian Fly. Mr. A. 
Cooper, of Treesbank, sent me specimens of 
wheat, saying under date of June 3: ‘I have 
noticed a great many dead and dying wheat 
plants in this locality this spring, and have ex- 
amined my own fields to try and learn the 
cause. When the injury was first noticed, the 
wheat was three or four inches high. To-da 
I find a small white maggot imbedded in that 
part of the stem below the ground between 
NY the surface and the seed, and, after examining 
YX, your report on Hessian Fly for 1899, page 167, 
* { came to the conclusion that this fly was the 
cause of the damage. The place where the 
damage is worst on my land, is on a piece of 
spring ploughed stubble land which bore a 
heavy crop last year and was ploughed five 
or six inches deep: this spring. The injury 
seems to be worst wherever the land is loosest. 
One place where my cattle had tramped the 
ee ground hard there is noinjury. <A neighbour’s 
Fig. 1.—The Hessian Fly: attacked barleystems; Summer-fallowed field is far worse than mine. 
1, elbowed down; 2, showing ‘flax seeds.’ fam afraid of further injury later in the sum- 
mer from these pests, which I suppose is bound to happen, should my diagnosis be cor- 
rect. —A. COoopER. 
This is the only district in which the attack on the root shoots was noticed, but 
later in the year several reports were received of injuries at Stockton, Wawanesa, 
Rounthwaite, Blythe and Aweme. When the wheat was cut, it was found that in 
certain places in western Manitoba many of the straws were broken down from having 
been injured by the Hessian Fly. Articles were published in the press by the Deputy 
Minister of Agriculture for Manitoba, and by Mr. W. H. Coard, of the Commissioner 
of Agriculture’s Branch at Ottawa, in which the life history of the Hessian Fly was given 
and the best means of dealing with it. There is only one annual brood of the Hessian 
Fly in Manitoba, the eggs being laid upon the leaves of the young plants, and, accord- 
ing to the development of the plant at the time the maggots attack it, the larve are 
found either in the axils of the leaves below the surface of the ground, or, if the stem 
has begun to shoot, in the axils of those leaves on the stem nearest to the ground. 
The maggots assume the flax seed or pupa condition about mid-summer ; but the flies in 
the hot dry autumns which prevail in Manitoba, probably in most cases and certainly 
in many, as I have seen by actual observation, do not emerge until the following spring. 
Therefore, the problem of controlling the Hessian Fly in Manitoba is far simpler than 
in the Hast, where the greatest damage is done to fall wheat in the autumn. In Man- 
itoba no fall wheat is sown; so, if any flies emerge in the autumn, they die without 
doing any harm, because no winter grain is sown in Manitoba, and the Hessian Fly does 
not subsist on any wild grasses. The remedy, therefore, is comparatively simple. 
When Hessian Fly is known to be present, grain should be cut high and the stubble 
burned over or ploughed down in autumn. For fear that any of the flax seeds might 
be carried in the straw, this should be fed to stock or burned before the time that the 
flies emerge the following spring. Many of the flax seeds may be seen beneath thresh- 
ing machines when straw has been badly infested. Therefore, all screenings or rubbish 
from machines should be put where poultry can get at it, or where it will be trampled 
into the ground during the winter by stock. 
