Linepithema humile (Argentine ant).
Abstract L. humile is one of the most invasive and problematic ant species in the world according to the Invasive Species Specialist Group (www.issg.org/database). Native to South America, it has spread worldwide in areas with Mediterranean-type climates usually associated with disturbed habitats as a result of human commercial activities. Its capacity to tolerate a wide range of abiotic conditions, its generalist dietary requirements and its unicolonial organization, which lead to the formation of large supercolonies, allow the species to spread easily and occupy a wide range of areas. In these areas, L. humile has impacted native ant faunas leading to changes in arthropod communities, ant-vertebrate interactions and ant-plant relationships. Its presence has also had economic effects, such as damage to infrastructure, and negative effects on crops and plantations due to its mutualistic interactions with hemipterans, which can affect the growth and production of the host plant.