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We describe the predatory interactions between Neivamyrmex texanus (Watkins 1972) and the fungal-farming ant Trachymyrmex septentrionalis (McCook 1881) in central Texas and between Nomamyrmex esenbeckii (Westwood 1842) and its numerous species of prey, including the leaf-cutter ant Atta texana (Buckley 1860), in southern Texas. Species of the genus Neivamyrmex are generalist social insect predators that attack termites and a wide variety of species of ants, whereas Nomamyrmex are well-known specialists that evolved heavy body armor and fierce column raiding that is crucial for predation on the well-defended nests of the leaf-cutting ants in the genera Atta and Acromyrmex. We observed a marked difference in the response to the predation by army ants between the raids by Neivamyrmex on T. septentrionalis compared to those by Nomamyrmex on the colonies of A. texana. Our observations suggest that there are two distinct defense adaptations to the army ants. They include either making a stand and fighting, or absconding with the brood and garden, or so-called flight. [ABSTRACT FROM AUTHOR]

Mycetosoritis hartmanni is a rarely collected fungus-farming ant of North America. We describe life history and nest architecture for a M. hartmanni population in central Texas, USA. Colonies are monogynous with typically less than 100 workers (average 47.6 workers, maximum 148 workers). Nests occur always in sand and have a uniform architecture with 1–3 underground garden chambers arranged along a vertical tunnel, with the deepest gardens 50–70 cm deep. Foragers are active primarily between April and October. After reduced activity between November and February, egg laying by queens resumes in April, and the first worker pupae develop in early June. Reproductive females and males are reared primarily in July and August, with proportionally more females produced early in summer (protogyny). Mating flights and founding of new nests by mated females occur in late June to August, but may extend through September. For a cohort of 150 established nests (nests that had survived at least one year after nest founding), the estimated mortality rate was 0.41–0.53, the estimated average lifespan for these nests was 1.9–2.5 years, and the longest-living nests were observed to live for 6 years. These life-history parameters for M. hartmanni in central Texas are consistent with information from additional M. hartmanni nests observed throughout the range of this species from eastern Louisiana to southern Texas. Throughout its range in the USA, M. hartmanni can be locally very abundant in sun-exposed, sandy soil. Abundance of M. hartmanni seems so far relatively unaffected by invasive fire ants, and at present M. hartmanni does not appear to be an endangered species. [ABSTRACT FROM AUTHOR]