Natural Enemies of Comstock Mealybug1 in the Eastern States

Abstract

Investigations of the natural enemies of Pseudococcus comstocki as an orchard pest have been carried on since 1939 Of 2 spp. of primary parasites found naturally established, Clausenia purpurea was reared abundantly from many mealybug-infested orchards, but is subjected to severe attack by native secondary parasites, especially Lygocerus sp. Allotropa convexifrons was reared from northern New Jersey and s.-w. Connecticut. Of 5 spp. of parasites imported from Japan and colonized widely, A burrelli and Pseudaphycus sp. have become generally established, have shown ability to increase and spread rapidly, and have been effective in increasing the total parasitization. An unnamed sp. each of Leptomastix, Allotropa, and Anagyrus, were introduced and colonized but failed to become established. Exptl. mass releases of the ladybeetle, Cryptolaemus montrouzieri, indicated that this predator was ineffective against the mealybug in Virginia. An unidentified entomogenous fungus frequently kills large numbers of Pseudococcus comstocki in Virginia apple orchards and has also been recovered from Ohio, W. Virginia, and New Jersey. Because of its dependence on favorable weather conditions, this fungus cannot be relied upon to effect satisfactory control. Parasites were shown to be of more consistent value in reducing the host population and keeping it at a low level.