The previous episode left our Pyractomena larva hanging – literally – doing some aerial pupation, very unusual behavior for a firefly! Forsaking the amphibious wanderings of its snail-eating childhood, the pupa now hangs quietly. But inside, a maelstrom of cellular reorganization and growth is transforming its larval body. In just a few weeks, it will emerge as an adult firefly. At this next stage, our Pyractomena will have only one thing on its mind: sex. And yup – you guessed it: Pyractomena fireflies have strange sexual habits, too!
Most male lightningbugs fly & flash to win females. But after racing to emerge early, Pyractomena borealis males forcibly mate with their child brides! Continue reading
We’ve already heard (previous post) about the weird hunting habits of Pyractomena larvae – they’re amphibious. So let’s continue our Pyractomena tour, moving along to consider another strange behavior: they pupate en plein air!
Once they’re ready to metamorphose into adult fireflies, the larvae of most North American lightningbugs seek safety underground. Immobile, they huddle for weeks in soil chambers, finally emerging to light up our skies as adult fireflies. But no cold dark cellars for Pyractomena fireflies! Instead, these strange fireflies climb up onto vegetation to undertake a feat known as aerial pupation.
Aerial pupation (photos from Faust 2012)
If you’ve been paying some attention, you probably already know that here in North America, we’ve got several different kinds of lightningbug fireflies. Those in the genera Photinus and Photuris are common and relatively well-studied. But the Pyractomena lightningbugs – also pretty common – are a black box. We know so little about them! And more’s the pity because Pyractomena have a pretty bizarre lifestyle, making them quite a bit different from our other fireflies.
Three North American lightningbugs, belonging to Photinus, Photuris & Pyractomena( L to R)
So here’s the first taste of Pyractomena strangeness: these amphibious larvae are snail-eaters! Continue reading
Each autumn the world seems aglow with foliage and jack-o-lanterns. But they’re not the only glowing things lighting up this season. Fall is also a great time to spot the crawling, glow-in-the-dark stage that all juvenile fireflies pass through.
Glowing firefly larvae (left) and pupae (photo by Siah St. Clair)
Hatched from eggs laid during summer months, these firefly larvae can now be seen crawling along roadsides or wooded paths, glowing dimly from two tiny lanterns. Photuris and Pyractomena larvae are the two types seen most often in the U.S. But one reader in Portland, Oregon even spotted the much rarer Douglas fir glow-worm, Pterotus, along a path in Mt. Tabor Park. Continue reading