INSECT ENEMIES OF WESTERN FORESTS 113 
Some attempts have been made in California to control outbreaks 
of this beetle in young pine stands by felling the trees and burning 
the infested bark much as is done for the control of the western pine 
beetle. Usually such methods are not warranted, as outbreaks are 
sporadic and can be avoided if roadway, line, or other slash is burned 
before the beetles emerge, or in logging oper ations 1f a continuous 
supply of fresh mater ial is provided to absorb developing broods. 
The Arizona five-spined engraver (/ps lecontei Sw.) 1s the south- 
western form of /. confusus. It attacks ponderosa and other pines in 
the southern Rocky Mountain region and at times is exceedingly 
destructive. Its characteristics and habits are very similar to those 
of its near relative, and the methods of control are the same. Re- 
cently some rather extensive operations have been carried on in 
Arizona to control this beetle. 
The Vancouver ips (/. vancouveri Sw.) is also closely allied in 
character and habits to 7. confusus, but is slightly larger. The adult 
beetles are reddish brown to black, about one-fourth inch in length, 
and with five spinelike teeth on the margins at each side of the 
concave elytral declivity, which is densely clothed with long, slender 
hairs. These beetles usually attack decadent or weakened western 
white pine, sugar pine, foxtail pine, lodgepole pine, and Sitka spruce 
throughout the Northwest, but under favorable conditions will attack 
apparently healthy trees. The gallery pattern is of a radiating, 
longitudinal type with three to five short eg@ galleries extending up 
and down the tree from the nuptial chamber. There are apparently 
two but possibly three generations a year. 
The Cloudcroft ips (/ . cloudcrofis Sw.) 1s a secondary enemy of 
pines in the high mountains of New Mexico. It is a slender species 
with five pairs of spines on the elytral declivity and is closely related 
to I. confusus in character and habits. 
The emarginate ips (/. emarginatus Lec.) is most frequently found 
associated with the mountain pine beetle in its attacks on ponderosa 
pine, lodgepole pine, and sugar pine, and with the Jeffrey pine beetle 
in Jeffrey pine, but is quite capable of and occasionally does kill trees 
on its own account. This is the largest western species of /ps. Its 
range extends through California, north to southern British Colum- 
bia, and east through Idaho to western Montana. The adults are 
dark-brown, cylindrical bark beetles about one-fourth inch in length, 
with three prominent spines along each side of the elytral declivity, 
and a fourth nearly obsolete spine. Their work is characterized by 
the long, straight, nearly parallel egg galleries from 2 to 4 feet in 
length, which run up and down the tree and connect at different 
points (fig. 55). Owing to the similarity in length and width of the 
egg galleries, its work is often confused with that of the mountain 
pine beetle with which it is so often associated. However, the pres- 
ence of a nuptial chamber and the absence of packed boring dust in 
the Zps galleries will distinguish their work. In the northern part 
of its range this species has two complete generations a year, while 
in the southern part there are a number of summer generations with 
considerable overlapping of broods. Control work has included this 
species when in association with more aggressive bark beetles, but no 
separate control ever has been required. 
136650°—38——_8 
