The veined wing of the clanger cicada kills bacteria solely through its physical structure — one of the first natural surfaces found to do so. An international team of biophysicists has now come up with a detailed model of how this defence works on the nanoscale. The results are published in the latest issue of the Biophysical Journal1.
The clanger cicada (Psaltoda claripennis) is a locust-like insect whose wings are covered by a vast hexagonal array of 'nanopillars' — blunted spikes on a similar size scale to bacteria (see video, bottom). When a bacterium settles on the wing surface, its cellular membrane sticks to the surface of the nanopillars and stretches into the crevices between them, where it experiences the most strain. If the membrane is soft enough, it ruptures.