Bagous binodulus

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 : 36

3. Bagous binodulus group

Diagnosis. Upper margin of eye at a level slightly higher than the forehead (char. 25.1). Glabrous, smooth and shining area over eyes and at base of interval 1 (char. 35.1). Basal portion of pronotum broadly covered with plumose scales (char. 29.1). Basal margin of elytra slightly to markedly costate from scutellum to, or almost to, humerus. Ventrite 5 with median impression with carinate margin (char. 44.2) bearing a row of long setae (char. 45.1). Ventrobasal margin of penis body with short, ventrobasal plate extending between apodemes and forming an acute median point, visible from above (char. 70.2). Sclerite complex within tube of penis body with a pair of submedian, subapical well-separated sclerites (char. 84.1). Submedian sclerites subtriangular with a point at base (char. 86.1). Basal sclerite complex of two pairs of flat sclerites (char. 90.4).

Remarks. This group is composed of a single Palaearctic species, i.e., the type species of the genus Bagous , which bears several striking nongenital as well as genital autapomorphic characters unique in the Bagoini. The penis shares certain general features with those of the species of the B. bipunctatus group. The presence of a basal plate of the penis body extending between apodemes is shared between the two groups, but a similar structure appears also in the subgenus Hydronoplus .

Species included. PAL: §* Bagous binodulus (Herbst, 1795) .