The Status of San Jose Scale Parasitization (Including Biological Notes)

Abstract

The marked reduetion in abundance of Quadraspidiotus Perniciosus Comstock in North America during the years subsequent to its accidental introduction from China was correlated with its acquirement of a parasitic fauna. The most important members of this fauna are the ectoparasites, A phytis diaspidis How. and A. mytilaspidis How., and the endoparasites, Coccophagoides kuuanae (Silv.) and Prospaltella pernieiosi Tower. P. pernieiosi, and its host, Q. Pernieiosus, presumably are native to China. Both were accidentally introduced into Australia, North America, and Brazil. P. perniciosi has been purposefully introduced into Chile, Europe, and South Africa. San Jose scale parasitization evidently caused a reduction in the incidence of infestations and enhanced the efficiency of control measures.