Parhydraena ancylis, 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 : 23-25

Parhydraena ancylis new species

( Figs. 46, 48, 94)

Type material. Holotype (male): South Africa: Western Cape Province, Heuningnes River , shore washing, 34° 42' S, 20° 2' E, 28.x.1983, Endrödy-Younga (#2028). Deposited in the TMSA . Paratypes (87): South Africa: Western Cape Province, 5 mi. SW Villiersdorp , 33° 59' S, 19° 16' E, 11.ii.1951, Brinck & Rudebeck (2 LUM) ; Agulhas Plain , wetland 110.1, 34° 41' S, 19° 43' E, 11.x.2007, M. Mlambo & M. Bird (1 UCT) ; Agulhas Plain , wetland 110.2, emergent vegetation, 34° 41' S, 19° 43' E, 11.x.2007, M. Mlambo & M. Bird, (4 UCT) ; Bontebok NP, river bank, sievings, 34° 4' S, 20° 27' E, 15.xi.1993, M. Uhlig (13 ZMHB) ; Cape Flats , ca. 3.5 mls . SE of Philippi , grassy flood pools, algae, 34° 2' S, 18° 36' E, 5.viii.1954, J. Balfour-Browne (347) (1 BMNH) ; De Hoop Nat. Res. , lake shore, reed sievings, 34° 27' S, 20° 24' E, 17.xi.1993, M. Uhlig (18 ZMHB) ; Elandsdrift , shore washing, 34° 39' S, 19° 53' E, 24.ii.1981, Endrödy-Younga (#1747) (1 TMSA) ; Great Berg River, Bridgetown Station 16, 32° 5' S, 18° 51' E, 20.ii.1952 (GBG 523A) (1 AMG) ; Great Berg River, Kersefontein Station 21, marginal vegetation, GBG 443B, 32° 55' S, 18° 20' E, 1.xii.1951 (2 AMG) ; Great Berg River, Kersefontein Station 21, marginal vegetation, GBG 508B, 32° 55' S, 18° 20' E, 29.i.1952, (3 AMG) ; Great Berg River, Piketberg Station 18, 32° 53' S, 18° 44' E, 9.ix.1952 (GBG 607K) (1 AMG) ; Great Berg River, Sandrift Station 19, marginal vegetation, GBG 547A, 32° 56' S, 18° 32' E, 28.iii.1952, (1 AMG) ; Grootvadersbosch N. R., Bushbuck Trail (near Grootvadersbosch R.), young afromontane forest; FMHD #204-009, flight intercept trap, elev. 330 m, 33° 59' S, 20° 48' E, 26.i–26.ii.2004, Newton, Thayer et al. (1075) (1 FMNH) ; Heuningnes River , shore washing, 34° 42' S, 20° 2' E, 28.x.1983, Endrödy-Younga (#2028) (3 TMSA) ; Hout Bay, Hout river margins with vegetation, 34° 2' S, 18° 21' E, 19.iii. 2001, I. Ribera & A. Cieslak (3) (3 BMNH, 8 MNCN) ; Olifants River at Citrusdal , 32° 36' S, 19° 1' E, 7.xi.1950, Brinck & Rudebeck (1 LUM) ; Piketberg , wetland 17.2, emergent vegetation, 32° 42' S, 18° 50' E, 5.ix. 2007, M. Mlambo & M. Bird, (3 UCT) ; Riverdale District, near Albertinia, rd. to Riversdale , 34° 13' S, 21° 35' E, 16.ii.1947, J. Omer-Cooper (1 BMNH) ; Riversdale Dist., Kaffir Kuil , 34° 22' S, 21° 26' E, 17.xi.1947, J. Omer-Cooper (1 BMNH) ; Small vlei near Cape Town , 33° 55' S, 18° 25' E, 18.xi.1947, J. Omer-Cooper (11 BMNH) ; Sout River , wetland 9.2, 33° 42' S, 18° 28' E, 17.ix. 2007, M. Mlambo & M. Bird, (1 UCT) ; Swellendam Dist. , irrigation stream, 17.xi.1947, J. Omer-Cooper (4 BMNH) ; Swellendam District , 20 mi. SE Swellendam , 34° 10' S, 20° 40' E, 3.i.1951, Brinck & Rudebeck (SSAE Stn. 110) (1 LUM) .

Differential diagnosis. Similar in dorsal habitus and maxillary palpus length to P. maureenae ; distinguished therefrom by the smaller size (ca. 1.75 mm vs. 2.00 mm), the narrower elytral intervals, and the denser punctation of the frons and pronotal relief ( Figs. 38, 46). Males of the two species have similar modifications of ventrite 6. Males of P. ancylis are distinguished from the externally quite similar P. seriata by the modification of ventrite 6. The aedeagi of the three species differ markedly, and should be examined for reliable determinations ( Figs. 40, 45, 48).

Description. Size (length/width, mm) holotype: body (length to elytral apices) 1.75/0.75; head 0.27/0.46; pronotum 0.42/0.64, PA 0.49, PB 0.56; elytra 1.10/0.75. Head dark brown to piceous, remainder of dorsum brown, disc of pronotum slightly darker than surrounding area; legs light brown; maxillary palpi light brown, distal 1/2 of last mere slightly darker than remainder of palpus. Holotype slightly teneral.

Head with eyes moderately large, in dorsal aspect 9 convex facets in longest series. Ocelli distinct round small shining, each located at base of shallow oblique interocular fovea. Frons on disc densely, rather coarsely punctate, ca. 1xef, interstices effacedly microreticulate, weakly shining, 0.5–1xpd; area between interocular foveae and eye microreticulate, punctate, dull. Clypeus dull, microreticulate and indistinctly punctate, punctures much smaller and less dense than those of frons disc, except anterior margin shining. Labrum dull, apicomedially emarginate to form rounded lobe on each side; laterally fringed with short arcuate setae. Maxillary palpi elongate, combined lengths of meres slightly less than width of head (ratio ca. 29/33); ratios of meres 2–4 ca. 10/6/13. Mentum and submentum sparsely finely punctulate, microreticulate.

Pronotum, except discal relief, densely punctate, some punctures confluent; anterior margin weakly arcuate, median 1/3 with extremely narrow hyaline border. Anterior angles obtuse, widely rounded. Sides rounded, widest just before middle, behind middle gradually attenuate, very weakly, if at all, sinuate. Posterior angle obtusangulate. Disc with posterior impression deeper than anterior, broadly U-shaped, with median anterior margin more abrupt where disc weakly elevate; punctation denser in impressions, sparser on discal relief, interstices shining, 1–3xpd; shallow wide impression at each posterior angle. Sculpture laterally subrugose, dull. Each puncture with anterior margin extended posteriorly as narrow ridge, dividing puncture into a pair of two smaller punctures each of which smaller than eye-facet, short recumbent or decumbent seta arising from posterior extreme of dividing ridge.

Elytra elongate-ovate, sides weakly arcuate, margins distinct from shoulder for 4/5 of length, sutural angle slightly more acute in female than in male. 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 apical declivity. Interval width 1–2xpd, shining, each with unilinear or irregular row of minute granules, each granule at its posterior side with short recumbent seta, setae very similar in length and density to setae of serial punctures.

Metasternum with moderately shallow median elongate oval impression in basal 1/2, midlongitudinal shining carina between anterior extreme of oval impression and mesoventral intercoxal process. Metaventrite and abdominal ventrites 1–4 hydrofuge pubescent. Ventrite 5, in male, hydrofuge pubescent in basal 1/3 laterally, posterior margin of pubescent area produced in middle to 4/5 length of ventrite, in female basal 1/2 of ventrite hydrofuge pubescent; shining part of ventrite 5 very sparsely pubescent in both sexes. Ventrite 6 very weakly, effacedly microreticulate, shining, in male middle part glabrous and swollen in anterior 2/3, posterior 1/3 depressed and sparsely setose, two minute papillae, side-by-side, in midline at juncture of swollen and depressed areas; in female shape simple, with transverse band of sparse setae across posterior 1/2. Male: last ventrite asymmetrical, apex lobiform and setose; last tergite with tuft of setae on each side of apicomedian notch into which fits lobe of last ventrite. Female: last ventrite sparsely pubescent, margin rounded; last tergite with small tuft of setae on each side of very weak apicomedian emargination.

Legs moderately long and slender, combined lengths of metatibia and metatarsus greater than width of head (ratio ca. 42/33), ratio of lengths of metatibia/metatarsus ca. 25/17. Basal 3 pro- and mesotarsomeres, in male, with pad of suction setae.

Wings fully developed in holotype and all dissected males.

Aedeagus length ca. 0.37 mm; distal piece with large strong hook-shaped process; main-piece wider in ventral than lateral view ( Fig. 48).

Etymology. Named in reference to the prominent hook-shaped process of the aedeagus.

Distribution. Currently known from southern and western Western Cape Province ( Fig. 94).