Hydraena camerocorona, 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 : 10-11

Hydraena camerocorona , new species

Figs. 1 , 8 (habitus), 8 (aedeagus), 42 (map)

Type Material. Holotype (male): “ Cameroon, Akonolinga , moist secondary forest and plantation, at light, 7.I.1978, Loc. #17 // Gardenforhall—Samuelson ” ( LUM).

Differential Diagnosis. Differentiated from other members of the genus in Cameroon by the combination of the very fine and widely spaced elytral punctures, the comparatively wide lateral explanate margins of the elytra, the pronotal macula, and the aedeagus ( Fig. 8 ).

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.26/0.56; head width 0.34; pronotum 0.31/0.4, PA 0.37, PB 0.38; elytra 0.75/0.56. Habitus as illustrated ( Fig. 8 ). Dorsum brown to dark brown or black, frons and diffusely margined pronotal macula darker, frons almost black, contrasting with light brown clypeus, palpi testaceous, tip of last palpomere not darker. Dorsum of head and pronotum sparcely 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; antero- and posterolateral pronotal foveae moderately deep, shallowly confluent, 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. 3–4xpd, 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 punctulate, dull. Genae raised, shining, without posterior ridge. Ratios of P2 width and plaque shape (P2/w/l/s) ca. 1/0.7/4/4. 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 wide, slightly converging toward one another 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 width at straight posterior margin ca. 2x P2. Tibiae slender, protibial very slightly arcuate, meso- and metatibiae straight. Abdominal apex symmetrical; last tergite with slightly off-center apical notch.

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

Etymology. Named in reference to the known distribution, and the wide lateral explanate margins of the elytra.

Figures

FIGURE 8. Hydraena camerocorona, new species, habitus and aedeagus of holotype.

FIGURES 1–2. 1. Dorsal habitus of Cameroonian species of Hydraena in Aedeagal Species Group 1; 2. Representative aedeagi of Aedeagal Species Groups 1–4.

FIGURES 42–43. Geographical distributions of Cameroonian Hydraena.