Bagous Germar, 1817

ROBERTO CALDARA, CHARLES W. O’BRIEN & MASSIMO MEREGALLI, 2017, A phylogenetic analysis of the aquatic weevil tribe Bagoini (Coleoptera: Curculionidae) based on morphological characters of adults, Zootaxa 4287 (1), pp. 1-63 : 34-35

Genus Bagous Germar, 1817

Diagnosis. Forehead between eyes sulcate or foveate (char. 24.1); postocular lobes well-developed (char. 30.1); prosternum with deep rostral canal (char. 31.2) and with postero-lateral margins of rostral canal sharply raised (char. 33.2) (except for the B. biimpressus group of the subgen. Macropelmus); elytral interval 5 usually with declivital callus obtuse to acute, poorly to well-developed (char. 36.1, absent in subgenus Parabagous and in B. exilis , B. frivaldszkyi and B. tubulus ). Tarsomere 3 cordate to linear; penis body ventrally membranous to fully sclerotized, usually with numerous basal or apical, more or less complex sclerites, with long to very short apodemes.

Remarks. In the all-species analysis the genus was almost maximally supported in BI (99% pp) but only weakly supported in ML (65% bs) and MP (63 % sr, Bremer support 1); in the type-species analysis its support in ML and MP was stronger (respectively, 78% bs and 72% sr, Bremer support 3).

Infrageneric classification of the genus Bagous is controversial. As already discussed, three large complexes of species are maximally, or nearly maximally supported: subgenera Parabagous , Hydronoplus and Hydrillaebagous new subgenus. The subgenus Macropelmus represents a further clade that includes a very large number of species sharing the shortening of the penis apodemes,. All other species, including B. binodulus , the type species of the genus, fall in a polytomy. The species available for the molecular analysis clustered in clades that match their placement in the topology of the BI reconstruction based on the morphological analysis. The type-species analysis produced the same pattern but with a further group (including Himaniphades and Abagous ) that was not present in ML and had only low support. In accordance with the all-species analysis, we refer it to the subgenus Bagous as a species-group ( B. bipunctatus group).