Wasp with "Venus Flytrap" Tail Discovered in Amber

Scientists have identified a remarkable new species of wasp, named Sirenobethylus charybdis, found preserved in 99-million-year-old amber from Myanmar.

This ancient insect possessed a unique feature never before seen: a structure on its abdomen that functioned like a tiny Venus flytrap, snapping shut to trap prey. Unlike any wasp we see today.

Discovery in Ancient Amber

The discovery was made from 16 fossil specimens, all female wasps, trapped in hardened tree resin (amber) from the Hukawng Valley in Myanmar. This amber dates back approximately 98.79 million years, placing it in the mid-Cretaceous period—a time when dinosaurs still roamed the Earth. Researchers used high-resolution Micro-CT scanning technology to study the tiny wasps in detail without damaging the fossils.

Sirenobethylus charybdis wasp with Venus Flytrap-like tail preserved in amber.

A One-of-a-Kind Abdomen

What makes Sirenobethylus charybdis stand out is the highly modified end of its abdomen (the rear part of its body). It featured three movable flaps. The lowest flap was distinctively shaped like a paddle and lined with small hairs. Because these flaps were found preserved in different positions across the specimens – some open, some closed – scientists concluded the structure was movable and served a specific purpose. No other known insect, living or extinct, has a comparable body part. The appearance and likely grasping function reminded the researchers of the carnivorous Venus flytrap plant.

How It Likely Lived and Used Its Tail

Researchers believe this wasp belonged to a group known as parasitoids—wasps that lay their eggs inside living hosts. Once the eggs hatch, the larvae feed on the host from within, ultimately killing it.

The most likely purpose of the wasp's unique abdominal structure was to physically grasp and hold onto a host insect while the female laid her eggs inside it. The wasp's egg-laying organ is located conveniently close to these flaps, supporting this idea. This specialized "trap" might have allowed the wasp to target and successfully capture more mobile prey, like small flying or jumping insects, which many other parasitoid wasps cannot easily handle. While other uses like capturing food for the adult or holding a mate are possible, the evidence strongly suggests it aided in egg-laying.

A New Branch on the Wasp Family Tree

Besides its unique abdomen, the wasp also had a distinct pattern of veins in its hind wings, different from any known wasp family. Based on this and its other unique features, scientists have proposed placing Sirenobethylus charybdis into its own new scientific family, named Sirenobethylidae.

Why This Discovery Matters

The discovery of Sirenobethylus charybdis is significant because it reveals a type of anatomical adaptation previously unknown in the insect world. It shows that life in the distant past included creatures with body forms and survival strategies that are vastly different from anything alive today. Fossils like this highlight the incredible diversity of life that has existed on Earth and underscore how much we can still learn about ancient evolutionary pathways.

What We Still Don't Know

Since all the specimens found so far are female, scientists don't know what the male Sirenobethylus charybdis looked like or if males also possessed the abdominal structure. Furthermore, because the wasp is extinct, the proposed function of the structure is based on the anatomical evidence and comparison, rather than direct observation, leaving room for further interpretation.

This research was published in BMC Biology.