INSECTS INJURIOUS TO THE APPLE AND PEAR 589 



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

 of 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 larva? tunnel 

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

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



FIG. 444. The round-headed apple-tree borer (Saperda Candida Fab.) 

 larvae, adults, and exit hole natural size. (After Rumsey and Brooks). 



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

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

 five-eigh.ths 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 borrows. The full-grown larva continues this burrow 



