180 INSECTS INJURIOUS TO FOREST TREES. 



hawk moths, Sesia bombyliformis, and tipuliformis, perforate the 

 branches and feed upon the pith of trees and shrubs. The cater- 

 pillar of many other moths and butterflies feed greedily upon the 

 leaves of trees and shrubs, few plants or trees being free from their 

 depx-edations. Most caterpillars that live upon the leaves of trees 

 are easily destroyed, when they can be got at, by dusting them 

 over in moist weather with snuff, hellebore, quicklime, or soot, 

 either of which, if properly applied, will destroy all such cater- 

 pillars. 



There are besides many other species of insects which, when 

 they are numerous, are very injurious to trees and shrubs, but, 

 owing to their small size and peculiar habits, they are not easily 

 discovered before they have inflicted grievous injury to the health 

 of the trees infested by them. When any of them are detected at 

 their mischief, every opportunity ought to be taken to diminish 

 their numbers and exterminate them altogether when possible. 



We too often see our woods thickly strewn with fallen and de- 

 caying branches and other arborial debris, which forms the best 

 breeding ground and nursery for many of the most destructive in- 

 sects that afterwards ravenously prey upon the living trees ; there- 

 fore, to assist in keeping our forests and plantations as clear of 

 insects as possible, no dead or fallen wood should be allowed to lie 

 rotting on the ground to harbour them, but it should be regularly 

 collected and burnt, if it cannot be more pi'ofitably disposed of for 

 firewood or some useful purpose. 



All primings and small thinnings should be similarly dealt with 

 as soon as possible after the operations have been performed. 

 When large trees are felled and found to be infested with insects, 

 the bark ought to be stripped off, carefully collected, and burned, 

 along with all the twigs and other parts likely to harbour the 

 vermin. 



By prompt and careful attention to such matters, the direful 

 ravages of insects will be considerably curtailed, and the numbers 

 of many species so far reduced as to be comparatively harmless, 

 and by continued perseverance they may be extinguished altogether 

 in many localities. 



As I have already suggested, all birds that prey upon insects 

 ought to be strictly preserved, and encouraged to increase by all 

 available means, such as the woodpecker, starling, chaffinch, gold- 

 finch, sparrow, wagtail, swallow, nuthatch, white throat, flycatcher, 

 titmouse, blackcap, goatsucker, redstart, greenfinch, robin, tomtit, 



