. Forest insect and disease conditions in the United States 1979. Insect pests United States. levels ranged from light (Valley of Enchantment) to moderate (Running Springs) to heavy (Miller Canyon and Frog Point). In the area sur- veyed, the California oakworm, Phryganidia californica Pack., and a tent caterpillar, Malacosoma sp., were associated with the leafroller. Jeffrey pine needle miner, Col- eotechnites sp. Population levels and feeding injur>^ by the Jeffrey pine needle miner in the Green Valley, Big Bear City, Fawnskin, and Lake Erwin areas in San Bernardino County continuted to de
. Forest insect and disease conditions in the United States 1979. Insect pests United States. levels ranged from light (Valley of Enchantment) to moderate (Running Springs) to heavy (Miller Canyon and Frog Point). In the area sur- veyed, the California oakworm, Phryganidia californica Pack., and a tent caterpillar, Malacosoma sp., were associated with the leafroller. Jeffrey pine needle miner, Col- eotechnites sp. Population levels and feeding injur>^ by the Jeffrey pine needle miner in the Green Valley, Big Bear City, Fawnskin, and Lake Erwin areas in San Bernardino County continuted to decline. No new areas of infestation were reported. Western pine beetle, Dendroctonus brevicomis LeC. Ponderosa pine mortality caused by the western pine beetle was lower than during 1978, but still above normal. In contrast to last year, pine mortality was con- centrated at higher elevations, and consequently much occurred on Na- tional Forests. Mortality caused by the western pine beetle was generally scattered throughout the Sierra Nevada with the exception of con- centrations of mortality south of Stumpy Meadows Lake. El Dorado County; the State Game Refuge south of Lumberyard. Amador County; Calaveras Big Trees State Park and the adjacent communities of Arnold and Dorrington, Calaveras County; the State Game Refuge south of Dorrington and the Mather Family Camp at Groveland, Tuolumne County; and much of the Stanislaus and Sierra National Forests and Yosemite National Park in Calaveras, Tuolumne, Mariposa, Madera, and Fresno Counties. In situations where scattered and concentrated ponderosa pine mor- tality occurred, overstocking, dwarf mistletoe, and overmaturity were major factors predisposing trees to at- tack by western pine beetle. Extensive ground checking in Oc- tober 1979 found very few green ponderosa pine infested with western pine beetle and low numbers of dead trees still containing brood or callow adults. An exception was in Lassen County where considerable infes
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