A New Genus and Two New Species of Fireflies from South America (Lampyridae: Lampyrinae: Photinini)

Abstract

Lampyridae taxonomy has traditionally relied on a few characters now deemed to be highly homoplastic, and their classification—especially at the genus level—is yet to be consolidated based on rigorous phylogenetic analyses. Recent studies highlighted the value of genitalic trait variation in the evolution in Lampyridae, particularly for the rich and poorly known South American Photinini fauna. Here, we describe a new genus, with a new species from the Cerrado and another one from the Atlantic Forest. Phylogenetic analyses based on Bayesian and Maximum Parsimony approaches recovered these two species as sister to each other, which we place here in Zoiudo gen. nov. Males of this new lineage of fireflies are overall strikingly similar to Photinus Laporte 1833, but can be readily distinguished by traits heretofore neglected, including the structure of tibial spurs and many genitalic traits. Instead, Zoiudo gen. nov. is strongly supported as sister to Ybytyramoan Silveira and Mermudes, 2014, supported by eight synapomorphies, the most conspicuous being the sternum VIII with lateral margins divergent up to basal 1/5, then convergent posteriorly, and the rudimentary ventral plate of phallus. Our study confirms the value of extensive character and taxon sampling towards a revised classification of Photinini taxa and highlights the need for a continued sampling and protection of South American biomes.