PT  - JOURNAL ARTICLE
AU  - Marvier, Michelle
AU  - McCreedy, Chanel
AU  - Regetz, James
AU  - Kareiva, Peter
TI  - A Meta-Analysis of Effects of Bt Cotton and Maize on Nontarget Invertebrates
AID  - 10.1126/science.1139208
DP  - 2007 Jun 08
TA  - Science
PG  - 1475--1477
VI  - 316
IP  - 5830
4099  - http://science.sciencemag.org/content/316/5830/1475.short
4100  - http://science.sciencemag.org/content/316/5830/1475.full
SO  - Science2007 Jun 08; 316
AB  - Although scores of experiments have examined the ecological consequences of transgenic Bacillus thuringiensis (Bt) crops, debates continue regarding the nontarget impacts of this technology. Quantitative reviews of existing studies are crucial for better gauging risks and improving future risk assessments. To encourage evidence-based risk analyses, we constructed a searchable database for nontarget effects of Bt crops. A meta-analysis of 42 field experiments indicates that nontarget invertebrates are generally more abundant in Bt cotton and Bt maize fields than in nontransgenic fields managed with insecticides. However, in comparison with insecticide-free control fields, certain nontarget taxa are less abundant in Bt fields.