Insects May Need Refuges from Biotechnology
CHICAGO, Illinois, August 30, 2001 (ENS) - Crops which have been genetically modified to resist pests are only useful until the bugs outsmart them, developing their own protections against the toxins produced by the plants. A Michigan entomologist argues that some crop eating insects must be protected in order to keep them all from becoming resistant to engineered crops.
The engineered crops are intended to save farmers money, by reducing crop damage from pests and reducing the amount of chemical pesticides they need to apply to their land.
But some biologists and agricultural experts warn that the rising popularity of engineered crops could have an expensive side effect. Just as insects and other crop pests can develop resistance to traditional pesticides, they may become resistant to engineered crops, producing so called "super pests" that will inflict severe damage on the nation's increasingly engineered food supply.
Instead, in a presentation at the annual meeting of the American Chemical Society in Chicago this week, Whalon said precautions should be taken to explore ways to combat resistance to genetically modified organism (GMO) crops before the bugs develop it.
"We'd like to think that science could manage resistance, but in truth, historically we've been pretty ineffective," Whalon said. "I think what's going on in the big GMO crops - corn and cotton - is that growers haven't yet gotten a high enough percentage of GMO plants in the field such that sufficient selection pressure has been mounted against the pests for resistance to develop."
Whalon's presentation - "Insect resistance to GMOs: What have we learned?" - explored speculation on whether pests will evolve to defend themselves from crops that produce defenses against them. Insects and mites have already proven deft at developing resistance to applied insecticides, with 540 arthropods now resistant to more than 310 insecticides and miticides.
Whalon is a proponent of working now to head off resistance in the field by learning to live with some of the insects. He argues that a certain number of crop eating pests need to be treasured - protected for the susceptibility genes they pass on to the next generation.
"It has never been good just to kill everything you can," Whalon said. "We should be trying to preserve a sufficient number of insects that are susceptible to the GMO crops."
"These bugs that normally would be killed need to be allowed to survive so they can provide susceptible genes to the population pool," explained Whalon. "Otherwise, we will select a strain of resistant bugs to destroy or mitigate the value of a promising new technology."
The practice of refugia is still experimental - and can be a tough sell to farmers skeptical of showing mercy to any crop eating pests.
"Susceptibility is a natural resource," Whalon said. "Just like there's only so much water and air, there's only so much susceptibility to be grabbed up and exploited. It's a natural resource that could be critical to the future of feeding generation of people to come."