A colony of woolly aphids. Credit: Courtesy of Griffin Dill

This is one Maine bug with some serious moves. But you won’t find the boogie-woogie aphids getting down at a local club.

These members of the insect family aphididae would rather spend time feeding on alder trees, beech trees or apple trees where their group movements look like a synchronized dance routine.

Also known as dancing aphids, wooly aphids or beech blight aphids, when a colony of these pests are disturbed, they lift their fuzzy hind ends high into the air and sway back and forth in unison as a warning. They aren’t harmful to humans, but when they feed on apple tree seedlings they can interfere with the tree’s growth.

“This time of year the ones that feed on alder trees are the ones you’re seeing,” according to Jim Dill, pest management specialist at the University of Maine Cooperative Extension. “You see these little fuzzy things floating by you and if you go to grab it thinking it’s a piece of dandelion fluff, all of a sudden you see a little aphid.”

The bug’s woolly or fuzzy appearance is because it’s covered with long white and waxy filaments.

“Like any aphid, they are pests — to a point,” Dill said. “It depends on what they are feeding on because most people think alders are pests, so it’s sort of a pest feeding on a pest.”

Beech aphids produce something called honeydew — the waste product of the sap they eat. They excrete it on beech tree trunks, branches and leaves where it attracts sooty-mold fungi. When enough aphids are on a tree, they produce so much honeydew that those molds become very thick and tar-like.

While it looks unsightly, beech blight does not damage the tree itself.

It’s a bit more serious when the aphids feed on apple tree seedlings. They cause twigs to wither and interfere with the tree’s growth.

There are other insects that prey on dancing aphids, and some will use the bugs’ behavior and appearance to their advantage, according to Dill, making them unwelcome guests at an aphid dance party.

“Those predators actually cover themselves with some of the ‘wool’ to mingle with the aphids,” Dill said. “They cover themselves with it and then sit right there with them and help themselves to a meal of aphids.”

Julia Bayly

Julia Bayly is a reporter at the Bangor Daily News with a regular bi-weekly column. Julia has been a freelance travel writer/photographer since 2000.