m 



EXPERIMENTAL FARMS 



80 



Fig. 1. — The Hessian Fly : attacked barley stems ; 

 1, elbowed down ; 2, showing 'flax seeds.' 



2-3 EDWARD VII., 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-day 

 I find a small white maggot imbedded in that 

 part of the stem below the ground between 

 the surface and the seed, and, after examining 

 your report on Hessian Fly for 1899, page 167, 

 I 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 

 ground hard there is no injury. A neighbour's 

 summer-fallowed field is far worse than mine. 

 I am 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. Cooper. 



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 larvae are 

 found either in the axils of the leaves l>elow tlie 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 East, 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 mac] lines should be put where poultry can get at it, or where it will be trampled 

 into the ground during the winter by stock. 



