The ancient world was even freakier than we knew. Research out this week details a parasitic wasp preserved in amber for nearly 100 million years that had a Venus flytrap-like belly it might have used to ensnare victims.
Scientists in China and Denmark detailed their discovery in a study published late Wednesday in the journal BMC Biology. They’ve named the wasp Sirenobethylus charybdis—a reference to the famous female sea monster of ancient Greek legend. The bug and its unique appearance likely represents a previously unknown lineage of insects, the researchers say.
As is often the case in Greek mythology, there are varying origin stories for Charybdis. But the most widely known version is in the Odyssey, where she’s depicted as a sea monster capable of creating massive whirlpools that threatened to impede the hero Odysseus’ journey home (travelers were forced to navigate between her and Scylla—another fearsome monster).
S. charybdis might have been a lot smaller than its eponym, but it certainly had its own monstrous-looking features.
The scientists examined 16 adult female specimens of the insect collected from amber originally found in the Kachin region of northern Myanmar. Based on an analysis of its physical characteristics, including X-rays to create a 3D reconstruction, the researchers determined that S. charybdis is a member of the parasitoid superfamily of insects called Chrysidoidea, albeit in an entirely new genus.
Parasitoids are parasites, usually insects, that spend their early lives inside or on a host before reaching maturity and living freely as adults—the chestbuster from the Alien movies, basically. Often, this freeloader lifestyle quickly kills off the host, but S. charybdis might have been a koinobiont, a parasitoid that allows the host to feed and even grow while it’s being invaded early on (hosts usually do still eventually die, though).
Though S. charybdis shares some traits in common with today’s parasitoids, its lower abdomen appears to be something that scientists have never seen before in an insect. The researchers directly evoke the Venus flytrap (Dionaea muscipula) in describing the insect’s unusual structure, composed of three horizontal flaps and hair-like bristles.
“The abdominal apparatus of Sirenobethylus is unlike anything previously reported from any [currently existing] wasp or indeed any insect known to us,” they wrote. “From the morphology and the different states of position of the lower flap preserved in different specimens, it seems evident that the apparatus had some grasping function.”
While it’s possible this apparatus was used by females to restrain males during mating, the researchers believe it was more likely deployed to hold onto the hapless hosts that females laid their eggs inside of. Much like a Venus flytrap, the wasp may have simply lied in wait with its belly open, its “leaves” shutting in response to the presence of a possible host (probably smaller insects).
There’s no known insect living today with a similar strategy for catching hosts, the researchers note. Accordingly, their discovery indicates that ancient parasitic insects like S. charybdis had all sorts of evolutionary adaptations that have since faded away.
“Our findings suggest that Chrysidoidea displayed a wider range of parasitoid strategies in the mid-Cretaceous than they do today,” they wrote.
Personally, given the vast array of parasites living out there today—including wasps that can turn their cockroach hosts into walking zombies—I’m glad that Mother Nature has forgotten some of her tricks.
