Composite asymmetry as an indicator of quality in the beneficial wasp Trichogramma nr. brassicae (Hymenoptera: Trichogrammatidae)

Abstract

Trichogramma are egg parasitoids that are widely cultured for the control of moth pests in commercial insectaries. Stock quality is often maintained by releasing wasps from a mass culture in an area with target host eggs and initiating fresh stocks from parasitized eggs. Here we test if variability among individuals as measured by fluctuating asymmetry can be used as an additional method of quality control in Trichogramma nr. brassicae by comparing fluctuating asymmetry levels between a random sample of wasps before release and wasps that successfully reach host eggs. Although the asymmetry of individual traits was not associated with wasp fitness, a total asymmetry measure based on combining the uncorrelated asymmetries of nine traits did predict the ability of wasps to reach the eggs. © 2001 Entomological Society of America.