Rare Ants Rediscovered That Grow Fungus With Insect Poo

This good-looking creature is a fungus-farming ant by the name of Mycetophylax asper, which researchers recently re-discovered in a Brazilian forest. Don Parsons courtesy of Jeffrey Sosa-Calvo

Ants invented agriculture long before humans, learning how to grow fungus on bits of leaves and other detritus, fungus which provided them with food. One of the more primitive fungus-farmers, known as Mycetophylax asper, was discovered in 1887, but has barely been seen since. Scientists weren't even sure it was still around.

But researchers have re-discovered it in a park in Brazil known as the Chapecó National Forest in huge numbers, as described in a study published in PLOS ONE. After being tipped off by a colleague named Rogeria Silva, an entomologist at the Museu Paraense Emílio Goeldi, the study authors traveled to the park to see for themselves. There, they collected 21 colonies of the creatures, some of which now live in the lab of Ted Schultz, a fungus-farming ant specialist at the Smithsonian Institution in Washington D.C. (But don't worry: The researchers say they only collected a small number of the ants from one location, and there are still large numbers of the species left in the forest.)

The ant has a number of bizarre and unique features. For one, it grows fungus on bits of detritus and frass, a technical term for insect poop. Physically, it is covered in erect hairs, which is unique for its genus, the taxonomic group above species, says study first author Jeffrey Sosa-Calvo, a postdoctoral researcher at Arizona State University. It also has a distinctive groove in its head called a "scrobe" that allows it to fold its antennae back, and a pronounced protuberance on its thorax (the middle body part) known as a turbercle.

Genetic analysis of the ant showed that it is one of the more primitive fungus-farmers, and further study of its relationship to the fungus it cultivates should help researchers better understand how these creatures evolved, Schultz says. The team's work also showed that the ant had been placed in the wrong genus, and the team's analysis led them to completely re-categorize its place in the fungus-farming world. (It also led to it being renamed from Mycetosoritis asper to Mycetophylax asper.)

"The more we learn about how farming evolved in ants, I think it will have implications for [improving] human agriculture," Schultz says. The ants are, after all, the original sustainable farmers, and they've been up to it for 60 million years, he says.