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Looking for the telltale signs of an exotic invasive beetle
10/17/2012
ODA trappers use outdoor classroom to prepare for Asian longhorned beetle survey

If Asian longhorned beetles are residing in the state, the Oregon Department of Agriculture would like to find them. But first, ODA trappers need to learn what to look for. An outdoor simulation course this month is training the trappers to become experts in spotting the trail of the dreaded invasive insect.

“We are doing an extensive Asian longhorned beetle survey within the Port of Portland’s operations,” says Helmuth Rogg, supervisor of ODA’s Insect Pest Prevention and Management Program. “Unfortunately, there aren’t any traps for these beetles that we can put out like our common gypsy moth traps. So our folks have to go out and physically look for holes in the trees.”

Survey technicians– another name for the trappers– have been using an outdoor classroom of sorts to become familiar with the pest and its tree-killing ways. Located on private property in Silverton, the simulation course comes complete with artificially-drilled holes in trees.

“They have used this kind of approach successfully in Canada,” says Rogg. “By using a simulation course, people have a better eye for real holes made by Asian longhorned beetle.”

Asian longhorned beetle is native to China and Korea. Infestations have been found in states back east but not yet in Oregon. The beetle is black with white spots, one to one-and-a-half inches long with extra-long black and white antennae. It attacks living and healthy tress by boring deep into the bark and wood. Adults leave large, dime-sized holes in the trunks, limbs, or exposed roots of infested trees. Coarse sawdust may be found around those holes, in crotches of branches, and around the bases of trees.

The fact that the insect bores deep into trees makes it all the harder to detect. Trees with craggy bark, moss, and lichen make it even more challenging. Looking at pictures in a book or brochure may not be good enough to truly train the trappers’ eyes.

“Two courses of 50 trees have been drilled with a 10 millimeter bit,” says Rogg. “They look like an exit hole from the Asian longhorned beetle. The drilled trees are in an area of about 200 trees total. Our trappers are sent into the area and need to successfully find the holes before they can help conduct the insect survey. This gives them a live experience to learn how easy or difficult it is to find the holes.”

Unlike the damage done by the real hole-bearing insect, these artificial holes do not cause significant harm to the trees. Each tree in the area, even those not drilled, have an identification tag. The course contains trees of differing degrees of difficulty. There is an area simulating low infestation– one or two holes in each tree– as well as heavy infestation– trees with a lot of holes. Trainees who fail at passing the course will receive more instruction and will try again. Once they successfully identify a certain number of “infested” trees, they can move on to searching the high-target areas for real.

The actual Asian longhorned beetle survey is scheduled for later this month and will run into November. About 3,000 trees will be examined in high risk sites associated with port activities.

“We have always done Asian longhorned beetle surveys in conjunction with other trapping,” says Rogg. “This is the first time we are doing a specific ALB survey. We have received funding to look at ports and port-related facilities. In addition to Portland, we will be looking in the Coos Bay area.”

There is no reason to believe this year represents any more danger for Asian longhorned beetle in Oregon than any other year. But the threat is real. Wood-boring insects continue to be transported around the world in raw wood products and solid wood packing materials. Large volumes of packing materials and dunnage from Asia are received by Oregon and other west coast ports and importers, placing those locations at high-risk for Asian longhorned beetle introduction and establishment. In addition, the fact that the beetle has established in locations back east increases the possibility of spread of the bug from eastern North America to the Pacific Northwest. In either case, the beetle commands a great deal of attention for an insect that has yet to show up in Oregon. The Asian longhorned beetle is routinely listed as one of the state’s 100 most dangerous invasive species for good reason. Maple trees are especially susceptible to ALB. Oregon has many maple trees in both urban and forest settings.

Asian longhorned beetle was first discovered in the US in Brooklyn, New York. It was then detected in the late 1990s in Chicago. Infestations have since been found in New Jersey, Massachusetts, and Ohio.

ODA entomologists traveled to Chicago a decade ago to learn more about the beetle. What they saw were dead trees, living trees with dead limbs, and trees with limbs cut off exposing large tunnels in the trunk made by the beetle. The sight left some lasting impressions of an insect Oregon does not want.

USDA’s Animal and Plant Health Inspection Service (APHIS) notes that the most effective method of eradicating ALB is to cut and chip or burn infested trees, replacing them with non-host species. Cooperative research continues in the United States and Asia in an effort to find acceptable alternatives to tree removal.

APHIS and New York, Illinois, and New Jersey state and local governments have invested more than $168 million to eradicate Asian longhorned beetle.

That’s a price tag Oregon hopes to avoid. Early detection of invasive species remains a key strategy for the Oregon Department of Agriculture.

“Hopefully, our trappers will continue not finding Asian longhorned beetle this year, but it’s really a matter of when, not if, the insect shows up considering all the trade that takes place,” says Rogg.

In the meantime, the outdoor training course in Silverton gives trappers a better chance of finding something, if it ever exists.

“I think you get a better connection to the pest and the damage it causes by going through a simulation course rather than looking at an abstract thing like a picture,” says Rogg.

For more information, contact Josh Vlach at (503) 986-6458


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