Environ. Biosafety Res.
Volume 9, Number 2, April-June 2010
|Page(s)||101 - 112|
|Published online||03 February 2011|
Assessing the effects of cultivating genetically modified glyphosate-tolerant varieties of soybeans (Glycine max (L.) Merr.) on populations of field arthropods
Nasu Research Center, National Institute of Livestock and
Grassland Science, National Agriculture and Food Organization,
768 Senbonmatsu, Nasushiobara,
2 Present address: The Wildlife Institute, Beijing Forestry University, Beijing 100083, P.R. China
* Corresponding author: email@example.com
Received: 1 September 2010
Accepted: 12 December 2010
We assessed the effects of cultivating two genetically modified (GM) glyphosate-tolerant soybean varieties (Glycine max (L.) Merr.) derived from Event 40-3-2 and a Japanese conventional variety on arthropods under field conditions, with weed control using glyphosate and conventional weed control for two years. Plant height and dry weight of the conventional variety were significantly larger than those of the GM varieties, but the GM varieties bore more pods than the conventional variety. We found arthropods of nine taxonomic orders (Araneae, Acari, Thysanoptera, Homoptera, Heteroptera, Coleoptera, Diptera, Lepidoptera, and Hymenoptera) on the plants. The arthropod incidence (number per plant unit weight pooled for each taxonomic order) on the soybean stems and leaves generally did not differ significantly between the GM and conventional varieties. However, the incidence of Thysanoptera and total incidence (all orders combined) were greater on the GM variety in the second year. The weed control regimes had no significant influence on the arthropod incidence on the soybean stems and leaves. The number of flower-inhabiting Thysanoptera (the dominant arthropod in the flowers) was not significantly different between the GM and conventional varieties. Asphondylia yushimai (Diptera, Cecidomyiidae) was more numerous on the pods of the GM variety in both years. Neither the soybean variety nor the weed control regime significantly affected the density of soil macro-organisms. However, the glyphosate weed control affected arthropods between the rows of plants by decreasing the abundances of Homoptera, Heteroptera, Coleoptera and Lepidoptera, and diversity of arthropods.
Key words: biodiversity / arthropods / environmental impact / genetically modified crops / glyphosate / herbicide tolerant crops / soil macro-organism / weed control
© ISBR, EDP Sciences, 2011