24 



INSECTS INJURIOUS TO THE APPLE. 



Fig. 8. 



The eggs are laid in the crevices of the bark of trees, 

 especially near the roots. The larvae live in decaying wood, 

 and are found in the trunks and roots of various kinds of 

 trees^ particularly those of old apple-trees; they are also 

 found in okl cherry-trees, willows, and oaks. They are 

 said to be six years in completing their growth, living all tlie 

 time on the wood of the tree, reducing it to a coarse powder 

 resembling sawdust. The mature larva is a large, thick, 

 whitish grub, with a reddish-brown, horny-looking head, 

 dark mandibles, and reddish legs. (See Fig. 8, a.) The body 



is curved when at rest, 

 the hinder segments being 

 brought towards the head. 

 When the larva has at- 

 tained full size it remains 

 in its burrow, and encloses 

 itself in an oval cocoon 

 (Fig. 8, 6) formed of frag- 

 ments of wood and bark 

 cemented together with a 

 glue-like secretion, and within this enclosure it is trans- 

 formed into a pupa of a yellowish-white color. Through the 

 partially transparent membrane the limbs of the future beetle 

 are dimly seen, and in due time the mature insect bursts its 

 filmy covering, crawls through the passage previously gnawed 

 by the larva, and emerges to the light of day. 



As this beetle affects only old and decaying trees, it seldom 

 does much harm. The use of the alkaline wash recommended 

 for Iso. 2 would no doubt deter the beetles from depositing 

 their eggs on trees so protected, and thus any mischief they 

 might otherwise do could be prevented. 



No. 6. — The Apple-bark Beetle, 



Monarthrum. malt (Fitch). 



The apple-bark beetle is a small insect about one-tenth of 

 an inch long (see Fig. 9, where it is shown much magnified) ; 



