Luck, R.F., & Dahlsten, D.L. 1975 Natural decline of a pine needle scale (Chionaspis pinifoliae (Fitch), outbreak at South Lake Tahoe, California following cessation of adult mosquito control with malathion.. Ecology 56: 893-904.
Notes: The population dyamics of a pine needle scale infestation Chionaspis (Phenacaspis) pinifoliae were studied from 1969 to 1971. A uniparental population on lodgepole pine, Pinus contorta, and a biparental population on Jeffrey pine, P. jeffreyi, declined dramatically during the study period. The dominant mortality factors for the lodgepole pine population were crawlers which failed to settle, parasitization by Prospaltella bella, predation by Chilocorus orbus var. monticolus and Cryptowesia atronitens and an unknown mortality of adult female scale. In the Jeffrey pine population, the dominant factors were crawlers which failed to settle, unknown mortality of immature scale, and predation by the same coccinellid species.