Clje Canadian d^ntomoloqist. 



VOL. XVI. LONDON, ONT., SEPTEMBER, 1884. No. 9 



SCOLYTUS RUGULOSUS IN BRANCHES OF PEAR TREES 

 WHICH WERE KILLED BY PEAR-BLIGHT. 



BY DR. H. A. HAGEN, CAMBRIDGE, MASS. 



During the years 1882-4, large branches of young pear trees in Cam- 

 bridge, Mass.. were killed by pear-blight. The next year other branches 

 were affected and killed, and finally the whole tree succumbed. All trees 

 had been in good and healthy condition. The branches were more or less' 

 densely covered by a Coccid, determined by Prof. J. H. Comstock as 

 Chionaspis fu7-furus (A. Fitch), described and figured in his Report -for 

 1880, p. 315, pi. 17, f I. The Professor thinks it much more probable 

 that the branches were killed by the Scolytid (directly to be mentioned) 

 than by the Coccids, and I believe this opinion is justified by the fact that 

 other pear trees and apple trees near by are also covered by the same 

 Coccid and are nevertheless in a healthy condition. 



The branches were densely inhabited by a Scolytus, which Dr. G. H. 

 Horn determined as Scolytus rugtciosus Ratzeburg. I was able to com- 

 pare the beetle with specimens from Germany, which proved to be identi- 

 cal. The species was first mentioned by Dr. J. L. LeConte as introduced 

 from Europe into the U. S., Proc. Amer. Philos. Soc, vol. xvii., p. 626, 

 No. 79. The specimens were received from Elmira, N. Y., attacking 

 peach trees. His collection contains, besides those from Elmira, N. Y., 

 several specimens from Hillsboro, Md. Prof Chas. V Riley informs me 

 that he has ready for publication an extended article, with illustrations, 

 upon S. 7-uguiosus, and drew my attention to his note in the N. Amer. 

 Entom., 1880, vol. iii., p. 298. The beetles were sent by Mr. J. L. Ben- 

 net, Red Bank, N. J. They had for several years destroyed all cherry, 

 peach and plum trees set out on a particular lot at Fair Haven. They 

 did not appear to injure seed fruit as yet, and are confined to a small 

 section. They bore little holes in the trees, which holes fill with gum, and 

 the tree soon dies. Mr. H. Boye, Coopersburg, Pa., communicated that 

 the same beetle had so profusely stung a young cherry tree, trunk and 

 branches, that it will not recover. Prof Riley has received it from Hills- 



