Hydraena camerofoveata, 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 : 16

Hydraena camerofoveata , new species

Figs. 3 , 17 (habitus), 17 (aedeagus), 41 (map)

Type Material. Holotype (male): “ Cameroon: C. S. Prov., 15 km. NW Yaounde, Isali River nr. Nouma, 2.i.1983, leg. P. D. Perkins ” ( MCZ).

Differential Diagnosis. Differentiated from other members of the genus in Cameroon by the combination of the small body size (ca. 1.24 mm), the densely coarsely punctate dorsum, the anterolateral and posterolateral foveae deep, shallowly confluent, the posterosubmedian foveae deep, the plaques absent or very small and very faintly indicated by less dense hydrofuge pubescence, located at sides of very shallow median depression, and the aedeagus ( Fig. 17 ). The habitus is quite similar to that of H. camerocrebrata , but that species has well developed metaventral plaques, and a different aedeagus.

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.24/0.54; head width 0.31; pronotum 0.31/0.44, PA 0.37, PB 0.38; elytra 0.73/0.54. Habitus as illustrated ( Fig. 17 ). Dorsum dark brown to black, maxillary palpi brown, tip of last palpomere not darker. Frons densely moderately coarsely, pronotum coarsely densely punctate, punctures much larger than those of frons, interstices shining, ca. 0.5–1xpd. Labrum apicomedially excised, free margins very weakly upturned. Pronotum with anterior margin weakly emarginate over middle 1/2; anterolateral and posterolateral foveae deep, shallowly confluent; posterosubmedian foveae deep; anteromedian fovea shallow.

Elytra with summit of posterior declivity slightly beyond midlength; lateral explanate margins moderately wide; on basal 1/3 punctures ca. 1–2xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior, each puncture with short and fine seta. Intervals not raised, width ca. 0.5–1xpd, as are interstices between punctures of a row. Apices in dorsal aspect separately rounded, in posterior aspect margins forming moderately strong angle with one another.

Venter: Mentum and postmentum sparsely finely punctulate, shining. Genae raised, without posterior ridge. P1 laminate; median carina sinuate in profile. P2 l/w ca. 4/1, sides parallel or slightly diverging toward blunt apex, apex raised slightly above mesoventral intercoxal process. Plaques absent or very small and very faintly indicated by less dense hydrofuge pubescence, located at sides of very shallow median depression. AIS width at straight posterior margin ca. 2.5x P2. All tibiae straight, moderately stout. Abdominal apex symmetrical, with very small apicomedian notch.

Distribution. Currently known only from the type locality ( Fig. 41 ).

Etymology. Named in reference to the known distribution, and to the deep pronotal foveae.

Figures

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

FIGURE 17. Hydraena camerofoveata, new species, habitus and aedeagus of holotype.

FIGURES 39–41. Geographical distributions of Cameroonian Hydraena.