Response of Natural Enemies to the Green Peach Aphid in Different Plant Cultures12

Abstract

In field tests in 1977 and 1978, both parasites and predators of the green peach aphid, Myzus persicae (Sulzer), displayed definite preferences for different host plants. Parasitic activity by Diaeretiella rapae (M'Intosh) was 6 and 10 × greater in broccoli plots than in either radish or sugarbeet plots, respectively, but predators were 2–5 × less active on broccoli. Some predators, including Geocoris bullatus (Say) and Coccinella transversoguttata Falderman, exhibited host plant preferences unrelated to prey density. Greenhouse tests with G. bullatus confirmed these findings.