Ancient, Parasitic Wasp Used Its Rear End Like a Venus Flytrap to Catch Insects and Lay Its Eggs on Them, Study Suggests
Scientists say they’ve never seen anything like this “truly unique” species, which was found encased in amber
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An ancient wasp may have used an odd structure at its rear end to capture insects and lay its eggs on or inside of them, according to a new study published Thursday in BMC Biology.
Researchers named the parasitic creature Sirenobethylus charybdis—both after the sirens of Greek mythology that lured in sailors to their doom and after Charybdis, a mythical sea monster that created large whirlpools to drag its unsuspecting victims underwater.
The wasps, which lived almost 99 million years ago, might have launched backward at their insect targets, then grasped them within their Venus flytrap-like abdomens.
“It’s unlike anything I’ve ever seen before,” says Lars Vilhelmsen, a study co-author and researcher at the Natural History Museum of Denmark, to Chris Simms at New Scientist. “It was very exciting, but it was also a challenge, because how can you explain how this animal worked when you have nothing like it today?”
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For the study, scientists examined 16 female specimens of the wasp, which had been found encased in amber in northern Myanmar. The wasps’ strange abdomens each had three flaps with small spikes and trigger hairs, similar to the motion-detecting hairs on a Venus flytrap. Three-dimensional X-rays show that the flaps could open and close, likely to trap other insects.
Perhaps most disturbingly, the researchers detected a needle-like structure that the parasitic wasps might have used to deposit their eggs in or on their prey. The baby wasps would then feed on their new host as they grew.
“I’ve seen a lot of strange insects, but this has to be one of the most peculiar-looking ones I’ve seen in a while,” Lynn Kimsey, an entomologist at the University of California, Davis, who was not involved with the research, tells Adithi Ramakrishnan of the Associated Press.
“This is a truly unique discovery,” Manuel Brazidec, an arthropod researcher at France’s University of Rennes who was not involved in the study, says to New Scientist. “What I find extraordinary is that the abdomen of Sirenobethylus charybdis is a brand-new solution to a problem that all parasitoid insects have: How do you get your host to stop moving while you lay your eggs on or in it?”
Among modern insects, cuckoo wasps might offer the closest comparison to these odd creatures. Like the bird of the same name, cuckoo wasps lay their eggs in the nests of other animals, specifically bees. The wasp larvae will hatch, then devour either all the young bees or all their food. But these brood parasites of today don’t have anything resembling the paddle-like flaps seen on the back end of Sirenobethylus charybdis.
It’s unclear how or when the wasp went extinct. But the discovery shows us how wonderful and weird—and even gruesome—the world of insects can be.
“We tend to think that the cool things are only found today,” says Gabriel Meló, a wasp expert at the Federal University of Paraná in Brazil who was not involved in the study, to the Associated Press. “But when we have this opportunity, we see that many really exceptional, odd things already happened.”
