Nebrioporus capensis ( Omer-Cooper, 1953 )

Toledo, Mario, 2009, Revision in part of the genus Nebrioporus Régimbart, 1906, with emphasis on the N. laeviventris-group (Coleoptera: Dytiscidae), Zootaxa 2040, pp. 1-111 : 100-101

Nebrioporus capensis ( Omer-Cooper, 1953)

Fig. 44

Potamonectes capensis Omer-Cooper (1953: 27) (orig. descr.); Omer-Cooper (1965: 140).

Nebrioporus (s.str.) capensis (Omer-Cooper) ; Nilsson & Angus (1992: 287); Nilsson (2001: 171).

Type locality. South Africa > Cape Town .

Type material. Holotype ♂ ( BMNH) "type [red circular BMNH label] \ S. Africa, Cape Town, 18.XI.1947, Omer-Cooper \ Type ♂ Potamonectes capensis O-C" . Paratype: ( BMNH) 1 ♀ "type [red circular BMNH label] \ S. Africa, Cape Town, S. Jackson, August 1947 \ P. capensis O-C - det. Omer-Cooper, Allotype " .

Additional material examined. South Africa: Western Cape, Philadelphia , 18.VI.1949, leg. B. Malkin, B. Malkin coll., B.M. 1956-234 (30 exs. BMNH) ; Western Cape, 10 km from De Hoop, entrance on Malgas road, sandy bottomed farm reservoir, 124 m, 342211S202836E, 8.IX.2003, leg. C. Turner (4 exs. CTP) ; Western Cape, South River to south of R 45 in Hopefield, Phragmites surrounded stream and silty grassy flood pools at margins, 36 m, 325648S180554E, 2.IX.2003, leg. C. Turner (9 exs. CTP) ; Western Cape, Grabouw, Du Toits riv., road. Grabouw to Franschhoek , 300–350 m, 31.XII.1991, leg. P. Mazzoldi (1 ex. PMB) ; Western Cape, Cape Agulhas, Soetendalsvtei marsh., 1.I.1992, leg. P. Mazzoldi (1 ex. PMB) ; Western Cape, 20 km W Bredasdorp , 5.I.1994, leg. G. Wewalka (5 exs. MTP, PMB) .

Description. TL 4.5–5.0 mm: MW 2.3–2.7 mm. Oval, slightly elongate, moderately convex. Angle between pronotum and elytra modest in males, more visible in females. Colouration yellow, pronotum with poorly developed dark markings, elytra vittate.

Head reddish-yellow with a narrow dark band behind the eyes. Antennae testaceous, with last four or five articles slightly darkened apically. Genae reddish or brownish. Mouthparts reddish. Last article of maxillary palpi usually darkened.

Pronotum transverse, with maximum width near the base. Lateral sides almost straight, converging inward, bordered. Posterior angles more or less rounded. Posterior border sinuate.

Elytra covered by a fine pubescence; oblong-oval, with lateral sides moderately rounded in apical half. Maximum width just behind the middle of the length. Longitudinal rows of punctures usually almost invisible. Subapical denticle poorly developed, but visible.

Dorsal colouration yellow ( Fig. 44a,b), slightly darker on head and pronotum; pronotum with a thin dark line along the posterior border and two poorly developed maculae on the disc. Elytra with five longitudinal vittae, plus two lateral maculae.

Underside yellow, with exception of metaventrite, metaepisterna and metacoxae, which are black, and prosternal process, reddish-yellow. Sternites can be completely dark, faded apically or completely yellow. Punctuation deep and impressed. Prosternal process bordered and keeled ( Fig. 44c).

Legs completely reddish-yellow; metafemora covered by a dense punctuation; external face of metatibiae without additional punctures under the main series.

Male: Protarsi slightly dilated. Anterior claws ( Fig. 44d,e) moderately long and robust, unequal: the inner with a ventral expansion. Median lobe of aedeagus and parameres as in Fig. 44f,g). Posterior margin of pronotum slightly wider than elytra.

Female: Posterior margin of pronotum slightly narrower than elytra, with posterior angles more rounded than in males.

Variability. C.R. Turner (personal communication, 2007) suggested a geographical association to the different colouration of the abdominal sternites. This requires the examination of further material before a definitive conclusions could be attained.

Habitat. There is no published data. It seems to be a species of lowland streams as well as temporary and seasonal still waters (C.R. Turner, personal communication, 2007). P. Mazzoldi in Cape Agulhas (personal communication, 2007) collected one female specimen in a brackish pond, near the seashore.

Distribution ( Fig. 57). South Africa: Western and Eastern Cape.