Burns, John M., Janzen, Daniel H., Hallwachs, Winnie D., Hajibabaei, Mehrdad and Hebert, Paul D. N.
Fades can fool taxonomists as well as predators. Neoxeniades motion (Codman)-one of the many, large neotropical skippers in the major mimicry group that includes all the cryptic species of the Astraptes fidget-at-or complex is misclassified. It really relates to a species of Rhinthon that differs greatly from it in facies and size. In both sexes, the genitalia of Rhinthon motion, new combination, and R. once (Plotz) are nearly identical, even down to a peculiar titillator on the left side of the aedeagus of the male. Males also share a secondary sex character along vein 2A of the forewing. DNA barcodes unite R. once and R. motion in a tight, two-taxon cluster: their sequence divergence is about 3.5%. Caterpillars of the two species are alike but distinguishable, and, in Costa Rica, they have been found feeding on various native species of Marantaceae-seven of which are the same and also on one and the same introduced species of Cannaceae (these are closely related plant families grouped in the order Zingiberales). Because Rhinthon is widespread and relatively speciose in Central and South America, it can no longer be considered a genus primarily of the Greater Antilles. DNA barcodes, which are useful for identifying known species and for indicating possible cryptic species, are useful in this study (in combination with other, more traditional, taxonomic characters) for pulling suppo sedly unrelated species together into the same genus.