Text by Paula Dittrick, TMNCPC blogmaster, photos from Firefly.org and also from Shawn Rosinski of South Bend, Ind.
Those firefly scenes that many of us fondly remember from our childhood summers sadly might not exist for children of future generations unless firefly populations can be sustained. Researchers believe certain firefly populations are declining across wetlands, grasslands, forests, and agricultural fields worldwide.
“Fireflies may fade forever, leaving our summer nights a little darker and less magical,” said the web site, Firefly.org.
Ben Pfeiffer of New Braunfels started that website along with Firefly Conservation & Research, a nonprofit organization launched in 2009. Pfeiffer is a Texas Master Naturalist with a biology degree from Texas State University. He and most firefly researchers blame population declines on two main factors: development and light pollution.
“The problem is that…our open fields and forests are being paved over, and our waterways are seeing more development and noisy boat traffic,” Pfeiffer said. “As their habitat disappears under housing and commercial developments, firefly numbers dwindle. Logging, pollution, and increased use of pesticides may also contribute to destroying firefly habitat.”
Pfeiffer said fireflies believed at greatest risk are the ones found to be very localized because those fireflies’ requirements are so specialized and their range is small. Some fireflies are habitat and dietary specialists while others are more generalists, enabling them to live in more ecologically diverse habitats.
Firefly.org offers a flash guide to firefly identification for fireflies in Texas and also lists tips on how to build firefly habitat in one’s own yard. Pfeiffer spoke to the Texas Master Naturalist Heartwood Chapter meeting on July 7, and his presentation is available online.
Internationally, firefly researcher and author Sara Lewis and several other researchers in January 2019 emailed a survey to 350 people on the Fireflyers International Network. Lewis is a biology professor at Tufts University in Boston.
In a February 2020 article in BioScience entitled “A Global Perspective on Firefly Extinction Threats,” Lewis and the other authors advocate the need for monitoring programs to track long-term populations trends for at-risk firefly taxa.
Habitat loss, artificial light at night, and pesticide use were identified as the three most serious threats worldwide. Additional threats were water pollution, tourism, overharvesting of fireflies, invasive species, and climate change. Some fireflies have very specialized habitat, causing them high risk from drought and sea-level rise associated with climate change.
All authors of the BioScience article are with the Firefly Specialist Group of the International Union for the Conservation of Nature Species Survival Commission. Lewis is co-chair of the IUCN-SSC Firefly Specialist Group.