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

Abstract

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 the Cerrado species, Blepharidatta conops Kempf, was found in the Caatinga biome, at the “Reserva Particular do Patrimônio Natural Serra das Almas” (RPPNSA), in Crateús (State of Ceará, northeastern Brazil). The aim of our study was to obtain information on nest architecture, size and composition of colonies, foraging behavior, and female castes morphology in this newly found population, and to compare it with other Blepharidatta species, particularly B. conops. The results show that Blepharidatta sp. and B. conops share key features of their biology like basic nest architecture, diet and foraging behavior, monogyny, and ergatoid queens with a phragmotic head. However, marked differences were also found in queen head and mesosoma morphology, nest architecture, colony size, and queen location in the nest. Two mutually exclusive hypotheses are discussed. The Blepharidatta population found in the RPPNSA would represent a new species, possibly endemic to the Caatinga biome or this population would represent one extreme of the phenotypic variations observed in populations forming B. conops species.

Keywords

• northeastern Brazil
• semi-arid environment
• ants
• Blepharidattini
• ergatoid queen