INSECTS INJURIOUS TO THE APPLE AND PEAR 521 



insect about three-quarters inch long. The antennae and legs are 

 gray, the head and under surface of the body silvery white and 

 the upper surface is light brown with two longitudinal white stripes. 

 Life History. The beetles emerge from late May to the middle 

 rof July and the females soon commence to deposit their eggs. The 

 female eats out a little slit in the bark, in which the egg is inserted 

 and often pushed under the bark and then covered with a gummy 

 substance. It is a pale rust-brown color, about one-third inch 

 long, of a broad oval shape, and usually concealed on young trees. 

 The egg hatches in two or three weeks. The young larvae tunnel 

 just under the bark on the sap-wood, usually working down 



FIG. 450. Work of the round-headed apple-tree borer: a, puncture in which 

 egg is laid; 6, same in section; e, hole from which beetle has emerged; 

 /, same in section; g, pupa in its cell. (After Riley. ) 



toward the base of the tree, the bark over these burrows often 

 cracking the next spring, and the fine castings and borings sifting 

 out. At the beginning of the second year the larva is about 

 five-eighths inch long. The larva continues in the sap-wood 

 during the second season, and it is at this time the most serious 

 damage is done, for where several occur in a tree they almost 

 girdle it. The next season they penetrate into the heart-wood, 

 and several of them will fairly riddle a small tree with their 

 cylindrical burrows. The full-grown larva continues this burrow 

 out into the bark, often cutting clear across a tree. The upper 

 part of the burrows are stuffed with fine borings and the lower 



