No doubt you saw them and walked through them over this past week, as well. They looked like tiny white fluffy seeds floating everywhere; pretty dense on parts of Central’s campus, and in the air across town and several parts of the valley.
On Tuesday, I stopped outside the new, rising, science building just to watch them as they swarmed around me. A young couple behind me were talking about them, too. The guy said, “Yeah, look. They aren’t floating – they have little wings and they’re moving themselves.” To which, she anxiously replied, “Stop looking and let’s get out of here – they’re in my hair and eyebrows and eyes – I think I’m being bitten.”
As Wildlife Information Officer for the Reecer Creek Rod, Gun, Working Dog & Outdoor Think Tank Benevolent Association, my responsibility was obvious. I reached out to Central’s insect pro, Entomologist Jason Irwin.
It’s a hectic time on campus, but Jason found a moment to respond. “Hi Jim. They are woolly aphids. The summer generations are parthenogenic (produce young without mating) and wingless. The final generation of the fall has wings, mates, and migrates to an evergreen tree to spend the winter (summer generations feed on herbaceous plants that won’t survive the winter). Definitely an interesting critter!” I started digging.
According to the WSU Tree Fruit Research and Extension Center, these are most likely woolly apple aphids, Eriosoma lanigerum (Hausman). First identified in 1842, they have a variety of hosts, overwintering originally on American elms and now well adapted to areas where apple trees and orchards are found.
The best summary and story I found of these critters was written by Claire Stuart. She writes for The Journal (www.journal-news.net). She calls herself The Bug Lady and you can find more at The Journal, or email her at [email protected]. The web is filled with pictures of them.
“I remember several years ago that another person had asked me about these creatures, saying that they looked like tiny fairies. They are insects called woolly aphids, Family Eriosomatidae, and one of their common names actually is “fairy fly.”
“Woolly aphids are sucking insects that feed on plant juices. They are closely related to the common true aphids (Family Aphidae) that we see just about everywhere, but there are a few slight differences. True aphids give off a sugary waste product called honeydew through a pair of structures called cornicles. The cornicles are found on the aphids’ rear ends, like dual exhaust pipes. Woolly aphids also produce honeydew, but cornicles are either reduced or absent. Since you usually can’t see an aphid’s cornicles (or lack of) without magnification, they really aren’t that relevant except as a matter of information for those who are curious. What matters is that woolly aphids are “woolly” and true aphids are not.
“Woolly aphids have special glands that produce wax in very long, thin streams. The wax covers the insect’s body and gives it the fluffy appearance. If you could wash a woolly aphid in something that dissolves wax, you would see an ordinary-looking aphid underneath. Wax protects the delicate aphids from predators while they feed. You can sometimes see big colonies of these aphids feeding together on plants in cottony masses. The wax serves as camouflage even though it is easy to see, because it can be mistaken for mold or fungus.
“When woolly aphids take flight, the wax strands catch the wind and let them drift effortlessly until they decide to take charge of the direction of their flight. In flight, they are still camouflaged from flying predators who are not interested in drifting seeds.
“They have a rather unusual life cycle because they usually require two separate food plants called the primary and secondary hosts. They live on the primary host plant during winter and spring, on the secondary host plant in summer, and then return to the primary host; but the same individual aphids do not travel from one host to another and back.
“Eggs were laid on the primary host in fall, and they hatch in spring into wingless females. These females give birth to live young without ever mating, in a process called parthenogenesis.
“In late spring or early summer, the wingless females start giving birth to winged females that fly to the secondary host plant, where they give birth to wingless females again. In late summer and early fall, winged females will again be born.
“They fly back to the primary host plants and a big change takes place. They give birth to both females and males. The new males and females mate and the mated females lay eggs. The adult aphids will die and the eggs will survive through winter to start the cycle again.”
Oh, yes, about that young woman’s concern; according to many blog entries, wooly aphids do bite. They are described as “itchy creepy nasty things” in hair and eyes and nose and ears. One woman writer said she felt crazy because no one would believe they were biting up inside her nose, and doctors treated her like a hypochondriac until they looked closer.
The world is filled with a wondrous variety of wildlife. Welcome to Paradise.
