Interactions between insect tolerant genetically modified plants and natural enemies

Insect natural enemies play an important role in the regulation of many pes t species. The effects of genetically modified (GM) crops on natural enemie s and other non-target species need to be evaluated to avoid disruption of natural biological control and ecosystem dynamics. This paper reviews progr ess with studying effects of GM plants on tritrophic systems involving para sitoids and predators. Experiments at Rothamsted using mixtures of GM and w ildtype oilseed rape plants in large cages have shown no differences in par asitism rates of the aphid Myzus persicae by the parasitoid Diaeretiella ra pae on GM and untransformed plants. Ongoing experiments are investigating t he effect of GM oilseed rape on the parasitisation and host searching behav iour of Cotesia plutellae, a larval parasitoid of the diamondback moth (Plu tella xylostella).