Hydraena camerobuloba, Perkins, 2022

Perkins, Philip D., 2022, Thirty-three new species of water beetles in the genus Hydraena Kugelann from Cameroon (Coleoptera: Hydraenidae), Zootaxa 5203 (1), pp. 1-66 : 24

Hydraena camerobuloba , new species

Figs. 5 , 29 (habitus), 29 (aedeagus), 43 (map)

Type Material. Holotype (male): Cameroon : Northwest Province. “ BRITISH CAMEROONS / Matute, / Tiko Plantation / 5.v.1949, B. Malkin ” ( UKNHM) . Paratypes: Same data as holotype (48 UKNHM) .

Differential Diagnosis. Differentiated from other members of the genus in Cameroon by the combination of the pronotum color, mostly black, contrasting with light brown to testaceous color narrowly along anterior and posterior margins, the elytral margins in posterior aspect forming very strong angle with one another, and the aedeagus ( Fig. 29 ).

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.25/0.54; head width 0.33; pronotum 0.30/0.43, PA 0.38, PB 0.39; elytra 0.75/0.54. Habitus as illustrated ( Fig. 29 ). Dorsum with head and most of pronotum black, pronotum narrowly along anterior and posterior margins light brown to testaceous, palpi testaceous. Frons and clypeus finely, moderately densely punctulate, interstices shining. Pronotum moderately coarsely, densely punctulate, interstices shining; punctures of pronotal disc ca. 2–3xef, interstices ca. 1xpd or less. Labrum apicomedially excised, free margins rounded, weakly upturned. Pronotum with anterior margin weakly emarginate over middle 1/2; anterolateral, posterolateral and posterosubmedial foveae moderately deep.

Elytra with summit of posterior declivity at about posterior 1/3; lateral explanate margins moderately wide; on basal 1/3 punctures slightly larger than largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, width ca. 1xpd or less, as are interstices between punctures of a row. Apices in dorsal aspect slightly separately rounded, in posterior aspect margins forming very strong angle with one another.

Venter: Mentum and postmentum moderately finely punctulate, shining. Genae raised, dull, without posterior ridge. Ratios of P2 width and plaque shape (P2/w/l/s) ca. 1/0.5/2/2. P1 laminate; median carina sinuate in profile. P2 l/w ca. 3/1, sides slightly converging toward blunt apex, apex raised slightly above mesoventral intercoxal process. Plaques moderately narrow, straight, parallel or nearly so, not raised, located at sides of deep median depression. Metaventrite with very short longitudinal ridge on each side, extended posteriorly from margin of each mesocoxal cavity. AIS width at straight posterior margin ca. 2x P2. All tibiae slender, protibia very slightly arcuate, meso- and metatibiae straight.

Distribution. Currently known only from the type locality ( Fig. 43 ).

Etymology. Named in reference to the distribution and the relatively large distal lobe of the aedeagus.

Figures

FIGURE 5. Dorsal habitus of Cameroonian species of Hydraena in Aedeagal Species Group 5.

FIGURE 29. Hydraena camerobuloba, new species, habitus and aedeagus of holotype.

FIGURES 42–43. Geographical distributions of Cameroonian Hydraena.