Bagous biimpressus

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 : 43-44

11. Bagous biimpressus group

Diagnosis. Segment 7 of antennal funicle elongate (char. 20.1), nearly as wide as segment 6 (char. 21.1). Antennal club structure indistinctly segmented, 1st segment elongate, glabrous and shining, 2nd and 3rd segments very short, distinctly pubescent (char. 23.1). Prosternal canal scarcely developed (char. 31.1), especially in its proximal half, which is higher than the distal half, forming a weak basal ridge (char. 32.1); postero-lateral margins of prosternal canal barely raised (char. 33.1). Female pygidium with apex broadly blunted (char. 54.1), forming a flat, thickened, arcuate margin (char. 55.1). Sclerites complex within tube of penis body with a pair of submedian subapical sclerites posteriorly joined (char. 84.2). Median setal brush behind orifice situated at base of subapical sclerites (excluding B. petro ) (char. 92.1).

Remarks. This group was also strongly or moderately strongly supported in the phylogenetic analyses. It traditionally formed the subgenus Ephimeropus and is characterized by several genital as well as non-genital characters, in part shared with other groups. Caldara & O’Brien (1998) separated three species— B. geniculatus , B. geniculatodes and B. mucronatus —in the B. geniculatus group, on the basis of several synapomorphies from external morphology—postocular lobe ventrally indistinct, not raised, not forming discontinuity with anterior prosternal margin (char. 30.0); tibiae with long fine swimming hairs, many of which are much longer than diameter of tibia (char. 47.1); third tarsomere sub-glabrous beneath, with few long setae (char. 53.2)—and of the male genitalia—penis body with more or less sagittate apex (char. 5 9.1), with orificial lateral sclerites apically attached to the sides of the penis body (char. 77.1) and distinctly laterally movable (char. 78.1), appearing like a dorsal process ("false" dorsal process).

This group is currently composed of five Palaearctic and one Indian species.

Species included. ORR: 4 Bagous geniculatodes O'Brien, 1995 ; PAL: *¹ B. biimpressus Fåhraeus, 1845 , *4 B. geniculatus ( Hochhuth, 1847) , *5 B. mucronatus Caldara & O’Brien, 1998 , *² B. perparvulus Rosenhauer, 1856 , §*³ B. petro (Herbst, 1795) .