Argentine Ant

Linepithema humile

Argentine Ant

Argentine ant (Eli Sarnat, USDA APHIS ITP, Antweb.org)

Argentine Ant

Argentine ant bait trail (Joseph LaForest, University of Georgia, Bugwood.org)

Argentine Ant

Argentine ant bait trail (Joseph LaForest, University of Georgia, Bugwood.org)

Identification

  • light to dark brown
  • 1/8 inch long
  • 12-semented antennae without a club
  • single node with sharp peak distinguishes from odorous house ant

Nesting Habits

  • outdoors: in soil, under rocks and logs; potted plants; landscaping mulch; concrete slabs; crawlspaces; piles of wood or organic matter; exterior walls behind brick 
  • indoors: in wall voids, under carpets and in basements, usually near moisture (sinks, tubs, leaks, etc.)
  • not a common pest in most of Utah

Diet

  • honeydew produced by aphids and other insects
  • feed on a wide variety of foods, but are partial to sweets

Significance

  • form supercolonies which encompass many individual colonies
  • invade buildings when conditions outside are too wet or too dry
  • may contaminate food

IPM Recommendations

  • Locate and destroy all nests. (Follow ants back from their food source.)
  • Trim back shrubs and trees that come into contact with the building.
  • Seal all potential ant entrances.
  • Use insecticidal baits, especially during winter – early spring when populations are smaller.
  • Control is difficult; consider hiring a pest management professional to manage Argentine ants.

Additional Resources:

IPM for Ants: Integrated Pest Management in Sensitive Environments (University of Nebraska-Lincoln Extension)