198 THE PROTECTION OF WOODLANDS. 



Prevention and Extermination. The best measures are keeping the 

 woods clean, removing all windfall and sickly trees, or stems having bore- 

 dust lying round them, or on which white resin-shells or entrance-holes 

 in thick bark indicate that they are already infested. From decoy -stems 

 placed here and there in spring and summer, the bark should be peeled 

 and burned at the proper time. Winter-felled timber may thus be used ; 

 but if not removed from the woods by the end of May, it ought then to 

 be barked. Collecting and burning hollowed shoots lying scattered on 

 the ground is of little use, as the beetles emerge before the twigs 

 break. 



*The Crutch Pine -beetle, Hylesinus palliatus (so called from the 

 main-galleries beginning with a boot-shaped or crutch-like bend), often 

 attacks along with H. piniperda in Scotland. Only about ^ in. long, it 

 is often overlooked, as it can breed in stems not freshly felled. 



* The Small Pine - shoot beetle, Hylesinus minor, f to J in. long, 

 having uninterrupted knob-like tubercles with brush-like tufts at the ends 

 of the shield-wings, and more red-brown than deep brown or black, is 

 also found with H. piniperda and H. palliatus in Scots Pine and Spruce 

 pole-woods and middle-aged crops. It breeds in sickly trees. 



* The black Pine - cambial beetle, Hylesinus ater, about to in. 

 long, and black with red-brown feelers and feet, only does damage as a 

 beetle, attacking 2- to 6-year-old Pine plantations. Common in Britain, 

 it is not very injurious. 



* The Ash-bark beetle, Hylesinus fraxini (Fig. 42), is destructive all 

 over Britain, and often bores into healthy Ash-poles and trees, which 

 soon sicken, then become much infested, and are quickly killed. 



About in. long, light to dark-brown, wing cases with five longitudinal 

 punctured lines. Beetles emerge from their winter quarters in late April or 

 early May, and lay eggs in the stem and branches of Ash-trees or in Ash-logs 

 lying in woods or parks, which are probably their chief breeding-places. 

 From 20 to 60 eggs are laid along each arm of the 2-armed mother-gallery, 

 and in a few days the larvae hatch out, reddish or purplish at first, with brown 

 head and jaws, legless, transversely furrowed, and tapering to the tail. 

 After feeding for about ten weeks, they pupate either in the bark or the 

 sapwood. The young beetles emerge in August (their exit-holes making 

 the trees look as if riddled with shot), and at once attack neighbouring Ash- 

 trees or freshly-felled logs, where they form galleries and feed during the 

 autumn, then remain dormant in winter, and feed again in March and 

 April, before emerging to pair. Prevention consists mainly in planting 

 Ash only on really suitable soil, and Extermination in removing logs be- 

 fore August, in cutting out sickly Ash-poles and trees by February and 

 March, in leaving decoy-logs in parks, and in barking all infested stems in 

 June and July and burning the bark. 



