PINE BARK-BEETLES. 721 
Occurring under the bark of the piue in Alaska, Canada, and Virginia, a bark-borer 
closely allied to Xyleborus, with the prothorax strongly punctured, not roughened in 
front; length, 4.4 mm (0.17 inch). (Le Conte.) 
50. The boring dendroctonus. 
Dendroctonus terebrans (Olivier). 
Order Coleoptera ; family Scolytid^:. 
Perforating larger holes in the bark than any of the preceding bark-beetles, and 
mining curved galleries in every direction in the inner layers of the bark, and slightly 
grooving the outer surface of the wood, a cylindrical light chestnut red or yellowish 
fox-colored beetle 0.23 to 0.33 long, bluntly rounded at each end, thinly clothed with 
yellowish hairs, its thorax narrowed anteriorly and with coarsish shallow punctures 
and a slightly raised line along the middle, at least on the posterior half, a faint black- 
ish line along the middle of the upper part of the head, and its wing-covers rough, 
with rather shallow furrows, in which are coarse indistinct punctures. Appearing 
abroad early in May, numerous in pine forests, and in lum- 
ber and mill yards. Its larva? common under the thick 
bark of pine logs and stumps; a yellowish-white footless 
grub thinly clothed with yellowish hairs, and divided into 
thirteen segments, its head polished and horny, of a tawny 
yellow color, with the mouth black, and the neck having 
on each side, above, a large polished spot tinged with 
tawny yellow. (Harris's Treatise, page 75.) 
With this account, taken from Harris, our 
own observations agree. The cells are smaller 
than those of Pissodes strobi. We have found 
the larvae and immature beetles in abundance 
in Brunswick, Me., in the middle of March. The 
burrrows are very irregular, winding about under FlG . m . -Dendroctonus tere- 
the bark, while the very irregular cells are from brans.— Smith, and Miss 
half an inch to an inch long, and nearly a quarter Sulllvan del 
of an inch wide, and surrounded with the white woody chips made by the 
larva before pupating. 
Le Conte states that in this species the prothorax is very densely and 
coarsely punctured ; the hairs of the elytra not being very long. It 
has been collected in Canada, Georgia, Oregon, and California, as well 
as the pine woods of New England and northern New York. u The 
specimens from the Pacific slope are larger, and the punctures of the 
prothorax are rather smaller and more dense, but these differences do 
not seem to me worthy of specific distinction. Some specimens from 
New Hampshire and Canada have the prothorax more sparsely punct- 
ured, almost as in the next species (D. similis), from which they are 
only distinguished by the shorter hairs of the elytra. Length 5.2 to 
8 mra (.2 to 3.2 inch). 
51. The red polygraphus. 
Polygraphia rufipennis Kirby. 
Boring irregular galleries under the bark of the pitch pine, somewhat like those of 
Tomicuspini, but much less regular and twice as wide and deep, a reddish brown 
bark-borer. 
5 ENT 46 
