254 



THE FRUIT GROWER'S GUIDE. 



removed, taking advantage of wounds and abrasions in the bark, there gaining access to 

 the soft tissues of the trees, and the result of the many punctures is a swollen, distorted 

 growth of the bark, having a knobbed appearance, similar to, yet easily distinguished 

 from canker. "When no vantage offers, the pest fixes on a tender part, seeming to best 

 relish trees with downy shoots and fleshy bark, and, by piercing the sap vessels and 

 sucking the juice, causes wounds, which increase in size with the increase of 

 insects, until a tree afflicted with American blight presents an unsightly, gnarled, 



useless aspect. The aphis attacks the 

 roots as well as the branches, producing 

 gall-like protuberances on the rootlets, 

 and excrescences of considerable size on 

 the larger roots. Thus woolly aphis 

 destroys the tissues of the apple and not 

 unfrequently imperils the lives of the 

 trees. A badly-infested tree is repre- 

 sented in the engraving, which will 

 enable growers to readily recognise the 

 pest should it affect their trees in twig, 

 branch, stem, or root. 



Prevention, is the great point. It 

 may not be practicable to prevent 

 American blight entering a garden or 

 orchard, because a tree in some neglected 

 spot may be infested, and the long 

 detached fragments of cottony matter, 

 hanging by slender threads and laden 

 with eggs or embryonic insects, may be wafted into the most cleanly and orderly fruit 

 plantation. Clean trees and careful pruning, the removal of dead boughs, rough bark 

 and other accumulations, are useful, inasmuch as harbourage favours infection, but the 

 most important point of all is to keep careful watch for the first sign of white wool, 

 and then treat with one or other of the following applications. 



Petroleum. A simple, safe, and certain remedy. Procure a half- worn painter's sash 

 brush, cleanse it of paint, and when dry, dip it in petroleum so as just to moisten the 

 bristles with the oil. Brush out each infested tuft or patch, taking care that the oil 



Fig. 74. WOOLLY APHIS ON APPLE TEEE. 

 Showing swellings occasioned on different parts of the 

 branches, stem, and roots ; the white cottony matter show- 

 ing as a film, clearly indicating the crannies haunted. 



