Résumé
ABSTRACT The sharpshooter genus Balacha Melichar, 1926 includes nine species and is distributed in southeastern and southern Brazil, Uruguay, Paraguay, and Argentina. All species of Balacha use only members of the genus Eryngium (Apiaceae) as host plants, except for a recently described species that is associated with Actinocephalus polyanthus (Eriocaulaceae). Here we describe and illustrate an additional species, B. caledonia sp. nov., from an alpine field in Nova Friburgo, state of Rio de Janeiro, southeastern Brazil, which is also associated with Eryngium. Among the known species of the genus, the new taxon is morphologically most similar to B. caparao Takiya & Mejdalani, 2004, but can be easily distinguished by the shaft of the aedeagus, which has a dorsal lobe on the basal half and no ventroapical lobe, and the female sternite VII with the borders of the posterior emargination sinuous. Our studies indicate that the type locality of the new species and its surrounding Atlantic Forest area in Nova Friburgo harbor an interesting and diverse but still poorly known sharpshooter fauna, including the recently discovered Paratubana auromarginata Côrte et al., 2021 (also from Eryngium) and Cavichiana caelivittata Mejdalani et al., 2023 (from bromeliads).