New fruit fly a challenge for cherry growers

By KYLIE RICHTER

Lake County Leader

As the cherry harvest begins, fruit flies move in. Chris Beason knows that better than anyone. Actually, the fruit flies are pestering orchards long before the cherries are picked.

They usually emerge in June, and won’t stop being an issue until late September. This year they were out a little early.

Beason, a teacher in Minnesota, comes to Montana in the summers to be the Cherry Pest Field Inspector for both Lake and Flathead County.

As he checked his flytraps last Tuesday, Beason was quick to point out the Western Cherry Fruit Fly. A native species to Montana, the fly has black stripes on its wings. “It’s pretty easy for me to identify them now,” Beason said as he examined the yellow sticky paper, which was covered in various types of insects.

In 2005, the Flathead Cherry fruit fly pest management area was established. It covers all land within two miles of the lake. By law, all of the cherry tree owners in the area are required to control the flies.

Unfortunately for cherry growers, another species of fly has moved into the area. The spottedwinged drosophilid (SWD), joined the Western fly a few years ago, causing more problems for orchard owners.

On a positive note, there are many sprays, both organic and non-organic, that can help control the insects. That’s where Beason comes in. He travels to over 100 orchards around the lake, checking his traps for fruit flies. If there are more than two or three on a trap, he notifies the orchard owners that they need to spray.

 It’s not always easy to get people to do it, according to Beason. “About twenty percent of the time I have to play the bad cop.” If the owners don’t follow the rules, eventually the county will hire people to spray, then charge the bill to the owners.

This year the cherries ripened a little early. However, that doesn’t mean anything to the flies. Even after the harvest, Beason said it is important to spray. “The flies will go for the rotten fruit on the ground,” he said. He added that it is important for cherry tree owners to clean up the rotten ones from the ground after they are done harvesting or it will cause problems for the following year.

“Its not a total eradication process like some people think,” Beason said of the spraying, “Even if an orchard has been spraying for 30 years, they are still going to have flies if they don’t spray.”

When the weather gets cold enough, the larva from the flies burrows into the ground. There, they can lay dormant for up to three years before reemerging.

Some people live off the income from their orchards or do it as a hobby, while others use the orchard as a tax break. Of the people using the orchards as a tax break, there are those who take care of the cherries, and those who forget about them. Those are some of the people who Beason has trouble getting to spray. “They buy the property and get their tax break, and within a few years they forget all about it.”

 While the flies usually only travel about 50 feet, Beason said he has seen more than one group of neighbors get upset at each other about the lack of spraying. An infestation can spread to other orchards nearby, causing hard feelings.

One can understand why people may get upset when one larva in a cherry can ruin an entire crop. Beason said a man lost his entire harvest one year because of the flies.  “The processing plant wouldn’t take them,” he said.