Transgenic GNA expressing potato plants augment the beneficial biocontrol of Lacanobia oleracea (Lepidoptera; Noctuidae) by the parasitoid Eulophus pennicornis (Hymenoptera; eulophidae)

The effect of expressing the gene encoding snowdrop lectin (Galanthus nival is agglutinin, GNA) in transgenic potato plants, on parasitism of the phyto phagous insect pest Lacanobia oleracea by the gregarious ectoparasitoid Eul ophus pennicornis, was investigated in glasshouse trials. Expression of GNA (approx. 1.0% total soluble protein) by transgenic plants significantly re duced the level of pest damage, thus confirming previous studies. Furthermo re, the presence of the parasitoid significantly reduced the levels of dama ge incurred either by the transgenic or control plants when compared to tho se plants grown in the absence of the parasitoid. For the GNA expressing pl ants the presence of the parasitoid resulted in further reductions (ca. 21% ) in the level of damage caused by the pest species. The ability of the was p to parasitise and subsequently develop on the pest larvae was not altered by the presence of GNA in the diet of the host. E. pennicornis progeny tha t developed on L. oleracea reared on GNA expressing plants showed no signif icant alteration in fecundity when compared with wasps that had developed o n hosts fed on control potato plants, although mean size and longevity of f emale parasitoids was significantly reduced. The number of F-2 progeny prod uced by parasitoids derived from hosts fed on GNA-expressing plants was not significantly different to those produced by parasitoids from hosts fed co ntrol plants. Results from the present study demonstrate that the use of tr ansgenic plants expressing insecticidal proteins can be compatible with the deployment of beneficial insects and that the two factors may interact in a positive manner.