Save our Glow. Fireflies at Risk.


Have you noticed our summer nights are a little less flashy? It seems that Pennsylvania’s state insect, the firefly (commonly known as the lightning bug), is declining not only in our backyards, but across the globe.

Since a study was published in the BioScience journal, fireflies have been making headlines. The study highlights several reasons for decline in the populations of the approximately 2,000 species of fireflies worldwide. A survey of 49 of the top firefly scientists around the world collated the reasons cited, including habitat loss due to development, artificial light from homes, street lights, cars, pesticides and water pollution (Guarino, 2020).

Fireflies are bioluminescent. This means that they produce a chemical reaction in their bodies that produces the light. Lightning bug flashes are used to attract mates and to warn predators that they are toxic (Higgins, 2016).

More studies are in the works to understand firefly populations. In fact, anyone in North America interested in participating can help count fireflies in their own back yard or in a nearby field by joining the Firefly Watch Citizen Science Project led by the Mass Audubon. Other things we can do to help keep the sparkle in our neighborhoods is to turn off outdoor lights (even for a week or two) and limit the use of pesticides in our lawns. Also, do not remove all of the leaf litter and debris in your yard since fireflies spend much of their lives in the ground as larvae. Lastly, while many of us spent many a summer night capturing the little flashing beetles and putting them in a jar, we also know they did not survive our curiosity. Instead, let’s encourage kids’ fascination to admire, but leave them be (Higgins, 2016).

Much of the future of fireflies is in our hands. Summer nights wouldn’t be the same without the magical flashes of lightning bugs. Their twinkles are just another gift of nature to enjoy!

If you would like to learn more about bioluminescent fireflies, join our free Winter Glow Hike at the Frick Environmental Center on Saturday, March 7 from 6:30 P.M. – 7:30 P.M. This hike is geared toward children ages 4 – 10. To learn more about the event or register, please visit

To read more about fireflies and the recent BioScience study, please visit the suggested articles below. 

Why are fireflies disappearing?

Fireflies are our state bug, but summer nights could lose those flashes

Fireflies Face Extinction Threats From Habitat Loss, Pesticides


Firefly. (n.d.). Retrieved March 1, 2020, from

Guarino, B. (2020, February 3). World's fireflies threatened by habitat loss and light pollution, experts warn. The Washington Post. Retrieved from

Higgins, A. (2016, July 6). Humans love fireflies, but we haven’t made life easy for them. The Washington Post. Retrieved from

Author: Beth Seibel