Scientists have recently discovered a unique type of parasitic wasp that uses a zinc-tipped "drill bit" to pierce into the tough skin of unripe figs.
This drill-bit-like power tool allows such female wasps to lay their eggs in the young fruit, hatching into little wasps that in turn parasitize the larvae of other insects growing inside the figs, according to the study, published in the Journal of Experimental Biology.
"If you look at this structure, it's so beautiful in the sense that it's hard but maneuverable, which is a tough challenge" for a drilling tool, study leader Namrata Gundiah told National Geographic. "These kinds of structures seem to bore so efficiently - that's what is really amazing about this system," she said.
Other insects have exhibited similar adaptations, researchers said, but none like these wasps' appendages, which are seemingly hard as steel and yet thinner than a human hair.
Gundiah and company wondered what made these long appendages, called ovipositor tips, so powerful and efficient.
Via an electron microscope and x-ray detector, Gundiah and her team from the Indian Institute of Science in Bangalore found that the wasp's fruit-drilling and egg-laying tool has teeth enriched with zinc.
Compared to the spoon-shaped tips of a pollinator wasp species (Ceratosolen fusciceps) that lays its eggs in the fig tree's soft flowers, the parasitic wasp (Apocrypta westwoodi grandi) had the aforementioned drill-shaped tip with teeth equipped for boring into the figs' hard shell.
Furthermore, scientists were baffled as to how the thin, zinc-enriched tip could penetrate the skin without breaking.
Gundiah learned that "it can't fracture when it buckles, so it's a very cleverly made design."
"I'm trained in studying steel and other kinds of synthetic materials," she added, "but if you try and apply the same ideas to look at such biological systems, suddenly it opens up so many possibilities of understanding how nature works."