THE LOCUST BOEEB. 9 



damage by the borer was very .slight in trees of all sizes. On August 

 26 many adults and a very few pupse, but no larvae, were found in small 

 trees in the valley, while the large trees in the same locality were but 

 slightly damaged. • 



OBSERVATIONS BY MEMBERS OF THE FOREST SERVICE. 



The following notes by Mr. 8. N. Spring, forest assistant in the 

 Forest Service, were submitted October, 1905, as a contribution to the 

 I'esults of cooperative studies. Early in July the work of the borer 

 was noticed in the central portion of Westmoreland County, Pa. The 

 first adult insect was seen on August 29. Evidence of the work of this 

 insect was found in the localities investigated, but, for the most part, 

 it was not serious enough to prevent the planting of locust for fence 

 posts. To the north and west of Greensburg, in "Westmoreland County, 

 and in Allegheny County many roadside trees were badly bored. The 

 work of the borer is slight on Chestnut Ridge and Laurel Hill, where 

 locust thrives. Posts and pit props cut in these mountains show slight 

 injury only. In the few places where injury was found to be great, 

 within the area studied, the trees were dying, and many branches were 

 broken off where the trees had been extensively bored by this insect. 

 Owing to the fact that places of serious injury were so few, it was 

 impossible to carry out any observations that would be of value in a 

 study of immunity. In general the locust on the two high ridges 

 thrived better than those on the lower elevation of Westmoreland and 

 Fayette counties, and less injury due to this insect was found among 

 the trees on the ridges. 



Mr. J. W. Fetherolf, of the Forest Service, informed the writer, on 

 January 26, 190.5, that a grove of black locust planted in Salt Lake 

 City, Utah, prior to 1850, is still in a thrifty condition and apparently 

 free from all insect injury. The same can be said about this species 

 seen elsewhere in the Salt Lake Vallej-. 



Mr. Wesley Bradfield, of the Forest Service, informed the writer 

 that he found the adult beetles common on badly damaged trees, 5 to 

 8 years old, near Marshall, Mich., in August, 1905; also, that accord- 

 ing to his observation the locust in the southern quarter of Michigan 

 was seriously damaged, while in the northern three-quarters, especially 

 toward Lake Michigan, it was not. 



RECENT OBSERVATIONS BY THE WRITER. 



On March 11, 1906, it was found at Arlington Farm, Virginia, that 

 the young larvae had passed the winter in minute cells which they had 

 excavated in the outer lavers of the living bark and just beneath the 

 outer corky bark (fig. 5), as recorded by Dearborn. So common were 

 these hibernating larvae in the trees that in the bark of some of them 

 there were fifteen or twenty within an area of a few square mches; 

 61830°— Bull. 58—10 2 



