Asian longhorned beetles not here yet

Last week, a concerned citizen brought what he thought might be an Asian longhorned beetle, or ALB (Anoplophora glabripennis), to the attention of The Lakeville Journal. To put this into perspective for readers who are not immersed in the world of invasive forest pests and pathogens, confirmation of this insect in our region would be a calamity for our hardwood forests, and most especially for our sugar maples. It would be a disaster for these species comparable to the arrival of plague-bearing rats in medieval Europe for our own species. A few quick calls to experts in the field strongly suggest that in this case, at least, we seem to have dodged a bullet, as ALB larvae generally emerge in the first week of July. Nonetheless, with known outbreaks in Worcester and Boston, Mass., and in four of five New York boroughs and in adjacent New Jersey, we are in the crosshairs and the odds are that this destructive insect will find its way here in the coming years.ALB larvae destroy the vascular systems of the trees they infest, and are a killer threat to maples, box elders, ash, horsechestnut, willow, poplar, sycamore and elm trees. The only way to combat an infestation is to quarantine the area and destroy any infested trees; 28,000 of them were destroyed in the greater Worcester area alone. It is vital to stop the transportation of wood from these regions, because the insects are carried in that wood. The Nature Conservancy actively promotes its Don’t Move Firewood campaign and website at www.dontmovefirewood.org, to raise awareness of the potential for this practice to spread new incursions of forest pests. The conservancy recommends that all firewood be consumed within 50 miles of where it was cut. As with all invasive species that have the potential to dramatically affect our region but are not yet known to occur here, the best hope we have is to develop an effective means of early detection and rapid response. The citizen who noticed the insect and brought it to The Journal represents a vital part of the network of trained observers that will be needed to catch new invasions when there is still hope for containment, or even eradication. The more time passes before a new threat is recognized for what it is, the more difficult and expensive the response. For some especially virulent invasive species, including ALB and the emerald ash borer, which is also on our doorstep, there is an exponential growth curve in the amount of resources required to address the problem with any hope of success once it becomes established. Time is not on our side.The insect that was found last week is likely one of several “look-alike species” of native sawyer beetles. ALB has very long black-and-white checked antennae and irregular white spots on its glossy black body. The white-spotted pine sawyer (Monochamus scutellatus) is frequently identified incorrectly as ALB, but lacks the black and white antennae. The male of this species is black with a single white dot at the base of its wing covers, while the female is brown with the white dot and additional white speckles. ALB lacks this prominent white dot. The southern white-spotted sawyer (Monochamus titillator) and northeastern sawyer (Monochamus notatus) are reddish gray or brown, respectively, lack the black and white antennae and infest conifer trees rather than hardwoods.According to the website on ALB maintained for Connecticut by the USDA Natural Resources Conservation Service (www.ct.nrcs.usda.gov/asian_beetle.html ): “The most important signs to look for are the ALB exit holes and egg-laying sites on tree trunks and branches. The exit holes are the most eye-catching; they look like someone shot large bullets into the tree. The holes are round (or somewhat six-sided) and 3/8 inch to 3⁄4 inch across. (A dime is just under 3⁄4 inch across.) “The exit holes are free of sawdust. ALB egg-laying sites look like the tree suffered some sort of shallow injury to the bark. The egg-laying sites are oval to roundish in outline. “A single egg is deposited. When it hatches, the tiny larva will bore into the tree. You can tell the difference between an egg-laying site and an injury by the chew marks (made by the egg-laying adult female) at the edge of the depression. “Further signs of a wood-boring insect larva inside the tree (not necessarily ALB) are the presence of bore dust (sawdust and larval excrement), or sap and foam flowing from the holes. You also may see bore dust at the base of the tree or in the crotches where branches meet the tree trunk.”If you do find such a site, or if you come across a suspicious-looking beetle between .75 and 1.25 inches long with black-and-white antennae and a glossy black body with irregular white spots, take clear photographs. Do not transport living beetles or larvae unless specifically instructed by the proper authorities to do so. Take careful notes about the location, including the types of trees. And contact the Connecticut Agricultural Experiment Station in New Haven.Early detection and rapid response only works if we know what to look for, and what to do if we find something. There is a good regional resource just up the road in Sheffield, Mass., where the Nature Conservancy bases its Forest Health Program. The Connecticut Department of Environmental Protection also has an excellent ALB website with links to many resources, at www.ct.gov/dep/cwp/view.asp?a=2697&q=421754. Tim Abbott is program director of Housatonic Valley Association’s Litchfield Hills Greenprint. His blog is at greensleeves.typepad.com.