Workers are polymorphic, from small garden workers to much larger foragers and defenders.
Fine-art photographic collection
Acromyrmex ambiguus
A southern leafcutter that turns harvested vegetation into a cultivated fungus crop.
About this species
Acromyrmex ambiguusEmery, 1888
Information reviewed15 July 2026
Acromyrmex ambiguus is a leafcutting ant of southern South America. Workers cut plant material, process it inside the nest and use it to cultivate the fungus on which the colony depends.
Taxonomy
Animalia · Arthropoda · Insecta · Hymenoptera · Formicidae · Acromyrmex
Source checked · checked 2026-07-15
Southern South AmericaBroad documented localities — not a complete range map.
Documented chiefly from Uruguay, southern Brazil, Paraguay and neighbouring parts of Argentina.
Grassland, pasture, agricultural landscapes and other warm open habitats with soil suitable for fungus chambers.
Foraging varies with temperature and humidity; columns may become most conspicuous during cooler parts of the day.
Workers harvest leaves and other vegetation as substrate for the colony’s cultivated fungus.
Colonies are organised around fungus gardens tended by workers of different sizes; a reproductive queen supplies the brood.
What makes this species remarkable?
The leaves are not eaten directly: they are prepared as growing medium for a symbiotic fungus.
Workers separate tasks such as cutting, carrying, garden care and defence partly by body size.
Fungus gardens must be kept within a narrow range of humidity and cleanliness.