Protozantaena labrata Perkins, 1997

Perkins, Philip D., 2009, Revisions of the genera Parhydraena Orchymont, Protozantaena Perkins, Decarthrocerus Orchymont, and Parhydraenopsis nomen novum, aquatic and humicolous beetles from Africa and Madagascar, and comparative morphology of the tribe Parhydraenini (Coleoptera: Hydraenidae), Zootaxa 2038, pp. 1-119 : 41-42

Protozantaena labrata Perkins, 1997

( Figs. 1, 3, 8, 15, 26, 67, 69, 98)

Protozantaena labrata Perkins, 1997: 175 . Type material. Holotype (male): Namibia: Naukluft , Naukluft Park, shore washing, 24° 16' S, 16° 15' E, 26.x.1974, Endrödy-Younga (#431). Deposited in the TMSA.

Differential diagnosis. Recognized among members of the genus by the comparatively long and distinctively shaped maxillary palpi (last palpomere wide subbasally, abruptly narrowed basally on anterior surface), the smooth and shining pronotal discal interstices, and the comparatively long tarsi ( Figs. 3, 67). The maxillary palpi of P. palpalis are also long (for the genus), but the two species are quite different in habitus, eye size, sculpture, among other characters. The aedeagus strongly indicates a relationship to P. malagasica ( Figs. 69, 70).

Description. Size (length/width, mm) holotype: body (length to elytral apices) 1.40/0.61; head 0.24/0.42; pronotum 0.33/0.54, PA 0.49, PB 0.47; elytra 0.90 /0.60. Color brown to dark brown, head and pronotal disc darker, sometimes piceous; legs and maxillary palpi brown to testaceous.

Head with eyes moderately small in dorsal aspect, ca. 6 rather coarse, convex facets in longest series. Ocelli indistinct, round small shining, each located at base of very shallow oblique interocular fovea. Frons finely punctulate, less than 1xef on disc, finer anteriorly, interstices ca. 2–4xpd. Clypeus effacedly microreticulate and very finely punctulate, weakly shining. Labrum rather large, longer than clypeus; in male with apical margin weakly upturned, in female simple; laterally fringed with short arcuate setae. Maxillary palpi moderately long, rather robust, last palpomere wide subbasally, abruptly narrowed basally on anterior surface, combined lengths of meres less than width of head (ratio ca. 19/28); ratios of meres 2–4 ca. 6/4/9. Mentum and submentum finely punctulate, interstices effacedly microreticulate, weakly shining; genae moderately swollen.

Pronotum with anterior margin arcuate, ca. median 1/2 with narrow hyaline border. Anterior angles moderately rounded. Sides anteriorly rounded, widest at about midlength, weakly attenuate and sinuate behind middle, in lateral view margin with single rim. Posterior angle obtusangulate. Discal relief very finely sparsely punctulate, punctures shallow, interstices shining; anterior and posterior impressions shallow, punctures much deeper and much larger than those on relief, some forming short transverse rows, each puncture with anterior margin extended posteriorly as narrow ridge, dividing puncture into a pair of two smaller punctures each of which ca. 0.3xef, short recumbent seta arising from posterior extreme of dividing ridge. Lacking impression at each posterior angle. Sculpture laterally subrugulose, dull.

Elytra weakly shining, attenuate posteriorly, sides weakly arcuate, explanate margins narrow. Ten-seriate punctate, not striate-impressed, punctures on disc rather large, round, ca. 2xef, interstices ca. 1xpd, without granules, punctures becoming much smaller and shallower over posterior declivity; intervals ca. 1–2xpd, each with unilinear row of short recumbent setae very similar in size and spacing to setae of serial punctures, without granules.

Metaventrite with shallow midlongitudinal groove, lacking carina between anterior extreme of groove and mesoventral intercoxal process. Metaventrite and abdominal ventrites 1–4 hydrofuge pubescent. Ventrite 5 hydrofuge pubescent in anterior 1/4, very sparse, long pubescence in transverse band across midlength. Ventrite 6 very sparsely pubescent in transverse band. Last ventrite very sparsely pubescent, free margin markedly arcuate; last tergite with moderately wide apicomedian emargination.

Legs moderately long, femora moderately broad, metafemora width/metatarsus length ca. 0.5; combined lengths of metatibia and metatarsus greater than width of head (ratio ca. 37/28), ratio of lengths of metatibia/ metatarsus ca. 21/16. Basal 3 protarsomeres, in male, with pad of suction setae.

Wings fully developed in holotype and all dissected males.

Aedeagus length ca. 0.46 mm (measured from base to bend in flagellum); gonopore bearing flagellum very long, arcuate, bending toward base, as long as main-piece; supporting flagellum slightly shorter; mainpiece straight or nearly so in ventral view, in lateral view arcuate and gradually decreasing in width from base to setose area, where widened; parameres very short, each with two setae ( Fig. 69). Spermatheca as illustrated ( Fig. 26).

Distribution. Currently known only from the type locality in Namibia ( Fig. 98).