Ochthebius (Aulacochthebius) latissimus, Perkins, 2023

Perkins, Philip D., 2023, Taxonomic revision of African water beetles in the genus Ochthebius Leach (1815) subgenus Aulacochthebius Kuwert (1887) (Coleoptera: Hydraenidae), Zootaxa 5228 (5), pp. 501-546 : 535-536

O. (Aulacochthebius) latissimus , new species

Figs. 2 , 4 , 17 , 23

Type Material. Holotype (male): South Africa ; “ S. Afr., c. Transvaal, Roodeplaat Dam, 25°37′S, 28°23′E, 14.8.1974, E-Y: 359, shore washing, leg. A. Strydom ” ( TMSA) . Paratypes (184): South Africa: Same data as holotype (15 TMSA) ; Cape Prov., Wilderness NP, car catcher, (33°59′S, 22°38′E), 13-14.xi.1997, leg. B. & M. Uhlig (6 ZHMB) ; Eastern Cape Province, De Hoop NR; Carex sievings, (34°27.2′S, 20°24.2′E), 10.xi.1997, leg. M. Uhlig (1 ZHMB) ; Wilderness NP, Langvlei; Malachite bird hide, Juncus krausi and bush litter sievings, (33°59′S, 22°41′6′′E), 30.xi.1996, leg. B. & M. Uhlig (3 ZHMB) ; KwaZulu-Natal Province, Hluhluwe Game Res. , (28°5′S, 32°4′E), 19.xi.1992, leg. Endrödy-Younga (#2832) (1 TMSA) ; same locality, 27.xi.1992, leg. Endrödy-Younga (#2862) (6 TMSA) ; same locality, 27.xi.1992, leg. Endrödy-Younga (#2861) (7 TMSA) ; Hluhluwe Game Reserve , (28°5′S, 32°4′E), 17.xi.1992, leg. Endrödy-Younga #2824 (#2824) (32 TMSA) ; Karkloof Grassveld , (29°19′S, 30°15′E), 12.ix.1989, leg. Endrödy-Younga & Klimaszewski (#2753) (1 TMSA) ; Mtubatuba , (28°22′S, 32°19′E), 4.iv.1974, leg. Endrödy-Younga (#318) (1 TMSA) ; Zululand, Dukuduku For. Sta. , (28°22′S, 32°19′E), 4.iv.1974, leg. Endrödy-Younga (#323) (1 TMSA) ; Mpumalanga Province, Bundu Inn , (25°28′S, 28°55′E), 24.iii.1974, leg. Endrödy-Younga (#304) (8 TMSA) ; Nelshoogte galery forest below St. , (25°51′S, 30°53′E), 2.xii.1986, leg. Endrödy-Younga (#2343) (3 TMSA) ; S. Transvaal, Roberts Drift , Vaal R., (27°2′S, 29°2′E), 8.x.1973, leg. EndrödyYounga (#190) (3 TMSA) ; Western Cape Province, 8 mi. E. Wilderness, (33°58′S, 22°43′E), 13.iii.1968, leg. P. J. Spangler (3 NMNH) ; De Hoop Nat. Res. , (34°27′S, 20°24′E), 17.xi.1993, leg. M. Uhlig (2 ZHMB) ; SW Cape, Verlorevlei Farm , (32°19′S, 18°22′E), 28.viii.1981, leg. Endrödy-Younga (#1857) (90 TMSA) .

Differential diagnosis. Differentiated from most other members of the O. (A.) tenuipunctus Group by the combination of the small size and wide body form, and by the aedeagus. Differentiated from the similarly wide and small species O. (A.) perlaevis by the very irregular elytral serial rows of punctures, and by the aedeagus.

Description. Size: holotype (length/width, mm): body 1.19/0.55 (length to elytral apices); head width 0.34; pronotum length 0.30, width at base 0.22, width at hyaline border 0.60, width of lateral sclerotized lobes 0.45 at anterior, 0.22 at posterior; elytra 0.67/0.55. Habitus as illustrated ( Fig. 17 ). Dorsum dark brown to black except hyaline borders of prothorax transparent. Eyes with moderately coarse, convex facets. Frons with deep impressions, borders of impressions rounded, smooth. Clypeus with very few, very shallow setigerous punctures. Labrum anterior margin arcuate in both sexes.

Pronotal reliefs very smooth, with very sparse and very short setae; anterior and posterior transverse impressions deep, anterior contiguous with shallow transverse impression immediately behind anterior margin of lateral lobe; median longitudinal impression absent. Pronotum lateral hyaline borders very wide, extended from posterior to anterior angles, outer margin strongly arcuate; sides of non-hyaline part with long conspicuous setae immediately above and resting on hyaline border; anterior hyaline border moderately wide; posterior hyaline border narrow.

Elytra slightly wider than non-hyaline part of pronotum, posteriorly acuminate, sides markedly arcuate; very smooth, non-punctate, with sparse, very short, random setae; lateral margin with dense, very long setae that extend outward from margin in dry specimens.

Venter ( Fig. 17 ): Tabella oval to suboval, very slightly angulate anteriorly, very slightly wider than long, slightly convex; first four ventrites bearing rather long hydrofuge pubescence; remaining ventrites glabrous, shining, with sparse setae.

Males slightly smaller than females: males ca. 1.10–1.25 mm; females ca. 1.15–1.30 mm.

Etymology. Named in reference to the very wide lateral hyaline border of the pronotum, and the long and numerous lateral setae of the elytra.

Distribution. Currently known from southern and eastern South Africa ( Fig. 23 ).

Figures

FIGURE 2. Dorsal habitus of species in O. (A.) tenuipunctus Group.

FIGURE 4. Venter and aedeagi (ventral view, flagellum deleted) of species in O. (A.) continentalis Group and O. (A.) tenuipunctus Group. Not to same scale.

FIGURE 17. O. (A.) latissimus n. sp., holotype habitus and aedeagus.

FIGURES 22–23. Geographical distributions. 22. O. (A.) copiosus n. sp. 23. O. (A.) latissimus n. sp.