As record producer Owl City once sang, “You would not believe your eyes if 10 million fireflies lit up the world as I fell asleep.” I would certainly not believe my eyes, but I sure would be mesmerized! There are around 270 firefly species found in North America and around 2,400 species worldwide. Many of these North American species can be found around the Chesapeake Bay region illuminating the land. It’s always magical to see these little lights dancing around in the night. These unique glowing insects aren’t actually flies, but are classified in the Lamprydiae family as beetles. Let’s get to know a few of these beautiful bioluminescent beetles commonly seen around the Chesapeake watershed!

The common eastern firefly (Photinus pyralis) is the most abundant species of firefly across North America. They are most easily identified by the J-shaped flight pattern males use to attract nearby females waiting in low vegetation.

Photo source: Terry Priest/flickr

The Pennsylvania firefly (Photuris pennsylvanica) is the state insect of Pennsylvania and is found throughout the state. This species is most easily identified by its dot-dash flashing pattern. The males tend to flash at a consistent rate while the females typically flash in response to males or to mimic other firefly species.

Photo source: Terry Priest/Flickr

The kneel-necked firefly (Pyractomena ecostata) has separated populations, one in the salt marshes around Delaware and New Jersey and the others around the Mobile Bay region of Alabama and Florida. However, they are moving into the Chesapeake Bay region. For the first time in 2023, Maryland Biodiversity project surveyors found this species along the Eastern Shore of Maryland. They are unsure how many individuals are spread along the eastern shore or how many will continue the trend.

Photo source: Abbott Nature Photography, iNaturalist

Documenting local species presence and their distribution is an important part of understanding firefly population trends. A current citizen science research project is underway in Maryland to better capture firefly species distribution across the state. Please click the link if you’re interested in how to participate or want to learn more! If you want to help fireflies from your own home consider leaving pockets of leaf litter in your yard or garden and turning off exterior lights at night. These simple practices can go a long way for these summer wonders. Maybe now you’ll notice one of these regional species making a habitat in your home, and you’ll gain a new appreciation for their summer glow!

Written by Eden Walrath, Urban Forestry Intern for Summer 2025