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ODA ready to set the trap for invasive insect pests

Early detection of gypsy moth, Japanese beetle, and other bad bugs a key strategy

Over the next few weeks, survey technicians with the Oregon Department of Agriculture will place thousands of traps for gypsy moth, Japanese beetle, and other exotic insect pests that pose a threat to the state’s environment and economy. It’s a spring ritual designed to achieve early detection of these invaders and an important component of ODA’s successful program to keep the plant-eating pests at bay. This year’s effort, however, requires more strategic focus as federal funds have been greatly reduced.

“Our typical gypsy moth and Japanese beetle traps will be placed this month, but we are also putting out traps for wine grape insect pests, grain pests, and insects that may threatened our stone fruit and blueberry fields,” says Helmuth Rogg, manager of ODA’s Insect Pest and Prevention Program.

This year’s challenge for gypsy moth detection is budget related. In normal years, ODA places about 15,000 traps statewide in an effort to be thorough and vigilant against the potentially devastating pest. Last year, only 8,500 traps were set up. This year, that number is expected to drop to about 7,000. That total is the lowest since ODA began looking for gypsy moths in the late 1970s.

“We are being more strategic and placing traps in areas of the greatest risk,” says Rogg. “No longer can we afford to place traps everywhere in Oregon.”

As an example, no gypsy moth traps have been placed in Eastern Oregon for the past couple of years. The risk of the insect isn’t nearly as great as it is west of the Cascades, where there is an abundance of deciduous trees and a greater human population that might bring gypsy moth into Oregon.

When it comes to gypsy moth, ODA is actually looking for two types of insects. The more common European gypsy moth has been the one most frequently discovered in Oregon. It is normally introduced when new residents or travelers from areas of high gypsy moth populations unwittingly bring the pest with them on such things as outdoor household furniture or other items that may harbor gypsy moth eggs. Traps for European gypsy moth will go up in the more populated areas of the state. But another spot of focused trapping is along the Columbia River and around the Port of Portland. These are areas where the Asian gypsy moth would likely be found. Unlike its European cousin, the female Asian gypsy moth has the ability to fly, which could lead to a more rapid infestation and subsequent spread. Single detections of Asian gypsy moth were made in the Portland area in 1991 and 2000.

“Our colleagues from US Customs and Border Protection have already found Asian gypsy moth egg masses on vessels coming into Portland from Asia, so we know the threat is real,” says Rogg.

ODA is looking to partner with other agencies this year in an effort to get traps placed in remote areas of the state.

“We are reaching out to agencies like the Oregon Department of Forestry and the US Forest Service, asking for their help in putting out additional traps in areas that are too far away for us to go, given the budget considerations,” says Rogg. “We can’t go visit every campsite or go deep into the forests like we used to.”

The good news for 2013 is that it appears populations of gypsy moth in Oregon are way down, if they exist at all. Last year, only one gypsy moth was trapped following a year of zero detections in 2011. By contrast, more than 19,000 gypsy moths were trapped in Lane County alone in the mid-1980s. As a result, there will be no gypsy moth eradication project in Oregon for the fourth consecutive year.

With fewer catches in recent years, is there really a need for all those traps? Yes, says ODA entomologist Barry Bai.

“It’s tempting to believe that gypsy moth is no longer a threat to Oregon, but it continues to be well established in other states back east. The insect can be introduced to Oregon once again, especially when the gypsy moth population cycle goes back up in those other states. That is why we need to continue setting up the traps in Oregon.”

Trapping and early detection give entomologists information they need to recommend any eradication program. Instead of
spraying first and asking questions later, ODA has been able to pinpoint gypsy moth populations through trapping and egg mass searching. That allows any spray project to be as small as possible.

Whereas the eradication phase targets the caterpillar stage of the gypsy moth, the detection phase goes after the adult male. Gypsy moth traps use a female sex pheromone to attract male moths. The interior of the cardboard trap contains a non-toxic sticky substance. The moth flies in, gets stuck, and remains in the structure until a trapper checks. Gypsy moth traps are expected to come down by the end of September.

The Japanese beetle trap looks more like a plastic funnel with a can on the bottom. The adult beetle flies into the funnel and ends up in the can where it soon expires. In 2012, ODA trapped a record number 36 Japanese beetles, most of them near the Portland International Airport. The beetles typically arrive in Oregon on aircraft from infested states back east. The good news is there were no catches in Cave Junction in Southern Oregon, the site of an eradication effort the previous two years.

About 2,500 Japanese beetle traps will be placed this year, almost half near the Portland Airport. ODA is using innovation and technology to be more efficient. About 250 traps will contain a tiny camera, which will take a nightly photo and transmit it to a website that can be checked by ODA the next morning. If something shows up resembling a Japanese beetle, a survey technician can be dispatched to the site of the trap to check it out in person instead of having to check each trap individually on a constant basis.

New technology or old-fashioned survey work, ODA’s detection of invasive insect pests remains critical. While ODA would be delighted to not find any bad bugs in the months to come, the truth is new introductions of plant pests to Oregon are routine. If any of the invasive insects are out there, ODA wants to find them.

For more information, contact Helmuth Rogg at (503) 986-4662.

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