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SHADE TREES INSECTS IN QUEBEC. 



J. M. Swaine, Assistant-Entomologist for Forest Insects, Ottawa. 



Practically all shade trees and ornamental trees grown in this Province 

 are subject to more or less injurious attacks by insect enemies. Probably 

 more than one-quarter of the shade trees we see are seriously injured by 

 them, and the annual loss from this cause is very great. It is possible 

 to control most insect attacks on trees which are valuable enough to war- 

 rant individual treatment; but very many of these injuries could be pre- 

 vented by proper handling of the trees, and considerable expense and 

 trouble could thus be avoided. 



Mistakes are made often in selecting the trees for- planting. Good 

 stock, should be chosen of varieties which are suited to the climate and 

 soil conditions of the location. Trees which are likely to succumb to local 

 insect pests should be avoided. It is almost useless, for instance, to plant 

 the imported cut-leaf birches in districts where the Bronze Birch Borer 

 is abundant, or the black locust tree in regions infested by the Locust 

 Borer. 



The trees should be planted carefully and properly; a good fertilizer 

 should be applied when it is needed, and an abundance of water should 

 be furnished to the roots in dry seasons. The weaker, unthrifty trees 

 should receive special attention. Numbers of our bark-boring and wood- 

 boring insects, which normally breed in dying trees, will attack trees in 

 an unhealthy condition, particularly when the insects are present in great 

 numbers. Other species which are notoriously destructive to healthy 

 trees prefer weakened bark and wood and attack it most readily; this is 

 true, particularly, of numbers of bark-beetle species. Vigorous trees 

 in full sap are much better able to withstand the attack of some of those 

 destructive borers, and are, of course, more likely to recover from attacks 

 by defoliating or sucking insects or from injuries of any sort. 



Protection from injuries and the proper treatment of those received 

 are of the utmost importance. Whenever the bark is broken and left 

 untreated, insects and fungi are almost certain to gain entrance. Many 

 of the most serious injuries from decay originate from wounds through 

 which the parasitic fungi enter. All such wounds should be properly 

 cared for. Broken branches should be trimmed off even with the trunk 

 and the bare surface coated with tar or paint. Wounds on the trunk 

 or limbs should be cut smooth and similarly coated. Any needed prunin 



