Moths are everywhere. Fluttering around trees. Flying into your windshield. Beating on the back door. But experts say the big problem is likely yet to come.

The fluttering horde is made up of gypsy moths, newly hatched from what is being described as the worst outbreak of the leaf-eating caterpillars since 1981.

Now, emerged from their cocoons, the moths are looking for mates and laying eggs—so that even more little worms can chomp on your trees next year.

The main reason for the severe outbreak this year is a lack of rain, causing the biggest gypsy moth outbreak since 1981, according to University of Massachusetts—Amherst entomology professor Joseph Elkinton.

The moths begin their lives as larvae, according to the UMass Amherst Center for Agriculture, Food, and the Environment. A female gypsy moth typically lays about 600 eggs at a time, and the eggs usually hatch in early May. You may recall the influx of caterpillars around that time.

The larvae complete several molts, then pupate toward the end of June. They emerge two weeks later as adult moths. The gypsy moth mating season usually continues until late July to early August.

A natural pathogen helps to keep gypsy moth populations under control in North America, according to Elkinton. The pathogen, a fungus called entomophaga maimaiga, works by attacking and killing gypsy moths in the larval stage. However, the fungus requires a certain amount of rainfall in the months of May and June in order to grow, which we didn’t get this year, Elkinton said.

“We’ve had a drought, not only this year, but last year as well,” Elkinton said. “With drought conditions, the fungus doesn’t do anything. There was a lot of [larval] survivability.”

At the Lloyd Center in Dartmouth, which sits on many acres of forests, the effects of the gypsy moths has been moderate, according to Research Director Mark Mello, but other areas around town have not been so lucky. He said some areas have been hit especially hard.

“This year it’s bad but it’s not to the point that the moths are totally defoliating everything,” Mello said. “There is a widespread infestation, but it is uneven.”

There are several options for homeowners to protect their shade trees from gypsy moths. Elkinton recommends hiring a professional to apply pesticides to trees in early May just before eggs begin to hatch.

“It’s expensive, but so is cutting down a dead tree,” Elkinton said.

Mello recommends inspecting trees for signs of gypsy moth egg masses during the fall and winter and removing them.