266 CONIFEROUS TREES 



attacks are confined principally to the Common 

 Spruce {Picea excelsa), but I have also known P. 

 orient alis, P. sitchensis, and P. nigra to be severely 

 damaged by the same insect. The attacked trees 

 are rendered very unsightly by reason of the cone- 

 like excrescences that are formed by the insect 

 on the shoots. It is brought about by the female 

 aphis piercing with her beak or sucker one of the 

 buds, and drawing off the sap, the consequence 

 being an unnatural growth at that part. The only 

 known remedy is to collect the cone-like excres- 

 cences and have them destroyed. 



Pissodes notata attacks young trees of several 

 species of Pinus, but principally such as are grow- 

 ing under unfavourable conditions. The eggs 

 are laid on pine trunks, and the larvae feed under 

 the bark. 



Abies nobilis, A. amahilis, and A, lasiocarpa, 

 particularly A. amahilis, are subject to the attacks 

 of an insect nearly allied to that which causes the 

 American blight on apple trees. The attacked 

 portions, generally the buds or base of the leaves, 

 present gouty, usually cup-shaped swellings, and 

 which, with the growth of the shoots, increase pro- 

 portionally in size. When cut into, the swollen 

 portions are of a spongy appearance, and these 

 unsightly deformities not only tell badly on the 

 health of the trees affected, but render them 

 utterly valueless from either an ornamental or 

 commercial standpoint. An application of fir- 

 tree oil has been found useful at the initial stage 

 of the disease. 



