SNOW FLEAS

The waning of winter in northern Michigan is marked by many events in nature. Most folks note the lengthening days, warming sun, returning birds, and radio interviews with Sparky Anderson as sign posts pointing towards the coming spring!

 There is one natural event that generates many phone calls and letters to the county extension and DNR offices across this part of the state every March. The inquiries usually go something like: "There are thousands of these little black things jumping around on the snow in my front yard. Are they fleas?"

 These little critters are commonly referred to as "snow fleas". Actually, they are not fleas at all. Like fleas they are insects. However, they are not very closely related. They belong to a very primitive group of insects named Collembola ( CO-LEM-BO-LA), commonly called spring tails.

 The group is so primitive that they do not possess wings. They get around by cocking and releasing a spring-like mechanism at the tail end of their body and by crawling.

 Snow fleas are active adults from November to March. They are most apparent when the snow pack starts to thaw in late winter. Their black color allows them to absorb heat from the sun. They congregate in great numbers on sunny days to feed on microscopic algae, bacteria, and fungi on the surface of the snow and to complete mating. As the trees absorb heat and the snow melts away from the base of the trees, the snow fleas move down this pathway to the leaf litter and deposit their egg load.

 The young hatch in the leaf litter later in the spring. They are less than a millimeter long and pinkish in color. They mature throughout the summer and become sexually active adults the following fall, usually in November.

 SNOW FLEAS DO NO HARM! They are a part of the natural processes that take place in the forests. Snow fleas are part of that complex of organisms that break down leaf and other organic matter on the forest floor. They are soil builders. They are not harmful to people or pets and they won't get in the house and contaminate foodstuff.

This is not an M.S.U. Extension Bulletin. 
It is an excerpt from a Landscape Crop Advisory Team Newsletter.
by Tom Ellis
Department of Entomology Michigan State University