A brand new find out about, printed in BMC Biology, came upon prehistoric wasp preserved in amber is popping heads on the earth of entomology with a rear finish immediately out of a science fiction film. With a peculiar Venus flytrap-shaped stomach, this historic insect provides an extraordinary glimpse into the evolutionary creativity of the Cretaceous length.
An Insect Like No Different
Trapped in 99-million-year-old Kachin amber from present-day Myanmar, the wasp has been recognized as a fully new species and circle of relatives, named Sirenobethylus charybdis. 16 grownup ladies have been preserved neatly sufficient for researchers to explain their anatomy intimately—and what they discovered used to be remarkable.
The insect’s entrance part resembles a contemporary wasp, however its posterior tells an overly other tale. The place maximum wasps taper right into a easy stinger or ovipositor, Sirenobethylus sports activities a rounded, paddle-like stomach, coated with bristly hairs and formed just like the carnivorous plant Dionaea muscipula—higher referred to as the Venus flytrap.
“Not anything identical is understood from another insect,” write the researchers, led through Qiong Wu of Capital Standard College in Beijing.
They describe the construction as “paying homage to a Venus flytrap (Dionaea muscipula), a carnivorous plant the usage of two opposing specialised leaves to seize insect prey.”
Sirenobethylus charybdis. (Qiong Wu)
A Prehistoric Predator With A Twist
Fashionable entomologists classify many wasps as koinobiont parasites, which means they lay eggs within are living hosts. Their larvae then devour the host from inside of. Sirenobethylus seems completely tailored to this grim survival technique.
The researchers recommend the flytrap-like appendage helped the feminine wasp seize and immobilize a number—most likely a fast-moving insect—simply lengthy sufficient to inject her eggs the usage of a central ovipositor.
Some trendy parasitic wasps goal gradual or sedentary prey like caterpillars or fly larvae. However the distinctive rear finish of Sirenobethylus could have given it a much broader vary of doable hosts.
Frozen In Time, Stuck In The Act
The amber fossils be offering extra than simply anatomical element—they seem to seize the wasps in movement. Around the 16 specimens, the stomach lure is preserved in quite a lot of positions, suggesting real-time dynamics.
Photographs within the find out about show those dynamic poses in each lateral and dorsal perspectives, in conjunction with detailed perspectives of the ovipositor—the egg-laying tube on the heart of the lure.
Ambush Predator With A Twist
As a substitute of actively chasing prey like trendy dryinid wasps, which snatch their objectives with forelegs, Sirenobethylus could have taken a extra passive method. Its trap-like stomach most likely functioned extra like an ambush tool.
“We consider it will have waited with the equipment open, in a position to pounce once a possible host activated the seize reaction,” the authors write.
The presence of cause hairs at the flaps strengthens the case. Those sensory bristles could have served as tripwires, permitting the wasp to reply right away when prey brushed towards them.
Credit score : Wu et al., BMC Biology, 2025
Men Lacking From The Document
To this point, all recognized specimens of Sirenobethylus charybdis are feminine. That absence complicates the trouble to know the total serve as of the stomach construction. If men are in the end came upon with out such an equipment, it will beef up the concept that the flytrap served a reproductive position simplest.
“Certainly, it will be distinctive for insect ladies to restrain the men all through mating, fairly than the opposite direction round,” the authors provide an explanation for. “We believe this an not likely serve as of the stomach equipment.”