This study aimed to evaluate the quality of the aphid Myzus persicae (Sulzer), Lipaphis erysimi (Kaltenbach) and Brevicoryne brassicae (L.) as hosts for the parasitoid Diaeretiella rapae (McIntosh). Parasitization by D. rapae was higher on M. persicae than on L. erysimi and B. brassicae. The time of development of D. rapae from egg to mummy or egg to adult male or female were shorter on M. pers...

Feeding damage to plants by insect herbivores induces the production of plant volatiles, which are attractive to the herbivores natural enemies. Little is understood about the plant biochemical pathways involved in aphid-induced plant volatile production. The aphid parasitoid Diaeretiella rapae can detect and respond to aphid-induced volatiles produced by Arabidopsis thaliana. When given experi...

Naturally occurring parasitoids may provide sufficient control of aphid pests in fields undisturbed by insecticides. Yet the efficacy of these parasitoids may be strongly influenced by characteristics of their hosts and by the availability of alternative hosts in neighbouring crops. In the present study, parasitoid guild structure was compared in two aphid species, Brevicoryne brassicae and Lip...

Response to the alarm pheromone, (E)-beta-farnesene, produced by many species of aphids, was assessed in laboratory bioassays using an aphid pest, Myzus persicae (Sulzer), and its primary endoparasitoid, Diaeretiella rapae (McIntosh). This was done in three separate studies, the first investigating responses of a large number of M. persicae clones carrying different combinations of metabolic (c...

In fall, Myzus persicae (Sulzer) (Homoptera: Aphididae) may exhibit population resurgence in winter oilseed rape in France. This resurgence may arise from pyrethroid treatments against Coleoptera (Psylliodes chrysocephala L.) that either kill parasitoids present during treatment or prevent recolonization by off-crop parasitoids. We studied the impact of Diaeretiella rapae (M'Intosh) (Hymenopter...

1. Host ranges of parasitoid wasps are mediated by behavioural responses to hosts and their environment (infectivity), and development in hosts (virulence). Determinants of host range were measured in Diaeretiella rapae (Hymenoptera: Aphidiidae), which has been described as a generalist that attacks more than 60 species. 2. In northern Colorado, this wasp mainly attacks two hosts: cabbage aphid...

We hypothesized that a parasitoid of an herbivore would be attracted to large rather than small patches of plants that provide food for the herbivore. We conducted experiments to determine whether such parasitoids would be more likely to find and/or less likely to leave large patches of their victims' host plants. We also examined whether prey density (independent of patch size) affects plant f...

Spatial distribution or how abundances vary through space is an important trait of insect populations. Knowledge of the spatial distribution provides a basis for understanding various aspects of population biology including resource exploitation, intraspecific competition or the dynamics of predators and parasitoids. For insect pests, information on the spatial structure of populations may help...