Beware Of Impostors

When Imitation is Not Flattery

For much of the season, there are many more male Photinus fireflies in a typical meadow than females, and the competition to mate is fierce. A slower male may find his intended already occupied by a faster suitor, so when he sees his flashing overtures reciprocated, it's in his best interest to act quickly -- or is it?

Female Photuris Imitating A Female Photinus

Impostors are common in most firefly meadows. Photuris females can imitate a number of flash patterns used by Photinus females.

A male Photinus firefly may see this flash and approach with mating on his mind. However, when he gets close enough, the Photuris female, about twice his size, can seize and eat him.

Male Photuris Imitating a Male Photinus

The male Photuris can also play the role of impostor, imitating a male Photinus in hopes of tricking a female Photuris – while she's busy trying to attract a meal, he may be able to locate a mate.

Photinus Males Get Wise

Occasionally, a female Photuris may give a faulty imitation of the female Photinus flash. This can scare off male Photinus who have grown wary of imitators. Some evidence suggests that male Photinus fireflies have even learned to imitate this faulty flash and use it to scare off other male Photinus fireflies from a receptive Photinus female, effectively eliminating the competition. However, much research still needs to be done before scientists fully understand the signals passed between fireflies.

When you join Firefly Watch, you're not only tracking firefly sightings in your yard; you're also helping local scientists with their research.
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Observing fireflies is a great summer activity. Join our network of volunteers and track your sightings throughout the season.
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Pick a location, observe it weekly, and use our online tools to follow your progress.
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You might see more than one type of firefly in your yard. New England fireflies fall into three main groups, and they can be identified by flash color, pattern, and location. Check out the Virtual Habitat to see what fireflies might look like in action.

- Go to the Habitat