This tiny parasitic wasp can dig through plastic

When Matvey Nickelshbarg was 13, he was obsessed with parasitic wasps, small insects that lay eggs on or in other insects. Under a microscope in a laboratory he assembled at his home, he discovered that one species had an astonishing superpower: it could use an organ protruding from its abdomen to drill through a plastic petri dish.

Nickelshbarg said his “amazement reached its peak” when he noticed that the wasp not only drilled through the Petri dish, but laid an egg outside the container that later grew into a healthy adult. The young researcher, who recently began pursuing a bachelor’s degree at Saratov State University in Russia, reported his discovery last month in the journal The Journal of Hymenoptera Research.

Jubileemus Messene It is a wasp whisper. Smaller than a grain of rice, and harmless to humans, these strange arthropods bore holes in tough plant growths called galls, with an organ called an ovipositor. The target of the insect is other larvae Types of wasps, which lay their eggs inside balls to protect them from danger. By penetrating the vegetative fortress of its prey, E. mesini It gives its young a ready meal, ironically giving it the same protection from the elements that its target originally sought.

In his at-home experiments, Mr. Nickelshbarg set out to study what would happen if there were multiple E. Messine wasps and only one host larva. Place one host in a petri dish with 12 females.

Most of the wasps immediately scrambled to poke the larvae with their eggs, he said, “and began pushing and biting each other in a competitive struggle to reproduce.”

But curiously, one of the wasps chose to stay out of the fray. Mr. Nickelsburg saw her choose a different “host” – the polystyrene wall of the dish itself.

Mr. Nikelshbarg reported his discovery to his teachers, Vasily Anikin, of Saratov State, and Alexei Polelov, of Lomonosov Moscow State University, and his sister Evelina Nikelshbarg, also of Moscow State University. They raised more wasps in hopes of seeing more plastic holes.

Of the 56 wasps the researchers raised, eight drilled holes in the plastic, including three that did so despite having a perfectly fine host sitting in the dish with them. The tedious process can take more than two hours, and the wasps often leave their work in progress to have a lunch or water break before returning to it. One industrious wasp dug five different holes over the course of the study.

E. mesene has to work harder to penetrate polystyrene than plant gall. The wasp pushes its ovipositor downward while rotating it in both directions, although it does not quite resemble the full circular motion of an electric drill. Once it has penetrated and laid its egg, the wasp retracts its egg-laying apparatus “with very sharp, rhythmic upward movements,” Nickelshbarg said. So-called extrusion movements were never seen when the parasites penetrated the balls, suggesting that “wasps of this species are indeed flexible in their digging behaviour.”

It’s interesting that the wasp can penetrate a soft Petri dish, said Uros Cerkvinic, a biologist at the University of Ljubljana in Slovenia, who was not involved in the study. It is believed that wasps typically exploit small cracks in the surface of the gall, but plastic supposedly “does not have such cracks.” While this study does not address how plastic is punctured, Dr. Cerkvinic said he would not be surprised if the wasps have an anatomy or behavior that supports laying eggs to avoid damaging them, and their ability to reproduce.

Not surprisingly, finding an almost microscopic wasp that can dig through plastic has led to more questions than answers. “Does drilling plastic corrode the egg-laying apparatus?” Mr. Nickelsburg asked. And why don’t any of the 14 other related species he studied dig through plastic? The answer to this mystery may also help understand the piercing tools used by other insects, such as the mouthparts of disease-carrying mosquitoes, and may even lead to the invention of new human tools.

“I wouldn’t be surprised if wasp-inspired needles became a common piece of standard surgical equipment,” Dr. Cerkvinic said.