Posted by

Wire Reports Wire Reports
This e-mail address is being protected from spambots. You need JavaScript enabled to view it


Maine Forest Service: Invasive forest insect spreads

Rate this item
(2 votes)
Maine Forest Service: Invasive forest insect spreads Connecticut Agricultural Experiment Station Archive, Connecticut Agricultural Experiment Station / / CC-BY-3.0-US
Time for landowners to be aware of bug movement 

AUGUSTA This past winter was a good one for an invasive forest insect threatening Maine's hemlocks, and this spring is a good time for home and land owners, particularly those along Maine's coast, to be aware of the potential for spreading it.

The hemlock woolly adelgid (HWA) has been moving inland and north along Maine's coastline. In addition to the recently-reported infestations found in Alfred and Mount Desert Island, the invasive insect now has been found in Arundel, Biddeford and Kennebunk, according officials with the Maine Forest Service, under the Maine Department of Conservation.

'The sites are all York County, all coastal and where we expected to find it,' MFS Forest Entomologist Allison Kanoti said.

Kanoti said MFS staff had visited the reported sites previously as part of the MFS annual and ongoing survey and had found nothing. The HWA, discovered in February, now 'has reached a detectable level of population over this winter,' she said.

On Mount Desert Island, MFS crews have been wrapping up their surveys, though Acadia National Park still has to be surveyed, Kanoti said. After checking more than three dozen sites on the island, including a number of private estates for which the crews received permission to survey, HWA has been found only in one additional tree, quite close to a reported site of infested, planted hemlocks. So far, it has not been found on any forest hemlocks, the forest entomologist said.

Hemlock woolly adelgid is a small, aphid-like insect that is covered with white, waxy wool-like material. This wool-like covering makes the insect resemble miniature cotton balls. It is most visible from late October through July, with woolly masses located on the undersides of the twigs at the bases of the needles. The insect begins its egg-laying in March.

The insect, which came from Japan in the 1950s, causes infested trees to have off-color needles, often with a grayish cast, premature needle drop and twig dieback, and eventually mortality.

HWA has been found in at least 19 states. In Maine, it was first discovered in the forest in Kittery in 2003 and has spread up the coast. The invasive insect has been found at three state parks, Ferry Beach State Park in Saco in 2008, Wolfe's Neck Woods State Park in Freeport in 2010, and Vaughan Woods State Park in South Berwick, also in 2010. Infested hemlocks in forested settings have been found in 35 towns in York, Cumberland, Sagadahoc and Lincoln counties.

This winter was a good one for HWA survival, Kanoti said, because there was no long stretch of very cold weather, which can reduce the insect population. 'They will have survived quite well, and what that means is that people are likely to see them in new places,' she said.

Kanoti said that this was both a good and bad time to be on the look-out for HWA. The bug's signature woolly masses are 'about as big as they're going to get' for the season and are easy to see, she said. For landowners, if they have hemlocks that they think are uninfested, it's a good time to check for the insect, but not after they've been near known infestations.

The danger is that HWA eggs underneath the woolly covering are now starting to hatch, and crawlers are starting to emerge. These eggs and crawlers are 'no larger than a speck of pepper,' Kanoti said, and can easily be transported on clothing, pets and cars.

'If you're out searching in an infested area,' she said, 'and you travel into a clean area, you can then carry the pest with you to a new location. If you've been down amongst hemlocks on the coast, you don't want to then go look at hemlocks in an uninfested area.'

In addition to being careful about searching for HWA, Kanoti recommended that homeowners consider removing bird feeders as birds can carry the insect or to move feeders away from hemlocks.

'When we're working in hemlocks, we work from clean' to dirty,' especially this time of year,' said Kanoti. 'What that means is we start our work away from known infested areas and work towards them. If we encounter adelgid, that is the end of our work in hemlocks for the day.'

The Maine Forest Service encourages others who work or recreate in hemlocks in the lower third of the state to follow similar practices and to be aware that they can be agents of spread this time of year.

If there is a choice, people should plan harvests and tree care in hemlocks, especially within 30 miles of the coast, for the period when eggs and crawlers are absent, roughly August through February. 'It would be a sad irony to bring this destructive insect to your trees when your intentions were to support their health,' Kanoti said.

Anyone who thinks they have found HWA should contact MFS Forest Entomologist Allison Kanoti at (207) 287-3147 or email  This e-mail address is being protected from spambots. You need JavaScript enabled to view it .

More information about hemlock woolly adelgid, including a list of professional pesticide applicators, can be found on line at

For more information about the Maine Forest Service, go to


The Maine Edge. All rights reserved. Privacy policy. Terms & Conditions.

Website CMS and Development by Links Online Marketing, LLC, Bangor Maine