Protozantaena birdi, Bilton, 2022

Bilton, David T., 2022, A new species of Protozantaena Perkins, 1997 from the Great Escarpment of South Africa (Coleoptera, Hydraenidae), Zootaxa 5125 (1), pp. 92-96 : 93-96

Protozantaena birdi sp. nov.

( Figs 1B & D , 2 )

Type locality. South Africa, Eastern Cape Province, Compassberg , permanent stream on south-east side of main peak, 31°44’31.12”S 24°32’58.42”E, 1,900 m .

Type material. Holotype (male): “ 13/iii/2018 South Africa EC// Compassberg —stream on// S side of peak @ 1,900 m // D T Bilton leg.” and red holotype label ( AMG).

Paratypes (19): 9♂, 7♀ same data as holotype ; 1♂, 2♀ “ 8/iii/2018 South Africa EC// Winterberg , stream above Huntley // Glen, 32° 22’ 19.02” S // 26° 10’ 55.05” E, 1,670 m // D T Bilton leg.” and red paratype labels ( AMG, CBP, DMSA, NMW) .

Description. Size: Holotype: BL 1.40 mm; EL 0.80 mm; EW 0.55 mm. Paratypes: Males BL 1.40–1.50 mm; EL 0.80–0.85 mm; EW 0.55–0.60 mm. Females BL 1.45–1.50 mm; EL 0.80–0.95 mm; EW 0.65–0.70 mm.

Colour: Dorsum ( Fig. 1B ) dark brown to black; pronotal and elytral margins paler. Antennae, maxillary palpi and legs yellowish brown. Venter dark brown; pronotal hypomeron and elytral epipleurs yellowish brown.

Head: Labrum transverse, large, rectangular, slightly longer than clypeus; apical margin weakly upturned; laterally fringed with short arcuate setae; dorsal surface shining, microreticulation restricted to traces of transverse lines, with sparse, fine micropunctation and long, sparse, fine adpressed setae. Frontoclypeal suture distinct, weakly arcuate. Clypeus, frons and vertex shining, with sparse, medium punctures bearing long, fine, adpressed setae, Microreticulation restricted to lateral border of clypeus and frons between interocular foveae and compound eyes, where it is elongate, and along posterior margin of vertex and occiput where it is transverse. Ocelli indistinct, shining, each located at the base of shallow, oblique interocular fovea, which extend forward to frontoclypeal suture. Compound eyes relatively small; eight ommatidia in longest series. Maxillary palpi moderately long, last palpomere elongate, widened slightly subbasally, then narrowed basally on anterior surface.

Pronotum: Transverse, widest just before middle. Anterior margin broadly arcuate; median 0.25 with distinct hyaline border; posterior margin weakly bisinuate around centre; lateral margins weakly attenuated and sinuate behind widest point, anteriorly arcuate to anterior angles; in lateral view appearing thickened, with upper and lower rim. Anterior angles broadly rounded, posterior angles weakly obtuseangulate. Anterior and posterior impressions very shallow, almost obsolete, relatively straight. Without impression at posterior angles. Surface strongly shining, especially on disc, microreticulation absent. Entire surface punctate, each puncture with anterior margin extended posteriorly as narrow ridge, apparently dividing puncture into a pair of two smaller punctures; long, fine, recumbent setae arising from posterior extreme of dividing ridge. Punctures denser towards lateral margins, less so along anterior and posterior margins, very sparse to absent on disc, where sparse micropunctures are also visible.

Elytra: Elongate, attenuate posteriorly. Sides arcuate, explanate margins narrow; apices truncately rounded. Ten-seriate punctate; punctures without granules, series not striate-impressed; punctures moderate, round, shallow, each bearing small, fine, white, recumbent or decumbent seta; spacing between punctures approx. 0.5–0.75 puncture diameter. Interstices shining, each with unilinear row of fine, punctures, bearing long, fine, recumbent setae, similar to those of puncture rows; punctures without granules.

Venter: Mentum, submentum, and genae shining, microreticulation absent; with sparse, fine punctures, bearing fine, white decumbent setae. Gula with sparse medium punctures bearing recumbent setae; surface between punctures with transverse microreticulation, overall appearance relatively dull. Prosternum rugosely microreticulate; punctate anteriorly and laterally, punctures bearing erect golden setae, particularly long centrally; mesoventrite rugosely microreticulate, punctate, with short, erect setae. Pronotal hypomeron broad, glabrous, with sparse, fine micropunctures. Elytral epipleurs broad anteriorly, narrowing over posterior 0.6 and absent at apices; surface shining, glabrous, without evident microreticulation or punctation. Metaventrite shining, with dense, medium punctures bearing shaggy hydrofuge vestiture; with shallow, longitudinal oval impression in centre. Abdominal ventrites 1–4 punctate as metaventrite and completely hydrofuge pubescent, some longer hairs scattered amongst shorter vestiture and along posterior margins of ventrites; ventrite 5 with row of pubescence at anterior margin only; ventrites 5-7 shining, each with an irregular transverse row of punctures, some bearing long, yellowish, decumbent setae. Last tergite with tuft of setae on each side of narrow, shallow apicomedial notch.

Legs: Moderately long, tarsal segments relatively narrow and elongate. Basal three tarsomeres with pad of suction setae.

Aedeagus: Elongate ( Fig 1D ), gonopore bearing flagellum very long, arcuate, bending toward base, as long as or longer than main-piece; supporting flagellum shorter. Main piece straight or nearly so in ventral view, with abrupt narrowing approx. 0.3 from apex; in lateral view arcuate, with distinct shift in angle of curvature just before mid-point of length and markedly narrowing in width towards setose area, where widened; parameres very short, each with two setae.

Differential diagnosis. The new species is close morphologically to P. labrata , known from the Central Namibia, sharing with this species the same general habitus, male labral modifications, maxillary palpal structure and aedeagal design. The two species differ consistently on a number of characters, however. Compared to P. labrata , P. birdi sp. nov. is less coarsely punctate dorsally, large punctures being almost absent from the pronotal disc, and elytral serial punctures being smaller and less strongly impressed ( Fig. 1A & B ). The new species is also relatively narrower and consistently darker in dorsal colouration than P. labrata , and has finer, more elongate, maxillary palpi. The aedeagus of P. birdi sp. nov. also differs consistently, if subtly, from that of P. labrata : the main piece of the new species is slightly longer and narrower, rather abruptly so approx. 0.3 from apex. The angle of curvature of the main piece of P. labrata is relatively consistent over its entire length, whereas that of the new species changes just before the mid-point. Note that the length and angle of curvature of the flagellae differ between specimens within both species, and can change as the aedeagi are moved between media and mountants—apparent differences between flagellae in Fig. 1 are not species-specific.

Etymology. Named after my friend and colleague Dr Matthew Bird, University of Johannesburg, who assisted with the collection of the type series in the Compassberg.

Distribution and ecology. Known from two relatively close localities in the Cape Midlands section of the Great Escarpment (sensu Clark et al. 2011); the Compassberg and Winterberg ( Fig. 2A ). In both localities, specimens were collected from the margins of small streams (e.g. Fig. 2B ), which retain some water in all but the driest years. The ecology of the species appears broadly similar to that of P. labrata , based on label data cited in Perkins (1997; 2009).

Figures

FIGURE 1. Protozantaena species. A) P. labrata Perkins, 1997, paratype, Namibia, Naukluft, habitus and labels; B) P. birdi sp. nov., holotype habitus; C) P. labrata, paratype, Namibia, Naukluft, aedeagus; D) P. birdi sp. nov., holotype aedeagus. Scale bars A & B) = 0.5 mm; C & D) = 100 μm.

FIGURE 2. Protozantaena species, distribution and habitat. A) Distribution of Protozantaena in Southern Africa, red symbol = P. labrata Perkins, 1997, blue symbols = P. birdi sp. nov.; B) Type locality of P. birdi sp. nov. South Africa, Eastern Cape Province, Compassberg, permanent stream on south-east side of main peak—yellow arrow indicates where stream was sampled (photo R. Perissinotto).