In the course of evolution, insects have developed some unusual adjustments – especially if they live parasitically. This also testifies to a fossil type of wasp that researchers have discovered in amber: the insect’s abdomen consists of three flaps that were likely to snap like fishing leaves of a carnivorous venous fly trap. This anatomical peculiarity indicates that the wasp parasitically laid its eggs in other insects, with temporarily holding the host temporarily.
Some insects specialize in parasitating other insects. The landlord often serves as food for your larvae. Some parasitic insect species paralyze the hosts that become the breeding ground. Others, on the other hand,, the so -called co -bione parasitoids, only briefly hold the victim to the egg laying and then leave it to its normal development. For example, hatching wasps lay their eggs on butterfly caterpillars. The hatching wasp larva then drills into the body of the caterpillar and gradually eats it up from the inside. It spares important organs until the end, so that the caterpillar only dies when the wasp larva is ready to pupate.
Griffal apparatus on the abdomen
A similar strategy apparently had a newly discovered fossil way of wasp 99 million years ago – with an amazing trick. This witnesses in amber from the Kachin region in northern Myanmar, which a research team around Qiong WU has now analyzed from Capital Normal University in China. The researchers examined 16 female wasps preserved in the amber, which they assigned to a new species called Sirenobethylus Charybdis.
The special feature: “The fossils have unique morphological changes at the top of the abdomen, which probably formed a kind of gripping apparatus,” reports the team. As micro-CT scans unveiled, the abdomen of the newly discovered insect species consists of three flexible flaps that are occupied with hair-like bristles. “The structure is reminiscent of a Venus fly trap,” the researchers describe. Similar to the fishing mechanism of this carnivorous plant, the trap on the abdomen of the wasp could probably also snap as soon as a victim came within reach.
Fall for hosts
However, the victim of the chalk -Age wasp was probably not caught permanently. Instead, according to the study, the fan apparatus was so adjusted that the prey was held but was not crushed, and was released after a short time. “This indicates that S. Charybdis did not want to eat her victims, but only immobilized briefly,” explain WU and her colleagues. According to this, S. Charybdis was probably a koinobioned parasitoid and the gripping apparatus served to catch hosts on or in which the wasp then took its eggs.
Parasitic insects known today usually use fishing legs for this purpose. A abdomen converted to the trap, on the other hand, is unusual. “No other insect is known,” the researchers write. “The sophisticated gripping apparatus indicates that the wasp aimed at high -mobile victims, for example cicadas or small fly. We imagine that it has been waiting with the apparatus open to let it snap as soon as a potential host activates the fan reaction.”
Source: Qiong Wu (Capital Normal University, Beijing, China) et al., BMC Biology, DOI: 10.1186/S12915-025-02190-2