DESTRUCTION OF SPRUCE FORESTS. 813 



mostly spent in Maine, demonstrated satisfactorily to my own mind that 

 large, healthy firs, a foot in diameter, may be killed by the attacks of 

 longicorn borers {Monohammus dentatus), assisted by the smaller and far 

 more numerous bark-borers, and aided, perhaps, by caterpillars, with 

 the final assistance of the common longicorn, Bhagium lineatum. Several 

 living firs with only the lower branches dead were observed with the 

 bark perforated with the holes made by the common longicorn pine-borer 

 {see p. 685) and a Buprestid borer, while the boughs were tenanted by 

 bark-beetles and their young. Fir trees along the road to Harpswell 

 from Brunswick were also observed to be perforated in the same manner; 

 and if a dozen longicorn borers can not only injure but kill outright 

 large, healthy sugar maples, as has been observed in Brunswick, Me. 

 (see p. 374), there is no reason why firs from 6 inches to 1 foot in dia- 

 meter should not perish from a similar cause; or if multitudes of small 

 timber beetles or bark-borers girdle the tree from top to bottom with 

 their mines, we do not see why this is not an eflScient cause of rapid decay 

 and death. 



A. (jt. Teuney, esq., has kindly handed us the following extract from 

 the Home Farm, for July 14, 1881, published at Augusta, Me. : 



Some time ago two or three articles appeared ia our journal concerning the injury 

 to the spruce timber in the northern [portions of our State, caused by a minute little 

 insect about whose history little seems to be known. Since then we have received 

 much information concerning them from a most intelligent gentleman resident in 

 northern Somerset, who has been extensively engaged in lumbering for many years, 

 and who has visited the spruce forests summer and winter, and observed the working 

 of this very destructive insect. 



The gentleman informs us that the first appearance of the insect was in 1874, and 

 he has reason to believe it is now much on the increase, as he thinks on some town- 

 ships there are now thirty dead trees from this cause, where two years ago, on adjoin- 

 ing townships, there was but one. The insect appears about the first of June, and on 

 landings and jambs of spruce; the air is full of them. They are about as large as a 

 black fly, and are of a brownish, or dark snuff-color, the head half the size or length 

 of the body. They are very tenacious of life, being hard and horny, and it is almost 

 impossible to crush one between the thumb and finger. They are seen for about two 

 or three weeks, during which time the logs and standing trees in the wood are bored 

 full of holes about the size of a timothy straw, in which the eggs are laid, the larvae 

 of which appear the next summer. In felling trees in winter, thousands of these 

 grubs drop out, from one-sixth to one-eighth of an inch long. The chickadees are 

 very fond of them, and may constantly be seen following the lumbermen and picking 

 up their food. If the spruce are cut the first year they are attacked, they make very 

 good lumber, but the second year, or after the sap-wood has turned black, they are 

 quite worthless, unless the tree is 2i feet through, in which case the heart-wood 

 is worth something for lumber, after the sap-wood is dead. The rapidity with 

 which the wood of standing trees that have been punctured by these insects decays 

 is noticeable from the statement that in autumn, when parties are exploring, 

 the blazing of an apparently sound tree with the axe reveals the fact that the sap- 

 wood is thoroughly gone. 



We have previously stated that Dr. Franklin B. Hough, the United States Commis- 

 sioner of Forestry, visited this State last autumn and made an exploration of our 

 northern forests, for the purpose of gathering information as to the extent of the 

 ravages of this insect. In a letter to us, under date of May 6, 1881, he writes: 



*' I am well informed as to the extent of damages being done to the spruce timber in 



