INSECT ENEMIES OF WESTERN FORESTS 153 
The obtuse sawyer (Jlonochamus obtusus Csy.) is a small brown 
beetle with gray markings, measuring from one-half to three-fourths 
of an inch in length. The antennae are over twice as long as the 
body, and the prothorax has a toothlike projection on each side. 
The larvae are from 1 to 114 inches in length and are destructive to 
pine and Douglas fir in Idaho, Montana, California, and probably 
other Western States. 
The black-horned pine borer (Callidium antennatum Newm.) (fig. 
76) 1s a common species in western forests which attacks the logs 
and limbs of dead ponderosa pine and sugar pine. It has recently 
FIGURE 76.—The black-horned pine borer (Callidium antennatum) : A, Larvae; B, pupa; 
C, adult; D, larva making tunnels on edging of pine board. A, B, C, natural size. 
attracted attention as a destructive borer in lumber stored in mill, 
yards in northeastern California, where it attacks strips of bark left 
on the edges of lumber stock. The larvae work under this bark and 
score the surface of the wood, then extend their mines into the sap- 
wood for a depth of 2 or 3 inches. They also injure seasoned rustic 
work by mining out the cambium layer and causing the bark to 
loosen from the log. The larvae are yellowish-white, apparently 
legless grubs about three-fourths inch in length when full grown. 
The adults are flat, shining, bluish-black beetles about one-half inch 
in length, with antennae about half the length of the body. Other 
closely related species are found in the various firs, pines, cedars, 
and redwood. 
Other species of wood-boring cerambycids which may be en- 
countered damaging the wood of western forest trees are the follow- 
1S 
Species Hosts and distribution 
Tragosoma harrisi Lec______--___. Pines. Western States. 
Asemum atrum Wsch 222 Pines, firs, and spruce. Western States. 
Liasemum nitidum Lee _-----_- Pines, firs, and Douglas fir. Pacific coast. 
Criocephalus productus Lec______-_ Pines, firs, and Douglas fir. Western States. 
Criocephalus asperatus Lec__-_-_--. Pines. Oregon and California. 
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