“Paraguay” (s. loc.) (MCSN, NHMB). Literature records: Pte. Hayes, “Paraguay” (s. loc.) (Emery 1905, Fowler 1985). NEW STATUS .
Atta (Acromyrmex) pubescens Emery 1905: 51. [w syntypes examined, MCSN , MHNG ; Paraguay ( Balzán )] .
Acromyrmex lundi var. pubescens (Emery) . Bruch 1914: 216.
Acromyrmex lundi st. pubescens (Emery) . Santschi 1916: 386.
Acromyrmex lundi pubescens (Emery) . Kempf 1972: 13.
Fowler (1985a) described the differing habitat associations of Acromyrmex lundii and Acromyrmex pubescens , noting that the former is found in open habitats and the latter in the patchy forest “islands” that occur in the chaco savannah. The two forms are sympatric and structurally similar, both bearing elongate lateral pronotal spines that are longer than the mesonotal spines. However, these ants are distinguishable in pubescence. Much of the integument of A. pubescens is covered in a dense decumbent pubescence while the integument of A. lundi is relatively bare. This difference is easiest to diagnose on the mesopleura, as the mesopleural pubescence of A. pubescens comprises overlapping hairs, while that of A. lundii is sparse and the hairs non-overlapping. Given the ecological and morphological differences in sympatry between these two forms, I elevate A. pubescens to species here.
