Laboratory selection for fenvalerate resistance was conducted in two colonies of the parasitoid, Cotesia plutellae, reared on two colonies of its host, Plutella xylostella, which differed in resistance to the insecticide. In the selection regime, the insecticide was applied to the host larvae that harboured the parasitoid larvae. Compared with the unselected parasitoid colony, the parasitoid co...

Despite the diverse array of mating systems and life histories which characterise the parasitic Hymenoptera, sexual selection and sexual conflict in this taxon have been somewhat overlooked. For instance, parasitoid mating systems have typically been studied in terms of how mating structure affects sex allocation. In the past decade, however, some studies have sought to address sexual selection...

We tested the enemy hypothesis for gall morphology on a model system comprising two Diplolepis rose gall wasp species and their associated parasitoids. The enemy hypothesis predicts both that gall traits will influence parasitoid attack rates within species, and that galls with contrasting morphologies will support different parasitoid communities. This hypothesis is supported by studies at bot...

Anaphes iole Girault is a solitary egg parasitoid which attacks Lygus spp. In a low-parasitoid-density experiment (parasitoid:host ratio 5 1:40) 10.0% of available Lygus hesperus Knight eggs were superparasitized by A. iole. However, in experiments with a high parasitoid density (parasitoid:host ratio 5 1:9), superparasitism of L. hesperus eggs was 33.3, 66.7, and 82.2% after exposure for 2, 6,...

Host recognition and use in female parasitoids strongly relies on host fidelity, a plastic behavior which can significantly restrict the host preferences of parasitoids, thus reducing the gene flow between parasitoid populations attacking different insect hosts. However, the effect of migrant males on the genetic differentiation of populations has been frequently ignored in parasitoids, despite...