Is what you see what you get? The relationship between field observed and actual aphid parasitism rates in canola crops

Abstract

BACKGROUND Estimating parasitoid abundance in the field can be difficult, even more so when attempting to quantify parasitism rates and the ecosystem service of biological control that parasitoids can provide. To understand how ‘observed’ parasitism rates (in-field mummy counts) of the green peach aphid, Myzus persicae (Sulzer) (Homoptera: Aphididae) translate to ‘actual’ parasitism rates (laboratory-reared parasitoid counts), field work was undertaken in Australian canola fields over a growing season. Parasitoids were reared within a controlled laboratory setting. RESULTS Total observed and actual parasitism rates of M. persicae varied considerably across regions, but less so on a field lev..