464 MAINE AGRICULTURAL EXPERIMENT STATION. I912. 



Saperda tridentata. 



ELM-BORER. 



Packard, Forest Insects, 1890, p. 224. 

 Forbes, Bui. 154, Univ. of Illinois Agr. Exp. Sta. 1912. 



This dangerous enemy of the elm is also at work in the State 

 and specimens were captured on the Campus July 10. " Lot 

 1504. 



Packard gives an account of this insect which reads in part : 



"Perforating and loosening the bark and furrowing" the surface of 

 the wood with their irregular tracks, flat white longicorn borers, chang- 

 ing to beetles in June and July ; the beetles flat, dark brown, with a 

 longitudinal three-toothed red stripe on the outer edge of each wing- 

 cover. 



"This is the most destructive borer of the elm in the Northern and 

 Eastern States, often killing the trees by the wholesale. Great numbers 

 of the larvae of different sizes have been found boring in the inner bark 

 and also furrowing with their irregular tracks the surface of the wood, 

 the latter being, as it were, tattoed with sinuous grooves, and the tree 

 completely girdled by them in some places. The elms on Boston Com- 

 mon have in former years been killed by this borer, and valuable trees, 

 we have been informed, have been killed by them in Morristown, N. J. 

 It has been found in all stages in the elm at Detroit, Mich., by Mr. 

 H. G. Hubbard." 



Dr. S. A. Forbes in the bulletin referred to gives an account 

 of this insect associated with "a fatal affection of the elm now 

 prevailing over a large part of southern Illinois." 



