GM Crop Lures Pest Killers

European and U.S. researchers have developed genetically modified (GM) plants that can resist pests by emitting a chemical called (E)-beta-caryophyllene that attracts insect-killing nematode worms, this article reports. The nematode worms that are attracted by (E)-beta-caryophyllene prey on the western corn rootworm, an insect whose larvae are major maize pests in North America. The researchers' strategy mimics the natural defensive strategies of many plants, which release volatile organic compounds to attract pest enemies when their tissues are damaged. The article says that proof-of-concept field tests have already been conducted. The researchers' next step will be to develop plants that emit (E)-beta-caryophyllene only at the specific times when insect pests attack. Nematode-attracting GM plants could allow farmers to avoid the problems associated with the application of synthetic pesticides, which can damage ecosystems and tend to lose their impact as pests acquire resistance, the article says. This strategy should allow farmers to reduce insect damage without eradicating the entire population of pests in a field's ecosystem, comments Guy Poppy, a chemical ecologist at the University of Southampton in the U.K. John Pickett, a biological chemist at the Rothamsted Research institute in the U.K., says he thinks future studies will be needed to address the effects that enhancing natural chemical signals might have on a whole ecosystem, including the resident populations of insect-killing nematodes. The article can be viewed online at the link below.