Chapter II, 
INSECTS INJURIOUS TO THE ELM. 
No shade tree is held in higher estimation than the elm. It is the 
pride of New England and New York towns and villages, as well as 
those of the northern, central, and middle Atlantic States. Kaltenbach 
enumerates 107 species of insects which in Germany live at the expeuse 
of the elm, while in this country we have about 80 species, the elm not 
occurring in the Rocky Mountains or on the Pacific coast. 
The species which are the most abundant and persistent in their at- 
tacks are the common elm-tree borer, the canker-worm, and a plant- 
louse which disfigures the leaves by crumpling and discoloring them. 
AFFECTING THE TRUNK. 
1. The common elm-tkee borek. 
Saperda tridentata Olivier. 
Order Coleoptera ; Family Cerambycid-E. 
Perforating and loosening the bark and furrowing the surface of the wood with 
their irregular tracks, flat white longicorn borers, changing to beetles in June aud 
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 num- 
bers 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 Common 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. 
Fitch remarks that it consumes the inner bark of the slippery elm 
{ Ulmus fulva), especially in dead and decaying trees. According to 
him, "the beetle deposits its eggs upon the bark in June, and the young 
larva 1 therefrom nearly complete their growth before winter, and soon 
after warm weather arrives the following spring they pass into their 
pupa state." We have found the larva 1 in abundance in the early 
spring in Providence in old dead elms. 
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