99-Million-Year-Old Wasp Had a Venus Flytrap Abdomen

A Prehistoric Predator with a Unique Hunting Strategy

Imagine a wasp, buzzing amongst dinosaurs, with a hunting strategy unlike anything seen today. Paleontologists have unearthed just such a creature, preserved in amber for 99 million years. This tiny predator, named Sirenobethylus charybdis, sported a Venus flytrap-like structure on its abdomen, a biological marvel that likely allowed it to ensnare other insects.

Sixteen specimens of this newly identified wasp, dating back to the Cretaceous period, were discovered in amber from Myanmar. The research, published in BMC Biology, details the extraordinary abdominal structure, unlike anything seen in modern insects.

A Startling Discovery Trapped in Time

Study coauthor Lars Vilhelmsen, a wasp expert and curator at the Natural History Museum of Denmark, described his initial surprise: “When I looked at the first specimen, I noticed this expansion at the tip of the abdomen, and I thought this must be an air bubble.” However, further examination revealed the truth: this unique feature was part of the wasp itself. “This was actually part of the animal.”

The researchers observed different positions of the structure across multiple specimens, confirming its mobility. "Sometimes the lower flap, as we call it, is open, and sometimes it’s closed," Vilhelmsen explained. "It was clearly a movable structure and something that was used to grasp something.”

A Bizarre Analog: The Venus Flytrap

The closest parallel to this strange adaptation exists not in the insect world, but in the plant kingdom: the Venus flytrap. This carnivorous plant's hinged leaves snap shut on unsuspecting prey, mirroring the wasp's presumed hunting technique. "There’s no real analog within insects," Vilhelmsen noted. "We had to go all the way out of the animal kingdom into the plant kingdom to find something that remotely resembled this.”

A Parasitoid's Life Cycle

Rather than killing its prey outright, the wasp likely used its abdominal trap to capture insects and inject them with eggs. The trapped insect, then released, would become an unwitting host for the wasp's parasitic larvae. The larvae would then consume the host from the inside out, a gruesome yet effective reproductive strategy. Similar parasitic behaviors are observed in some modern wasp species, though none utilize such a remarkable trapping mechanism.

Ethical Considerations and Future Research

While the flytrap hypothesis is compelling, it remains somewhat speculative. Phil Barden, an associate professor at the New Jersey Institute of Technology, commented, “There appears to be clear evidence that the abdominal components would have had a range of motion… However, plausible, the flytrap hypothesis is “a bit speculative.” He also suggested alternative functions for the structure, such as prey detection in soil or even transporting young wasps.

The amber containing the Sirenobethylus charybdis fossils was sourced from Myanmar's Kachin region. The ethical concerns surrounding amber from this area, particularly after the 2021 military coup, underscore the complex backdrop of this exciting paleontological discovery.

A Cretaceous Weirdo: Pushing the Boundaries of Imagination

This “Cretaceous weirdo,” as Barden calls it, expands our understanding of the incredible diversity of prehistoric life. "This is significant because there are around a million known insect species — even with all of that living diversity, there are still lots of unexpected surprises in the fossil record that are beyond imagination,” Barden remarked.

Vilhelmsen sums up the discovery perfectly: "This is something unique, something I never expected to see, and something I couldn’t even imagine would be found. It’s a 10 out of 10.”