AUGUSTA, Maine — Maine Forest Service bug trappers got some good news this fall — they didn’t catch any of the most troublesome pests they had targeted.
While the Maine Forest Service entomology staff, under the Maine Department of Conservation, did find some bugs they weren’t expecting, they nonetheless have found none of the most dangerous invasive insects that threaten the state’s forests from outside of Maine’s borders, according to a DOC press release.
Out of the 2,600 trap samples the forest service staff processed this past year, “we got a lot of zeros” for such dangerous insects as the Asian longhorned beetle and emerald ash borer, according to Charlene Donahue, forest service entomologist.
“We didn’t catch anything we were looking for,” Donahue reported, adding, however, that two new beetles were discovered and added to the forest service collection of more than 50,000 native and exotic insects.
“Although you can’t prove that something isn’t here in some localized spot at an extremely low level, these results, when added to work from previous years, are reassuring — at least for now,” Dave Struble, Maine state entomologist, said. “As pests like ALB and EAB continue to spread toward Maine, this is no time to drop our guard.”
In addition to monitoring native and established pests already in the state, the Maine Forest Service each year puts out numerous bug traps to see what might be making its way into the Maine woods. This annual surveillance project is a cooperative effort subsidized by the USDA, with forest service results rolled in with results from Maine Department of Agriculture trap networks and additional sites monitored by the Penobscot Nation. The trapping effort has taken place for decades, Donahue said.
Maine isn’t the only state doing the annual bug trapping. The state efforts are coordinated with regional, national and continental projects, the forest entomologist said, adding that there is plenty of collaboration between states and Canadian provinces.
In recent years, however, the intensity of the trapping efforts has increased “because there is more global trade, and more insects are coming into the United States, and it’s recognized as a problem,” Donahue said.
Asian longhorned beetles and emerald ash borers are of particular concern because they have been found in other states and provinces near Maine and they threaten to destroy the state’s forests.
The two invasive insects alone have destroyed millions of acres of trees in other states. The Asian longhorned beetle has infested the Worcester, Mass., area and recently was discovered in Boston. The emerald ash borer, which has killed millions of ash trees, has been found in 15 states plus the Canadian provinces of Quebec and Ontario.
This year, forest service staff put out 82 traps using pheromones — scents of the targeted insects — or kairomones — scents of insect food — from York to Limestone. The traps were out from April through October, Donahue said. The staff collected samples from each trap two to 12 times during the year depending on the type of trap and the life cycle of the targeted insects, she said. The effort specifically targeted 16 high risk-invasive insects, which also include the brown spruce longhorned beetle and other serious pests that are not yet known to be in Maine.
“These are insects that could come in with regional or global movement of materials, and they have potential to seriously damage our forest,” Donahue said. Some already are in the U.S. and Canada and could spread to Maine, while others have a high potential for inadvertent import on raw wood or packing materials. And once here they could become established in Maine forests. The actual list of which bugs to target in this survey is developed annually through negotiations between state and federal scientists, she said.
Each of the 2,600 samples from the traps was examined under a microscope by forest service staff, Donahue said, and while no invasive species were found, two new insect species were added to the forest service’s insect collection. The two insects found this year are thought to be native to the state, but “just not common,” the entomologist said.
The results of the trapping efforts are reported to federal agencies and shared with Maine stakeholders and other states, Donahue said. When compiled and examined, the results can show patterns of spread and “give a heads-up to forest and tree owners on pest problems,” she said.
The role of the public in the state’s annual bug-trapping efforts is highly significant, the forest service entomologist stressed. Most of the traps are placed on private land with the permission of land owners. The effort also is being supported by such businesses as bark mulch processors, sawmills, campgrounds, recycling centers, biomass users and large warehouses that have opened their wood-use facilities for trapping.
“People have been very cooperative,” Donahue said. “They understand there’s a risk bringing in materials. They want to be part of the solution and not the problem.”
For information about invasive insect species, go to www.maine.gov/doc/mfs.