Bt Crops Relatively Kind to Non-Target Insects

A recent study suggests that crops modified with insect-resistance are relatively kind to non-target insects. An analysis of 46 field experiments shows that Bt fields contained more invertebrates than fields sprayed with insecticide. But both have fewer insects than fields that were not sprayed with insecticides. Michelle Marvier of Santa Clara University, California and colleagues used a meta-analysis approach to obtain a clearer picture of life in the field. The researchers combined the data from field studies that measured invertebrate populations near Bt crops and the results of field trials submitted to the Environmental Protection Agency as part of the approval process for the engineered crops. The approach may also address other concerns about transgenic crops, such as whether they promote new types of pests, or encourage weeds that have a knock-on effect on butterflies and other insects.

Read the news article at http://www.nature.com/news/2007/070604/full/070604-9.html and the abstract of the paper “A Meta-Analysis of Effects of Bt Cotton and Maize on Nontarget Invertebrates” at http://www.sciencemag.org/cgi/content/abstract/316/5830/1475.