Meranoplus nanus

Boudinot, B. E. & B. L. Fisher, 2013, A taxonomic revision of the Meranoplus F. Smith of Madagascar (Hymenoptera: Formicidae: Myrmicinae) with keys to species and diagnosis of the males., Zootaxa 3635 (4), pp. 301-339 : 312

Diagnosis of the M. nanus species group (worker)

The Meranoplus nanus group ( Bolton 1981) is herein expanded to six species, with the inclusion of M. radamae , M. cryptomys , and M. sylvarius , in addition to the three Afrotropical species M. clypeatus Bernard, 1953 , M. inermis Emery, 1895 , and M. nanus Emery, 1895 . Two characters from Bolton’s ( 1981) diagnosis of the M. nanus group must be expanded: postpetiole squamiform to nodiform, rather than squamiform to anteroposteriorly compressed; and propodeal spines absent, short, or well-developed. Otherwise characters used by Bolton (1981) to diagnose the M. nanus group stand, and six additional characters are provided in the species group diagnosis. Although a few males of the African M. nanus group species have been examined for this study, a diagnosis of males or gynes of this species group would be premature until a larger sample size is available.

The following characters set the species of the M. nanus group apart among the Afrotropical species-group schemata of Bolton (1981) and the Oriential species from Schödl (1998, 1999); unique character states for the M. nanus group among the Afrotropical and Oriental species are italicized:

1. Four mandibular teeth. 2. Promesonotum broader than long, with length measured from apices of anterolateral to posterolateral denticles. 3. Promesonotal shield overhanging pleurae laterally. 4. Promesonotal shield overhanging propodeum posteriorly. 5. Promesonotal-propodeal suture distinct and strongly arched medially. 6. Propodeal spines absent through well-developed. 7. Petiole narrow-cuneate; without spines or teeth dorsally. 8. Anterior and posterior faces of petiole smooth and shining. 9. Lateral face of petiole with one or two longitudinal curvaceous carinae which extend posteriorly from above the spiracle and join with the posterior collar. 10. Postpetiole squamiform to nodiform; never cuboid nor with a posteriorly-directed process. 11. Fourth abdominal sclerites with stellate setiferous punctures.