14 
and also in the bark on the roots of the stump of a recently felled 
tree in the Black Hills. This is also a common species of the Rocky 
Mountain pine regions. 
Branch and twig beetles.—The large and small branches and termi- 
nal twigs of the trees that were dying from the attack of the pine- 
destroying beetle were found to be infested by a number of described 
and undescribed species of the genus Pityophthorus and by Pityogenes 
cariniceps, all of which attack the bark as soon as the trees commence 
to die, and contribute, more or less, to hastening the death of the trees. 
Ambrosia or timber beetles and wood-boring grubs.—The wood of the 
trees was found to be infested by the Western hemlock wood stainer 
(Gnathotrichus sulcatus Lec.), the Western pine wood stainer (Gnatho- 
trichus occidentalis Hopk. MS.), and several unidentified Buprestid 
and Cerambycid larvae, which attack the trees, and when they com- 
mence to die bore into the sapwood and contribute to its rapid decay 
by giving entrance through their burrows to wood-decaying fungi. 
SMALL TREES DYING FROM OTHER CAUSES. 
The rock-pine pitch worm.—In addition to the trees killed by the 
pine-destroying beetle, quite a number of young pines 2 and 8 inches 
in diameter were found in the vicinity of Spearfish and Crow Peak 
that were seriously injured by the larva of an undetermined Sesiid 
moth working in the living bark of the main stem and causing ugly 
wounds. Successive attacks on the same tree weaken its vitality and 
attract the Oregon Tomicus and species of Pityogenes and Pityophtho- 
rus, which infest the main stem and branches, while a number of the 
root-infesting bark beetles and a pine weevil attack the base and roots, 
and the tree soon dies. Only a dead and dry larva and a dead chrysa- 
lis of this insect were found. The characters exhibited by these speci- 
mens do not agree with the descriptions of the larva of the sequoia 
and pine-destroying Sesiid (Lembecia sequoia= Vespamima sequoie Hy. 
Edw.*) or of the larva and chrysalis of the pine Sesiid (/Zarmonia 
pin= Parharmonia pint Kellicott”). 
The destructive habits of this class of enemies of trees (which 
includes the common peach-tree borer) suggest that this may be a 
common and destructive enemy of ‘‘ reproduction” pines in the Black 
Hills and other pine-producing areas of the West. 
The pine weevil.—In another section near the Wyoming and South 
Dakota lines many young trees were observed which were apparently 
dying from the attack of a pine weevil (/%ssodes sp.), or the combined 
attacks of this insect, a root fungus disease, and a number of species 
of bark beetles. 
“Mem. Am. Mus. Nat. Hist., vol. 1, part vi, Mongr. Sesiidee. Am. North of Mex. 
1901, p. 263, with bib. ref. 
»Tbid., p. 264. 
