What the Fluff?

All, Stories

On any given morning, a walk around the lake at Miami Whitewater Forest can present you with some interesting sights. A great blue heron waiting patiently for its morning catch, an avid fisherman doing the same or a flock of noisy geese flying overhead would not be uncommon. This time of year, however, a walk around the lake might lead you to encounter a more unusual sight.

Amongst the alder trees off the side of the Shaker Trace Trail, there is what appears to be fuzzy white mold on many of the branches. Closer inspection will reveal that that mold is on the move and isn’t actually mold at all but rather a group of tiny insects called woolly aphids. Woolly aphids (Erisoma lanigerum) get their name from the fluffy, wax-like substance that covers their bodies and serves as a deterrent to predators. These aphids, sometimes called “flying-fuzz balls” have sucking mouthparts that allow them to live on the fluid of plants and trees. They typically do not cause permanent damage to their host plants, but can present an alarming sight and a “What’s wrong with that tree?” reaction to passing observers.

These interesting insects have a complex life cycle that includes two different host plants, winged and wingless generations and generations that reproduce both sexually and asexually. The young woolly aphids are green or blue in color. Adults are less than an inch long and are a pinkish brown color. Each adult can produce up to five live young per day. After a few generations, winged adults develop to spread to new branches and nearby trees.

Even their waste is fascinating! Like other aphids, these “snow bugs” secrete a waste product known as honeydew. The presence of this sweet, watery substance attracts (you guessed it!) ants. The two species enjoy a mutually beneficial relationship whereby the aphids feed the ants and the ants protect the aphids from other predators.

The next time you are out and about in the parks, I encourage you to investigate something new to you. Take your time, slow down and look a little closer. You never know what you might see!

Heather Ficke, Naturalist, Miami Whitewater Forest