Wing pattern morphology of three closely related Melitaea (Lepidoptera, Nymphalidae) species reveals highly inaccurate external morphology-based species identification

Abstract

Abstract. Wing morphology of the three closely related species of Melitaea -M. athalia (Rottemburg, 1775), M. aurelia (Nickerl, 1850) and M. britomartis Assmann, 1847 -co-occurring in the Balkans (SE Europe) was investigated in detail through visual inspection, morphometric analysis and multivariate statistical analysis. Results are compared to recent phylogenetic studies, searching for concordant patterns and discrepancies between the two approaches. The morphology of the genitalic structures is also compared with the results of the other two approaches. The main conclusions are as follows: (1) small albeit significant differences in wing morphology exist among the three species and (2) while the structure of male genitalia and phylogenetic position of the three species are concordant, they are (3) in discordance with the wing morphology. The present study represents another example where identification based on external morphology would lead to highly unreliable determinations, hence identification based on phylogenetic studies and/or genitalia is strongly recommended not only for the three studied species but also more broadly within the genus. Furthermore, we show that some of the characters generally used in the identification of these three Melitaea species should be avoided in future.

On two recently published books on the genus Colias Fabricius, 1807 (Lepidoptera: Pieridae)

“…In the case of "subspecies" whose borders are definitely intergrading, to rely on the wing pattern only is extremely naïve. It has been repeatedly demonstrated for many groups of Lepidoptera that wing pattern characters are quite unreliable for differentiation of similar species in the genera considered as very variable, like Colias (the most recent example -similar species of the genus Melitaea [Jugovic, Koren, 2014]).…”

A synonymic list of names associated with western Palaearctic Melitaea phoebe (Denis & Schiffermüller, 1775) species group taxa (M. phoebe; M. punica Oberthür, 1876; M. ornata Christoph, 1893) (Lepidoptera, Nymphalidae)

“…Adults are invariably orangebrown on the upper surface, with a series of black lines and other markings; several Melitaea species are notoriously difficult to separate using wing morphology due to their similarity in appearance (Jugovic and Koren 2014).…”