ONTARIO DEPARTMENT OF AGRICULTURE. 



TORONTO, ONT. MAY 1. 1898. 



THE SPRUCE GALL-LOUSE. 



{Chermea abietis.) 

 Prepared for the Bureau op FeRssTRY by Wm. Brodie, Toronto. 



In the spring of 1897 many spruce trees in and around Toronto were found 

 to be more or less injured by a pseudo-gall insect. The galls were enlarged and 

 deformed buds of the previous year, usually towards the tips of the twigs. 

 Investigation showed that these galls were formed by a small insect popularly 

 called the spruce gall- louse, the Chermes ahietes of entomologists. A short 

 account of this destructive pest, as then known in Ontario, appeared in the 

 annual report of the Olerk of Forestry for the Province of Ontario for 1897. 

 ISince then it has spread with astonishing rapidity and has been detected at 

 many points, from Peterborough to the county of Bruce, where it was lately 

 detected by Dr. Hunter on native spruce trees in a swamp in the township of 

 CulrosB. It has also been found ou native spruces in Muskoka, near Utterson 

 station. So far it would appear that unless this insect is checked by some 

 artificial means it will soon destroy our ornamental spruce trees and hedges and, 

 extending northwards, do immense injury to our spruce forests. 



The trees already attacked by this spruce gall-louse in Ontario are the 

 European spruce, Picea excelsa, the double spruce or black spriico, Picea nigra, 

 the white spruce, Picea alba, and the balsam fir, Abies balsartiea, and it may also 

 be found on the hemlock, Tsnga Canadensis. This insect is native to Northern 

 Europe and was introduced into the United States on imported spruce trees and 

 thence into Ontario, or it may have been introduced here direct from Europe, 

 as for many years there has been an annual importation of young European 

 spruce trees into Ontario. 



