206 THE CANADIAN ENTOMOLOGIST 



they grow, cause the leaf to curl right up and enclose them — the 

 curled leaf freciuently becoming a living mass of aptenc. By their 

 constant sucking the foliage becomes more and more contorted, 

 and CNcntualh-, both from the sucking of the insects and their 

 excrement, which seems to have a scorching efTect, the leaves turn 

 l)rown, and may or ma\ not fall oft. Not only does this aphis 

 feed on the leaves at the top of the shoots, but also on the shoots, 

 and the result is contorted and stunted growth. The internodes 

 are shortened, and consequently a \ery "stubby" appearance is 

 produced, cspecialK- in young stock. 



The first alata' 1 have found occurred on June l^th, 1899, 

 and I have found them onwards until 29th of July, in 1914. Al- 

 though these Plant Lice become alate in masses, a few always 

 occur some tiiiic before the main swarm, and others later. The 

 winged females are very sluggish, and, like those of Aphis rumicis, 

 collect together in masses, usualK- choosing the underside of 

 a fairly large branch of the tree near its junction with the trunk. 

 Man\- of these groups of alatie were noticed in 1915 to die off 

 and remain attached to the branches. This winged summer 

 generation Hiesoft^ in Jul\, but where to I ha\e been unable to 

 trace. It dies out on the apple and pear from mid-July. In the 

 f)eginning of September a few return migrants may appear, but 

 the majorilN in October. These j)roduce the sexual generation of 

 apterous o\i{xirous females and alate males. The sexupara^ may 

 occur on into mid-November, and I have several times found the 

 oviparous females in the first week in December. The females and 

 males occur under the leaves, and, when fertilized, the females 

 crawl to the shoots and lay their eggs either singly or in small 

 groups; never in dense masses as is done by Aphis pomi. Many 

 of the o\iparous females fall to the ground with the ripe leaves 

 before they have oviposited. These may lay their ova on the 

 leaves as they lie upon the; ground. The ova are at first yellowish, 

 but soon become the normal shiny black 



I have vainly tried to trace this species to other plants this 

 last six years. Weeds and their roots have been searched, to no 

 avail. Recently, W. R. Ross writes me that he has found sorbi 

 of the apple on the roots of Plantago in summer in Canada. 



In one or two localities I have noticed that the attack of this 



