riNE-WEKVIL. 227 



season of pairing. Those beetles which emerge during the 

 autumn do but Httle injury, as they do not appear in such 

 numbers as in the spring ; except for a few belated individuals, 

 they proceed at once to coi^ulate. Nearly the whole summer 

 through both larvae and imagos may be found. The latter 

 pass the winter under moss, dead leaves, in the ground, in 

 hollow stumps, under stacks of wood, etc. Von Oppen found 

 that they prefer to winter in dense thickets of 10- to 15-year- 

 old plants rather than in older woods. 



The generation lasts generally one year only, but may 

 extend to 15 months ; only under very favourable climatic 

 circumstances can it be less than a year. 



The beetle frequently appears in extraordinary numbers on 

 felling-areas, where it is bred, and in plantations which it 

 destroys. It is very common in most pine woods throughout 

 Great Britain. 



It rarely if ever flies, moves slowly along the ground, and 

 in times of great heat or cold conceals itself in grass, refuse of 

 felled trees, earth, etc. 



c. Relations to the Forest. 



This species is important in the perfect state alone, by the 

 injuries it inflicts on young coniferous plants; weakly Scots 

 pine and spruce of 3 to 6 years old are preferred, but younger 

 plants, even yearlings, are attacked, and exceptionally other 

 conifers (black and Weymouth pines, Douglas fir, silver-fir 

 and larch). Even broadleaved trees are attacked, chiefiy 

 oaks and other species planted in old coniferous woods, or 

 employed as a shelter-wood for Scots pine. The insect is 

 therefore clearly polyphagous. 



The damage is done from May to September, the Ijark of 

 the young plants being gnawed all along the stem, down to 

 the rootstock. The bast or sapwood is exposed in patches, 

 which may be as large as a bean, and resin exudes from the 

 torn walls of the points of attack. More of the outer bark is 

 always removed than of the bast, so that the injuries appear 

 as irregular and shelving erosions of the surface. 



Frequently in this way the young trees are girdled, and 

 very small plants are completely peeled, up to their crown. 



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