“I admire all insects. People say that insects will inherit the earth, but entomologists know better. The earth already belongs to the insects. They were here long before us and they’ve taken over every niche. We wouldn’t be here without them — without pollination and decomposition. The earth is theirs. We’re just trying to share it for a while.”
— Clint McFarland, agricultural enforcement officer, Animal and Plant Inspection Service, U.S. Department of Agriculture, after eight years of fighting the Asian long-horned beetle.
The Asian long-horned beetle, or ALB, is a charismatic creature with a black-and-white body about an inch long and as wide of your little finger, bluish legs and two banded antennae that curve back over its body. Until the middle of the last century, it lived an inconspicuous life in the forests of China Korea and Japan, and was not considered a serious pest.
Between 1960 and 1980, the Chinese government planted millions of poplar trees to control erosion and mitigate deforestation. In essence, they set the table for the ALB, since poplars, along with maples, birches and elms, are the herbivore’s favorite trees.
As the poplar forests matured, the beetle population soared. Millions of trees were infested and tens of thousands of forest acres were cut down to control the spread of the ALB.
Then came the boom years for foreign trade. Between 1980 and 2000, the U.S. greatly amplified shipments of products from Chinese ports, products packed in crates or on pallets made of poplar wood carrying ALB larvae.
In August 1996, beetles were found on Norway maples in Brooklyn, N.Y., and officials began cutting down thousands of infested trees, chipping them to destroy the larvae. Other infestations occurred in Chicago and Toronto where, as in Brooklyn, the ALB was confined to urban areas with relatively few trees.
But the most recent finding of ALB in Worcester, Mass., has authorities truly troubled. Worcester is a city filled with trees, most of them hardwoods. And even more troubling, the city is located on the southern edge of the great Northern hardwood forest, a biome that extends through Maine. More than 25,000 trees have been cut down within the Worcester city limits this year.
The range of the ALB now lies within 100 miles of Maine’s southern border. All it would take to start an infestation in Maine would be a single infested firewood log left unburned at a campsite in the woods. With more than 2 million visitors each year to Acadia National Park alone, I think it is only a question of when the invasion will happen.
Maine’s gardeners are on the front line in the war against the ALB. We spend a great deal of our time outdoors and thus are more likely to see either the adult beetles or the holes left by emerging adults. And we love trees; we are more likely to notice something going wrong.
The ALB first attacks the crown of a tree, making a pair of binoculars necessary for early detection. With careful observation, you may be able to see the oval to round pits in the bark of canopy branches. These are egg-laying sites chewed out by the female beetle.
The perfectly round holes on the trunk and branches are exit holes made by adult beetles as they emerge from the tree. They become more numerous over the several years that it takes for the beetles to kill a tree.
Other signs to look for include accumulation of coarse sawdust around the base of the tree where one branch joins another. This sawdust is created by the larvae boring into the wood. Also, sap may ooze from egg pits during the summer. Visit: http://www.invasivespeciesinfo.gov/animals/asianbeetle.shtml.
If you think that you have an infested tree or see an adult ALB on your property, contact the Maine Forest Service at 287-2431 or 800-367-0223 (in-state). And help spread the word: Responsible visitors to Maine do not bring firewood from home.
Send queries to Gardening Questions, P.O. Box 418, Ellsworth 04605, or to rmanley@shead.org. Include name, address and telephone number.