Insects Injurious to tJie Apple. 



145 



and ^Ir. Gliavles Louusbury state to be a fact, but whii'h fniit-^umwers 

 of \ery great skill have proved to be the case in Australia, Xew 

 Zealand a.nd Soutli Africa. 



The mere i)resence on the trunk and boughs is nothing as long as 

 we can prevent its occurrence below ground. 



The damage caused by the Woolly Aphis is particularly severe 

 to young stock, but old trees also sufl'er in t«"0 \\i\\^. First, the 

 aphides lessen the \-itality of the tree by constantly 

 sucking out the sap; secondly, by the wounds 

 caused by their punctures on young wood, they 

 cause an abnormal growth of soft tissue, wliicli 

 forms rounded swellings, so very characteristic 

 of "Woolly Aphis presence (Fig. 119). These 

 swellings split later on, and from them arise those 

 large rugose deformities, so often put down to 

 "canker." At the same time the>- cause similar 

 damage on tlie roots, but the swollen gall-like 

 growths that they produce do not necessarily 

 split in the way we fiird aliove ground (Fig. 

 11 S). In these two ways the life of the 

 tree is gradually sapped, and not infrequently 

 young trees die under this rough usage. In 

 any case stunted deformed trees result, and 

 lint scanty and poor quality fruit is borne by 

 the trees. 



But there is a third way, 1 feel certain, in 

 wliich this Woolly A]diis work's injuriously. 

 After keeping records during the past twenty 

 years, I find that in nearly all cases trees infested 

 with canker have or have had Woolly Aphis 

 attacking them. During the summer of 11103 

 two trees (Worcester I'earmain and a Eusset), 

 wliich were perfectly clean, were infected with 

 Woolly Aphis ; next year both were attacked )iy 

 canker. <> " to them not attacked by the Schizoneura is 



still clea 



The at indirectly this apliis, by causing wounds 



of "reatCi ny other species on the apple, predisposes the 



trees to the Ku ^ .neniy, for which we have no known remedy. 



The importance of knowing the life-history is therefore very great, 

 for It is only liy so doing that we can learn how, when and where to 

 apply any satisfact(jry treatment. 



[i-:t:. 



J'lC. lin.^EAKLY STACK 

 nF ATTACK UF ^\<.inLL'i 

 APHIS i>X YOr.NG (M:iiiIi. 



