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| Metallacantha aculeata Engelking, Ghirotto, Fianco, Sobral, Silva-Neto & Mendes, in Ghirotto, Engelking, Fianco, Martins, Sobral, Silva-Neto et Mendes, 2025. |
Abstract
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.
Keywords: New species, taxonomy, peacock-katydid, South American dry diagonal, Brazilian fauna
Class Insecta Linnaeus, 1758
Order Orthoptera Olivier, 1789
Family Tettigoniidae Krauss, 1902
Subfamily Pterochrozinae Walker, 1870
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| Holotype ♂ of Metallacantha aculeata Engelking, Ghirotto, Fianco, Sobral, Silva-Neto & Mendes gen. et sp. nov. (DZUP), from Santa Teresinha, Bahia, Brazil. A. Habitus in lateral view. B. Body in lateral view. C. Habitus in dorsal view. |
Metallacantha Engelking, Ghirotto, Fianco, Sobral, Silva-Neto & Mendes gen. nov.
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| Live holotype ♂ of Metallacantha aculeata Engelking, Ghirotto, Fianco, Sobral, Silva-Neto & Mendes gen. et sp. nov. (DZUP), from Santa Teresinha, Bahia, Brazil. A–D, F. Different positions. E. Male raising hind leg after being handled. Image not to scale. |
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| Live ♀ of Metallacantha aculeata Engelking, Ghirotto, Fianco, Sobral, Silva-Neto & Mendes gen. et sp. nov. from Anagé, Bahia, Brazil (not deposited). A. In situ, when found. B. Female raising hind leg after being handled. C–D. Habitus of the same female. Image not to scale. |
Diagnosis: The new genus can be differentiated in both sexes from all other known Pterochrozinae by the broad pronotum that is wider than long; the very reduced hind wings not extending more than two tergites in length; the very robust, large legs in relation to the body (the whole third leg being 1.9–2.1× longer than the body); the large, widened and dorsoventrally flattened spines on hind tibiae; the conical spines on the dorsal surface of hind femora. For females, the wide and short subgenital plate that is wider than long also readily differs the new genus from the females of all other Pterochrozinae.
Furthermore, other characteristics that can help differentiate the new genus, but are not exclusive of it, are the short tegmina that do not or barely surpass the end of the abdomen (shared with Asbolomma and Tanusiella); a white band running through the lateral region of the head, the middle of the eyes, the lateral edge of the pronotum, lateral region of the thorax, and dorsal edge of the tegmina (shared with Paracycloptera); the unspotted hind wing (shared with Celidophylla, Cycloptera, Mimetica, Paracycloptera, Typophyllum, and Roxelana); hind femora with two ventral rows of conical spines (Metallacantha gen. nov. presents rows both in the dorsal and ventral surfaces of the hind femora, while other genera, such as Paracycloptera, bear only ventral rows); fore wings with R and M veins not conjoined in lateral view, running parallel and very closely apart, side by side (shared with several other genera such as Paracycloptera).
Etymology: Taken in reference to the large and wide spines with a metallic iridescent shine present on the metatibiae that readily distinguishes the new genus from other Pterochrozinae genera. The name is derived from the Latin words “metallicus” (= metallic) and “acanthus” (= spines). The gender is feminine.
Metallacantha aculeata
Engelking, Ghirotto, Fianco, Sobral, Silva-Neto & Mendes gen. et sp. nov.
Etymology: From Latin aculeata, meaning “spiny” in reference to the many distinct spines of this katydid, especially the enlarged ones on its hind legs.
Victor M. Ghirotto, Phillip W. Engelking, Marcos Fianco, Samuel M. Martins, Rafael Sobral, Alberto M. da Silva-Neto and Diego M. de Mello Mendes. 2025. The Sertão Leaf Katydid – A New Genus of Pterochrozinae Walker, 1870 (Insecta, Orthoptera) from the Caatinga in Northeastern Brazil. European Journal of Taxonomy. 1007(1); 279-310. DOI: doi.org/10.5852/ejt.2025.1007.3013
