Studies on an Enigmatic Blepharidatta Wheeler Population (Hymenoptera: Formicidae) from the Brazilian Caatinga

Blepharidatta is a rare Neotropical ant genus formed by predatory species whose small colonies nest in soil or leaf-litter. A population of Blepharidatta that presents affinities with Blepharidatta conops Kempf was found in the Caatinga biome, at the "Reserva Particular do Patrimonio Natural Serra das Almas" (RPPNSA), in Crateus (State of Ceara, Brazil). The aim of our study was to obtain data on the nest architecture, size and composition of colonies, foraging behavior, and female castes morphology for this newly found population, and to compare it with other Blepharidatta species, particularly with B. conops. The results show that Blepharidatta sp. and B. conops share key features of their biology such as their basic nest architecture, diet and foraging behavior, and the presence of a single ergatoid queen with a phragmotic head. However, marked differences were also found in head and mesosoma morphology of the queen, nest architecture, colony size, and queen location in the nest. Two alternative hypotheses are presented. The newly found Blepharidatta population represents a new species, possibly endemic to the Caatinga biome or it represents an extreme of the phenotypic variations observed among the populations forming B. conops.