Smaller Than a Flake of Pepper': World's Smallest Fly Feeds on Ant Brains

Here's a new one for the record books. A new species of fly has flown in and taken the spot of world's smallest. Euryplatea nanaknihali is so small it is hardly visible with the naked eye even when viewed on a microscope slide.

Although you might think the fly's .4 millimeter size would be its claim to fame, it has another interesting feature. Scientists are pretty sure that the fly is a parasite that in its larval form feasts upon the brains of ants.

Brian Brown with the Natural History Museum of Los Angeles who identified the fly and published the finding in the Annals of the Entomological Society of America, said even ants as small as .5 millimeters in size are probably not safe.

"It had always been assumed that smaller species of ants would be free from attack because it would be physically impossible for flies that are 1-3 millimeters in length to develop in their relatively tiny heads," he said, according to Discovery News. "However, here we show that even the smallest host ants in a host-parasitoid system cannot escape parasitism."

Still, we can't be too quick to judge the fly. It hasn't officially been seen eating ant brains and making a home of the shell. It is hypothesized this is what they do as a close relative of the fly sets up shop the same way.

Live Science has more on the discovery in general:

The type specimen, a female, was picked up by the Thailand Inventory Group for Entomological Research in Kaeng Krachan National Park. The fly is the first of its kind discovered in Asia. [Microscopic Monsters: Gallery of Amazing Bugs]

It has smoky gray wings and the female they discovered has an egg-depositing organ that is pointed to make it easy to lay eggs inside another insect, as a parasitic fly would. While it's not the smallest insect (that title belongs a species of fairy wasp, coming in at 0.14 millimeters in length, about the size of a human egg cell), it is the world's smallest fly.

"When you get really small like that, the environment changes," Brown said. "The viscosity of air starts to become a problem and wind currents are major events. It's amazing how small something can be and still have all of its organs. This is a new frontier, and publishing this tiny fly is basically a challenge to other people to find something smaller," he said.