Smallest Free-Living Insect Confirmed: Meet the Beetle

It's a small world, after all. A featherwing beetle named Scydosella musawasensis has just been confirmed, with new measurements, as the world-record title holder for the smallest recorded free-living insect.

That's according to Lomonosov Moscow State University scientist Alexey Polilov, who took new measurements of the tiny bug. Polilov writes in the journal Zookeys that S. musawasensis measured just 325 micrometers (0.325 millimeters, 0.0127 inches).

S. musawasensis is yellowish-brown, with a stretched oval body and 10-segmented antennae, and it's been down the measurement road before.

It was first described in 1999, when a specimen measured at 300 micrometers (0.30 millimeters, 0.0118 inches) took the "smallest" crown. But those readings, Polilov writes, were of insects embedded in preparations for microscopy study, making precise measurements difficult.

New measurements, then, were needed to accurately confirm S. musawasensis's state of extreme tininess. Polilov collected 85 new samples of the insect from Colombia and then took new measurements of his own, using a scanning electron microscope and specialized software.

When all of the measurements were in, "the smallest beetle and the smallest known free-living insect has a body length of 325 µm," Polilov wrote.

The "free-living" part of the beetle's title differentiates it from parasitic insects, the smallest of which, the male Dicopomorpha eschmepterigis , is understood to be the smallest parasitoid, at 139 micrometers.

From Discovery News