98 ROMANCE OF THE INSECT WORLD CHAP. 



goat-like odour. The caterpillars are hatched in 

 crevices in the bark, and at first they feed in the bark, 

 or between that and the wood. As soon as size and 

 strength permit, they penetrate into the living tree, 

 and make galleries and chambers, larger perhaps than 

 those of any of our wood-boring enemies. Propor- 

 tionately as the larva increases and its growth is 

 amazing the diameter of its burrow becomes en- 

 larged ; and since its course is erratic, and it remains 

 in the larval condition for fully three years, the mis- 

 chief it perpetrates is great. During the winter, how- 

 ever, it lies dormant, and does not feed, in a cocoon 

 ingeniously constructed from wood-chips roughly 

 spun together with silk thread. This nest is often 

 over two inches long and one in width. 



The larvae of the Scarabaeidse, the giants of their 

 order (Coleoptera), are likewise notable wood-borers. 

 Fortunately for us, for the amount of vegetable 

 matter that they consume must be enormous, the 

 larger species live exclusively in countries where a 

 luxuriant vegetation can best afford their depreda- 

 tions. At home perhaps no wood-boring beetle is 

 better known than the little Scolytus destructor. It 

 is destructive, particularly to elms, both in its mature 

 and larva states, and many large trees, and even whole 

 forests, succumb to its attacks. The mother enters 

 the tree in search of food ; and to lay her eggs she 

 squeezes herself in between the bark and the wood, 

 where she bores out a cylindrical gallery, usually 

 from three to five inches long, taking her about three 

 weeks to complete. Along the sides the eggs are laid 

 at regular distances apart, to the number occasionally 



