The colorful genus Erotylina Curran was proposed to include a group of species originally described in Erotylus Fabricius but differing by the lack of three longitudinal carinae on the tibiae. The taxonomy of Erotylina is mostly based on coloration while information on mouthparts, thorax, male and female abdominal terminalia remain unknown. In addition, little is known about the factors underlying coloration in Erotylina and Erotylidae in general. Here we redescribe the type species of Erotylina, Erotylus leopardus Lacordaire providing the first descriptions of several morphological structures, and new data on its geographical distribution. Erotylus nicaraguae Crotch is proposed as new junior synonymy of E. leoparda. Lectotypes are designated for the following species: Erotylus leopardus Lacordaire, Erotylus nicaraguae Crotch and Erotylus confluens Crotch. Based on the geographical records, specimen labels, literature and online environmental databases, we show that E. leoparda includes two discrete morphs distributed across a latitudinal gradient, with intermediate and continuous variations distributed across altitudinal and temperature gradients. The present study sheds light on the taxonomy of Erotylina and provides the first clearest evidence of a relation between coloration, latitude, altitude, temperature variations and the distributional patterns of a taxon in Erotylidae.