The effect of snowdrop lectin (GNA) delivered via artificial diet and transgenic plants on Eulophus pennicornis (Hymenoptera : Eulophidae), a parasitoid of the tomato moth Lacanobia oleracea (Lepidoptera : Noctuidae)

Snowdrop lectin (Galanthus nivalis agglutinin, GNA) has previously been sho wn to confer significant levels of protection against the lepidopteran pest Lacanobia oleracea when expressed in transgenic potato. The effect of GNA on the parasitism of L. oleracea by the gregarious ectoparasitoid Eulophus pennicornis was investigated. Maize-based, and potato leaf-based diets cont aining GNA, and excised transgenic potato leaves expressing GNA, were fed t o L. oleracea larvae from the beginning of either the third or fourth larva l instar. Lacanobia oleracea larvae were individually exposed to single mat ed adult female E. pennicornis parasitoids from the fifth instar onwards. The success of the wasp was not reduced by the presence of GNA in any of th e diets, or by the length of feeding of the host prior to parasitism. Howev er, the mean number of wasps that developed on L. oleracea reared from the third instar on the GNA-containing maize diet was significantly higher than on the controls (20.6 and 9.3 adults/host respectively). In all other case s differences were not significant. Eulophus pennicornis progeny that devel oped on L. oleracea reared on GNA-containing diets showed little or no alte ration in size, longevity, egg load and fecundity when compared with wasps that had developed on hosts fed the respective control diets. The results suggest that expression of GNA in transgenic crops to confer re sistance to lepidopteran pests will not adversely affect the ability of the ectoparasitoid E. pennicornis to utilise the pest species as a host. Crown Copyright (C) 1999 Published by Elsevier Science Ltd. All rights reserved.