Trachymyrmex

Definition

A genus of fungus-growing ants in the family Formicidae, subfamily Myrmicinae, characterized by cultivating symbiotic fungi on vegetable matter as their primary food source. The genus is predominantly tropical, with most species distributed in Central and South America. Workers are typically small to medium-sized with distinctive spiny or tuberculate body sculpturing, reflected in the etymology of the name (Greek trachys, 'rough' or 'spiky' + myrmex, 'ant').

Etymology

Greek trachys (τραχύς, 'rough', 'spiky', or 'jagged') + myrmex (μύρμηξ, 'ant'), referring to the spiny or tuberculate body surface characteristic of many species.

Example

Trachymyrmex septentrionalis, one of the few temperate species in the genus, occurs in the southeastern United States and cultivates fungi on insect frass and other organic debris, unlike its tropical relatives that more commonly use fresh leaf material.

Related Terms

• Atta
• Acromyrmex
• Myrmicinae
• Formicidae
• fungus-growing ant
• leafcutter ant
• myrmecophyte
• symbiotic fungus
• gongylidia

Usage Notes

Distinguished from the more derived leafcutter ant genera Atta and Acromyrmex by generally smaller colony size, less specialized foraging on diverse vegetable substrates rather than exclusively fresh leaves, and morphological differences in mandibular dentition and clypeal structure. Some species formerly placed in Trachymyrmex have been transferred to other genera based on molecular phylogenetic studies; the genus as currently circumscribed remains non-monophyletic in some analyses, with ongoing taxonomic revision. The common name 'fungus-growing ant' applies broadly to Trachymyrmex and related genera in the attine tribe, though 'leafcutter ant' is usually reserved for Atta and Acromyrmex.