Hydraena camerocontinua, 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 : 25-26

Hydraena camerocontinua , new species

Figs. 5 , 31 (habitus), 31 (aedeagus), 42 (map)

Type Material. Holotype (male): “ Cameroon: N. Prov., 35 km N. Ngaoundere, stream, 1.v.1982, leg. P. D. Perkins ” ( MCZ).

Differential Diagnosis. Differentiated from other members of the genus in Cameroon by the combination of the relatively wide and short P2, l/w ca. 1/1, sides slightly diverging toward apex, apex very indistinct, fused with and at same level as mesoventral intercoxal process., the anterolateral pronotal foveae moderately deep, posterolateral pronotal foveae very shallow or absent, and the aedeagus ( Fig. 31 ). Somewhat similar in habitus to H. cameroarida , but differing in finer, sparser dorsal punctation, ventral characters, and aedeagal morphology.

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.47/0.67; head width 0.39; pronotum 0.37/0.52, PA 0.42, PB 0.47; elytra 0.91/0.67. Habitus as illustrated ( Fig. 31 ). Dorsum brown to dark brown or black, frons and diffusely margined pronotal macula darker, palpi testaceous, tip of last palpomere not darker. Dorsum of head and pronotum sparcely moderately finely punctulate, more sparsely punctulate on macula than on surrounding areas, interstices shining; punctures of frons disc and pronotal disc ca. 1xef, interstices ca. 1–3xpd or slightly larger; punctures of clypeus obsolete. Labrum apicomedially excised, free margins weakly upturned. Pronotum with anterior margin weakly emarginate over middle 1/2; anterolateral pronotal foveae moderately deep, posterolateral pronotal foveae very shallow or absent, posterosubmedial foveae very shallow.

Elytra with summit of posterior declivity at or very near midlength; lateral explanate margins wide; punctures fine, on basal 1/3 punctures ca. 1xpd of largest pronotal punctures, punctures becoming gradually smaller toward posterior, each puncture with very short and very fine seta. Intervals not raised, width ca. 2–3xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming very weak angle with one another.

Venter: Mentum very sparsely very finely punctulate, shining; postmentum very finely densely micropunctulate, moderately shining. Genae raised, shining, without posterior ridge. Ratios of P2 width and plaque shape (P2/w/l/s) ca. 1/0.3/1/1.3. P1 laminate; median carina sinuate in profile. P2 relatively wide and short, l/w ca. 1/1, sides slightly diverging toward apex, apex very indistinct, fused with and at same level as mesoventral intercoxal process. Plaques narrow, slightly converging toward one another anteriorly, very weakly raised, located at sides of deep median depression. AIS width at straight posterior margin ca. 1.3x P2. Protibia slender, arcuate. Meso- and metatibiae slender, straight. Abdominal apex symmetrical, with apicomedian notch.

Distribution. Currently known only from the type locality ( Fig. 42 ).

Etymology. Named in reference to the known distribution, and to the fused intercoxal processes of the meso- and metaventrites.

Figures

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

FIGURE 31. Hydraena camerocontinua, new species, habitus and aedeagus of holotype.

FIGURES 42–43. Geographical distributions of Cameroonian Hydraena.