Hydraena (Hydraenopsis) scabra d’Orchymont, 1925

Freitag, Hendrik & Jäch, Manfred A., 2007, Revision of the species of Hydraena Kugelann (Coleoptera: Hydraenidae) from Palawan and Busuanga, with descriptions of eleven new species, and redescription of Hydraena (Hydraenopsis) scabra d’Orchymont, 1925, Zootaxa 1431, pp. 1-44 : 6-11

Hydraena (Hydraenopsis) scabra d’Orchymont, 1925

(Figs. 3, 15a–h)

Hydraena scabra d’Orchymont 1925a: 200 (original description; placement in subgenus Hydraena s.str.), [1925b (incorrect identification: H. knischi d’Orchymont, 1928 )], 1926 (redescription, lectotype designation), 1928 (check list), 1932 (redescription; illustration of aedeagus). – Yano et al. 1983 (faunistic record; illustration of pronotum and aedeagus). – Hansen 1998 (world check-list). – Jäch et al. 2000 (world check-list; transferred to subgenus Hydraenopsis ).

Type locality. Montalban, Laguna Province, central Luzon, Philippines.

Type material. Lectotype ɗ ( ISNB): “ɗ \ Montalba[n] Philippines \ Type \ A. d’Orchymont det. H. scabra TYPE \ AEDEAGUS DRAWN BY P. D. PERKINS”. The aedeagus is kept in a microvial mounted on the same pin. The lectotype ɗ was identified as “?female” by d’Orchymont (1926) (see also d’Orchymont 1932).

Additional material examined. Palawan: 1 ɗ ( NMW): “ PHIL.: Palawan, Taytay; Tributary Manguao Stream, half-way to highway 10°46'N 119°31' E 0 3.4.1995, leg. Freitag (1)M”; 1 ɗ ( NMW): “ PHIL.: Palawan, Taytay; Tributary Manguao Stream, half-way to highway 10°46'N 119°31' E 0 3.4.1995, leg. Freitag (7)M”; 1 ɗ ( NMW): “ PHIL.: Palawan, Taytay; Tributary Manguao Stream, half-way to highway 10°46'N 119°31' E 0 3.4.1995, leg. Freitag (11)M”; 1 Ψ ( NMW): “ PHIL.: Palawan, Taytay; Tributary Manguao Stream, half-way to highway 10°46'N 119°31' E 0 3.4.1995, leg. Freitag (5)M”; 1 ɗ ( NMW): “ PHIL.: Palawan, Taytay; Lake Manguao tributary, Alipuran Stream, semi-prim. forest c. 40m asl, 10°45'N 119°32' E 29.4.1995, leg. Freitag (15)M”; 1 ɗ ( NMW): “ PHIL.: Palawan, Puerto Princesa, Tagabinet River, Bridge near Babuyan R. 10°04'N 118°52' E 25.3.1995, leg. Freitag (2)M”; 8 exs. ( NMW): “ PHIL.: Palawan, P.Princesa; Junction to Napsan, 8km SW PPC; 20m S Binuan Bridge, sec.veget. c. 20m asl 9°43'N 118°40'E, 28.3.1995 leg. Freitag (22)M”; 2 exs. ( NMW): “ PHIL.: Palawan, P.Princesa; Luzvimin-da,Villa Bukit, garden/farmland creek 8km SSW PPC; 20m asl 9°40'N 118°43'E, 25.3.1995 leg. Freitag(21)M”; 6 exs. ( NMW): “ PHIL.: Palawan, P.Princesa; S. Vincente Taranaban Riv; 0.5km N of Highway, mountain riv. resid. pool, 10m asl 10°01'N 119°01'E, 30.4.1995 leg. Freitag (16)M“; 3 exs. ( NMW): “ PHIL.: Palawan, P.Princesa; Luzviminda, forest creek, small fall, 9km SSW PPC; rocky banks, riffle, c. 50m asl 9°39'N 118°38'E, 14.12.1994,leg.Freitag(17a)M”; 6 exs. ( NMW): “ PHIL.: Palawan, P.Princesa; Luzviminda, forest creek, small fall, 9km SSW PPC; sandy banks, pool, c. 50m asl 9°39'N 118°38'E, 14.12.1994,leg.Freitag(17b)M”; 12 exs. (9 exs. NMW; 3 exs. IRML): “ PHIL.: Palawan, P.Princesa; Luzviminda, forest creek, small fall, 9km SSW PPC; side pools w/ leaves, c. 50m asl 9°39'N 18°38'E, 14.12.1994,leg.Freitag(17c)M”; 16 exs. ( NMW): “ PHIL.: Palawan 9 km W P. Princesa, Iwahig, 7.- 8.4.1994 leg. Zettel (60)”; 1 Ψ ( NMW): “ PHIL.: Palawan 17 km WSW P. Princesa, Tagbuna riv. 26.3.1994 FIGURES 3–6. Habitus of Hydraena . 3) Hydraena scabra d’Orchymont ; 4) H. jojoorculloi sp. n.; paratype Ψ; 5) H. nielshaggei sp. n., paratype ɗ; 6) H. zetteli sp. n., holotype.

FIGURES 7–10. Habitus of Hydraena . 7) Hydraena castanescens sp. n., holotype; 8) H. claudia sp. n., paratype Ψ; 9) H. kodadai sp. n., paratype ɗ; 10) H. palawanensis sp. n., paratype ɗ.

leg. Zettel (51)”; 1 ɗ ( NMW), 1 Ψ (WPU) “ PHIL.: Palawan 7 km N Narra, Estrella Falls 2.4.1994 leg. Zettel (57)”; 12 exs. ( NMW): “ PHIL.: Palawan 1994 7 km N Narra, 5.4. Estrella Falls leg. Zettel (59)”; 1 ɗ ( NMW): “ PHILIPPINEN: Palawan 10 km NE Quezon, Tumarbon Falls 3.– 4.4.1994 leg. Zettel (58)”; 34 exs. ( NMW): “ PHIL.: Palawan Brooke’s Point Mate 31.3.1994 leg. Zettel (54)”; 1 ɗ ( UPLB): “ PHILIPPINES: Palawan Port Barton, 66 km N Puerto Princesa, puddle 2.9.1994 A. Zwick”; Busuanga : 32 exs. (31 exs. CZW; 1 ex. NMW): “ PHILIPPINEN: Palawan Pr. Busuanga Is., 2 km W Coron, 23.2.1996, leg. H. Zettel (80a)”; 15 exs. (13 exs. CZW; 2 exs. NMW): “ PHILIPPINEN: Palawan Pr. Busuanga Is., 13 rd km WNW Coron, Balulu Falls, 24.2.1996, leg. H. Zettel (81)”; 27 exs. (25 exs. CZW; 2 exs. NMW): “ PHILIPPINEN: Palawan Pr. Busuanga Isl., 13 rd km WNW Coron, Balulu Falls, 2.2.1999, leg. H. Zettel (171)”; Mindoro: 34 exs. ( NMW): “leg. Jäch (1) PHILIPPINEN — Mindoro E Puerto Galera Sabang 13.11.1992 ”; 31 exs. ( NMW): “leg. Jäch (4) PHILIPPINEN — Mindoro 4km SE Puerto Galera 14.11.1992 ”; 1 ɗ ( NMW), 1 Ψ ( NMW): “leg. Jäch (5) PHILIPPINEN — Mindoro 10km W Puerto Galera 17.11.1992 ”; 1 ɗ ( NMW): “leg. Jäch (7) PHILIPPINEN — Mindoro E Puerto G., Sabang Balaitigi 19.11.1992 ”; 4 exs. (3 exs. NMW; 1 ex. IRML): “leg. Jäch (9) PHILIPPINEN — Mindoro S Puerto Galera Alag River 13.11.1992 ”; 2 exs. (1 ex. NMW; 1 ex. UPLB): “ PHILIPPINEN — Mindoro 10 km W Puerto Galera 24.– 25.11.1992 leg. Schillhammer (12)”; 1 ɗ ( NMW): “ PHIL.: Mindoro W Puerto Galera Tamaraw Beach (19) 2.12.1992 leg. Zettel”; 3 exs. (2 exs. NMW; 1 ex. WPU): “leg. Jäch (6) PHILIPPINEN — Mindoro SW Calapan, Baco Baco River 18.11.1992 ”; Luzon: 1 ɗ ( ISNB): “ɗ \ Zambalos Luzon XII \ A. d’Orchymont det. H. scabra \ Prép. Micr. N o 710709.24”; 1 Ψ ( ISNB): “Ψ \ Zambalos Luzon XII \ A. d’Orchymont det. H. scabra ”; 1 ɗ ( ISNB), 1 Ψ ( ISNB): “Pagsanjan Luzon” [coll. d’Orchymont, ISNB]; 1 Ψ ( ISNB): “Ψ \ Los Banos Luzon \ A. d’Orchymont det. H. scabra ”; 1 Ψ ( ISNB): “Ψ \ Mt. Makiling Luzon Baker \ 21374 \ A. d’Orchymont det. H. scabra ”; 1 ɗ ( NMW), 1 Ψ ( NMW): “ PHILIPPINEN — Luzon Los Banos (6) 17.11.1992 leg. Schillhammer”; 2 ɗɗ ( NMW): “ Philippines, Luzon: Lagunas Los Banos, stream in botanical garden, 200m, 28. XI. 1995, J. Kodada lgt.”; 63 exs. (62 exs. NMW, 1 ex. UPLB): “ Philippines, Luzon: Lagunas Los Banos, small river, 28. XI. 1995, Kodada & Rigová lgt.”; 24 exs. ( NMW): “ PHIL.: Luzon, Bulacan; 14km E SanMiguel,Biak na Bato NP, river 300m upstr. B. Panici Cave;c. 100m asl, 15°06'N 121°06'E; 10.4.1995 leg. Freitag (28a)M”; 13 exs. ( NMW): “PHILIP.: Luzon, Prov. Benguet, S Baguio Kennon Road, Bridal Falls 17.11.1992 leg. Schödl (9)”; 1 ɗ ( NMW): “PHILIP.: Luzon, 17.2.1999 Prov. Benguet, W Baguio Asin Road, ca. km 7 leg. Schödl (11)”; 2 exs. ( NMW): “PHILIP.: Luzon, 17.2.1999 Prov. Benguet, W Baguio Asin Hot Spring leg. Schödl (12)”; Marinduque: 1 ɗ ( NMW), 1 Ψ ( NMW): “ PHILIPPINES: Marinduque 1 km N Sihi, Malinao Spring, 16.2.1998 leg. H. Zettel (139)”; Panay: 18 exs. ( NMW): “PHILIPP.: 20.III.1994 Panay, Prov. Antique, 50 km NE San Jose leg. Schödl (6)”; 26 exs. ( NMW): “PHILIPP.: 22.III.1994 Panay, Prov. Ilo-Ilo, 10 km N Igbarass ca. 400m leg. Schödl (8)”; 5 exs. ( NMW): “ PHIL.: Panay 1994 (43) Prov. Antique, S.Remegio 50km N San Jose d. B. leg. Zettel 20.3.”; Negros: 46 exs. ( NMW): “PHILIPP. 18.III.1994 Negros occ., Caliban river SE Murcia ca. 250m; leg. Schödl (5)”; 7 exs. ( NMW): “ PHIL.: Negros 1994 SE Murcia, ca. 250m Caliban riv./Barangay 18.3. leg. Zettel (41)”; 1 ɗ ( NMW): “PHILIPP. 15.III.1994 Negros occ., Mambucal SE Bacolod ca. 900m leg. Schödl (1)”; 7 exs. ( NMW): “ PHIL.: Negros 1994 Mt. Canlaon, ca. 900m Mambucal, 15–16.3. leg. Zettel (39a)”; 1 ɗ ( NMW): “ PHIL.: Negros 1994 Mt. Canlaon, ca. 900m Mambucal, 16.3. leg. Zettel (39d)”; 12 exs. ( NMW): “PHILIPP.: 16.III.1994 Negros occ., Mambucal Seven Falls ca. 900m; leg. Schödl (2)”; Bohol: 16 exs. ( NMW): “ PHIL.: Bohol, NNO Tagbilaran; Antequera, Mag Aso Falls; 28.3.1995, leg. Freitag (6)“; Camiguin: 1 ɗ ( NMW), 1 Ψ ( NMW): “ PHIL.: Camiguin,c. 3km S Mambajao, Bal-bagon, Maubog c. 1km S Enigmanta; small creek, sec. vegetation c. 50m asl 09°13'N 124°44' E 16.4.1995 leg. Freitag (40)M”; Mindanao: 10 exs. ( NMW, 1 ex. mutilated): “ PHIL.: Mindanao, Cagayan de Oro Prov, c. 5km S Balingoan, Caipaan Riv., side pool, sec. vegetation c. 20m asl 08°57'N 124°48' E 16.4.1995 leg. Freitag (39)M”; 3 exs. ( NMW): “ PHIL.: Mindanao, c. 5km ESE Surigao, Cagniog Escalope River, limestone sec.forest c. 30m asl 09°45'N 125°31' E 22.4.1995 leg. Freitag (54)M”; 22 exs. ( NMW, 3 exs. mutilated): “ PHIL.: Mindanao, c. 3km ESE Surigao, Cagniog rural field creek, rice field / settlement c. 10m asl 09°45'N 125°30' E 22.4.1995 leg. Freitag (55)M”; Siargao: 16 exs. ( NMW): “ PHIL.: Siargao, c. 10km NNE Dapa; rd.to Pilar, mini pool, Coconut plantage c. 5m asl 09°53'N 126°04' E 21.4.1995 leg. Freitag (51)M”; 2 exs. ( NMW): “ PHIL.: Siargao, Sta.Monica, Tangbo, c. 2km N Buntay; riverside downstr. Tak-Tak Fall, sec.forest c. 20m asl 10°01'N 126°04' E 21.4.1995 leg. Freitag (52a)M”; 15 exs. ( NMW): “ PHIL.: Siargao, Sta.Monica, Tangbo, c. 2km N Buntay; riverside upstr. Tak-Tak Fall, sec.forest c. 30m asl 10°01'N 126°04' E 21.4.1995 leg. Freitag (52b)M”; 18 exs. ( NMW): “ PHIL.: Siargao c. 13km NNW Dapa; 1.5km Sayak to Mayahay, undergr. creek down-str. cave, sec.veget c. 30m asl 09°50'N 126°02' E 22.4.1995 leg. Freitag (53)M”.

FIGURES 11–14. Habitus of Hydraena . 11) Hydraena manguao sp. n., holotype; 12) H. hosiwergi sp. n., paratype ɗ; 13) H. busuanga sp. n., paratype Ψ; 14) Hydraena sp. 3.

Redescription. Body 1.40–1.50 mm long. Habitus as in Fig. 3. Pronotum and elytra grey-brown to goldbrown, medially slightly darker in some specimens; frons dark brown to black; legs and maxillary palpi pale brown to yellowish.

Pronotum wider than long, broadest at posterior 0.3–0.5; entire pronotum densely punctate, punctures deeply impressed, interstices convex and glabrous; anterior margin slightly concave; anterior angles rounded; lateral rim denticulate; lateral margins anteriorly slightly convergent, posteriorly sinuously convergent; posterior margin convex; lateral portions moderately deflexed; lateral hypomeron obliquely deltoid, distinctly broader than profemora, mesal hypomeron narrow, inconspicuous.

Elytra elongately oval, usually not conjointly rounded apically, with ca. 15 longitudinal, quite regular, distinctly impressed rows of punctures (nine between suture and shoulder); punctures large and deeply impressed; interstices and intervals convex, glabrous; lateral portion of elytra moderately explanate, not reaching elytral apex; inflexed lateral portion (pseudepipleuron and epipleuron) anteriorly approximately as broad as metafemur; pseudepipleuron reaching ca. posterior 0.25, without row of punctures; epipleuron reaching ca. posterior 0.7.

Mesoventrite with well developed longitudinal ridges; mesoventral intercoxal process narrow, slightly wider than epipleuron, medially deeply impressed; metaventral disc moderately impressed; metaventral plaques distinct, less widely separated (as wide as pseudepipleuron), anteriorly slightly convergent, moderately narrow, glabrous; metaventrite and ventrites 1–4 in male and ventrites 1–5 in female distinctly pubescent.

Femora slightly dilated; tibiae almost straight and symmetric in both sexes.

Aedeagus ( Figs. 15 a–c). Main piece rather stout, with one dorsal apical seta in some specimens, with two very conspicuous hump-like ventral projections (lateral view) at basal 0.40 and 0.55 of aedeagus; phallobase asymmetric, projections in some specimens more distinct than depicted in Fig. 15 a. Distal lobe intricately shaped, not clearly delimited from main piece, with several more or less distinctly sclerotized appendages, one of these appendages densely covered with spinules and papillae apically, another appendage (positioned dorsally) furcating into remarkably setiform structures and thus resembling a paramere. Parameres articulately connected with main piece, moderately long; left one inserted at about basal 0.35 of aedeagus, subtriangularly produced ventrad, with more than 20 moderately long setae (in a row at the apical and subapical lateral rim); right paramere inserted at about basal 0.45 of aedeagus, with about 20 moderately long setae.

Gonocoxite ( Fig. 15 e) subtrapezoidal; with one long seta near each anterior corner; lateral margins strongly convex subbasally; border between apical and basal area not clearly defined; basal area sparsely setose; condyles prominent; dorsal plate surpassing proximal rim of ventral plate, with two joint cavities.

Spermatheca ( Figs. 15 f–g). Proximal portion strongly bent, U-shaped; distal portion cone-shaped.

Secondary sexual characters. Ventrite 6 slightly longer and more glabrous in male. Male terminal sternite elongately subheptagonal, with slightly emarginate apical margin, firmly connected with rather short, distinctly curved spiculum gastrale ( Fig. 15 d). Male tergite X distinctly excised apically. Female tergite X ( Fig. 15 h) almost subcircular; lateral margins widely rounded; disc sparsely covered with setae; subapical fringe medially with short blunt setae and with a few longer trichoid setae laterally; hyaline apical margin with a rather small medial notch.

Differential diagnosis. Hydraena scabra can be distinguished externally from most other Palawan/ Busuanga species by its slender overall habitus, and the evenly greyish brown colour in combination with deeply impressed elytral punctures arranged in regular narrow rows, which are slightly impressed at least in the median portions. Its intricately shaped aedeagus is unique among Palawan/ Busuanga species due to its paramere-like dorsal appendage with remarkable setiform structures ( Figs. 15 a–c).

Distribution ( Figs. 29 , 30 ). Hydraena scabra is widely distributed in the Philippines, where it is obviously endemic (no non-philippine specimens were found among the rich collection of unidentified South-East Asian Hydraena in the NMW). So far, it has been collected on nine islands, including Palawan and Busuanga .

Ecology. Hydraena scabra occurs in stagnant water (shore pools, residual pools, paddy fields) and in running water including crenal, rhithral, and potamal habitats (torrents with gravel and boulders as well as in slow-flowing waters with fine substrates). It appears to be quite abundant in disturbed riverine systems. In rather undisturbed, natural sites displaying a high Hydraena diversity, this species is often missing. These dispersal patterns suggest a high ecological potency, but low competitiveness.

Figures

FIGURE 15. Hydraena scabra d’Orchymont. a – c) aedeagus (specimen from Taytay, Palawan) in ventral, dorsal (parameral setae omitted) and lateral view (setae of left paramere omitted); d) male sternite X and spiculum; e) gonocoxite; f – g) spermatheca; h) female tergite X.

FIGURE 29. Geographical distribution of Hydraena scabra d’Orchymont; including one record from Mindanao (white circle) by Yano et al. 1983 (material not studied).

FIGURE 30. Collecting sites and geographical distribution of Hydraena species in Palawan and Busuanga, including enlarged map of St. Paul National Park: Hydraena scabra d’Orchymont, H. jojoorculloi sp. n., H. nielshaggei sp. n., H. zetteli sp. n., H. castanescens sp. n., H. claudia sp. n., H. kodadai sp. n.