title: Impact of Bt maize pollen (MON810) on lepidopteran larvae living on accompanying weeds.
abstract: Environmental risks of Bt maize, particularly pollen drift from Bt maize, were assessed for nontarget lepidopteran larvae in maize field margins. In our experimental approach, we carried out 3-year field trials on 6 ha total. Three treatments were used in a randomized block design with eight replications resulting in 24 plots: (i) near-isogenic control variety without insecticide (control), (ii) near-isogenic control variety with chemical insecticide (Baytroid) and (iii) Bt maize expressing the recombinant toxin. We established a weed strip (20 x 1 m) in every plot consisting of a Chenopodium album (goosefoot)/Sinapis alba (mustard) mixture. In these strips we measured diversity and abundance of lepidopteran larvae during maize bloom and pollen shed. C. album hosted five species but all in very low densities; therefore data were not suitable for statistical analysis. S. alba hosted nine species in total. Most abundant were Plutella xylostella and Pieris rapae. For these species no differences were detected between the Bt treatment and the control, but the chemical insecticide treatment reduced larval abundance significantly. Conclusions regarding experimental methodology and results are discussed in regard to environmental risk assessment and monitoring of genetically modified organisms.
authors.affiliation: Aachen University, Institute of Environmental Research, Chair of Ecology, Ecotoxicology and Ecochemistry, Worringerweg 1, 52062 Aachen, Germany. achim.gathmann@bvl.bund.de
authors.forename: Achim
authors.initials: A
authors.lastname: Gathmann
authors.forename: Ludger
authors.initials: L
authors.lastname: Wirooks
authors.forename: Ludwig A
authors.initials: LA
authors.lastname: Hothorn
authors.forename: Detlef
authors.initials: D
authors.lastname: Bartsch
authors.forename: Ingolf
authors.initials: I
authors.lastname: Schuphan
mesh_terms: D000818:Animals; D027462:Chenopodium / Q000187:drug effects / Q000254:growth & development; D006540:Herbicides / Q000494:pharmacology; D007306:Insecticides / Q000494:pharmacology; D007814:Larva / Q000187:drug effects / Q000254:growth & development; D007915:Lepidoptera / Q000187:drug effects / Q000254:growth & development* / Q000502:physiology; D009149:Mustard Plant / Q000187:drug effects / Q000254:growth & development; D030821:Plants, Genetically Modified; D011058:Pollen / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D018570:Risk Assessment; D012987:Soil; D013997:Time Factors; D003313:Zea mays / Q000187:drug effects / Q000235:genetics / Q000502:physiology*
chemical_list: D006540:Herbicides; D007306:Insecticides; D012987:Soil