Nebrioporus canariensis ( Bedel, 1881 )

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 : 97-98

Nebrioporus canariensis ( Bedel, 1881)

Fig. 41

Hydroporus canariensis Bedel (1881: 265) (replacement name for H. tessellatus Aubé , preoccupied by Drapiez (1819));

Régimbart (1895: 15); Bedel (1925: 351). Deronectes (Potamodytes) canariensis (Bedel) ; Zimmermann (1919: 187; 1920: 123). Deronectes (Potamonectes) canariensis (Bedel) ; Winkler (1924: 226); Uyttenboogaart (1930: 216); Zimmermann (1933:

155); F. Balfour-Browne (1940: 224). Potamonectes canariensis (Bedel) ; Guignot (1940: 11). Potamonectes (Zimmermannius) canariensis (Bedel) ; Guignot (1949b: 6; 1959a: 443). Nebrioporus (Zimmermannius) canariensis (Bedel) ; Nilsson & Angus (1992: 287); Nilsson (2001: 171; 2003: 67); Foster (2004: 158). Hydroporus tessellatus Aubé (1838b: 516) (orig. descr.); Wollaston (1864:79). Deronectes tessellatus (Aubé) ; Sharp (1882: 425); Branden (1885: 49). Potamonectes (Zimmermannius) tessellatus (Aubé) ; Machado (1987: 45). Potamonectes (Zimmermannius) canariensis ssp. gomerensis Guignot (1949b: 6) (orig. descr.); Guignot (1959a: 443);

Machado (1987: 45) (synonymy of H. tessellatus Aubé ).

Type locality. H. canariensis : Spain > Canary Islands; P. canariensis ssp. gomerensis : Spain > Canary Islands> La Gomera> Barranco de la Laja.

Type material. Hydroporus canariensis : Syntypes ( MNHN), not studied .

Potamonectes canariensis ssp. gomerensis : Holotype ♀ ( IRSNB) "La Gomera: Barr. De la Laja 420 m. 26.IV.1935 [glued on IRSNB label " Coll. R.I.Sc.N.B. Espagne: Islas Canarias A. d’Orchymont] \ Dr. F. Guignot det. Potamonectes canariensis var. gomerensis Guign. Type \ Type [red rectangular label]"; paratype ♂ ( IRSNB), immature, same data as holotype except for " R. Mouchamps det. Potamonectes canariensis ssp. gomerensis Guign. \ Paratype [orange rectangular label]".

Additional material examined. Spain, Canary Islands: Tenerife, Igueste , 100 ft., 22.V.1952, J. M. Fernandez, B.M. 1952-343 (5 exs. BMNH) ; " Canary Isl., Teneriffe , 67-56, Sharp Coll. 1905-313" (5 exs. BMNH) ; " Canar. Ins., Polatzek , Coll. Dr. J. Fodor " (3 exs. HNHM) ; " Teneriffa , Coll.Reitter " (3 exs. HNHM) ; Gomera, Hormigua, Barranco de Monteforte , 18–22.III.1988, leg. L. Hendrich (17 exs. LH, MTP) ; Gran Canaria, San Bartolome , 1100 m, 5.VI.1989, leg. M. Balke & L. Hendrich (20 exs. LH, MTP) .

Description. TL 5.4–6.0 mm; MW 2.6–2.8 mm. Elongated oval, almost depressed. Angle between pronotum and elytra well visible. Dorsal colouration pitch-black, with pale, not well defined spots on elytra.

Head reddish-brown, darkened around the eyes. Antennae reddish-yellow, darkened at the apex of each segment, exception made for the first three. Ventral face of head black, microreticulate and with a small area covered by a fine punctuation just behind the eyes; postocular ridge hardly visible. Mouthparts dark reddish.

Pronotum rather narrow, with maximum width near the base, lateral sides converging inward, rounded and thickly bordered. Surface covered by a fine, shallow and diffuse punctuation, together with larger punctures along anterior and posterior margins; lateral and inner margins shagreened by longitudinal grooves of different sizes, larger and deeper along the posterior margin. Angle between pronotum and elytra well defined in both sexes.

Elytra elongated, with maximum width just behind the middle of the length, covered by a short, grey pubescence and a fine but deep punctuation. Two series of longitudinal rows of punctures are well visible, running inside a kind of shallow groove along each elytron. Subapical spines obsolete, but clearly visible as a sinuation in the females.

Dorsal colouration ( Fig. 41a,b) almost completely pitch-black, except for the reddish antero-lateral sides of pronotum and the more or less developed yellow spots on elytra, situate mostly at the base and preapically (resembling traces of longitudinal vittae).

Underside black, proepisterna, hypomera, epipleuron, prosternal and metacoxal process and apex of last four sternites reddish. Surface covered by a fine, impressed, not very dense punctuation; small and shallow grooves are present, sparse, between the punctures, especially on metacoxal plates and first sternites. Prosternal process with a blunt and flat medial carena, laterally with two series of large punctures. Sternites without a visible apical comb of setae.

Legs reddish, with pro and mesotarsi slightly darkened. Metafemora covered by a dense punctuation. Anterior face of metatibia with sparse supplemantary punctures.

Male: Protarsi slightly dilated. Anterior claws ( Fig. 41c,d) longer and straight than in females, inner claw, basally, with a clear ventral tooth. Median lobe of aedeagus ( Fig. 41f) elongate and slender, regularly curved in lateral side; parameres ( Fig. 41e) narrow apically.

Female: A bit duller than males. Pronotum usually narrower, with larger punctures on its surface less deeply impressed. Subapical sinuation on each elytron normally visible; elytra apically protruding.

Habitat. Barrancos (streams) in open areas in the lowlands (less commonly in the highlands) in various kinds of habitat such as rock pools, slow-flowing water with algal vegetation, among gravels on stream bottoms, etc. where it can be abundant (after Machado 1987).

Distribution ( Fig. 55): Canary Islands: Gomera, Gran Canaria, Hierro, La Palma, Tenerife. The record of this beetle from the island in the Outer Hebrides of Scotland (see Balfour-Browne F. 1940), has been recently rejected by Foster (2004).