INSECT ENEMIHS OF WESTERN FORESTS 25 
Other species of Pissodes which work in the terminals of young 
trees include the following: 
Species Hosts and distribution 
Pissodes yosemite Hopk—-_~-—_-_- Ponderosa pine, western white pine, and 
sugar pine. California, Oregon, and Wash- 
ington. 
Pissodes schwarei Hopk——-—-__-_- Ponderosa pine. Rocky Mountain region. 
Certain species of the genus Magdalis are also twig borers during 
the larval period (fig. 15). The adults feed on the foliage and make 
punctures in the twigs of conifers and broadleaved trees, in which 
egos are deposited. The grubs burrow beneath the bark and cause 
the death of small branches 
and terminal twigs. The 
larvae are white, legless, 
ahd curled and are practi- 
cally indistinguishable from 
those of Pissodes, but the 
work is usually distinct in 
that the larval borings are 
fine-grained and powdery 
instead of shredded, and the 
pupal cells are oval and 
smooth, without the lining 
of shredded wood fiber. The 
adults are bright blue, 
green, or black, with promi- 
nent curved beaks. West- 
ern species include the fol- 
FIGURE 15,—Pine twig weevils (Magdalis lecontei), 
natural size. lowing: 
Species Hosts and distribution 
Magdalis lecontei Horn (fig. 15)_ Pines. Pacific States. 
Magdalis cuneiformis Horn--_~-~- Ponderosa pine. Western States. 
Magdalis hispoides Lec_____--__. Lodgepole and other pines. Maine to British 
Columbia, New Mexico, and California. 
Magdalis gentilis Lee___________- Jeffrey pine. California. 
Magdalis proxima Fall__________- Monterey and probably other pines. Cali- 
fornia and Oregon. 
Magdalis alutacea Lec__---__---- Spruce. Colorado and other Western States. 
MAGCUAMS OAciiis WWees.= ths Fruit trees and broadleaved trees. Califor- 
nia, Nevada, and New Mexico. 
Magdalis aenescens Lec_____----- Alder and apple. Alaska to California and 
eastward to Montana. 
TWIG BORERS AND GIRDLERS 
A few bark and wood boring insects (407) belonging to the families 
Buprestidae and Cerambycidae are of some importance as twig 
borers, or girdlers, in various forest, park, and shade trees. 
Beetles of the family Buprestidae lay their eggs on the bark of 
twigs, and the larvae, which are referred to as “flatheaded borers” 
on account of their horseshoe-nail appearance, work under the bark 
and into the wood, forming nearly flat tunnels filled with boring 
dust. The larvae are slender and white, without legs, and the 
enlarged forward segment of the body has horny plates on both the 
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