OREGON STATE UNIVERSITY

OSU tests new 'come-hither-and-die' insecticide

07/16/1999

HOOD RIVER - A bit of goo on a pear tree carries a lethal disappointment for codling moths, but it could be a new way for fruit tree owners to control the voracious fruit-eating worms.

Helmut Riedl, an entomologist at Oregon State University's Agricultural Research and Extension Center in Hood River, said control of codling moths in apple and fruit orchards is an ongoing battle.

Adult codling moth females lay an egg near the fruit tree's flower when it blooms. When the voracious larvae hatches, it bores inside the growing fruit and begins feeding. Without some method of control, codling moth larvae can eat their way through half an orchard of apples or pears, said Riedl.

"Codling moths are the worm in the apple," he said.

Franz Niederholzer, a pest management expert with the OSU Extension Service, is among those testing a pheromone insecticide at the Hood River center that would provide a new method of controlling codling moths. Its primary benefit will be to smaller-scale growers and backyard gardeners who would prefer to treat fruit trees individually for codling moths without traditional broadcast spraying.

The new product, named "Last Call," was developed by a Swiss company, but it will be distributed domestically by a U.S. firm.

Riedl said "Last Call" works as its name implies on what is called the "attract-and-kill" basis: Adult male codling moths are lured by the pheromone-created artificial scent of a receptive female moth, only to find themselves in contact with a pea-sized droplet of a powerful insecticide.

The insecticide paralyzes the moth almost immediately, with death shortly thereafter, effectively putting an end to mating.

"Last Call" must be applied when the male codling moths begin their mating quest, because its effectiveness wanes quickly - a trait that reduce risks of human exposure to the insecticide.

OSU's Hood River center is one of dozens of agricultural and scientific entities along the West Coast testing "Last Call" this summer before the product is released to the public next season. Its advantage is that its attractant targets only male codling moths, limiting insecticide exposure to beneficial insects such as bees and lady bug beetles that may be inadvertently killed by more traditional broad-spectrum insecticides.

Strictly pheromone-based products disrupt the natural mating cycle of a targeted species to reduce or eliminate egg production in the applied area.

Perhaps the biggest advantage of "Last Call" is its ease of limited application by backyard tree owners, allowing them to treat a few trees without spraying.

Whether "Last Call" proves more reliable than mass spraying will be among the questions addressed at this summer's trials.

The results of the "Last Call" test are expected to be among the most-watched reports due at the Hood River center's upcoming field day tour. Scheduled for Aug. 4, the day will feature additional discussions and variations on pheromone technology.

For more information about "Last Call" and the tour, contact Niederholzer at 541-386-3343 or Riedl at 541-386-2030, ext. 14.