Transgenic Insecticidal Crops and Natural Enemies: A Detailed Review
GABOR L. LO¨ VEI (1,2) DAVID A. ANDOW (2,3)
Environ. Entomol. 38(2): 293-306 (2009)
(1) Corresponding author: Department of Integrated Pest Management, Aarhus University, Faculty of Agricultural Sciences, Flakkebjerg Research Centre, DK-4200 Slagelse, Denmark (e-mail: gabor.lovei@agrsci.dk).
(2) These authors contributed equally to this paper.
(3) Department of Entomology and Center for Community Genetics,
(4) ENEA National Agency for New Technologies, Energy and Environment, Research Centre Trisaia, 1-75026
This review uses a data-driven, quantitative method to summarize the published, peer-reviewed literature about the impact of genetically modified (GM) plants on arthropod natural enemies in laboratory experiments. The method is similar to meta-analysis, and, in contrast to a simple author-vote counting method used by several earlier reviews, gives an objective, data-driven summary of existing knowledge about these effects. Significantly more non-neutral responses were observed than expected at random in 75% of the comparisons of natural enemy groups and response classes.
These observations indicate that Cry toxins and proteinase inhibitors often have non-neutral effects on natural enemies. This synthesis identifies a continued bias toward studies on a few predator species, especially the green lacewing, Chrysoperla carnea Stephens, which may be more sensitive to GM insecticidal plants (16.8% of the quantified parameter responses were significantly negative) than predators in general (10.9% significantly negative effects without C. carnea). Parasit! oids were more susceptible than predators to the effects of both Cry toxins and proteinase inhibitors, with fewer positive effects (18.0%, significant and nonsignificant positive effects combined) than negative ones (66.1%, significant and nonsignificant negative effects combined). GM plants can have a positive effect on natural enemies (4.8% of responses were significantly positive), although significant negative (21.2%) effects were more common. Although there are data on 48 natural enemy species, the database is still far from adequate to predict the effect of a Bt toxin or proteinase inhibitor on natural enemies.