322 Studies in Forestry [CHAP xiv. 



whilst thinnings should take place as often as funds permit, and 

 considerations relative to the maintenance of a full leaf-canopy 

 and the safeguarding of the productive capacity of the soil 

 dictate. Wherever damage has been done by frost, snow, ice, 

 wind, or fire, measures should not be delayed in rectifying it, 

 so far as may be possible ; and care should be taken to have 

 the injured timber either barked, or, better still, removed from 

 the vicinity of the woods as soon as convenient, in order that 

 species of Bostrychini and Hylesinini may not become attracted 

 to them as favourable breeding-places. Felling of coniferous 

 crops during the summer and careful removal of the bark from 

 the stems are therefore to be recommended. But when, from 

 one reason or another, winter fellings have to be made, then 

 some of the logs should be left here and there with the bark 

 on, in order to act as decoy stems. These should be peeled 

 during the following May, and the bark burned so as to destroy 

 the various broods of Scolytidae that may have been deposited 

 in it. 



Wherever any possible market for firewood makes it feasible 

 to grub up the stumps of coniferous species of trees, without 

 incurring much outlay, this should be done immediately after 

 the fall of the timber, so as to diminish the number of natural 

 breeding-places offered to the dangerous classes of weevils 

 ( Curculionidae) and cambial-beetles (Hylesinini}. Even casual 

 examinations of palings formed of coniferous poles will show 

 how many breeding-places Bostrychini and Hylesinini find in 

 the bark and cambium. Barking of the poles, therefore, before 

 they get dry, would not only help to reduce the number of 

 insects generated, but would also otherwise contribute to the 

 durability of the wood, and to its protection against attacks 

 from saprophytic fungi. 



But, whilst mixture of different kinds of trees in the forma- 

 tion of the crops, and careful tending, are the principal means 

 of preventing the abnormal increase of any kind or kinds of 

 injurious insects, everything should at the same time be done 



