Azollaebagous, ROBERTO CALDARA, CHARLES W. O’BRIEN & MASSIMO MEREGALLI, 2017

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

Genus Azollaebagous gen. n.

( Figs 4 A–B, 5G)

Type species: Bagous clarencensis Blackburn, 1894 . Gender: masculine.

Diagnosis. Body very small in size, 2.0 mm or less in length (rostrum excluded) (char. 1.1). Postocular lobe ventrally indistinct, not raised, not forming discontinuity with anterior prosternal margin (char. 30.0). Prosternal canal weak (char. 31.1). Side margins of prosternum barely raised (char. 33.1). Elytra subquadrate (char. 34.1), with posterior declivity in lateral view strong at 75 degrees (char. 37.1); declivital callus absent (char. 36.0); scales of elytral intervals arranged in regular pairs (char. 41.1); vestiture with a semicircular white stripe at posterior third (char. 40.1). Tibiae with slightly arcuate apices (char. 48.1). Penis with long apodemes (char. 110.0) and with endophallus generally lacking sclerites.

Description. Body short and broad-oval, very small in size, 2.0 mm or less in length (rostrum excluded), densely clothed with hydrofuge pitted scales. Rostrum in female usually distinctly longer than in male. Antennae with 7-segmented funicle, usually inserted at midlength. Forehead between eyes foveate. Pronotum moderately transverse, with sides weakly rounded, disc moderately to strongly transversely convex. Postocular lobe ventrally indistinct, not raised, not forming discontinuity with anterior prosternal margin. Prosternal canal weak, with side margins weak. Elytra slightly longer than wide, with humeri subquadrately rounded, with parallel sides, posterior declivity in lateral view strong at 75 degrees, lacking callosities; scales of elytral intervals arranged in regular pairs, side by side, each interval with two individually distinct rows of round scales; vestiture with a semicircular white stripe at posterior third. Tibiae with slightly arcuate apices, lacking distinct denticles and with setae very short and indistinct; tarsi short, with tarsomere 3 broad and slightly cordate, clothed beneath with fine, dense, recumbent pubescence. Penis with long apodemes and with endophallus generally lacking sclerites. Apodemes of spiculum ventrale straight, long, parallel.

Remarks. This genus is associated with Azolla and easily identified by five apomorphies (char. 1.1, 34.1, 37.1, 40.1, 41.1), all in nongenital characters: body very small in size, elytra subquadrate with posterior declivity strong and with a semicircular stripe of white scales at posterior third, elytral interstriae covered with two regular rows of scales (homoplastic with other species of Bagous ). Azollaebagous was maximally supported in BI and ML and strongly supported in MP (97% sr, Bremer support 3).This genus shares with Memptorrhynchus the almost indistinct prosternal canal and the tarsi short, with broad cordate tarsomere 3.

Etymology. The name is composed by the joining of the name Azolla to the name Bagous highlighting that all the species of this new genus appear to live on Azolla , a genus of the water fern plant family Azollaceae .

Species included. AUS: *¹ Azollaebagous clarenciensis (Blackburn, 1894) n. comb.; ORR: ² A. alexanderi (O'Brien, 1995) n. comb., ¹ A. contrarius (O'Brien, 1995) n. comb., ¹ A. pygmaeus (Voss, 1960) n. comb.; PAL: *² A. pygmaeodes ( O'Brien & Morimoto, 1995) n. comb.

Figures

FIGURE 4. Habitus of Azollaebagous clarencensis, in (A) dorsal and (B) lateral view; Bagous (Hydrillaebagous) hydrillae, in (C) dorsal and (D) lateral view. Venter of (E) Bagous (Bagous) binodulus; (F) Memptorrhynchus crispus. Detail of ventrite 1 after removal of scales of (G) Bagous (Macropelmus) affaber; (H) Bagous (Macropelmus) collignensis. Not at the same scale.