REPORT OF TEE EXTOMOLOGIST A\D BOTANIST 213 



SESSIONAL PAPER No. 16 



For a short period, and in restricted localities, with all conditions favourable, good results 

 have occasionally been obtained; but the difficulty of preserving the spores alive and 

 using them when required, has been so great that all entomologists who have experi- 

 mented with the fungus have, after a short time, relinquished the effort in favour of 

 other methods not so dependent for their most effective use on climatic conditions. 

 Hopper dozers and other mechanical contrivances have proved of much service ; but 

 the best results have followed agricultural^methods of control, such as the early plough- 

 ing down of all stubble lands, in which by preference the eggs are laid, before the 

 young emerge in spring or have grown to such a size as to be able to save themselves 

 by hopping or flying, so as to avoid being ploughed down and buried. 



The Hessian Fly (Gecidomyia destructor, Say.). — Injury by this destructive 

 enemy of the wheat crop has been slight this year. Most reports merely refer to its 

 absence. Last year specimens were found as far west as Indian Head, N.W.T. In 

 Manitoba it has done less harm by far than in 1903. Mr. Norman Griddle, who has 

 been on the lookout for it, says : ' The only report of this insect comes from Mr. 

 Cooper, of Treesbank, who states that quite a number of pup?iria were to be found on 

 his stubble fields this autumn and that he estimated the damage on his farm at about 

 half a bushel to the acre. Elsewhere in the province, it is just possible that this 

 insect may have escaped notice on account of the damage done by rust. There was 

 no appearance of Hessian Fly here at Aweme.' 



Prof. F. M. Webster, who is making a special study of wheat insects in the United 

 States, writes at the end of this season : ' I found Hessian Fly in large quantities in 

 North Dakota, quite as bad as in many places further south. You will be interested 

 in hearing that from a lot of stubble collected west of Fargo, I have not reared a single 

 adult this autumn; but from stubble collected at Lincoln, Nebraska, we get plenty of 

 adults, showing that there must be a dropping out of the fall brood somewhere between 

 these two localities.' 



This observation confirms the opinion that there is only one brood of the Hessian 

 Fly each year in our western wheat fields. This is an important fact, as indicating 

 a proper remedy, and shows the value of cutting wheat high and then burning over tlic 

 stubble before the time when the flies emerge in spring. In the Ontario November 

 Crop Eeturns we find : ' The crop suffered much less than in recent years from Hes- 

 sian Fly and other insects ;' and ' in the new fall wheat little injury was complained 

 of, compared with the ravages of this pest during the past three or four years.' In 

 Prince Edward Island, where the Hessian Fly is always present to some extent, little 

 harm was done, but specimens of infested straws were received from Mr. A. M. Mc- 

 Millan, of Eldon, P.E.L 



Wheat-stem Saw'fly \Ceplius pygmceus, L. (?)]. — The intermittent manner in 

 which this insect attacks wheat in the North-west was again demonstrated this year. lo 

 was not reported from any of the localities where it did harm during the past two 

 years. The only place where a crop was injured conspicuously was at North Portal, 

 Assa. Mr. George Harris writes under date August 24 : 'I send samples of wheat 

 injured by a small white worm. The attack is worst on the edges of fields, but is pre- 

 sent all through the grain. Where the plants stand thick, you can cut with a binder; 

 but where thin, the wheat falls down -and there are patches three and four feet square, 

 which are quite flat.' 



The worm which causes this breaking of the straw is the larva of a slender black 

 four-winged sawfly, about one-third of an inch in length, banded and spotted with 

 yellow. The eggs are inserted into the straw by tlae females near the top of the steir. ; 

 and the grub on hatching eats its way down to the root, near which it passes the winter 

 in a cocoon spun inside the stem, but above which it has first gnawed almost through 

 the walls of the straw, so that about harvest time injured stems fall over easily and 

 break off, leaving the grub inside the stubble, where it remains, and about June of 

 the following year turns first to a pupa and then to the perfect fly. Burning over 



