Photo courtesy US Forest Service
In mid-December, a delegation from the Vermont Forestry Division and the Agency of Agriculture traveled to Quebec to meet with emerald ash borer (EAB) specialists immersed in the Carignan infestation – Carignan’s a town southeast of Montreal. The group visited an infested stand, a municipal garage that receives tree waste, and some firewood dealers. State Forest Health Coordinator Barbara Burns wrote up a report on the trip that contained some interesting, if depressing, information.
Burns reports that the Canadian government has taken a number of pro-active steps to slow human-caused spread of the insect. They’re trying to police the movement of wood out of the quarantine area; they’re working to develop receiving facilities in the area that are set up to process potentially infested ash; they have a firewood inspection program designed to make sure firewood has no ash in it.
But there’s definitely a you-can-slow-it-but-not-contain-it undercurrent that pervades the report. Burns says that it’s nearly impossible to detect signs of the insect in a lightly infested stand. And once the bug is established, it spreads quickly. While Asian longhorned beetle (ALB) battles in the US effectively utilize slash and burn techniques whereby infested trees are flagged and destroyed, in Carignan, no trees infested with emerald ash borer are being cut. Burns writes: “No attempt is being made to eradicate or isolate the infestation … because this has never worked.” She points out, bluntly, that eradication efforts have been tried repeatedly in the US and Canada and every one has failed. She cites one noteworthy example where, in 2004, a 10-km wide host-free ‘firewall’ was created in Ontario by cutting all ash trees along the eastern edge of the quarantine zone, between Lakes Erie and St. Clair. About 100,000 healthy trees were destroyed. Infested trees were found at a number of sites east of the firewall later that year.
It seems that if there’s any chance to stop this bug, it’s going to have to involve biological control. And the realist in me feels powerless, and a touch foolish, even composing that sentence.
In the meantime, non-scientists like you and me wait and watch as the bug continues to make inroads into the Northern Forest. The one thing we can do is keep banging the drum: don’t move firewood. Don’t move firewood. Don’t move firewood.