I’m so happy to be home, especially because the first firefly of the summer was out last night!
Fireflies create their glow with the help of a protein with the awesome name of luciferin.
Why do they glow? SEX. If you watch for a while, you’ll notice many different patterns of flashing.The photo on that webpage shows the results of time lapse photography from some classic research. Different species have different flash patterns (except for a sneaky predatory mimic, who can lure unsuspecting males to their death). The flash is the firefly way of saying “Yo, Baby! Check out my shiny elytra!”
The female replies with a flash, usually from a safer perch in the grass or a tree. I won’t tell you what she says for modesty’s sake :)
You definitely want these fellows in your garden, since the larvae (and some adult species) are predatory.
There’s been some concern about a decline in fireflies from past years–general consensus is that there does seem to be a decline, and that habitat loss is probably to blame. Work is ongoing to quantify the numbers, and to verify the decline.
This article does an awesome job of explaining everything firefly, and also discussing the type of habitat they like best–dampish to swampy.
Enjoy the magic!