166 EXPERIMENTAL FARMS 



5-6 EDWARD VII., A. 1906 



time most of these will faU with, the rubbish beneath the machine, or will be left in 

 ■•he straw. All dust and screenings, therefore, should be destroyed, and all straw and 

 small seeds should either be used up during the winter or burnt before spring. In 

 Ontario and the eastern provinces there are two annual broods of the Hessian Fly. 

 The flies of the first brood appear in June and lay their eggs on spring and fall wheat 

 and on rye and barley. Of the second brood the flies appear in Sept-ember and lay their 

 eggs on fall wheat and fall rye. Wheat, barley and rye are the only known food plants 

 of the Hessian Fly in America, and neither oats nor the grasses are attacked. 



The remedies which have given the best results against the autumn brood are 

 late sowing and careful preparation of the land, so as to induce a vigorous growth. 



The Western Wheat-stem Sawfly (Cephv^ oceidentalis, Eiley & Marlatt). — 

 For several years the larva of a wheat-stem sawfly has done some injury to growing 

 wheat at different places in Manitoba and the North-west Territories. It was at first 

 supposed, from the similarity of the attack and from a few reared specimens, that the 

 insect was the European species, Cephus pygmceT.Ls, L., which had appeared suddenly 

 in injurious numbers at Ithaca, N.Y., in 1889. This attack was treated of at length 

 by Prof. Comstoek in ComeD Agricultural College Bulletin No. 11, 18S9. The fol- 

 lowing year the insect disappeared entirely, and nothing has been seen of its work 

 from that time. In previous reports I have referred to this western sawfly as C. 

 pygmcev^, but recently si>ecimens of our Northrwestem insect have been submitted to 

 Prof. A. D. MacGillivray, of Cornell University, who has identified them as Cephus 

 oceidentalis, Riley and Marlatt. The insect has been studied by Mr. Norman Criddle, 

 of Aweme, Man., and he has added very materially to our knowledge of the species 

 and its work. He has discovered its native food plants and also that thffie are far 

 more attractive to it than the wheat plant, which it occasionally infests, 



* July 10, Aweme, Man. — I collected several specimens of the Cephus yesterday. 

 They were all resting on Agropyrum caninunu. So far, I have been unable to find 

 them elsewhere ; and, though they are always found rather plentifully around the edges 

 of wheat or indeed anywhere, infesting the above grass, I have very seldom been able 

 to find wheat plants attacked by them. I have not yet been able to get hold of the 

 species which breeds in AmmophUa longifoliaj but I am confident that it will prove 

 to be a distinct species, as the larva is very different, being quite yellow in colour, 

 while that of the Agropyrum species, C. oceidentalis, is white.' 



* July 30. — I found to-day two stallvs of wheat infested by Cephus and several 

 stems of Agropyrum were found also attacked within a few feet of them. I after- 

 wards hunted over a large area of wheat, but was unable to find another wheat plant 

 which was infested, though any amount of Agropyrum caninum was found which had 

 been attacked. In several cases the grass was in the wheat fields. I think, therefore, 

 that the wheat being attacked must be considered an accidental occurrence. At the 

 eame time, if the grass failed for any reason to form heads, these insects might pos- 

 sibly develop into a pest of some magnitude.' 



' Aug. 4. — Two more stalks of wheat have been found attacked by the Agropyrum 

 Cephus in a place where that plant was rare. I also found it quite numerously yester- 

 day infesting our native quack grass, Agropyrum glaucum, R. & S., var. occidentale, 

 V. & S.' 



' Aug. G. — Cephus oceidentalis has now been found here, feeding in the following 

 grasses : Agropyrum caninum, A. glaucum, var. occidentale, and A. tenerum, and also 

 in rye and wheat, the first named and possibly the second being the native food plants, 

 the others being only occasionally attacked.' — Norman Criddle. 



From the above it is evident that several native grasses are more attractive to the 

 Western Wheat-stem Sawfly than is wheat. Some of the above species of grasses are 

 common in almost all parts of the West, and their occurrence may be hoped to protect 

 wheat from serious attack under ordinary circumstances. Should the larv£E, however, 



