A Partner Highlight from the H2O Water Network
Introduction by John Detisch, H2O Water Network
One of the things I love most about the H2O Water Network is the chance to spotlight the incredible work happening across our partner organizations. Today I’m excited to share a story from John Wenzel and the Conemaugh Valley Conservancy — a story that connects river restoration, science, and those magical summer evenings we all remember.
John Wenzel joined the Conemaugh Valley Conservancy (CVC) in 2022 as Executive Director. Based in Johnstown, PA, CVC oversees a strong water monitoring program spanning hundreds of sites across five counties, along with river-related recreation events that bring people back to waterways that were once written off. One of John’s current goals is to publicize the great success stories of river restoration in this region of once-deeply polluted watercourses — and this one is a perfect example.
We’d love to hear your success stories too. Consider sharing it with the H2O Water Network. Submit your story and send pictures to John@h2owaternetwork.org.
Now, here’s a story you don’t hear every day — one about beetles, glowing lights, and what they tell us about the health of our waterways.
The Connection Between Fireflies and Clean Water
Everyone knows fireflies light up summer nights. But did you know they need good aquatic habitat to reproduce?
Female fireflies lay their eggs beside streams and ponds, where the larvae hunt for snails and worms. Also called lightning bugs, fireflies are actually beetles — not flies or true bugs. And with the restoration of our rivers and streams across western Pennsylvania, the insects that rely on aquatic habitats are doing better now than in decades past. Fireflies are among them.
That’s a detail worth sitting with. When you see fireflies blinking over a field on a warm June evening, you’re looking at evidence that the nearby waterways are healthy enough to support their life cycle. It’s one of those quiet indicators of environmental recovery that most people never think about.
Why Do Fireflies Glow?
Here’s something that might surprise you: the origin of the firefly’s glow is actually a warning. Fireflies are toxic, and while many toxic insects rely on bright colors to signal danger, those visual warnings fade in the dark. A yellow-green glow, however, remains highly visible at night — making it a more effective deterrent to predators.
As John Wenzel explains, “Although the photic signals originated as a warning, once adults evolved the ability to control the light organ to generate flashes, some species began using flashes in courtship, generating the nighttime displays everyone loves. Some species were originally described because their flash patterns differed from more well-known species.”
So the light show started as a “stay away” sign and evolved into a love letter. Those nighttime mating flights often occur over lawns, fields, and open areas — the displays people enjoy on summer evenings. After mating, the females fly back to lay eggs beside the stream, completing the cycle.
Pennsylvania’s First Firefly Inventory
Despite how familiar fireflies are, we actually know very little about which species live where in Pennsylvania. The Conemaugh Valley Conservancy, along with Penn State and the University of Florida, is working to change that by creating the first inventory of the fireflies of Pennsylvania, funded by the PA Wildlife Resource Conservation Plan.
CVC Executive Director John Wenzel puts it plainly: “Fireflies are poorly known, as are many small nocturnal insects. We will review the vast collections of several of the major museums to record what species are known to occur where, and we will use ecological models to predict where we might find species of special interest in PA.”
This isn’t just a counting exercise. The research team is combining museum collection data, in-person field verification, and ecological modeling to build a comprehensive picture of firefly distribution across the state.
Professor Marc Branham of the University of Florida says, “Our project will be the first to combine collection data, in-person verification at selected sites, and use niche-modeling to predict species ranges. In the process, we will check the accuracy of species identification in museums, which is rarely done.”
Professor Andrew Deans of Penn State adds even more perspective: “There is a lot to get excited about regarding this project. Fireflies are inherently interesting and familiar to the public. There are even firefly festivals that bring people together to celebrate the natural history and behavior of these beetles, such as the Pennsylvania Firefly Festival in Tionesta, the last week of June. As such, we have an opportunity to engage people on multiple levels. What also excited me, though, is the refinement of natural history collection data. Museums hold untold treasures. These specimens represent occurrences through time, going back more than a century, and I can’t wait to see what surprises lie inside, to understand better how firefly populations and ranges have changed throughout time.”
What This Means for Our Watersheds
This project is bigger than fireflies. It’s a story about what happens when communities invest in restoring their waterways. The Conemaugh River and its tributaries were once among the most polluted in the region — scarred by decades of coal mining and industrial practices. Thanks to the sustained efforts of organizations like CVC and their partners, these rivers are coming back to life.
And when rivers come back, so does everything that depends on them — including the beetles that light up our summer nights.
Share Your Story
The H2O Water Network wants to hear about the restoration successes happening across our region. Whether it’s a stream that’s recovering, a species that’s returning, or a community project that’s making a difference — we want to help tell that story.
Submit your story and send pictures to John@h2owaternetwork.org.
