Chapter XVI. 



INSECTS INJURIOUS TO THE SPRUCE. 



Abies nigra and alba. 



Although most of the insects of the spruce also occur on the fir and 

 those of the latter tree may, with very few exceptions, occur on the 

 spruce, yet for the sake of clearness we will treat of them separately. 



The spruce, owing to the rarity of the pine, is the most valuable soft- 

 wood timber tree of New England. It still abounds in the northern 

 parts of Maine, New Hampshire, and New York, and with judicious 

 treatment on the part of lumber owners will remain a perennial source 

 of profit. Locally the most deadly foe of spruce and fir is the Bud 

 Worm, while both trees have for some years and still are being deci- 

 mated by the attacks of timber beetles, as set forth in the following 

 pages. 



AFFECTING THE TRUNK AND BRANCHES. 



Timber or bark beetles. 

 Species of Scolytidce. 



The destruction of spruce and firs in northern New England in 1878-'87, 

 ^see map, Plate xii.) — The forests of spruce and fir in Maine, northern 

 New Hampshire, and New York began about the year 1874 to be de- 

 stroyed by the wholesale. 



The main cause of destruction of the spruce and fir in northern New 

 England and adjacent parts of Canada and New Brunswick we now 

 believe to be due to the attacks of bark-borers of different species. 



The agent in the local destruction of the spruce and fir along the 

 Maine coast from Portland to Thomaston was without doubt a caterpil- 

 lar, the larva of Tortrix fiimiferana, described in succeeding pages. 

 The following remarks will therefore apply to the damage wrought in 

 northern New England, away from the coast : 



In the summer of 1880, during a hasty visit to Brunswick, Me., 

 and the shores of Casco Bay, I noticed the great destruction that had 

 been effected in the spruce growths on Merepoint and on some of the 

 adjacent islands of Casco Bay, but failed to detect the cause of the 

 disease, supposing that it was too extensive to be attributed to the 

 attacks of insects, and that some meteorological cause, as severe winters 



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