Hydraena camerocameola, 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 : 24-25

Hydraena camerocameola , new species

Figs. 5 , 30 (habitus), 30 (aedeagus), 39 (map)

Type Material. Holotype (male): “ Cameroon: N. Prov., 22 km. N. Maroua, desert stream, 14.i.1982, leg. P. D. Perkins ” ( MCZ) . Paratypes: Same data as holotype (9 MCZ); Same locality, 27.v.1982, leg. P. D. Perkins (5 MCZ)

Differential Diagnosis. Differentiated from other members of the genus in Cameroon by the combination of the rather elongate body form, the very coarse and very dense pronotal and elytral punctures, interstices narrow walls, shining, the narrow, long plaques, located at sides of deep longitudinal groove-like median sulcus, and the aedeagus ( Fig. 30 ).

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.48/0.60; head width 0.36; pronotum 0.34/0.44, PA 0.40, PB 0.42; elytra 0.92/0.60. Habitus as illustrated ( Fig. 30 ). Body form elongate. Dorsum generally brown to dark brown, maxillary palpi, testaceous, pronotum with diffusely margined weakly defined dark brown macula. Dorsum of head and pronotum coarsely, very densely punctulate. Frons punctures distinctly smaller and less dense than pronotal punctures, interstices shining; punctures of frons disc and ca. 2–3xef, interstices ca. 1–2xpd. Pronotal punctures very coarse and very dense, interstices narrow walls, shining. Clypeus very finely sparsely punctulate in median 1/3, shining; lateral areas densely micropunctulate, dull. Labrum apicomedially excised, free margins rounded, very weakly upturned. Pronotum with anterior margin weakly emarginate over middle 1/2; antero- and posterolateral foveae deep, confluent, posterosubmedial foveae deep, very coarsely punctate.

Elytra with summit of posterior declivity at about midlength; lateral explanate margins wide; on basal 1/3 punctures ca. 1xpd of largest pronotal punctures. Intervals not raised, width ca. 0.5xpd or less, sometimes narrow walls, as are interstices between punctures of a row. Apices in dorsal aspect jointly rounded, in posterior aspect margins not forming angle with one another.

Venter: Mentum and postmentum rather coarsely densely micropunctulate, dull. Genae raised, shining, without posterior ridge. Ratios of P2 width and plaque shape (P2/w/l/s) ca. 1/0.5/2.3/1.3. P1 laminate; median carina sinuate in profile. P2 narrow, l/w ca. 3/1, sides slightly converging toward blunt apex raised slightly above mesoventral intercoxal process. Plaques narrow, long compared to P2, straight, slightly converging toward one another anteriorly, weakly raised, located at sides of deep longitudinal groove-like median sulcus. AIS width at straight posterior margin ca. 2x P2. Protibia moderately arcuate, slightly widened on inner margin over distal 1/3. Meso- and metatibiae slender, straight. Abdominal apex symmetrical, with apicomedian notch.

Distribution. Currently known only from the type locality ( Fig. 39 ).

Etymology. Named in reference to the known distribution, and to the cameo-like aedeagus.

Figures

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

FIGURE 30. Hydraena camerocameola, new species, habitus and aedeagus of holotype.

FIGURES 39–41. Geographical distributions of Cameroonian Hydraena.