112 



Quite frequently during the fall mouths other species of aphides, having 

 a similar "woolly" appearance, are often mistaken for the true " apple woolly 

 aphis," and specimens of woolly aphides of different species were sent to Dr. 

 Fletcher, who writes in regard to them as follows : — " In the box of which 

 you describe the specimens as taken off an apple twig badl.v infested with 

 woolly aphides ; these were the true >Sf. lanigera. but amongst them were some 

 other specimens of aphis maUfolia;, which has the venation very similar to 

 that of apJiis mali. The difference between these two last-named species is 

 chiefly coloiirational and in the size of the insect. The other box containing 

 specimens of the " woolly aphis," which has given you so much trouble to 

 identify, and which are flying in such m.vriads in your woods, are neither the 

 alder aphis nor the true icooUy aphis, but a species called PcDijiliigus pyri. 

 which belongs to the same genus as the alder woolly aphis. 



" The difference between these two genera is very easy to recognise when 

 once pointed out, and that i-s, in the genus Schixonciira the third discoidial 

 vein is forked, while in pemphigus all the veins are simple. 



" Peniphigus pyri probably is a native species with you, and occurs 

 through your woods on different species of pyrus and Crataegus." 



This species of woolly aphis (Pemphiijus texsellata) is very common upon 

 iilder trees in lower British Columbia, and is often confounded with the 

 woolly aphis of the apple, from which it is quite distinct. Like other aphide.s. 

 they rejiroduce by giving birth to living young. Vast numbers of winged 

 specimens appear in the fall and spread over the country, the air sometimes 

 appearing full of the insects moving with the wind. They have not been 

 found injurious to fruit trees, although man.v of these winged specimens are 

 found on them. They do not seem to reproduce except on their proper food 

 plant. 



Wheat Midge (Diplosis trilici, Kirby). j 



Attack. — AYhen wheat is in blossom in the month of .Tune, minute yellow 

 midges with black eyes may be found, particularly towards evening, flying 

 over the fields and laying eggs in the florets of the ears of wheat. These eggs 

 in about a w^eek hatch into small reddish-orange maggots, which sometimes 

 to the number of ten or twelve lie inside the chaff and suck the juices from 

 the swelling kernel. When mature, they leave the ears of wheat and pene- 

 trate about an inch beneath the surface of the ground, where they spin tiu.v 

 cocoons, inside which they remain normally until the following spring, when 

 the perfect midges emerge. Under special circumstances, however, some of 

 the flies appear in late summer and lay their eggs upon volunteer wheat or 

 the young fall wheat. 



It is many years since the Wheat Midge, which is generally known by 

 farmers and millers as " the weevil," has been the cause of much loss in the 

 wheat crop of the Dominion. Fifteen years ago the losses were enormous; 

 but, just when it seemed at its worst, it suddenly disappeared entirely and 

 since that time has not been the cause of widespread injury. There have 

 been occasional outbreaks, as in the Niagara district in ISOS, and last year 

 in the fertile Chilliwack district of the Fraser River Valley, B. C. where it 

 was estimated that in some fields fully half the crop was destroyed. 



