1921 ENTOMOLOGICAL SOCIETY. 33 



tember 22nd; third sowing, September 29th; fourth ©owing, October 5th; last 

 sowing, October 9th. The infestation will be checked up in the spring as other 

 work prevented this from being done this fall. We do know, however, that the 

 first planting is fairly heavily infested. 



It is gratifying to mention that the campaign launched the past summer 

 to delay the sowing of wheat as late as possible has met with a fairly generous 

 response. Talking to Mr. Noble, the agricultural representative of Essex Co., 

 I am informed that little if any wheat was planted before the middle of October. 

 In Middlesex Co. some wheat was sown early and all such wheat examined is in- 

 fested. In Elgin Co. very little wheat was planted before October. Most of my in- 

 formation regarding the sowing of wheat has been obtained from the weekly report 

 of the Ontario Department of Agriculture, Toronto, Ontario. The area sown 

 to wheat this year is less than that last year, and generally speaking planting 

 has been delayed from two to three weeks later than last year. The fine open 

 fall has been perfect for the late planting of wheat, and this may mean a material 

 check on fly increase. How long the flies were on the wing this fall is not known. 



Notes on the Stages and Life History of the Insect. 



The eggs which are small, long, slender, and of a shining reddish colour, 

 are usually placed in the grooves on the upper surface of the wheat leaf. Some- 

 times they are placed at the base of the leaf and stem. Eggs hatch in from four 

 to six or .seven days, depending on temperature and the moisture content. The 

 maggot on hatching is a bright red colon 1 ", and apparently makes its way down 

 between the leaf sheath and stalk through the agency of moisture. In the 

 outside insectary where the moisture content can be controlled, the young maggots 

 died on the surface of the leaf where moisture or dew was withheld, while nnder 

 normal conditions outside, the larva? were able to get between the leaf and 

 stem and develop. A maggot may be scratched with a dissecting needle, but no 

 movement is observable, but in the presence of water, it squirms vigorously. 

 For the first few days the young maggot is almost translucent, as feeding pro- 

 gresses the colour changes to a greenish white. The larval stage lasts in the 

 spring about three weeks. Mies were aJbundant May 17th, and the first flax- 

 seed was discovered June 7th. In the fall conditions vary, some larva 1 may 

 winter over in small numbers as maggots, but the majority as flax-seeds. In the 

 fall practically all the maggots and flax-seeds are located at the base of the 

 plants and around the roots, but in the spring the larvae usually change to the 

 "flax-seed" stage at the first or second joint above ground. At the time wheat 

 is .starting to head ninety-five per cent, of the maggots will have changed to 

 the flax-seed state. The injury is too well known to need description. The 

 killing- of the tissue of the stem interferes with the passage of food material, and 

 the plant is consequently starved, and the degree of infestation governs whether 

 the plant will be killed outright, or produce a dwarfed head of shrivelled grain. 



Means of Control. From the few parasites that were obtained this year, 

 it would indicate that other means of control are necessary. The destruction of 

 all volunteer wheat, the careful ploughing under of all infested stubble as soon 

 after the harvest as possible, rolling the ground as firm as possible, thorough 

 preparation of the seed-bed, generous application of fertilizers, the avoidance 

 of planting wheat after wheat, and delaying the planting of wheat as late as» 

 possible to insure sufficient growth before winter, will materially check the ravages 

 of this pest. As there are two broods, one in the spring, and another in the fall, 



