Activity Period and Flash Signal
Adults are active in June and July. Males emit a characteristic greenish dot-dash flash pattern, comprised of a quick flash followed by a long flash that lasts up to three seconds.
The dot-dash firefly is found in DC, Delaware, Maryland, New Jersey, New York, and Pennsylvania.
This species is a habitat specialist associated with high quality tidal and non-tidal freshwater wetlands, such as shrub and forest acidic seepage swamps, emergent marshes, fens, fresh-water tide marshes, and floodplains.
The main threat to this species is habitat degradation due to sea-level rise, invasion of the non-native plant common reed (Phragmites australis), and development.
- We need to know more about the distribution of this species. Report sightings of any fireflies you see to iNaturalist, or consider participating in Firefly Watch!
- Turn off your outdoor lights at night so the lights of this firefly aren’t diminished by light pollution. You can read more about firefly-friendly lighting in our fact sheet.
- Avoid pesticide use, which could harm this firefly, its habitat, or its prey.
- More research on population size, trend, and life history is needed for this species.
Candace Fallon, The Xerces Society for Invertebrate Conservation, based on the IUCN Red List assessment