146 THE SCOLYTID BEETLES. 
It is evident that the price of cleaning becomes then very high; but we are com- 
pensated by preserving precious trees to continue the existence of the planting. 
In conclusion, we counsel, therefore, repeated visits during the summer months in 
the forests where the presence of D. micans has already been determined and in those 
where it may be expected; then, visits less frequent during the months of spring and 
winter. We counsel, also, the assembling of all the official personnel of the forest 
service as soon as the presence of the insect is found and the giving of instruction as 
to the characteristic appearances attended by the insect attack. If necessary, a bounty 
might be paid. 
After examining the trees designated, the foresters will decide whether it is best to 
cut down the trees or clean them. 
In this manner it will be everywhere as in Herzogenwald, where a rigorous sur- 
veillance, but not at all expensive, has rendered the existence of the insect almost, 
impossible. 
SPECIMENS. 
This species is represented in the forest-insect collection of the 
Bureau of Entomology by 90 specimens, including adults, larvae, 
and work. 
BIBLIOGRAPHY. 
Ratzeburg, 1839 (under Hylesinus (Dendroctonus) micans), p. 217; Stein, 1854, 
(under Hylesinus micans), pp. 277-279; Kollar, 1858, pp. 23-28; Eichhoff, 1881, pp. 
125-128; Altum, 1881, pp. 262-266; Judeich u. Nitsche, 1889, pp. 458-462; Menegaux 
et Cochon, 1897, pp. 206-209; Severin, 1902, pp. 72-81, 145-152; Weber, 1902, p. 108; 
Brichet et Severin, 1903, pp. 244-258; Baudisch, 1903, pp. 151-152; Quairiere, 1904-5, 
torn 11, pp. 626-628, torn 12, pp. 183-186; Quievy, 1905, pp. 334-335; Nusslin, 1905, 
pp. 175-178; Severin, 1908, pp. 1-20; Hopkins, 1909, pp. 143-146. 
No. 22. THE BLACK TURPENTINE BEETLE. 
(Dendroctonus terebrans Oliv. Figs. 95, 96.) 
The black turpentine beetle is a large, stout, dark-brown or black, 
cylindrical barkbeetle, 5 to 8 mm. in length, with broad prothorax, 
coarsely punctured pronotum, the sides slightly narrowed toward 
the head, but not strongly constricted; the elytra with coarse, trans- 
verse to oblique rugosities between distinct to obscure rows of punc- 
tures; the declivity convex, with moderately deep grooves, the 
intervening spaces slightly convex and roughened, and the entire 
body sparsely clothed with long hairs. (See fig. 95.) It attacks the 
living bark, usually at the base of injured, dying, or healthy trees, or 
the stumps of felled pine and spruce, from Long Island, N. Y., south- 
ward to Florida and westward to Texas and. West Virginia, but it is 
more common in the South Atlantic and Gulf States. The parent 
beetles excavate broad, somewhat irregular, winding, longitudinal 
or sometimes transverse egg galleries through the inner bark and 
groove the surface of the wood. The eggs are placed in groups or 
masses at intervals along the sides of the galleries. The stout, yel- 
lowish-white, cylindrical larvae, with reddish heads and stout spines 
