Evolutionary gain of male secondary sexual structures in the widespread Neotropical montane genus Lathecla (Lepidoptera, Lycaenidae, Eumaeini)

Abstract

Lathecla is a widespread, primarily montane, Neotropical genus. It consists of seven species that have a relatively uniform adult wing pattern coupled with a diverse set of male secondary sexual structures. Taxonomically, we describe five species Lathecla mitzi Robbins new species, Lathecla fernandezi Robbins & Busby new species, Lathecla vichai Robbins & Busby new species, Lathecla carolyna Busby new species and Lathecla winnie Robbins & Busby new species and remove one name from synonymy Thecla mimula Draudt, revised status. Evidence is presented for transferring Lathecla from the Thestius Section of the Eumaeini to the Micandra section, next to Podanotum. Topology of an inferred phylogenetic tree for Lathecla is stable when male secondary sexual characters are omitted or under a variety of implied weighting options. A scent patch on the cubital vein of the dorsal surface of the forewing is unique to Lathecla and evolved (and was not lost) in the ancestor of a four-species lineage. Its sister lineage contains two species. A scent patch on the ventral surface of the forewing evolved (and was not lost) in the ancestor of a six-species lineage in Lathecla. Its sister lineage contains one species. These results, along with previous data, show the viability for the Eumaeini of the hypothesis that the evolutionary gain of a male secondary sexual organ increases the rate of species diversification.