Parhydraena divisa, Perkins, 2009

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 : 16-17

Parhydraena divisa new species

( Figs. 35, 37, 103)

Type material. Holotype (male): Sudan: Gilo , water cache shallow duck pond, 4° 2' N, 32° 51' E, 28.vi.1979, A. L. Armstrong. Deposited in the MCZ.

Differential diagnosis. Recognized by the coarsely, densely punctate frons and pronotal relief, the coarsely punctate elytra, the comparatively short maxillary palpi (palpus length/head width ca. 0.57), and the comparatively large body size (length ca. 1.98 mm) ( Fig. 35). The aedeagus, while unique, perhaps indicates relationships with P. maculicollis and P. parva ( Figs. 37, 41, 44).

Description. Size (length/width, mm) holotype: body (length to elytral apices) 1.98/0.85; head 0.33/0.53; pronotum 0.46/0.72, PA 0.60, PB 0.61; elytra 1.25 /0.85. Dorsum black, maxillary palpi dark brown, legs brown except "knees" piceous; venter dark brown to piceous.

Head with eyes large, in dorsal aspect 10–11 convex facets in longest series. Ocelli distinct round small shining, each located at base of shallow oblique interocular fovea. Frons on disc coarsely densely punctate, ca. 2–3xef, interstices narrow walls, effacedly microreticulate, moderately shining; area between interocular foveae and eye microreticulate, punctate, dull. Clypeus dull, strongly microreticulate except anterior margin shining, indistinctly punctate, punctures much smaller and much less dense than those of frons disc. Labrum large, as long as clypeus, dull, anterior margin straight or very weakly arcuate and distinctly reflexed; laterally fringed with short arcuate setae. Maxillary palpi short, combined lengths of meres much less than width of head (ratio ca. 21/37); ratios of meres 2–4 ca. 7/4/10. Mentum densely, moderately finely punctulate, microreticulate. Submentum finely sparsely punctulate, shining.

Pronotum very densely, coarsely punctate, subrugulose, punctation slightly coarser laterally than on disc; anterior margin moderately arcuate, median 1/3 with extremely narrow hyaline border. Anterior angles obtuse, moderately widely rounded. Sides rounded, widest just before middle, behind middle gradually attenuate, very weakly sinuate. Posterior angle obtusangulate. Disc with anterior and posterior transverse impressions very shallow; very shallow wide impression at each posterior angle. Each puncture with anterior margin extended posteriorly as narrow ridge, dividing puncture into a pair of two smaller punctures each of which ca. 1xef, and some of which confluent with adjacent puncture pair; short indistinct recumbent seta arising from posterior extreme of dividing ridge.

Elytra elongate-ovate, sides weakly arcuate, narrow explanate margins distinct from shoulder for 4/5 of length, apices conjointly weakly truncate. Ten-seriate punctate, only first series striate-impressed in distal 1/2, punctures ca. 2xef, longitudinally separated 0.5–1xpd, becoming finer and shallower on posterior declivity. Interval width 1–2xpd, each with unilinear row of distinct granules, each granule at its posterior side with short recumbent seta, setae very similar in length and density to setae of serial punctures.

Metaventrite with rather deep median elongate oval impression in basal 1/2, midlongitudinal low shining carina between anterior extreme of oval impression and mesoventral intercoxal process. Metaventrite and abdominal ventrites 1–4 hydrofuge pubescent. Ventrite 5 hydrofuge pubescent in basal 1/3 laterally, posterior margin of pubescent area produced in middle to 1/2 length of ventrite. Ventrite 6 shining, posterior margin arcuate, median area weakly concave, with transverse band of sparse setae across posterior 1/2. Last ventrite asymmetrical, apex with very small lobe; last tergite with tuft of setae on each side of apicomedian notch into which fits lobe of last ventrite. Female unknown.

Legs moderately long and slender, claws large, combined lengths of metatibia and metatarsus greater than width of head (ratio ca. 44/37), ratio of lengths of metatibia/metatarsus ca. 25/19. Basal 3 pro- and mesotarsomeres, in male, with pad of suction setae.

Wings fully developed in holotype.

Aedeagus length ca. 0.48 mm; main-piece, in ventral view, with short process on left side, in right lateral view with narrow, sharply pointed process; distal piece large, hood-like, with bifurcate apex, median ventral area with fine strigulations ( Fig. 37).

Etymology. Named in reference to the divided pronotal punctures.

Distribution. Currently known only from the type locality in southern Sudan ( Fig. 103).