Biological Control of Comstock Mealybug12

Abstract

The successful importation, mass release and establishment of exotic natural enemies on the Comstock mealybug, Pseudococcus comstocki (Kuwana), in the residential area of Porterville, CA, within the San Joaquin Valley have resulted in the biological control of this mealybug. Other infested areas in the Valley receiving parasite introductions followed the same pattern. The natural enemy complex consists of 3 imported parasites, Pseudaphycus malinus Gahan, Allotropa burrelli Muesebeck, A. convexifrons Muesebeck, and Zarhopalus corvinus (Girault), an indigenous parasite of P. maritimus (Ehrhorn), plus native predators, mainly Leucopis ocellaris Malloch and Chrysopa spp. A. convexifrons, the last to be established, is now the dominant parasite. The population density of P. comstocki was reduced by a maximum of 68% in East Porterville from 1972 through 1976, 71% in Central Porterville, and 73% in West Porterville from 1974 through 1976 as a result of the newly established natural enemy complex. The regulation of the mealybug by its natural enemy complex at these lower population levels was below economic importance in residential areas which contributed to the termination of the California Department of Food and Agriculture’s eradication program.