Complete Excavation and Mapping of a Texas Leafcutting Ant Nest

A medium-sized nest of the Texas leafcutting ant, Atta texana (Buckley), in northern Louisiana was excavated completely, and a three-dimensional model of its external and subterranean features was constructed. In total, 97 fungus gardens, 27 dormancy cavities, and 45 detritus cavities were located. At the lower center of the funnel-shaped nest was a large central cavity, which in winter functions as a domicile for the colony and where the alate brood is reared. Vertical tunnels, possibly as deep as 32 m, may serve as wells leading to the water table. Winter mean annual temperatures within the central cavity may limit the northern geographical range of A. texana to =33" N latitude. The inquilines Attaphila fungicola Wheeler, Pholeomyia comans Sabrosky, Ceuthophilus sp., Lobopoda subcuneatus Campbell, Geomysaprinus nr. formicus (Hinton), species of Aleocharinae, and a species of Annelida were seen in nest cavities and galleries.