INSECT ENEMIES OF WESTERN FORESTS 149 



Species of Buprcstis Hosts and distribution 



B. adject a Lee Jeffrey, lodgepole, and other pines. West- 

 ern States. 



B. connexa Horn Jeffrey pine and ponderosa pine. California, 



Oregon, Idaho, and Montana. 



B. laeviventris Lee Ponderosa pine and otlier pines and Douglas 



fir. California, Oregon, Washington, Idaho, 

 and Arizona. 



B. maculativentrw var. suhornata 



Lee Pines. Western States. 



B. rusticorum Kirby Douglas fir and balsam firs. Throughout the 



Western States. 



B. langl Mann Douglas fir and ponderosa pine. All Western 



States. 



B. viridisuturalls N. and W Poplar, cottonwood, and white alder. Cali- 

 fornia and Oregon. 



B. confluenta Say Poplar and aspen. Throughout the United 



States. 



B. gihbsi Lee Oak and cottonwood. California, Oregon, 



Washington, and Colorado. 



The dicerca beetles, members of the genus Dicerca, are medium- 

 sized, robust, roughly sculptured, metallic, wood-boring beetles of a 

 dull bronze color, with the tips of the wing covers prolonged into 

 narrow points. The larvae work under the bark and into the wood 

 of various species of trees that are sickly, dying, or dead. Of the 10 

 species recorded from the Western States, those most frequently 

 found breeding in the wood of forest trees are the following : 



Species of Dicerca Hosts and distribution 



D. tenebrosa Kirhy (fig. 73) Pines, balsam firs, Douglas fir, and Engel- 



mann spruee. California, Oregon, Wash- 

 ington, Idaho, Montana, and Eastern 

 States. 



D. sexualis Croteh Douglas fir, ponderosa pine, Jeffrey pine, 



and knobcone pine. New Mexieo, Ari- 

 zona, California, Oregon, and Washington. 



D. crassicollis Lee Lodgepole pine and Douglas fir. California, 



Oregon, Washington, and Idaho. 



D. prolongata Lee Aspen, eottonwood, poplars, alder, and other 



broadleaved trees. All Western States. 



D. Jiorni Crotch Alder, madrona, oak, sycamore, and other 



broadleaved trees and shrubs. Montana, 

 Idaho, Washington, Oregon, and Cali- 

 fornia. 



D. divaricata Say Alder, birch, and other broadleaved trees. 



Colorado. 



The w^estern cedar borer (Trachyhele hlondeli Mars.) {llf.) {Ifia) 

 mines in the sap wood and heartwood of living, injured, dying, or 

 dead trees of western red cedar, cypress, and related species and is 

 very destructive to trees used for poles, shingles, cooperage, ship- 

 building, or other purposes where sound wood is required. The 

 adults, which are roughly sculptured beetles about five-eighths of 

 an inch in length, of a very beautiful, bright emerald green with 

 a golden sheen, lay their eggs on the wood of scars on the trunk or 

 branches of standing trees, and the flatheaded larvae mine about in 

 the wood for a period of 2 or 3 years before reaching maturity. 

 The newdy formed beetles remain in the wood for about 6 months, 

 from September to May, before they emerge and start a new genera- 

 tion. There is no practical means of control under present forest 

 conditions. The variety T. hlondeli juniperi Burke is found in 

 junipers in California. 



