This could make the African country the “ground zero” for a dominant ant species with high global invasion potential, suggests the scientist who discovered the species, Dr Daniela Magdalena Sorger.
A supercolony emerges when individual nests with their own queens join together in a network. The number of associated colonies can spread out over a very wide area, with the largest supercolony discovered in this region of Ethiopia measuring 38km across, said Dr Sorger, a post doctoral researcher with the North Carolina Museum of Natural Sciences.
The ant species involved is Lepisiota canescens and it becomes one of only about 20 ant species capable of forming supercolonies. This however makes it a highly undesirable invasive species, able to either displace or overwhelm native ants before having them for dinner.
Their invasive potential was seen last year when the ants were discovered in Darwin Port in northern Australia. A quarantine area was immediately set up to poison the ants but they quickly occupied two other locations outside the biosecurity ring.
The way the ant comes to dominate territory is reminiscent of an invasive species, said Dr Sorger, who is lead author of a research report published in Insectes Sociaux.
“The species we found in Ethiopia may have a high potential of becoming a globally invasive species,” she said. This species is “exploding in numbers” into land broken up by human disturbance such as agriculture or road and urban construction.
Invaders such as this often spread from region to region in the company of humans, carried in plant material or luggage. “All it takes is one pregnant queen. That’s how the fire ants started,” said Dr Sorger.
The ants that come together to form a supercolony are not related as might have been assumed. The researchers determined these ants were genetically diverse.