OREGON STATE UNIVERSITY

'Soft' insect control reduces pesticide use, cost

08/05/1997

MEDFORD - Southern Oregon fruit growers have found a soft punch is the best way to knock out a tough insect pest.

Sex attractants, oils and smart scouting can save $250 to $279 per acre and reduce use of hard pesticides by 80-89 percent, Oregon State University studies show.

"By using soft, non-disruptive chemicals and biological control we can keep the codling moth in check without killing everything else," said Rick Hilton, an OSU research entomologist at Southern Oregon Experiment Station.

Codling moth control is a must. "It can wipe out 50 to 90 percent of a crop," said Phil VanBuskirk, an OSU Extension Service integrated pest management specialist at the station.

VanBuskirk and Hilton work with six growers who now have proof that a low-pesticide approach works.

Their grower-involved project includes 400 acres of pears and 100 acres of apples in southern Oregon, a site that's one of six in the nation involved in a U.S. Department of Agriculture study.

The Codling Moth Area-Wide Management project (CAMP), now in its fourth year, involves several strategies. Using sex attractants, or pheromones, growers hang dispensers in their trees near bloom in the spring. This confuses the male moth so he can't find a female and won't mate.

Horticultural spray oil works to suffocate eggs that have been laid, and suppress not only the moth but also spider mites and psylla. And pest monitoring is a key. It tells the grower when and why to spray or to use some other form of control.

The CAMP project started just south of Medford in 1994 on 75 acres and has grown to 500 acres this year. Grower coordinator Laura Naumes and husband Mike operate Naumes, Inc. With 2,800 acres of tree fruits in Oregon and more than 8,000 acres in three states, it's one of the world's largest orchards.

"So far we're real happy with the way the project is going," Laura Naumes said. "We see very little damage from the codling moth itself. Last year we had a little leafroller damage, but this year we watched for the insect and did some late dormant treatments. All in all, the project works well."

The "soft" approach to controlling insects in Oregon goes back many years.

"Pete Westigard, an OSU entomology researcher, started looking at soft pesticides more than 20 years ago," Hilton said. "From his early work we learned that if we could eliminate organophosphates (hard pesticides), natural predators and parasites would control most other pests of pears except codling moth, rust mite and San Jose scale."

Today more than 9,000 acres of the western United States are involved in what has become a USDA-Agricultural Research Service funded program.

All participating growers use mating disruption for codling moth control. The Oregon site is the only one that addresses all fruit insect pests and involves a total pest control program, including the use of horticultural oils.