68 



INJURIOUS INSECTS OF KANSAS. 



The young larvre or borers are hatched in about two weeks, 

 and bore into the inner bai'k and sap-wood, where they remain in 

 shallow cavities for the first year of their existence, feeding until 

 the wititer months, when they move down to the lower part of 



Fig. 38. Egg-laying and final exit of Round-headed Aijple-tree Borer; a, incision 

 where egg is laid; b, same, with the wood split lengthwise along the line a, e, and 

 turned so as to show an egg in place; c, same, with the bark split on the same line, 

 and removed to the left, so as to show the manner in which the egg is commonly 

 thrust to one side under the bark; d, the egg, enlarged; e, hole of exit of beetle; 

 /, the same, as it appears from the side when split along the line a, e; g, the burrow 

 as it appears while the insect is in the pupa state, and before the bark is perforated. 



their burrows, frequently below the surface of the ground, lying 

 inactive till spring. In the spring the larva moves up, and feeds 

 again on the inner bark and sap-wood until the following winter. 

 During this second season it attains about half its growth, and 

 does much damage to the tree by more or less completely gird- 

 ling it. After another winter's rest it becomes active again, and 

 during the third summer of its existence it cuts cylindrical chan- 

 nels into the heart-wood of the tree, and, in the fall, being full- 

 grown, bores outward to the bark, lining a cavity at the end of 

 its burrow with its castings and wood dust. In this cavity it lies 

 inactive till the following spring, when it pupates. Finally, about 

 the first of June, it changes to the perfect beetle and gnaws its 

 way out through the bark. 



When full-grown the larva is a little over an inch long, fleshy, 

 footless, with a round, chestnut-brown head. 



