Ochthebius (Asiobates) bupunctus, Perkins, Philip D., 2011

Perkins, Philip D., 2011, New species and new collection records of aquatic beetles in the genus Ochthebius Leach from southern Africa (Coleoptera: Hydraenidae), Zootaxa 3093, pp. 1-34 : 22-23

Ochthebius (Asiobates) bupunctus , new species

( Figs. 15 , 16 , 27 )

Type Material. Holotype (male): Namibia: Kaokoveld, Kunene River, Swartbooisdrift, shore washing, 17° 19' S, 13° 49' E, 10 ii 1975, Endrödy-Younga (#645) ( TMSA). Paratypes (6): Angola: Rocadas, R. Cunene, 16° 45' S, 14° 59' E, 19–22 ii 1972, Southern African Exp. BM (6 NHM).

Differential Diagnosis. This species is a member of Ochthebius (Asiobates) and is somewhat similar in dorsal habitus to O. andronius . It is differentiated from O andronius by the more robust body form ( Fig. 15 ), the slightly larger size (ca. 2.12 mm vs. 1.98 mm), the more coarsely punctate pronotum, the deeply striate-impressed elytral series, and the more complex aedeagus ( Fig. 16 ).

Description. Size: holotype (length/width, mm): body (length to elytral apices) 2.12/1.00; head 0.43/0.53; pronotum 0.54/0.77, PA 0.63, PB 0.63; elytra 1.22/1.00. Color: Dorsum dark brown to black, head and pronotum usually darker than elytra. Structures in ventral view rather uniform brown to dark brown, femora slightly darker than tibiae. Head: Eyes moderately large, in dorsal aspect 8–9 weakly convex facets in longest series. Interocular foveae large and deep, each equal to distance separating them. Ocelli distinct. Frons punctures distinct, sparse, less than 1xef, each puncture with a fine short seta, interstices shining, 1-6xpd, with extremely sparse indistinct micropunctulate ground sculpture. Sides of head distinctly indented at frontoclypeal suture. Clypeus with sides very slightly diverging anteriorly, nearly parallel-sided, width of anterior margin twice length; anterior angles pointed; alutaceous and dull except near anterior margin where smooth and shining; punctation similar to frons; lateral margins with long setae. Labrum large, transversely slightly declivous from midline to sides, more distinctly so in male; anterior margin evenly arcuate from side to side, margin of lateral 1/3 weakly reflexed; punctation size and density similar to clypeus, each puncture with short seta. Mandibles in male with prominent lateral fringe of spiniform setae. Pronotum: Anterior margin shallowly emarginate between middle and anterior angles. Sides produced in point at posterior of lateral depression, excavate between point and posterior angles. Anterior hyaline margin moderately wide. Lateral hyaline margin beginning at about midlength of lateral depression, edge weakly arcuate, widest at posterior excavations. Posterior hyaline margin very narrow. Punctures deep, dense and coarse, irregularly spaced and of varying sizes, ca. 0.5–3xef, punctures finer near anterior and posterior margins. Interstices shining, varying from narrow walls to 3xef. Midlongitudinal sulcus narrow, not microreticulate. Lateral fossula shining, coarsely punctate, non-microreticulate. Lateral depressions continuing transverse curvature of disc; punctation similar to larger punctures on disc. Elytra: Sides rounded, widest near middle, explanate margin moderately wide, declivous, shining, apices narrowly separately rounded. Ten-seriate punctate, series striate-impressed; punctures larger basally finer apically, on disc ca. 1xpd of largest pronotal punctures, longitudinally separated by narrow walls to 1.5xpd, each puncture with exceedingly fine and short decumbent seta; intervals shining, rounded, ca. 1.5– 2xpd. Venter: Mentum moderately shining, moderately coarsely punctate. Metaventrite pubescent laterally, entire large disc strongly shining, glabrous except few setiferous punctures on each side near midlength. Abdominal ventrites 1–5 entirely clothed with dense hydrofuge pubescence; 6 effacedly microreticulate, weakly shining, very sparsely pubescent. Legs. Male with last mesotarsomere arcuate, penultimate tarsomere with two spinform setae beneath. Females (n=3). Clypeus shining, not alutaceous; labrum with shallow apicomedian emargination, edge not reflexed; mandibles without spiniform setae; mesotarsi simple.

Etymology. Named in reference to the very coarse pronotal punctation.

Distribution. Currently known from one locality in northernmost Namibia and one locality in nearby Angola ( Fig. 27 ).

Figures

FIGURE 15. Ochthebius bupunctus, dorsal and lateral habitus of holotype.

FIGURE 16. Ochthebius bupunctus, aedeagus of holotype.

FIGURES 25 – 28. Geographical distributions of Ochthebius. 25. O. namibiensis. 26. O. sitiensis. 27. O. bupunctus. 28. O. extremus.