LARGE PINE- WEEVIL. 201 



Pines or Spruce, and sometimes Larch and Silver Fir. It chiefly attacks 

 poles, tree-tops, and stacked fuel. 



The Wood -boring Bark -beetle, Bostrichus lineatus, is cylindrical, 

 blackish, to ^ in. long, with dull yellow-brown elytra, antennee, and 

 legs, and three dark longitudinal stripes along each shield-wing (hence 

 lineatus), but has no tooth-like processes at their ends. In Scotland this 

 beetle chiefly attacks recently-felled Scots Pine, Spruce, and Larch, and 

 only exceptionally poor standing crops, and often riddles the wood 

 with holes ; but as the borings are mostly confined to the sapwood, the 

 damage is not great, though it spoils poles for cellulose-making. 



The Oak bark- and wood-boring beetle, Bostrichus dispar, black, with 

 reddish feelers and legs, ? in., T V in. long, elytra well rounded at ends, 

 and with rows of deep punctures, mostly attacks Oak and Beech, but also 

 attacks other hardwoods, Birch, and Alder. The larvae often kill off Oak 

 saplings and transplants, and the beetle sometimes bores into and breeds 

 in the stems of sickly old Oak, Beech, or timber lying on the ground, and 

 spoils the timber. Trees or saplings infested show bore - dust on the 

 ground. 



B. SNOUTED WEEVILS (Curculionidce). ' 



* The large Pine- weevil. Hylobius abietis (Figs. 43, 44), is the most 

 destructive insect in our woodlands, though the damage is only done 

 during the adult stage. It attacks young plantations of Pines, Spruce, 

 Larch, Douglas Fir, and Silver Fir up to about 5 or 6 years old, and gnaws 

 the bark, thus causing an outflow of resin in scab-like patches. Whole 

 plantations are sometimes ruined, especially in warm, dry seasons. When 

 the bark thickens and hardens there is less risk of damage, and planta- 

 tions of 8 to 10 years are fairly safe. It sometimes attacks older trees, 

 but the wounds soon get coated with resin and heal up. As it breeds 

 in fresh sappy stumps, it is only found where Conifers have been recently 

 felled. Weevil about ^ to ^ in. long, stoutly built, convex in shape, deep- 

 red to dark-brown or black, and having a long thick snout, with feelers 

 springing from near its tip. It is marked with clusters of yellow scales 

 or hairs between the eyes, on the sides of the thorax and abdomen, 

 and on the elytra. These yellow patches look like cross-bands on the 

 elytra, and are very distinct when the beetle emerges, but gradually 

 become fainter. The beetles live two years or more, so that those recently 

 emerged (distinctly marked) and older beetles (faintly marked) that have 

 been out for some considerable time, as well as larva) in every stage of 

 development, may all be found simultaneously. Beetles appear from 

 April till June, and crawl or fly to fresh Conifer falls, and lay eggs in 

 the sappy stumps and roots. Pairing and reproduction continue in 

 summer and autumn, as long as fresh stumps are available for breeding- 



