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Vermont Maple Trees Under Attack

If you live in Vermont, you may recognize this fuzzy little creature, known as the Forest Tent Caterpillar. This North American native insect is found throughout most of the United States and Canada, mostly in the eastern regions wherever hardwoods can be found, where they favor sugar maples, ash and red oak trees. A Forest Tent Caterpillar outbreak is currently underway in Vermont, with heavy defoliation occurring because these very hungry caterpillars love our sugar maples leaves. The last outbreak of Forest Tent Caterpillars was in 2006. Although the damage can be unsightly, the good news is that these infestations rarely threaten the lives of the trees.

Here is an update on the Forest Tent Caterpillar from the Vermont Maple Sugar Makers Association.

Update On Forest Tent Caterpillar:

As many sugar makers are aware, an outbreak of Forest Tent Caterpillar (FTC) has occurred in parts of Vermont this summer, most notably in portions of Lamoille, Orleans, and Caledonia Counties. The last significant outbreak of FTC to occur in Vermont was in 2006. While the defoliation that has occurred is locally very noticeable and alarming, the good news is that maple trees are remarkably resilient in the face of such insect pests. Since FTC is a native insect, maple trees have evolved to deal with such outbreaks and will grow new leaves this summer, mitigating some of the impact.

Although there is little existing research into the effects of FTC on maple syrup production, there is also little reported mortality in maple trees following an outbreak. An outbreak does place additional stress on trees, so it will be important to monitor any additional source of stress that may occur this summer such as drought or additional insect pressure.

UVM Extension and the Department of Forest, Parks and Recreation are monitoring this outbreak and the Department, through your County Forester, will be offering to conduct egg mass surveys later this year. Egg mass surveys are an indication of the severity of an outbreak as FTC populations usually spike over several years. The Department is also exploring whether or not aerial spraying of Bt, a biological insecticide, will be warranted in 2017.

For more information on Forest Tent Caterpillar, what to look for in your woods, and info on egg mass surveys, please see this update from the Department of Forest, Parks and Recreation.

You may also want to watch Across The Fence which aired a segment today on Forest Tent Caterpillars in Vermont.

Here is a story that recently ran on WCAX.

Photo by Greg Hume