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Volunteers Hunt Destructive Insect

September 01, 2009 - PORTLAND -- Jeff O'Donal stood with his head thrown back Thursday, gazing with binoculars into the canopy of a massive Norway maple at Deering Oaks.

O'Donal, owner of O'Donal Nursery in Gorham, was one of 30 volunteers, all striking similar poses, as they fanned out across the neighborhoods around the park looking for signs of the destructive Asian longhorned beetle. He said he volunteered because the only way to prevent the pest from spreading is to destroy the trees.

"Once you remove their food source, there is not much left for them," said O'Donal.

Toting clipboards, pencils and binoculars, the volunteers were led by City Arborist Jeffrey Tarling, entomologist and survey coordinator Karen Coluzzi, and other specialists from the state and U.S. Departments of Agriculture on an inspection of hundreds of trees.

They were looking for the traces that would indicate the pests' presence: round, nearly dime-sized holes, sawdust on the ground and branches, and the distinctive one- to one-and-a-half-inch shiny black and white spotted insect.

"This is the crown jewel of the city, and we want to protect it," said Coluzzi.

Ever since the beetle was discovered last summer on a tree by a curious resident in Worcester, Mass., government officials have stepped up a campaign to search for signs of the beetle in other parts of New England. About 25,000 trees have been removed and destroyed in Worcester and surrounding communities as the infestation has continued for a second year this summer.

Coluzzi said the problem would not have become so severe if more people were familiar with the pest. That is why Maine received $75,000 from the federal agriculture department to launch an inspection program, train volunteer inspectors and raise awareness about the insects.

Tarling and Coluzzi said Portland is vulnerable to an infestation because it has a lot of out-of-state visitors who could track the beetles into Maine. The city provides other hitchhiking opportunities through its sea port and industrial areas.

The Asian longhorned beetle – not to be confused with the white spotted sawyer, which looks similar but attacks fir trees – bores deep into deciduous hardwood trees such as maples and ash. The adult female beetle chews depressions into the bark of the tree and deposits its eggs before plugging up the depression.

The eggs hatch into small white larvae, which bore into the tree's heartwood, forming tunnels that weaken the tree, eventually killing it. The adult beetles emerge a year later, from June through October, by chewing their way out, leaving behind a neat, round hole.

The beetles are believed to have traveled to the United States from China, Korea and Japan on wood packing material, such as pallets and crates. The beetle was first detected in the United States in 1996 on several trees in Brooklyn, N.Y., and has since been found in Chicago, Jersey City and Middlesex and Union counties in New Jersey, and on Staten and Prall's islands in New York. While the Jersey City and Chicago infestation have been wiped out, the others continue.

The beetles also have been found in warehouses in most parts of the country.

John Crowe, pest survey specialist with the federal agriculture department, said surveying trees from the ground is only 30 percent effective compared to climbing the tree or inspecting them from aerial lifts, because it is so hard to see signs of the beetles in foliage high off the ground.

He said it is better to survey trees in winter when the leaves are gone, but finding volunteers to crane their necks for hours at a time in frigid conditions is not always easy.

Crowe said one factor in Portland's favor, compared to other New England cities he has helped survey, is its diversity of tree species, which makes it less likely that entire neighborhoods would be denuded if the beetles were detected.

Right now the only effective way to stop the beetle is to remove the tree and its roots and chip or burn it. There are insecticides that work, but they are so expensive they are generally used only to treat a prized specimen, Crowe said.

By the end of Thursday's three-hour inspection, volunteers had examined 878 trees. Volunteers detected five trees with possible signs of the beetle, which will be examined more closely by the Maine Department of Agriculture in the next week.

By BETH QUIMBY, Staff Writer, Portland Press Herald, August 28, 2009


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