REPORT OF THE ENTOMOLOGIST AND BOTANIST. 167 
SESSIONAL PAPER No. 8a 
bered that there is on spring wheat in spring an early attack at the roots similar to that 
on fall wheat in autumn, by which very large numbers of wheat plants are destroyed 
without making stems at all. This attack is, as a rule, not noticed by farmers, because 
the plants which are left living, stool out more and fill up the gaps. 
In a field which I had under constant observation during the summer of 1890, many 
plants were entirely killed by the spring attack, and others bore only a single weakly 
stem, most of the shoots having been destroyed ; but, from the stooling of the uninjured 
plants, the general appearance of the field was that of a fair crop, and noneof the straws 
could be found containing puparia, showing that all the eggs were laid before the plants 
began to shoot. Without close observation this attack would have been overlooked and 
would not, in all likelihood, have been noticed by farmers. Nevertheless the puparia of 
the insects which had done the harm, were still in the fields to emerge later and carry 
on the injury. This same state of affairs may have been the casein Manitoba last year, 
and much injury then done which was unnoticed. Although not detected, the Hessian 
Fly must certainly have been present in Manitoba in considerable numbers last year for 
eggs to have been laid over such a wide area. I have no doubt from an examination 
of specimens collected in various parts of Manitoba last autumn, that in that province 
there is only one brood of the Hessian Fly. This insect confines itself in a remarkable 
degree to the wheat plant, and, although barley and rye are occasionally attacked, this 
is exceptional ; the very rare occurrence of pupz in timothy, which has been recorded, 
must be regarded as quite accidental. No fall grain of any kind is grown in Manitoba, 
and puparia formed in the straws last summer still (December 30, 1899) contain living 
larve in good condition. 
Prof. F. M. Webster, the author of most valuable studies on wheat pests, has main- 
tained for many years that the Hessian Fly would be found to be single-brooded when 
a point sufficiently far north or south of its metropolis, or centre of distribution, was 
reached, the extremes either of cold or heat preventing the production of food in suit- 
able condition for the second brood, the summer brood instead of emerging in autumn 
hibernating as flax seeds in the north and in the south remaining in a quiescent con- 
dition (zstivating) as flax-seeds during the hot dry period of the protracted southern 
summer. 
This theory of the insect’s power to adapt itself to varying conditions was explicitly 
set forth by Prof. Webster in Ohio Bulletin No. 51, 1893, and as late as March last the 
same author writes:—‘As you know, I have always questioned the occurrence of a 
second brood of Hessian Fly so far north as North Dakota, but I have never had an 
opportunity to substantiate my position. I had hoped that you might settle this Hessian 
Fly problem, and put the question to rest once for all with respect to the number of 
broods. The insect certuinly occurs in areas where there is no fall wheat, but an 
abundance of spring wheat, and it does not seem to me possible that it could survive in 
such localities if it were double-brooded, as there is nothing on which a fall brood could 
winter over, except the spring wheat stubble.’ 
The importance of exact knowledge as to the number of broods is seen to be very 
great when we come to a consideration of remedies. The severity of the attack during 
the past season and the interest which has been created in the subject, through the 
agricultural journals, added to the fact that the weather has been most propitious this 
year for autumn work, have induced farmers to make themselves acquainted with the 
natural history of the Hessian Fly, and to adopt the methods which experience has 
shown are the best : namely, to burn over the stubble when possible before ploughing, 
and, at any rate, to plough down deeply all stubble this autumn or before the season for 
the flies to appear next spring. 
As Mr. Greig has stated in the Yarmer’s Advocate for October 20 :—‘ Whether or 
not the stubble is burned off, the land should. be carefully ploughed. Even with no 
Hessian Fly, careful ploughing is really one of the great essentials to a successful crop. 
The work eannot be too well done. Not only does good ploughing leave the land in 
better shape and kill more weeds, but it greatly reduces the amount of harrowing and 
after work necessary to get the land into the best condition for the seed ; and no doubt 
grain that comes away vigorously and early, and makes rapid growth, has more chances 
of escaping this or any other pest.’ 
