The study, conducted at the National Center for Ecological Analysis and Synthesis at the University of California-Santa Barbara, analyzed environmental impact data from field experiments involving corn and cotton plants with a Bt gene inserted for its insecticidal properties.

Biotechnology and genetic engineering are controversial because of concerns about risks to human health and biodiversity but few analyses exist concerning the effects genetically modified plants have on other non-modified species.

In the new study, researchers analyzed 42 field experiments and found the Bt gene modification, which causes the plant to internally produce an insecticide, can have an environmental benefit because large-scale insecticide spraying can be avoided.

"This is a groundbreaking study and the first of its kind to evaluate the current science surrounding genetically modified crops," said Peter Kareiva, chief scientist of The Nature Conservancy. "The results are significant for how we think about technology and the future of sustainable agriculture."

The study, which included scientists from Santa Clara University, appears in journal Science.