APPENDIX. 347 



FOOD PLANTS AND NATURE OF INFESTATION. 



This borer is pi'actically limited in its food supply to the apple and kin- 

 dred woody plants. It is most injurious to quince and apple, and somewhat 

 less troublesome to pear. It also infests crab apple, and thorns of different 

 species, choke-berry and June-berry, in short practically all except one or 

 two kinds of trees and shrubs belonging to the genera now included in the 

 restricted family of Pomacetn. The wild plants are its natural food and 

 certain varieties at least, although often inhabited by this insect, are for 

 some reason not so susceptible to injury by it as our cultivated trees. 



This species inhabits more particularly the base of the trunk of trees, 

 often being found below the surface of the earth, especially in young nur- 

 sery stock. It is to such trees that if is most injurious as it soon works 

 around the tree, separating the wood from the bark, interfering with the 

 flow of sap and producing the effect of girdling, a result which is very apt to 

 be produced even when no more than two or three larvai occur upon the 

 same tree. Very frequently four or five larva? dwell together in a single 

 small tree and in a short tJme injure it entirely beyond recovery. In older 

 trees larvae occur somewhat higher up the trunk, in exceptional cases at 

 a distance of several feet from the base or even, still more rarely, in the 

 lower limbs; but as a rule they are seldom found except within a foot or 

 two of the base. Trees of all sizes are frequently killed or so weakened that 

 they are unable to mature a full crop of fruit. 



The experience of many years shows that injury follows where grasses, 

 weeds, or other rank vegetable growth are permitted to accumulate about 

 the trunks of the trees, since the beetle, like all nocturnal insects, naturally 

 seeks concealment, and the conditions thus afforded are most favorable for 

 its attack on cultivated plants. 



LIFE-HISTORY. 



The beetles make their first appearance of the season late in May and in 

 June, according to locality, coming forth from the trunks of the trees in 

 which they have bred during the night, at which time the species, being 

 nocturnal, may be seen in flight. During the day the beetles hide away in 

 some secluded place under the leaves or in similar situations on the trees 

 which they inhabit. 



Soon after their first appearance the sexes mate and eggs are deposited. 

 The female first makes an incision in the bark, whether by means of her 

 mandibles or ovipositor is not plain, causing it to split slightly, then turn- 

 ing, head upwai'd, places an egg under the bark nearly a quarter of an inch 

 from the incision, accompanying the deposition by the extrusion of "a 

 gummy fluid which covers and secures it to its place and usually fills up the 

 aperture. In young trees with tender bark the egg is usually thoroughly 

 hidden, while in older trees it is sometimes so shallowly imbedded as to be 

 readily seen." 



"The egg is pale rust- brown in color, one-eighth of an inch long, one- 

 third as wide at the middle, flattened so as to have a depth of about one- 



