LAUSR

Abstract Amydetinae is an exclusively Neotropical subfamily of fireflies, distributed among three genera: Amydetes Illiger, 1807, Magnoculus McDermott, 1964, and Memoan Silveira & Mermudes, 2013. Here, we describe three new species of Amydetinae: two belonging to Amydetes (A.alexisp. nov. and A.marolaesp. nov.) and one to the previously monotypic Memoan (Me.conanisp. nov.). All three species are known only from the Atlantic Forest in southeastern Brazil. Endoskeletal structures of Memoan and Magnoculus species are described and compared with those of Amydetes for the first time. After studying the type material, Photinusfruhstorferi Pic, 1942 is transferred to Memoan, generating Memoanfruhstorfericomb. nov., and Me.ciceroi Silveira & Mermudes, 2013 syn. nov. is placed as a junior synonym. We also redescribe Magnoculusobscurus Olivier, 1885 and compare it to other species of genus and to other amydetine taxa to identify potential new diagnostic traits for the Amydetinae and its constituting genera. We provide an updated diagnosis for Memoan, illustrations for all four species, and a distribution map for the three new species, as well as a key to adult males of the three amydetine genera, and an updated key to Amydetes species based on males.