Pacific Pests, Pathogens and Weeds - Online edition

Pacific Pests, Pathogens, Weeds & Pesticides

Yellow crazy ant (364)

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  • Worldwide distribution. Common in Pacific island countries. Favours disturbed agriculture, forest areas, houses. Characteristic long antennae and quick jerky movements. Does not sting; sprays formic acid. Among world's 100 worse invasive species.
  • Nests on ground or in trees; forms super-colonies (10-150ha), up to 20 million workers/ha. A scavenger. Eats seeds, other insects, molluscs, smaller vertebrates, and honeydew. Forages day and night.
  • Direct damage: vegetable seeds; loss of biodiversity; indirectly by defending aphids, mealybugs, scales and whiteflies from natural enemies.
  • Tramp ant. Spread by 'budding' - queens and workers leave the colony; spread via international trade.
  • Biosecurity: requires risk assessments, regulations preventing introduction, protocols in case of breaches, and ability to make rapid response. Pacific Ant Prevention Plan available (IUCN/SSC Invasive Specialist Group).
  • Cultural control: hot water at 47°C kills ants; over 49°C kills plants.
  • Chemical control: use (i) stomach poisons (fipronil, Amdro®, borax), (ii) growth regulators (methoprene, pyriproxyfen), (iii) nerve poisons (bifenthrin, fipronil, imidacloprid). See (
Common Name

Yellow crazy ant, long-legged ant

Scientific Name

Anoplolepis gracilipes

AUTHOR Grahame Jackson
Information from CABI Anoplolepis gracilipes (yellow crazy ant) (2018) Invasive Species Compendium. (; and Pacific Invasive Ant Toolkit. (; and Anoplolepis gracilipes. AntWiki. (; and AntWeb. (; and from Anoplolepis gracilipes (2018). Global Invasive Species Database.( Photos 1-3 Ken Walker (2005) Yellow crazy ant (Anoplolepis gracilipes): PaDIL - ( Photo 4 Amy Carmichael (2005) Yellow crazy ant (Anoplolepis gracilipes). Queensland University of Technology. PaDIL - (

Produced with support from the Australian Centre for International Agricultural Research under project HORT/2016/185: Responding to emerging pest and disease threats to horticulture in the Pacific islands, implemented by the University of Queensland and the Secretariat of the Pacific Community.

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