Range Maps

Photinus Geographical Distribution and Flash Patterns

In 1966, Dr. James Lloyd, the world's leading expert on fireflies, published "Studies on the Flash Communication System in Photinus Fireflies." Based on specimens from the collections of many museums and universities, specimens sent to Dr. Lloyd, and his own personal observation, the pamphlet includes distribution maps and flash patterns for most of the species of Photinus fireflies in North America, as well as information on the habits of each species.

The distribution maps are more than 40 years old and are by no means all inclusive. However, along with flash patterns showing male and female behavior over time for the three featured species, these maps can help you identify which species you are seeing in your area. Keep in mind that the data only covers Photinus fireflies. To learn more about the difference between Photinus and the other groups of fireflies, read the Types of Fireflies section and remember that Photuris fireflies can be tricky impostors.

Read Dr. Lloyd's full report to view range maps for other types of fireflies that might be in your region.

Photinus ignitus

Season: Mid-June to late July

Male flash activity: Begins 30 – 45 minutes after sunset and continues for one or more hours

Male flight: Straight, level, and slow, 1 – 2 meters above the ground

Male flash (at 74°F): Single flash repeated after 5 second interval

Female response: Single flash, 4 seconds after male flash

Photinus macdermotti

Season: Early April in Florida

Male flash activity: Begins 8 – 30 minutes after sunset

Male flight: Straight, level, and very slow, 3 – 5 meters above the ground. Double flash emitted every 1–2 meters of flight with upward flight on second flash

Male flash (at 73°F): Double flash with 2 seconds between flashes, repeated every 6 seconds

Female response: Single flash, 1.5 seconds after male flash

Photinus marginellus

Season: Late June through late August in New York

Male flash activity: Begins between sunset and one half hour after sunset

Male flight: Flight is a series of hops close to the ground. Flash emitted between hops while male hovers

Male flash (at 74°F): Single flash repeated after 3.5 seconds

Female response: Single flash 0.3 seconds after male flash


When you join Firefly Watch, you're not only tracking firefly sightings in your yard; you're also helping local scientists with their research.
:: Read More
Observing fireflies is a great summer activity. Join our network of volunteers and track your sightings throughout the season.
:: Sign Up
Pick a location, observe it weekly, and use our online tools to follow your progress.
:: Read More


Wear bug spray to protect yourself from mosquitoes, but take caution if you're handling fireflies.

- Get More Tips