Arthropods on Maize Ears for Detecting Impacts of Bt Maize on Nontarget Organisms

• Published in: Environmental entomology 2006-04, Vol.35 (2), p.554-560
• Main Authors: Eckert, J, Schuphan, I, Hothorn, L. A, Gathmann, A
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Animal, plant and microbial ecology; Applied ecology; arthropod communities; arthropod community; Bacillus thuringiensis; Biological and medical sciences; biological assessment; Bt corn; Bt maize; corn ears; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on protozoa and invertebrates; Fundamental and applied biological sciences. Psychology; Genetic engineering applications; Genetics and breeding of economic plants; insecticides; monitoring; nontarget organisms; Plant breeding: fundamental aspects and methodology; risk assessment; transgenic plants; TRANSGENIC PLANTS AND INSECTS; Zea mays
• ISSN: 0046-225X; 1938-2936
• DOI: 10.1603/0046-225X-35.2.554

A 3-yr study (2001–2003) was conducted to determine if the cultivation of Bt maize (Mon810, cultivar Novelis), compared with an isogenic maize line (cultivar Nobilis) with and without an insecticide treatment, has unintended effects on nontarget organisms of the arthropod community in maize fields. Furthermore, suitable monitoring organisms and appropriate methods should be selected. Maize ear samples were taken in Bt maize, an isogenic maize variety, and an isogenic maize variety with insecticide treatment. The community of arthropods was monitored and evaluated. In the first year of the study, the abundance of the mycetophagous/saprophagous beetle species Cortinicara gibbosa was significantly higher in Bt maize than in the isogenic control. These differences in arthropod communities between Bt maize and the isogenic control were not reproducible in the following years. No other significant differences in arthropod communities between Bt maize and the control were observed. Several significant differences between the insecticide-treated plots and the other treatments were detected. The abundance of the aphid Rhopalosiphum padi was significantly higher in the insecticide-treated plots than in the Bt maize or control plots over all 3 yr. The same was observed for the ladybird Coccinella septempunctata in 2003. Thrips populations were influenced negatively by the application of insecticide in 2002 and 2003. Sampling of maize ears is a suitable method in detecting changes of arthropod abundance on the community level.