268 



PRoriocrioN acain.st insects. 



distance of 1 to t] in. 



Fig. 127.— Piue-bark with cham- 

 bers («), pupae (b) and imagos (e) 

 J/, pimpcrda, L. 

 [Xatural size.) 



Fig. 128.— I'ine-shoot, hdllowed 

 out by J/, jjiiiipcri/d, L., witli 

 two beetle-holes. 



pine forests. Fig. 128 si 

 a cone. Such twigs may 



from their extremities, choosing 

 especially those of sickly or old 

 trees, in preference on sumiy 

 borders of woods ; they eat out 

 a burrow about an inch long, 

 working upwards to the buds. 

 The entrance - holes into these 

 nhoots are surrounded by a 

 whitish ring of resin. The beetle 

 leaves the hollowed - out shoot 

 either by the original bore-hole 

 or by a fresh hole made at the 

 end of the burrow, and recom- 

 mences his destructive work in 

 another shoot. In these galleries 

 excrement is never found, and 

 thus the action of M.piiiipcrda, L., 

 may be distinguished from that 

 of Tortrix huoliana, Schifif., the 

 caterpillar of which also bores out 

 Scots pine shoots, but always 

 leaves excrement in the borings. 

 Weak side-shoots which have been 

 bored break off generally at the 

 bore-hole, and fall to the ground. 

 Stronger shoots from the crown 

 develop the su])pressed buds be- 

 tween the pairs of needles, which 

 with favourable spring - weather 

 grow into short needles, and give 

 the shoots a bushy appearance. 

 The height, growth and develop- 

 ment of the crown are thus 

 seriously affected ; and the pro- 

 duction of cones being materially 

 reduced greatly impairs the success 

 of natural regeneration of Scots 

 lows a hollowed-out twig bearing 

 be found lying on the ground 



