Argentine ant (Linepithema humile)

Invasive

Argentine ants are found in the cooler and temperate parts of Australia (including Tasmania), but not in Queensland or the Northern Territory. They are found in urban and disturbed areas, and can be a pest in horticulture.

Argentine ants will often build their nests in wall cavities but outside will build their shallow nests under leaf litter, rocks, logs and pavers.

Argentine ants are one of the worst invasive species capable of developing super-colonies that can completely dominant an area. They are multi-queen, multi-nest colonies, with up to 1 queen per 100 workers. The nest expands through budding, where males and females will mate within the parent nest and then leave with a small number of workers to create a new nest nearby. These nests are interconnected and the resulting supercolonies can cover thousands of square kilometres over time.

Colour: Mid-brown

Size: 2.5 – 3.0 mm (workers are of variable size)

Nodes on petiole: 1

Argentine ants have a strong preference for sugars, and are big ‘farmers’ of sap feeding insects, from which they harvest honeydew. However, they show a noticeable increase in protein intake during the warmer months in response to the food requirements to support increased production of young.

• In areas of significant infestation, massive numbers of ants and brood will be found on the soil surface under leaf litter, sheeting, rocks, pavers, etc
• They can produce extensive foraging trails over many tens of metres, often 10 or more rows of ants wide.
• They have a high level of nest mobility, frequently moving the nest in response to the environmental conditions (heat & moisture)
• They can often invade buildings in large numbers looking for food or when moving nest

Argentine ants do not sting but will bite (mild)

Argentine ants maintain the highly productive supercolony by executing the least productive queens each spring. Up to 90% of queens are executed by workers to be replaced by younger more productive queens as the season develops.