bark (fig. 4), where they pass the winter, and in the spring bore 

 through the bark into the sapwood and heartwood. Here they trans- 

 form in July and August to pupa and in August and September to 

 adult beetles, which soon emerge from the trees and deposit eggs for 

 the next annual generation of borers and beetles. 



The injury to the trees consists of wounds in the bark and sapwocxl 

 which, if sufficiently severe or repeated year after year, result in either 

 a stunted, worthless growth or the death of young and old trees, while 

 the numerous worm holes in the wood reduce its commercial value or 

 render it worthless. 



The presence of the insects in injurious numbers is indicated (1) by 

 the frequency of the adults on the golden-rod flowers and on the trees 

 from the last of August until in October or later; (2) by the 'slight 

 flow of sap and by the brownish borings where the j'oung larvae are at 

 work in the bark during April ; (3) by the yellowish borings lodged in 

 the rough bark, in the forks of the tree, and on the ground around the 

 base of the trunk, by the breaking down of the branches and young 

 trees, and by the sickly appearance of the young twigs and leaves dur- 

 ing May, June, and July. 



This insect appears to be present and more or less injurious in all of 

 that part of the United States which is east of the Great Plains and 

 north of the Gulf States. Published information and reports of forest 

 officials and others indicate that in Oklahoma and Indian Territory and 

 west of the Great Plains the locust is now quite free from injury by the 

 borer, but that these regions will remain exempt is by no means certain. 



EXTENT OF DAMAGE AND LOSS. 



So extensive is the damage to natural growth, artificial plantations, 

 and shade trees that in some sections within the natural range of the 

 tree in the Eastern States, but particularly in the Middle West, where 

 both the tree and the insect have been introduced, it is considered 

 unprofitable to grow the tree for shade or timber, and in such sections 

 the natural sprout growth is often considered a pest rather than otherwise. 



The loss resulting from defective timber, stunted growth, and the 

 death of trees is represented by the difference in value between the 

 damaged growth, or product, and the same if uninjured and health}'. 

 This, if expressed in dollars, would represent a large sum. 



CHARACTER OF THE INJURIES. 



The destructive nature of the work of the locust borer is a matter of 

 great economic importance. The borer attacks the otherwise perfectly 

 healthy trees, and in addition to causing the detrimental worm-hole 

 defects in the wood, it often kills the trees or renders an otherwise 

 valuable product worthless except for fuel. It is much more destruc- 

 tive in some localities and sections than in others, and also much more 



