'Good guy' nematodes chase bad cranberry pests


CORVALLIS - Cranberry connoisseurs have a new ally - a friendly, microscopic animal that likes to eat cranberry pests.

Oregon State University entomologists Ralph Berry and Jie Liu discovered the species of nematode near Seaside, Ore., in 1993. Since then, they have been working to mass-produce the good nematode.

This year they will have enough to conduct experiments in cranberry bogs to provide a natural control of black vine weevil and cranberry girdle, pests that take a major toll each year on cranberry yields and quality. In Oregon, cranberries are a substantial industry - last year, the state harvested about 35 million pounds, from 2,000 acres in Coos and Curry counties, worth more than $21 million.

"We are very optimistic," Berry said. "The nematode worked very well in our research trials last year, and we think these nematodes have excellent potential for use in Oregon and other states that produce cranberries."

The nematodes are in the genus Heterorhabdtis and the species is marelatus, which means "by the sea." They were first found in dunes near the Oregon coast about 25 miles from the Washington border in 1993.

Since then, Berry and Liu have found new strains near Bandon, in the heart of Oregon's prime cranberry-producing area, about 80 miles north of the California border. In both instances, the nematodes were found in "foredunes" away from the beach.

"The wide adaptation of the nematodes and their excellent ability to control cranberry pests is good news for growers and consumers," Berry said. The challenge now is to mass-produce the nematode, so enough will be available for effective biological control.

The leading cranberry-producing states, in order, are Wisconsin, Massachusetts, New Jersey, Oregon and Washington. Most of the crop goes into cranberry juice.