J Flash Guide
Looking for J-shaped Flashes
Firefly Watch began as a project focused on firefly activity in New England, but here's an opportunity for those of you in other areas, particularly in the mid-Atlantic states, to tell us more about what you're seeing.
You might have noticed a new question under "Focused Firefly Reporting" that asks whether the fireflies you saw were flashing while flying in a "J" shape. Your ability to identify fireflies by this distinctive flash pattern can help firefly researcher Kristian Demary in her studies on the effects of ambient light on fireflies.
Identifying this species — called Photinus pyralis — will aid Dr. Demary in determining whether dusk-active fireflies are coming out during the dark-active period, when street light simulates natural light of the dusk hour.
Photinus pyralis is very common in and around the mid-Atlantic region and is active primarily around dusk. Here's what to look for:
- The male P. pyralis flies in an "S"-shaped path, flashing while in an upward turn to form a "J."
- The male makes this flash about every 6 seconds.
- From the ground, the female responds with a flash every 2 - 2.5 seconds.
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