Fireflies vs Lightning Bugs
Depending on where you grew up, you may call those summer night glow fun critters fireflies or lightning bugs, but no matter what you call them, there is no debating the magical wonder they cast over summer nights.
Personally, I call them lightning bugs (or really lahtnin' bugs if I want to reveal how thick my accent was as a child and how it still reemerges at will on certain words), but firefly is a bit shorter to type and I like the abundant alliteration F offers, so I'll go with firefly for now.
Not in North America? What do you call these night glow insects?
These etherial creatures filled my childhood summer evenings and many jars full of wonder and fun. I remember being at my grandmother's house and after dinner and a bath we were allowed to go out at dusk in our pjs with jars and catch the lightning bugs before bed and keep the jar by our bed as a nightlight. I'm not unique in this and it is a joy that so many people share this experience in common.
Perhaps it's the childhood wonder or perhaps the mystery of a benign glowing creature at the edges of cultivated land, but whatever it is, I think it is impossible to not have a fond smile and twinkle in the eye emerge at the thought or sight of fireflies.
On the Edges
Find fireflies in summer at the edges. That's where I always find them anyway, and perhaps that is what adds to their mystery. By the edges I mean on the edges of mowed and foresty, meadowy, and marshy areas. For example, see on the left side of the photo above how there is a mowed grassy area in front of a darker wooded area? Well at dusk that spot is teeming with glorious glows!
Last week I finally had time to listened to a presentation by the organization Wild Virginia with Dr. Ariel Firebaugh, Director of Scientific Engagement at Blandy Experimental Farm in Winchester VA. She is a literal PhD in fireflies! So keep reading to discover some of the fascinating firefly facts she shared!
* And while it is rare that I use photos that aren't my own, taking photos of fireflies is no easy feat, so I have used and credited photos by those more skilled than I at the task of capturing the glow on film.*
Who are these Glowing Creatures?
These glowing "bugs" are actually beetles in the Lampyridae family. They are found on every continent (except Antartica) and boast about 2000 individual species.
The species North American east-coasters adore is the Common Eastern Firefly, Photinus pyralis, also known as the Big Dipper Firefly. They are active at sunset and the adults are slow flying - which is why they are so easy for children to catch.
Their predators are mostly spiders and other fireflies. They have no vertebrate predators because they produce compounds that make them taste bad.
But while the adults don't have many predators, and don't really eat at all themselves because they only live a couple months, the larva are fierce predators.
Firefly larva? I know I never thought of them either! But guess what - they glow too!!
Fireflies stay in larva stage for 1-2 years, during which time they do most of their eating. They are the same size as an adult, but don't have wings and look kinda like a flat roly-poly.
The larva devour large quantities of beetles, worms, grubs, snails, and other soft bodied invertebrates by injecting a venom into the prey.
Are you still caught on why you've never seen a firefly in the glowing larva stage?
I know, me too!
Well guess what? Now is a perfect time to try to find the larva!
Late September- Mid October, after the adult summer mating season is over, is when the larva hatch. Hence the title of this post, fall fireflies! (Lightning bug larva could have worked too, I guess, but isn't as seasonal sounding.)
The adults lay eggs all summer in the leaf litter and grassy areas beneath summer firefly activity.
So if you know such a spot, go there after dark this week. Turn off all lights, sit looking at the ground and look for faint green glows in the grass and leaves. What a fun adventure!
Though fireflies are not studied as important pollinator insects, the insects themselves and their lives are still a bit of a mystery to biologists. And many are beginning to believe that the ravenous and busy firefly larva play a role in soil health.
Dr. Firebaugh says that this area of firefly larva, and firefly lives in general, is a great place for research if anyone knows a budding biologist smitten with glow bugs and looking for a career path!
The Science of the Glow:
So why and how do these mystical creatures glow anyway? Well, the adults flash a glow from a part of their abdomens called "the lantern" as part of their mating process.
The average eastern firefly male flashes about every 5 seconds and females every 2.
Firefly anatomy is generally similar to any other beetle/insect, except they have the lantern area in the abdomen, and they have a shield that extends from their thorax up over their head. I'm not sure why, but you can see it in the photo above
The quintessential glow comes from a chemical reaction when oxygen mixes with a few chemicals in their bodies - including the enzyme luciferase which is used to detect bacteria on food. (& is now produced in a lab fortunately for fireflies.)
Now that you know more about the hows and whys of these wonder-filled creatures. What might you do to help them thrive?
- Avoiding pesticide and herbicide use is a first major step. Especially near known habitat areas.
- Light pollution is another suspected issue, so turn off those flashlights, outside spotlights, and bright porch lights. They aren't good for the fireflies mating flashes. And they prevent you from seeing the critters as well as seeing the stars!
- Get involved in conservation efforts to protect wild lands and prevent habitat loss. Allow a few wild areas on your property (the edges remember) with a few low hanging tree branches, taller grasses, and leaf litter. These offer the moisture and denseness firefly habitats require.
- Get involved in firefly citizen science initiatives. Check the links below in the Seeds to Sprout section!
What's your favorite firefly memory?
Share in the comments below!
Share your firefly inspired art & photos on Instagram #wingswormsandwonder!
Seeds to Sprout:
Fungi & Foxfire
Fireflies aren't the only things glowing in the summer forest night! Check out this post on foxfire! (Aka the jack-o-lantern mushroom) and how it literally glows in the night!
Learn More About Fireflies!
Check out this fascinating Wild Virgina lecture about the lives of Fireflies with Dr. Ariel Firebaugh, Director of Scientific Engagement at Blandy Experimental Farm in Winchester VA. She has an actual PhD in fireflies!
Firefly Citizen Science
Get involved in the lives of Fireflies!
Photo credit Mass Audubon