As we enter the peak season for invasive insect activity, the Maine Department of Agriculture, Conservation and Forestry and the United States Department of Agriculture call on everyone to help protect our beloved trees. Throughout August, we encourage everyone to spend just a few minutes checking the trees in their communities and forests for signs of invasive species.

Invasive species, which include nonnative plants, animals and diseases, can cause significant harm to our environment, economy and even human health. These invaders can wreak havoc without natural predators or diseases to keep them in check.

State Horticulturist Gary Fish puts it this way: “Our first defense against invasive species is to prevent their arrival in the first place. Our partners at USDA (Animal and Plant Health Inspection Service) and Customs and Border Protection here in the U.S. and the Canadian Food Inspection Agency north of the border frequently stop plant pests before they can gain a foothold in North America. However, the volume of trade and travel prevents them from stopping every pest.”

Watch for four primary invasive species:

• Asian longhorned beetle: This large (over 1-inch) black and white beetle has a taste for maples and other hardwood or broad-leaved trees. Look for oval to round wounds on the bark where the females have chewed out a site to deposit eggs, round holes in the trunks and branches of trees, and piles of coarse sawdust at the base of trees.

• Emerald ash borer: This small (less than 1/2-inch) metallic green beetle is deadly for ash (Fraxinus) trees. Look for small (1/8-inch) D-shaped adult exit holes in the bark, winding frass-filled (sawdust-like waste) feeding galleries under the bark, woodpecker feeding, crown dieback, and epicormic shoots. Emerald ash borer has been found in parts of Androscoggin, Cumberland, Kennebec, Oxford, Penobscot and York counties in the southern half of the state and northwestern Aroostook County in the north.

• Oak wilt disease: This deadly fungal disease of oaks is found in other parts of the United States, including the closest known infestations in New York. Look for leaves suddenly turning brown or dropping in the red oak group (pointed lobes on leaves) trees during summer months.

• Spotted lanternfly: This colorful planthopper, not known to be established in Maine yet, is an expert hitchhiker with a broad appetite. Spotted lanternfly feeds on and can damage various plants. It is best known for its impact on grapes and hops. Look for the brightly colored nymphs and adults, but be aware that this insect hitches a ride most subtly as dull-colored egg masses. Like the infamous spongy moth, the adult lays eggs on almost anything.

For more detailed profiles on these and other threats, visit the Maine Forest Service website: maine.gov/forestpests.

Take 10 minutes and inspect the trees in our yards, neighborhoods and local forests. If a suspected invasive pest is identified, take a picture and send it to foresthealth@maine.gov. Ensure the photograph is detailed enough for verification – placing a coin or pencil next to the pest for scale can be helpful. If possible, capture the insect in a rigid container and store it in a cool place until you receive a response.

Taking a few simple actions can make a big difference: Buy firewood where you’ll burn it or gather it on site if permitted; moving firewood can spread invasive pests. Check vehicles, bags and boxes for insects when traveling locally or moving to a new area; invasive insects can easily hitch a ride.

We all have a role to play in preventing the spread of invasive species. We appreciate everyone’s dedication to protecting Maine’s trees and forests. Your vigilance and action are invaluable.