July 10th, 2025
Did you know fireflies live EVERYWHERE? From Arizona to Florida, Washington to Maine, around the world on every continent except Antartica, fireflies light up our nights and our the world! They are magical, glowing treasures which inspire our imaginations. Like stars in our midst! Yet we know so little about the many species out there! For instance, did you know the largest firefly is found in Southeast Asia and can get up to 4 inches long? Or did you know that our backyard firefly larvae are fearsome slug + snail predators, protecting our gardens (and lettuces!) from these common garden pests? Who knew?!
Firefly populations, like many other insects, are in trouble, and yet we have so little data on fireflies it is hard to truly understand what species need help and where to focus efforts. And therein lies the tremendous opportunities for home naturalists. It is why the Xerxes Society for Invertebrate Conservation put together a website called Firefly Atlas. Their goal is to educate and collect data to and from citizen scientists on fireflies, focusing on a number of species of special concern like Florida’s Dark Scrub Firefly, Arizona’s Twice-Wounded Firefly and the East Coast’s Keel-Necked Firefly. Anyone can join. Anyone can contribute either by contributing data or giving fireflies the habitat they need to thrive.
Citizen scientists are increasingly important for tracking biodiversity. Did you know that iNaturalist - a freely available nature ID app - can help anyone identify bugs, birds, animals, plants and fungi AND contribute to global citizen science data? In fact, their newest version uses AI to ID species in realitime.
Amateur naturalists have ALWAYS been important, and now they are becoming essential. For the first time anyone can easily map out biodiversity in a neighborhood, city or park. This info is now being used in thousands of studies and offering break through in conservation which anyone can participate in!
Check out this inspiring TED Talk (12 minutes) "The Surprising Power of Your Nature Photos" by iNaturalist Executive Director Scott Loarie on the many remarkable power of your nature photos! Like the birdwatcher on holiday in New Zealand who happened to photograph a moth which hadn’t been seen for over a century! Or regular people who just merely noticing something interesting and discovered a new species never before observed! These seemingly small creatures are the lifeblood of our planet and are intimately linked to our health and the health of the planet through the array of ecosystem services they provide for clean air, water and thriving soils. Greater biodiversity = greater ecological resilience!
So what do fireflies really need? So glad you asked!
For those of us with fireflies in our backyard, firefly conservation can start right where we are once we get to know what they need.
Abundant Larval Food Sources: Like snails, slugs, earthworms… oh yes! We gardeners have got this one covered!
Safe Places to Overwinter: Such as trees, leaf litter, underground burrows, a few fallen logs… leave the leaves in the fall (or even a small patch!) if you can! Many fireflies lay eggs into soil duff, logs, or other moisture places… and some eggs will GLOW slightly!!
Native Vegetation of Varying Heights: This is important for perching, shelter, food, and protection. Layer your plants and “keep the flower restaurant open” says ecologist Heather Holm, “24 hours a day, 7 days a week!” Think of your backyard as a buffet with nectar and pollen sources essential on the menu! Early spring and mid to late fall are particularly vulnerable times for MANY beloved bugs.
Clean Water Sources: Have enough water - especially moisture - on site. Drastically dropping water tables or drought can negatively effect fireflies. One way backyards can help is by maintaining healthy soils which can hold onto water longer. Ways to do this: keep soil covered + protected, maintain living roots in the soil for as much of the year as possible, minimize soil disturbance, and have a diversity of plants aboveground to support a diversity of soil microbes underground.
Protection from Pesticides and Ground Disturbances: Avoid large land disturbance, excessive trampling (ex: livestock around water sources), or land upheaval, especially during months when fireflies are mating and laying eggs (often on the ground) after displays in June and July. The larvae often live in leaf litter so limit or eliminate chemical usage on site whenever possible. Check out the resource listing below for
Dark Nights : Turn off bright lights or put them on timers especially during the firefly main mating season often in later spring to mid summer, depending on species. Lights can be problematic for many species not just fireflies. If you live in an urban area, request shielding on streetlights to more effectively direct the light downward (where we often want it to go anyways…) as opposed to reflecting up into the night sky.
(Adapted from the Xerxes Society’s Firefly page)
Fireflies are like flying jewels lighting up our night skies with summer magic. There are fireflies all across the country, in woods, deserts, marshes and mountains! The range of species is astounding and despite how deeply they entrance us we still know surprisingly little about so many of them. Summer is the perfect time to join forces with other citizen scientists and gardeners to track, wonder, and watch the fireflies.
And just imagine how good it would feel to be able to say, "I was one of those who brought back the fireflies."
Fireflies need larval food sources, safe places to overwinter, vegetation of variable heights for perching and shelter, clean water sources, protection from pesticides and ground disturbance, and dark nights during their peak mating season. Even small actions can make a difference, starting with a backyard.
Let us light up our nights with fireflies!
We got this.
Resources:
Firefly Atlas: Project focusing on tracking endangered or data-deficient species. https://www.fireflyatlas.org
iNaturalist.org : free nature app that allows anyone to identify plants, fungi, animals and bugs AND contribute to citizen science data https://www.inaturalist.org
TED Talk (11 min) from iNaturalist Founder : "The Surprising Power of Your Nature Photos": https://www.ted.com/talks/scott_loarie_the_surprising_power_of_your_nature_photos?language=en
Conserving the Jewels of the Night PDF xerces.org/sites/default/files/publications/19-049_01_Firefly guidelines_web_1.pdf
Heather Holm’s Top Gardening Activities for Support Native Bees (PennState Extension) https://extension.psu.edu/heather-holms-top-gardening-activities-to-support-native-bees https://
Alternatives to Chemical in Land Management: Quick Guide Brochure (Northeast Organic Farming Association CT) https://conservect.org/southwest/wp-content/uploads/2018/01/organiclandcare.pdf
Standard for Organic Land Care: Practice for the Design and Maintenance of Ecological Landscapes (NOFA CT) https://www.mwra.com/sites/default/files/2023-11/2011-nofastandards.pdf