Hydraena camerocrebrata, 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 : 14-15

Hydraena camerocrebrata , new species

Figs. 3 , 14 (habitus), 14 (aedeagus), 42 (map)

Type Material. Holotype (male): “ Cameroon: Yaounde : Mt. Febe, 950 m., hygropetric, 10.iv.1982, P. D. Perkins collector” ( MCZ) . Paratypes (120): Same data as holotype (28 MCZ) ; same data except 7.iv.1982 (5 MCZ) ; same data except 18.vi.1983 (64 MCZ) ; same data except 14.vi.1983 (12 MCZ) ; Yaounde , Mt. Mbankolo, 900m, hygropetric microhabitat, 20.v.1982, P. D. Perkins collector (11 MCZ) .

Differential Diagnosis. Differentiated from other members of the genus in Cameroon by the combination of the very densely punctate dorsum, the very narrow P2 (l/w ca. 4/1) and the aedeagus ( Fig. 14 ). Also refer to the diagnosis of H. camerocompressa . Although the aedeagi of H. camerocrebrata and H. cameropetila distinctly differ in several characters, a relationship of the two species is indicated by the shapes of the parameres: large, wide and with similar clusters of setae ( Figs. 14 , 18 ).

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.33/0.57; head width 0.31; pronotum 0.33/0.48, PA 0.41, PB 0.42; elytra 0.85/0.57. Habitus as illustrated ( Fig. 14 ). Dorsum dark brown to black, pronotum without macula, palpi brown. Dorsum of head and pronotum moderately coarsely, very densely punctulate, each puncture with short, distinctive whitish seta, interstices dull; punctures of frons disc and pronotal disc ca. 2–3xef, interstices ca. 1xpd or less; punctures of clypeus fine, dense. 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 rather abrupt posterior declivity at about posterior 1/3; lateral explanate margins narrow to moderately wide; on basal 1/3 punctures ca. 2xpd of largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, width ca. 0.5xpd or less, as are interstices between punctures of a row. Apices in dorsal aspect very slightly separately rounded, in posterior aspect margins forming very weak angle with one another.

Venter: Mentum and postmentum nitid, dull. Genae very slightly raised, very weakly shining, with posterior ridge. Ratios of P2 width and plaque shape (P2/w/l/s) ca. 1/1/6/6. P1 laminate; median carina weakly sinuate in profile. P2 very narrow, l/w ca. 4/1, sides parallel, apex blunt. Plaques narrow, straight or very slightly arcuate, slightly convergent anteriorly, weakly 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 weakly concave, width at arcuate posterior margin ca. 2.5x P2. Pro- meso- and metatibiae straight, moderately stout.Abdominal apex symmetrical, without apicomedian notch.

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

Etymology. Named in reference to the known distribution and to the very densely punctate dorsum.

Figures

FIGURE 3. Dorsal habitus of Cameroonian species of Hydraena in Aedeagal Species Group 2.

FIGURE 14. Hydraena camerocrebrata, new species, habitus and aedeagus of holotype.

FIGURE 18. Hydraena cameropetila, new species, habitus and aedeagus of holotype.

FIGURES 42–43. Geographical distributions of Cameroonian Hydraena.