Brown Marmorated Stink Bug — Halyomorpha halys (Maine Dept of Agriculture, Conservation & Forestry) (Has been detected in Maine but it does not appear to be established ‘outdoors’ as yet) | Brown Marmorated Stink Bug Videos (Northeastern IPM Center)
Emerald Ash Borer (found in Maine on 5/22/18 in Madawaska and as of November 2020 it had been confirmed in several other Maine towns as well including Van Buren, Frenchville, Gorham, Ogunquit, Parsonsfield, Shapleigh, Grand Isle, Acton, Lebanon, Portland, Newfield, Berwick and South Berwick)
European Red Ant (Myrmica rubra) – The European Red Ant is also called the European Fire Ant; It is an invasive insect in Maine, increasing in both its geographical range (particularly in coastal communities) and in its encounters with homeowners. However, these ants are only distantly related to the ‘true’ fire ants found in the southern U.S. and Latin America.
Leek Moth (BugGuide.net) — Leek moths were captured in a pheremone trap in Jackman, Maine on 5/19/2020, the earliest capture to date in Maine. Leek moth as of 2019 had also spread to the Rangeley, Maine area and it is expected to continue its spread in Maine. The larvae of this moth are destructive to all members of the Allium plant family, but especially to leeks.
Red Pine Scale (Matsucoccus matsumurae) (Maine Forest Service)
Spotted Lanternfly (often abbreviated SLF) (9/29/2020: Some SLF egg masses have now been found in Maine!). This pest is not a fly or a moth, but rather a type of Homopteran commonly called a planthopper. It is native to China, India, Taiwan and Vietnam. Its first infestation in the U.S. was in Pennsylvania. As of October, 2019 it was present in 14 counties in southeastern PA, nine counties in NJ, one county in DE, and one county in northern VA. Specimens have been found in MD, NY, MA, and CT but most are believed to have been inadvertent hitchhikers, with no confirmed populations established as yet in the other states. If you find this insect or its egg masses, please report the sighting to an appropriate state authority. neipmc.org/go/slfqri has reporting instructions for various states in the region. Those in Maine wishing to report a sighting are asked to contact the Maine Department of Agriculture, Conservation and Forestry.
Tree of heaven (invasive plant and favorite host of Spotted Lanternfly but it also has over 70 other host plants, including apples, stone fruits, hops and especially grapes) (NH Department of Agriculture)
Spotted Wing Drosophila(invasive) (a unique fruit fly native to Asia which has spread from west to east across North America all the way to Maine) (see Fruit Flies)
Swede midge (Cornell) — [serious pest of cruciferous plants] Present in Maine: Found in Farmington starting in 2019 and the first detection of it there in 2020 was in early June; There are no effective sprays for home gardeners. Cultural practices and row covers, where Swedemidge has not been established, offer some protection against crop damage.
Jumping Worms (Maine’s Department of ACF would like to emphasize that this worm is relatively widespread at this point–13 counties as of August 2023–so please do not panic if you believe or know that you have some on your property.)
If you believe you’ve found a Jumping Worm in Maine from a town where the worms haven’t been confirmed as yet, or if you’ve found the specimen(s) in the woods, then please submit a Jumping Worm(s) Report Form (Maine Dept of ACF) (otherwise there is no need to report to the Maine Dept. of ACF at this time and if your town is already in their list of confirmations, the form will not allow you to continue with the submission)
