Criteria of differentiation between the females of Morpho marcus (Schaller, 1785) and of M. eugenia Deyrolle, 1860 (Lepidoptera, Nymphalidae)

The females of Morpho marcus (Schaller, 1785) [= adonis (Cramer, 1779)] and M. eugenia Deyrolle, 1860, have never been separated with certainty. The present authors have evaluated material from diverse public and private sources constituting a heterogeneous collection, within which identification of individual specimens was uncertain. Separation of the two species, each with two subspecies, is proposed according to analytical results of three types of measurement relating to wing shape, wing pattern, and the relative disposition of the ocelli. Results of these three parameters are based on discriminant analysis for linear measurements and on parcimonius calculations for visual estimations. Specimens of gynandromorphs of both species as well as a pair of M. eugenia captured in copula were used for confirmation. Genitalia of the four taxa are illustrated. In conclusion, a simple method of identification is proposed as well as a revision of the material studied.