﻿OF THE STATE ENTOMOLOGIST. 73 



are pale yellow, and irregularly ribbed or corrugated,* are glued by 

 the female by preference under the loose scales or within the cracks 

 and crevices of the bark, several of them being not unfrequently 

 found together. Yet they must also be laid at times on perfectly 

 smooth bark, as I have found the newly hatched larva in such bark, 

 and under circumstances that would indicate that the beetle some- 

 times uses her jaws to puncture the tender bark so as to allow the 

 insertion of the egg. The young larvtB hatching from them gnaw 

 through the bark and feed upon the fiber, boring broad and flattened 

 channels, and very soon girdling the smaller trees. When its jaws 

 get stronger it usually bores into the more solid wood, working for 

 awhile upward, and when about to transform it invariably cuts a pas- 

 sage back again to the outside, leaving bui a thin covering of bark 

 over the hole. It then retreats, and after packing the excrement 

 around it so as to form a smooth cavity, changes to the pupa state 

 (Fig. 12, h). The pupa at first white, by degrees exhibits the colors of 

 the future beetle, and in the course of about three weeks the latter 

 gnaws its way through the thin bark door which, as larva, it had left 

 closing its passage-way. It is a singular instinct that thus teaches the 

 larva, which has powerful jaws, to prepare for the exit of the beetle, 

 which has much more feeble ones; and this instinct is most strikingly 

 illustrated when the infested tree is surrounded with some covering 

 like wire gauze, which is proof against even the jaws of the larva. In 

 such an event, even though the wire touch not the bark, the larva 

 will work its way through the latter, and test in every conceivable 

 way the resistance of the wire, and frequently succumb in the effort 

 to penetrate it. Yet normally this same larva would take every pre- 

 caution not to penetrate the bark. 



Whether this borer remains in the tree nigh upon one or two 

 years after hatching, no one has definitely determined. The general 

 impression is that it acquires its full development in a single year. 

 Be this as it may, the larvae are found of different sizes during the late 

 Summer, and young ones may be noticed even in Winter. In May 

 they are mostly found full grown or in the pupa state. The figures 

 which accompany this article will sufficiently illustrate the appear- 

 ance of the insect in all its stages, no drawing of the pupa having 

 ever been made before. 



NATURAL ENEailES. 



Hidden as this borer naturally is within the retreat of its own 



*Eggs which I have found on apple trees, and taken for those of this insect, and which accord ia 

 appearance with those taken from the abdomen of the female beetle, are about 0.02 inch long, ovoidal, 

 with one end flattened; the shell very thin, and irregularly ribbed. 



