The Sertão Leaf Katydid – a new genus of Pterochrozinae Walker, 1870 (Insecta, Orthoptera) from the Caatinga in Northeastern Brazil

Pterochrozinae are katydids endemic to the Neotropics, commonly known as peacock or leaf katydids. Several areas in the Neotropical are poorly sampled for leaf katydids, and there are few experts working with this group. Most of Pterochrozinae diversity occurs in rainforests, while only a single genus occurs in the savannic Cerrado, and no Pterochrozinae is known for the Caatinga, a semi-arid biome. Here, we present a new Pterochrozinae genus and species, Metallacantha aculeata Engelking, Ghirotto, Fianco, Sobral, Silva-Neto & Mendes gen. and sp. nov., from the Caatinga. The new genus can be distinguished from all other Pterochrozinae by its robust body, enlarged legs, large and flat hind tibial spines, and extremely shortened hind wings. We describe the new genus and species based on three adult females, three adult males, and one nymph from different areas in the Southern Sertanejo Depression of the Caatinga biome, Brazil, also presenting notes on its biology, acoustics, and behavior. Furthermore, we present discussions on the relationship of some Pterochrozinae genera.