April 30, 2001

venomous Australian spider holds the potential to provide farmers with the ideal pesticide - one that can target and kill a specific crop-destroying insect, while posing no threat to other insects, humans, or animals, according to Glenn King, a research scientist at the UConn Health Center.

The spider is a funnel-web, a primitive spider about the size of a small crab, found only in Australia, where King began his research at the University of Sydney. Its venom is made up of more than 100 different compounds. King has located several compounds that kill only insects.

"By isolating these compounds from the spider venom and putting them in a common virus that affects only insects, the virus can deliver the toxin to a specific pest, fatally breaking its neurological connection," he says. "The result is not only an environmentally safe pesticide but one that targets a different brain connection from standard pesticides."

The pesticides now common have attacked the same limited number of brain connections in insects for decades, says King. This causes the insects to become more and more resistant, resulting in superbug survivors and creating the need for more toxic pesticides, followed by more superbugs, and so on. King's pesticide attacks a brain connection that pesticides have not previously targeted. It is unlikely that insects will rapidly develop resistance to the new pesticide.

A major problem with almost all chemical pesticides, says King, is that they not only kill the offending pests but also all other insects, such as butterflies and bees that pollinate crops.

"We have a very good reason to look for a safer, nontoxic, and more efficient pesticide," he says. "More than a billion pounds of pesticides are sprayed in the United States each year. That's four pounds per person. A millionth of a pound can sometimes be deadly." In addition, the chemical toxins that currently end up in the food and water supply pose a serious threat to animals, fish and birds. An estimated 70 million birds die annually from chemical pesticides.

Pesticide use is expected to increase as the need for more crops rises. To feed the estimated 7.7 billion people in the year 2020, the yield per acre of cereal crops must double, and we will need to triple food production by 2050, says King. Currently, 20 to 30 percent of the world's crops are lost to insect pests.

"Insects are adaptable. They can be harmful and they can be helpful," he says. "We need to be able to protect not only our crops, but ourselves and other creatures.

"I think this can replace chemical pesticides," he adds. King's next step will be a field study of the non-toxic pesticide.

Jane Shaskan