Wednesday, March 5, 2014

Spotlight on... Winter Firefly

If you’re like me, you probably don’t think much about fireflies in the winter. After all, they’re summer insects, dancing over darkened fields and backyards on humid July and August evenings, flashing heatless lightning. Except some are not just summer insects; some – like the Winter Fireflies currently huddling on tree trunks across Cape May County – are around right now.

As fireflies go, the Winter Firefly (Ellychnia corrusca) may seem to be a bit of a dud. It flies during the day, rather than at night, and it doesn’t have any light-producing organs. Instead, it uses pheromones (chemical substances released into the atmosphere) to attract a mate. But it’s an incredibly hardy species which overwinters even in areas where temperatures regularly drop below freezing.

In the winter, adult Winter Fireflies are found on tree trunks, where they shelter in grooves and folds of the bark. From late September to mid-March, they don’t fly at all, instead marching up and down a trunk in search of sap flows. They are particularly fond of maples, and can reportedly become a real pest at maple syrup collection pails. Since they have a high survival rate -- from 88 - 99% per month in some locales -- they should be quite common out there at the moment. Watch for them on a maple near you!