THE LOCUST BOREK. 7 



appears now that ita attack is confined entirely to Robinia. It is not 

 necessary that a tree or branch should be some inches in diameter 

 before it is damaged, for the writer has found full-grown larvae in 

 sprouts and branches less than one-half inch in diameter. 



In the writer's opinion, all attempts to cultivate locust in the eastern 

 United States should not le abandoned on account of the borer, although 

 this has been recommended by some recent writers. It has been stated 

 that the locust would probably not be injured by the borer in the 

 southern limit of its range and in the country west of the Great 

 Plains. While this may be true, precaution should be taken to pre- 

 vent its introduction into such localities, since it is not improbable 

 that if the insect be introduced and become established it may prove 

 even more destructive there than in its natural home, as was demon- 

 strated in the Mississippi Valley. 



Nearly all methods heretofore recommended arff subject to practical 

 application to shade trees and small plantations only; therefore there 

 is special need for suggestions of practical methods of combating the 

 insect and preventing losses in large commercial plantations and in 

 natural forest growth, and it is hoped that this paper will contribute 

 something of value along this line. 



OBSERVATIONS BY THE WRITER, 1890-1905. 



Adults were collected on golden-rod flowers at Piedmont, Md. , and 

 Mineral County, W. Va., on August 25, 1890, and on golden-rod and 

 locust leaves at Morgantown, W. Va., September 16 and 17, 1891. 

 Young larvae were found mining in living bark of trees at Kanawha 

 Station, W. Va., May 1, 1891, and on May 20 the same larvas had 

 entered the wood, but a great many had died. 



It was frequently noted that the locust in the forests of Chestnut 

 Ridge in Monongalia and Pendleton counties. Laurel Hill in Preston 

 County, and especially on Rich Mountain in Randolph County, W. Va., 

 showed but slight damage by the borers. Similar observations were 

 made in many other sections of the State, while in near-by and widely 

 separated sections the damage was found to have been severe and contin- 

 uous during the life of some of the older trees. In 1898 it was observed 

 that badly damaged shade trees near Morgantown, W. Va., which 

 I had been severely pruned in March and April, had recovered, and the 

 crowns were renewed by dense, vigorous, healthy growth, which sug- 

 gested this method of treating badly damaged shade trees. 



On October 9, 1904, it was found that the locust in the vicinity of 

 Chevy Chase, Md. , was but slightly damaged by the bbrer, although 

 beetles were found in numbers on golden-rod and feeding on sap from 

 wounds in bark of living sumac. This habit of feeding on sap is of 

 special interest from the fact that it suggests the possibility of killing 



