REPORT OF THE ENTOMOLOGIST AND BOTANIST. 175 



above mentioned would appear to be much more at home than where it attacked only a 

 cultivated plant of exotic origin, such as wheat is in America. 



From Mr. Wyatt's observations it would appear as though at least two or three 

 different kinds of insects were attacking the wheat on Prince Edward Island. 



Samples of Hessian fly were received from several other places on Prince Edward 

 Island. One sample, which came through Mr. F. G. Nash, of the Charlottetown 

 Patriot, and was taken from a field of wheat on the farm of Mr. Joseph Wise, was found 

 to be very much pai-asitized by minute hymenopberous enemies. 



The Wheat-stem Maggot {Meromyza Americana, Fitch). — The presence of this 

 insect in a crop of wheat is very easily detected in the summer time when the ears of 

 attacked stems turn white before the rest of the crop ripens. This injury is known 

 under various names in different parts of Canada, such as " white heads," "bald heads," 

 "silver top." If these stems are examined, it will be found that the base of the top- 

 most joint of the stem has been gnawed away by a slender glassy green maggot a quarter 



of an inch in length, pointed at one end and having 

 black horny mouth parts ; to this injury is due the 

 dying of the heads before the grain ripens. In 

 addition to the above, there is another attack on 

 the wheat crop by the same insect, similar to that 

 of the autumn brood of the Hessian Fly, in the root 

 shoots of fall wheat ; it also occurs in many kinds 

 of wild grasses. There is besides an intermediate 

 brood which feeds upon grasses and volunteer wheat 

 and barley. The severity of the summer attack in 

 ^ wheat fields seems to vary very much in different 



Fig. 4.— The Wheat-stem Maggot: a, egg; years, according to the season. Occasionally the 

 h, maggot ; c, pupa ; d, flj — all enlarged. injured stems will constitute as much as 5 per cent 

 (Figure by Prof. H. Garman.) ^^ ^.y^^ ^^^^ This was the case nine years ago in 



Ontario. When full-fed the larva of the brood which attacks the stems works its way 

 up to the upper portion of the sheath and turns to a slightly flattened and very trans- 

 parent green puparium, from which the fly emerges at the end of July and during 

 August. 



The perfect insects, of which three distinct broods appear at Ottawa, viz., in Ihe 

 beginning of June, at the end of July, and at the end of September, are active, greenish- 

 yellow flies, one-fifth of an inch in length, with shining green eyes and three dark stripes 

 extending down the back (Fig. Ad). The hind thighs are much thickened, and when the fly 

 is at rest the fore part of the body is raised. Very soon after emerging, the sexes pair and 

 the eggs for the next brood are laid. These are snow-white, spindle-shaped, beautifully 

 marked with narrow longitudinal lines, some of which run into each other. These lines 

 are connected with each other by much slighter transverse lines. When looked for, 

 the eggs are easily seen on the upper sides of the leaves, owing to their white colour, 

 although, of course, they are comparatively minute, about -^^ of an inch (Fig. 4a). 



The Wheat-stein Maggot, which, owing to its attack at the roots of wheat, is also 

 called the Wheat-bulb Worm, occurs all through Eastern Canada, and although the 

 adult flies are enormously abundant in meadows and prairies all the way from northern 

 Quebec through the Lake Superior region, Manitoba and the North-west Territories, its 

 attacks in grain fields have not been complained of under its own name until last season, 

 when it was discovered by Mr. George Greig, the Manitoba agent of the Farmers 

 Advocate, that this insect is the cause of a considerable part, at any rate, of the injury to 

 wheat in Manitoba which has of late years attracted so much attention under the name 

 of " dead heads ". In company with Mr. Greig, I was able to confirm this obser- 

 vation at several points in the province of Manitoba during the past summer. There 

 were, however, several stems of wheat which showed the " dead heads ", in which we 

 could find no injury by the Wheat-stem Maggot. Some of these stems in one locality 

 had been bruised, without being broken down, by hail. In no case could I find any trace 

 of fungus attack. From the observation of Prof. Otto Lugger, it appears that " dead 



