Polyplectropus annulicornis

Chamorro, Maria Lourdes & Holzenthal, Ralph W., 2010, 2582, Zootaxa 2582, pp. 1-252 : 50-52

Polyplectropus annulicornis species group, newly recognized

The P. annulicornis species group is established for 11 species, 8 here described as new, sharing the characteristics outlined below. The species-level phylogeny suggested a sister relationship between P. paysandu Angrisano and the clade containing the remaining 10 species of the group ( P. annulicornis group sensu stricto). Polyplectropus paysandu from Uruguay is included in the P. annulicornis group even though it possesses several unique, autapomorphic characteristics not shared with other species. Future collecting in southern South America may reveal additional species possessing characters currently only found in P. paysandu , which may warrant the creation of another species group. However, in this study the definition of the P. annulicornis group is broadened to include P. paysandu instead of establishing a monobasic P. paysandu species group. The P. annulicornis group is characterized by the combined possession of the following traits:

1. Presence of an elongate, cylindrical dorsolateral process of the preanal appendage (absent in P. paysandu ) ( Figs. 32A–C);

2. Mesoventral process of preanal appendage with digitate dorsal projection (absent in P. paysandu ) ( Figs. 32A–C);

3. Intermediate appendage digitate bearing apical setae (upturned and apically sclerotized in P. paysandu ) ( Figs. 32A–C);

4. Inferior appendage with pandurate or oblong dorsal branches, generally directed posterad or posterodorsad and digitate ventral branch; dorsal branch at least 2x as long as the ventral branch, usually no more than 3x longer;

5. Anterior base of inferior appendage anteriorly bilobed;

6. Phallic endothecal membrane with embedded sclerotized spines.

Several species in the group are dark-brown, appearing almost black. Dark-brown species may have slight grey markings on the forewings. Other species are brown and have greyish mottling on the wings. Additional species have both color patterns (i.e., P. matatlanticus ).

Most species in the group are quite similar to one another in the shapes of the preanal and intermediate appendages and to a lesser extent in the shape of the inferior appendage. The ventral branch of the inferior appendage varies among species in the group, particularly in the presence or absence of dorsal projections and in the shape of the apex. Additionally, the dorsal lobe of the mesoventral process of the preanal appendage varies between species in length and at times it is a diagnostically important character. However, in P. hystricosus this character varies within the species. For most species, differences among the species are characterized by the shape of the endothecal spines, visible only when the genitalia have been cleared.