Clemnius, Fery, 2017

Fery, Hans, 2017, A new classification of the tribe Hygrotini Portevin, 1929 (Coleoptera: Dytiscidae: Hydroporinae), Zootaxa 4317 (3), pp. 499-529 : 503

Genus Clemnius n. gen.

Type species: Hyphydrus decoratus Gyllenhal, 1810 : XVI, by present designation.

The new genus Clemnius n. gen. includes eight described species distributed in the Nearctic (including the north of MeXico, sometimes treated as Neotropical) and in the Palaearctic zoogeographical region ( Fig. 2 and Table 1).

Diagnosis. In the new classification Clemnius n. gen. is one of two genera of the tribe Hygrotini . All species of this and the second genus Hygrotus have two carinae in each antennal cavity (see Figs 4–6 ), a unique character among the entire subfamily Hydroporinae . The new genus—which corresponds to clade A in Fig. 1 —is a heterogeneous assembly of relatively small species with different morphological characters. It is subdivided into two sister-clades each treated as a subgenus: Cyclopius n. subgen. and Clemnius s. str. n. subgen. (see Fig. 2 ).

Figures

FIGURE 1. Phylogeny of Hygrotini, modified from Villastrigo et al. (in press). Numbers above nodes are bootstrap support values. Note that here the former generic and subgeneric names are still used.

FIGURE 2. Dendrogram showing the new classification of Hygrotini. A number of species without molecular data (no voucher number) have been inserted near morphologically similar species with molecular data. Acronyms refer to biogeographical regions.

FIGURES 3 – 4. Antennal cavities of: (3) Hydroporus dorsalis (Hydroporini) and (4) Hygrotus (Leptolambus) lagari (Fery, 1992) (a: carina delimiting capsule for scape; b: fronto-lateral border of clypeus; c: second carina).

FIGURES 5 – 6. SEM micrographs with details of head and antennal cavities of: (5) Hygrotus (Leptolambus) impressopunctatus (frontal view) and (6) Hygrotus (s. str.) inaequalis (oblique ventral view) (a, b and c as in Figs 3 – 4; d: clypeal stripe; e: labrum).