Common eastern
Photinus pyralis
Also called: Big Dipper firefly, common eastern firefly
At a glance
- Flash
- A single warm-yellow flash in a rising J-shaped swoop, about once every 5–6 seconds
- Habitat
- Lawns, meadows, forest edges and gardens, usually near moisture
- Range
- Eastern and central North America
- Season
- Late spring through mid-summer
- Size
- 10–15 mm
- When active
- The first hour after sunset
Overview
The most familiar firefly of North American summers. At dusk the males fly low over open ground, each tracing a J-shaped path and emitting a single warm-yellow flash on the upswing — the movement that earns it the name 'Big Dipper.' Females wait in the grass and answer with a flash of their own a couple of seconds later, and the two exchange signals until the male finds her.
Like all fireflies it is a beetle, not a fly, and it makes its light through a cold-light reaction of luciferin, the enzyme luciferase, and oxygen — almost no heat is wasted. The larvae live for a year or more in damp soil, glowing faintly (the original 'glow-worms') as they hunt snails, slugs and worms. The winged adults live only a few weeks and barely feed; their whole job is to find a mate and signal.
Sightings logged here
548 sightings of this species have been logged on Alitaptap.
When they have been seen
| January | February | March | April | May | June | July | August | September | October | November | December |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 0 | 0 | 2 | 8 | 6 | 28 | 236 | 202 | 45 | 11 | 9 | 1 |
Most reported in July.
80% of these 548 records were made in July and August. None has been logged in January and February yet.
This shows when 548 records were made, not when fireflies fly. A place people only visit in one season looks seasonal for that reason alone, so treat a thin month as “nobody looked” rather than “nothing there”.
Where people saw it
- Waco, United States
- Piracema - MG, Brazil
- Austin, United States
- Cecil County, United States
- W Blaine Ave SE, United States
- Bexley, United States
Where and when it has been seen
| Place | Date | Source |
|---|---|---|
| Waco, United States | iNaturalist → | |
| Waco, United States | iNaturalist → | |
| Piracema - MG, Brazil | iNaturalist → | |
| Austin, United States | iNaturalist → | |
| Cecil County, United States | iNaturalist → | |
| W Blaine Ave SE, United States | iNaturalist → | |
| Bexley, United States | iNaturalist → | |
| Kings Mountain | iNaturalist → | |
| 34.12, -118.04 | Community | |
| Chapel Hill, United States | iNaturalist → | |
| West Chester, United States | iNaturalist → | |
| Stillwater, United States | iNaturalist → | |
| Norfolk, United States | iNaturalist → | |
| Walker Ranch Park, United States | iNaturalist → | |
| Salado Creek Greenway, United States | iNaturalist → | |
| Salado Creek Greenway, United States | iNaturalist → | |
| Salado Creek Greenway, United States | iNaturalist → | |
| Walker Ranch Historic Landmark Park, United States | iNaturalist → | |
| West Ave. & Nakoma, United States | iNaturalist → | |
| Mansfield, United States | iNaturalist → |
Showing the 20 most recent of 548 records.
Browse all sightings →How to identify
Look for the unmistakable J-stroke, where the flash brightens as the male sweeps upward, and note the warm yellow colour, not green. Active low over open lawns and meadow edges in early darkness.
Conservation
Still common, but sensitive to lawn pesticides and light pollution. A dark, un-sprayed yard with some longer grass gives local populations exactly what they need.
Photographs
Sources & further reading
Photographs load live from Wikimedia Commons and remain © their photographers under the licences shown.