CHAP, xiv.] Insect Enemies 331 



usual number of injurious insects, and of the necessity that 

 then exists for adopting exterminative measures. Enemies 

 that might during the first spring be annihilated at a moderate 

 outlay, may necessitate a vastly greater expenditure in the 

 following and subsequent years, not to mention the monetary 

 losses involved by having to fell and reproduce crops that repre- 

 sent considerable capital but have not yet attained their normal 

 marketable or financial maturity. Thus, during 1892, no less 

 than 75,000 was spent in the State Forests of Bavaria on 

 ringing stems with patent viscous tar for fear of a recrudescence 

 of the attacks of the Spruce moth, whose devastations during 

 the previous three years had involved the loss of hundreds of 

 thousands of pounds in the destruction of the timber crops. 

 Large quantities of timber had to be thrown on markets that 

 were soon glutted, and in which prices sank very low; and 

 immature crops had to be felled and removed in order to 

 try and hinder the otherwise inevitable appearance of enormous 

 plagues of bark-beetles, cambial beetles, and weevils, that would 

 have been bred within the sickly stems and the stumps in the 

 ground. 



It is true that, with our comparatively limited woodland 

 areas, we are not exposed to anything like these extensive 

 calamities in Britain. But it is worth while learning the lessons 

 which such devastations teach ; and these are, firstly, that the 

 formation of mixed woods should be favoured to as great an 

 extent as convenient (especially in the case of conifers), and 

 secondly, that dangers from insect enemies are minimized when 

 the woods are kept properly tended throughout all the 

 various stages of their development. 



