New species and new records of Pterosthetops: eumadicolous water beetles of the South African Cape (Coleoptera, Hydraenidae)
Author
Bilton, David T.
text
Zootaxa
2014
3811
4
438
462
journal article
45587
10.11646/zootaxa.3811.4.2
dad75c9b-1930-47fb-ba79-eb519a90c45a
1175-5326
253023
99629EFB-F2F6-4DE8-AABA-D71069106912
Pterosthetops uitkyki
sp. nov.
(
Figs 3
D & 4D)
Type
locality
.
South Africa
, Western Cape, Cederberg mountains, wet rock face in Uitkyk Pass above
Algeria
, D.T. Bilton leg. (
Fig 5
C).
Type
material
.
Holotype
(male): “
24/ix/2012
South Africa
WC// Cederberg Uitkyk Pass above// Algeria—rockface seepages// D T Bilton leg.” (genitalia extracted and mounted on same card) and red
holotype
label (
SAM
).
Paratypes
(5):
South Africa
:
2 ♂
, 2 ♀ “
24/ix/2012
South Africa
WC// Cederberg Uitkyk Pass above// Algeria—rockface seepages// D T Bilton leg.” (
CDTB
;
NMW
);
1 ♂
“
21/ix/2010
South Africa
WC// Cederberg Uitkyk Pass above// Algeria—rockface seepages// D T Bilton leg.” (
SANC
). All with red
paratype
labels.
Description
. Size:
Holotype
: BL
2.25 mm
; EL
1.45 mm
; EW
0.85 mm
.
Paratypes
: ♂s BL
2.35–2.45 mm
; EL
1.45–1.5 mm
; EW
0.85–0.9 mm
. ♀s BL
2.55–2.65 mm
; EL
1.55–1.65 mm
; EW
0.9–0.95 mm
. Dorsum (
Fig. 3
D) dark brown to black, explanate elytra; margins somewhat lighter; upper surface with a brassy metallic sheen. Maxillary palpi pitchy brown to black, legs dark reddish brown; femora and tarsi darker than tibiae. Venter predominantly dark piceous, with silvery hydrofuge pubescence.
Head: Labrum transverse, broadly rounded at sides and front agles, with marked apicomedian emargination, running approx. 0.5 of length. Sides and anterior angles of apicomedian emargination distinctly raised. Surface of labrum dull, with strong microreticulation and scattered long decumbent setae, especially close to apical and lateral margins. Upper surface of head, with the exception of small patches either side of central vertex, with strong punctulate microreticulation, rather dull. Smooth areas of vertex with scattered short setae, in shallow, irregular sockets. Scattered stout, decumbent setae towards lateral margins of frons and clypeus. Frons with a central elevation, broken by a slightly elongate concavity between the well-marked, shining ocelli; sides of concavity steep anteriorly, open posteriorly. Arcuate sulci present, running from just in front of each ocellus towards the lateral corners of the frontoclypeal suture, opening onto clypeus. Frons slightly raised and thickened anterior to eyes. Eyes large, occupying slightly less than 0.5 of the lateral margins of the head; convex facets in longest series.
Pronotum: Distinctly cordate, with broadly and strongly explanate sides. Anterior angles obtusely rounded. Sides very weakly crenulated and weakly to sharply arcuate over anterior 0.6, then almost straight to slightly acute posterior angles (
Fig. 3
D). Anterior broadly rounded, with weak hyaline border in middle. Posterior margin strongly bisinuate to centre. Explanate portions of anterior pronotum with very weak microreticulation, giving a rather shining appearance. Disc of pronotum with weak isodiametric microreticulation, strongest close to front and hind margins, and in fovea. Disc with shallow coarse ounctures with short, decumbent setae. Punctures largser and deeped in transverse fields close to anterior and posterior margins. Median longitudinal sulcus foveate anteriorly and posteriorly; anterior fovea elongate; posterior less so. Foveae with more strongly impressed microreticulation. Posterior admedian fovea shallow, elongate aneriolaterally; microreticulate as median fovea. Anterior admedian fovea open; obsolete. Adlateral fovea well-marked, small, rounded and pit-like. Trace of longitudinal canal between anterior and posterior adlateral fovea.
Elytra: Elongate, with rounded shoulders and apex. Broadest just behind middle, with sides weakly and evenly rounded to shoulders and posterior angles. Explante lateral margin present from shoulder to apex; narrow behind shoulder, but relatively broad over most of length. Apices separately rounded. Each elytron 10-seriate punctate, and with a shallow, transverse depression (saddle) close to middle, occupying intervals 2–4; flat region of interval 4 extending the saddle region in front of the flat areas of intervals 2–3 by approx. same length. Saddle occupying approx. 0.25 of elytral length. Additional, very shallow saddle depression posteriolateral to saddle, occupying intervals 6–7. Punctures of elytral striae each bearing a small seta. Elytral series somewhat irregular in saddle. Intervals 1–7 weakly to moderately elevated outside saddle and other depressions. Interval 8 narrower than previous 7, and more strongly raised over front 0.6 of elytra. Intervals with small, setose tubercles; setae long, white, recumbent, those outside saddle region reaching next tubercle on intervals 1–4; those on shoulder region of interval 5 also reaching next tubercle in row. Elsewhere setae very short, especially towards apex. Entire upper surface shining, with some traces of microreticulation on intervals 1–6.
Venter: Mentum shining, microreticulate with sparse setae. Submentum also shining, without microreticulation and with scattered long decumbent setae. Genae shining, with isodiametric microreticulation anteriorly, becoming strongly transverse towards rear. Gular shining, with weak, transverse microreticulation; strongest laterally. Pronotal hypomeron shining, finely microreticulate and wrinkled. Prosternum dull, finely wrinkled, with a weak central ridge, and distinct hydrofuge vestiture, particularly towards lateral margins. Meso and metaventrites with well-developed squamose hydrofuge vestiture; vestiture shorter and less dense towards lateral and hind margins. Mesoventral plaques visible, glabrous, but dull. Median ridge splitting to form admedian ridges apically, forming an inverted Y. Admedian ridges weak and pilose. Border between mesoventrite and anepisternum 2 marked by a glabrous ridge. Metaventrite with distinct longitudinal depression over rear 1/2 of sternite; foveate anteriorly. Elytral pseudepipleurs with weak microreticulation; finely wrinkled, shining. Epipleurs narrow and ridge-like; shining. Abdominal ventrites 1–4 fringed with long, closely-set squamiform setae at hind margins. Ventrites 1–5 with triangular patches of hydrofuge setal vestiture anterio-laterally. Central area of ventrites 1–4 shining, with traces of weak, transverse microreticulation interior to hydrofuge vestiture. Ventrites 5–6 with weak, transverse microreticulation throughout. Ventrites 5 & 6 with transverse row of long, adpressed hair-like setae, positioned ¾ of the way down the sternite.
Aedeagus: Elongate, with parameres attached near base, and extending well beyond apex of main piece. Main piece with centrally-directed tooth in ventral view, and stout ventral setae. Distal lobe elongate and tube-like; curved in lateral and ventral view, and extending well beyond apices of parameres (
Fig. 4
D).
Female: Elytral microreticulation stronger than that of males.
Variation: Elytral sheen varies between
paratypes
, sometimes being almost absent. Also some variation in the extent of elevation of elytral intervals.
Differential diagnosis.
Recognized by a combination of the shining elytra which lack microreticulation, the long, single elytral saddle, the long recumbent setae in rows on the inner elytral intervals and the first elytral interval being raised in the saddle region. Male genitalia characteristic (see
Fig. 4
D).
Distribution
. Known to date only from the
type
locality, a wet rock face in Uitkyk Pass, one of the wettest areas of the Cederberg range in the Western Cape region (
Fig. 9
).
Etymology
. Named after the
type
locality, Uitkyk Pass in the Cederberg (
Figs 5
C & 7C); uitkyk (Afrikaans) = lookout, view (English).