200 THE PROTECTION OF WOODLANDS. 



plantations, pole-woods, and living or dead branches of Pine-trees. The 

 larvse hatch out in June and July, feed about 4 weeks, pupate in July and 

 August, and emerge as beetles in August and September. The main- 

 galleries radiate in star-shape, but differ from those of B. chalcographus 

 by greater irregularity, by both the main- and the larval-galleries entering 

 more or less into the sapwood, and by the pupal-chamber being mainly in 

 the sapwood. The first generation usually emerges in July and proceeds 

 to pair and produce a second generation, appearing in September. This 

 second generation of beetles usually hibernates till the following May or 

 June ; but in warm dry seasons it can produce a third generation, which 

 hibernates as larvse. 



Prevention and Extermination consist in keeping the woods clean, thin- 

 ning and removing sickly poles, and laying down traps of small thin- 

 barked branches and twigs (such as may be cut from decoy-stems set for 

 larger bark-beetles), and then burning them after egg-laying is finished 

 in June. Seedlings or saplings attacked should be pulled up and burned, 

 and infested poles felled and barked, and the bark burned. 



* The Acuminate Pine-bark beetle, Bostrichus acuminatus, is some- 

 times destructive in the crowns of middle-aged and maturing Scots Pine 

 woods. The beetle is about g to J in. long, and brown with yellowish-grey 

 down. The shield-wings have regular rows of punctures, and are sharp 

 pointed where they meet near their upper end (hence acuminatus) ; 

 and each shield-wing has there 3 tooth-like processes, the third being the 

 largest. Beetles fly in April and May, when the ? lays eggs high up in the 

 crown of old Scots Pine. The brood-galleries are stellate, with 3 to 5 arms 

 radiating from a large pairing-chamber, and biting deep into the sapwood. 

 The larval-galleries are mostly in the cambium, confused, irregular, often 

 crossing each other. The beetles emerge in July and August, pair, and 

 produce another brood, which emerge as beetles in autumn, hibernate 

 under the bark (along with stragglers of the summer brood), and pair 

 in the following spring. Prevention and extermination. Fell and remove 

 mature timber before spring is far advanced, and thin out sickly trees 

 in old woods. As the eggs are laid high up in the crowns of old trees, 

 it is difficult to trap this beetle in decoy-trees. 



The large 6 -toothed Pine-bark beetle, Bostrichus sexdentatus, largest 

 of the bark-beetles, \ to | in. long, glossy black or dark -brown with 

 yellow hairs, but not very destructive or common, generally lays its eggs 

 in freshly -felled timber, windfalls, and fuel-stacks, and mostly attacks old 

 thick-barked Scots Pine when felled, but also woods from 20 to 30 years 

 of age upwards. 



The Larch Bark-beetle, Bostrichus laricis, f to J in. long, and usually dark- 

 brown, is often found in Conifer-woods, but chiefly (despite its name) on 



