Argentine Ant

Linepithema humile is one of the most successful invasive species in the world. Native to the Paraná River basin in Argentina, the species has established invasive populations across the Mediterranean, California, Japan, Hawaii, Australia, and South Africa over the past 150 years. The species' extraordinary feature is the formation of 'super-colonies' — vast inter-cooperating networks of nests that share chemical recognition and treat each other as nestmates. The European super-colony spans 6,000 km from northern Italy along the Mediterranean coast through Spain to Portugal — a single continuous network. The Californian super-colony spans most of the state. The Japanese super-colony covers the Honshu Island Pacific coast. Argentine ants from any of these regions can be transferred to colonies on other continents and instantly merge as if they were siblings — chemical recognition is consistent across the global super-colony. This makes the Argentine ant the largest cooperative animal society ever documented. Within the super-colony, there are no territorial disputes; the ants instead direct all their aggression toward other ant species, displacing native ants from invaded ecosystems. The species causes major agricultural damage by tending honeydew-producing pest insects (aphids, scale insects).