Porrorhynchus marginatus Laporte, 1835

Suksai, Benjamart, Gustafson, Grey T., Sites, Robert W. & Sangpradub, Narumon, 2021, The Gyrinidae (Coleoptera) fauna of Thailand: Key to tribes and genera, with new records and keys to species of Dineutini and Gyrinini, Zootaxa 5071 (1), pp. 97-117 : 111-114

Porrorhynchus marginatus Laporte, 1835

( Figs. 1H , 4E–F , 6E–G , 7H , 8B )

Material examined. THAILAND: Amnat Charoen Province: Tat Yai Waterfall, Khok Kong Subdistrict, Chanuman District , 16°04'12.0"N 104°57'01.9"E, 160 m a.s.l., 23.XII.2017, leg. B. Suksai, 1 male, 1 female ( THNHM) . Chaiyaphum Province: Huay Tad Fa Noi, Khon San district , 16°27'14.8"N 101°41'19.8"E, 7.II.1996, leg. N. Sangpradub, 1 male ( KKU) ; Nam Nao Natl. Park, Phromlaeng Stream, Thung Phra Subdistrict , Khon San District , 16°38'22.8"N 101°34'55.6"E, 800 m a.s.l., 15.XII.2013, leg. N. Sangpradub & R. Somnak, 2 females ( THNHM) ; 11.V.2014, leg. N. Sangpradub & R. Somnak, 1 female ( KKU) ; same locality except for, 19.VII.2014, leg. N. Sangpradub & R. Somnak, 1 female ( KKU) ; same locality except for, 16°38'19.5"N 101°34'57.2"E, 790 m a.s.l., 19.VII.2014, leg. N. Sangpradub & R. Somnak, 1 male ( THNHM) ; same locality except for, 16°38'20.8"N 101°34'55.8"E, 794 m a.s.l., 15.XII.2013, leg. N. Sangpradub & R. Somnak, 1 female ( THNHM) ; same locality except for, 19.VII.2014, leg. N. Sangpradub & R. Somnak, 1 male ( THNHM) ; Phu Khieo Wildlife Sanctuary , "Nam Prom", 16°19'59.9"N 101°36'59.8"E, 4.IV.1994, leg. W. Shephard, WDS A 1053, 7 spec. ( NHMW) ; Phulong Stream, Tadrinthong Village, Sa Phon Thong Subdistrict, Kaset Sombun District , 16°12'08.1''N 102°06'01.8''E, 500 m a.s.l., 30.VIII.2003, leg. C. Srichan, 1 male, 2 females ( KKU) . Chanthaburi Province: 15 km E Chanthaburi City, stream at Philiu Waterfall , 12°36'09.4"N 102°14'46.3"E, 29.I.1995, leg. P.P. Chen, 1 spec. ( NHMW) ; Khao Soi Dao Wildlife Sanctuary, stream from Khao Soi Dao Waterfall , 13°05'48.6"N 102°10'19.9"E, 523 m a.s.l., 17.I.2016, leg. R.W. Sites, L-1911, 1 male, 1 female ( UMC) ; stream of Phlio Waterfall, Khom Bang Subdistrict, Mueang Chanthaburi District , 12°31'29.2"N 102°10'25.5"E, 115 m a.s.l., 30.V.2017, leg. B. Suksai & C. Yatfung, 1 male, 1 female ( THNHM) . Chiang Mai Province: " Soppong-Pai ", 19°00'28.1"N 98°43'39.4"E, 1800 m a.s.l., 1–8.V.1993, leg. P. Pacholatko & L. Dembicky, 1 spec. ( NHMW) . Chumphon Province: Khun Mae Yai Moun Wildlife Sanctuary, Haew Lome Waterfall , water surface, 9°43'N 98°40'E, 120 m a.s.l., 22.V.2005, leg. R.W. Sites, A. Vitheepradit & T. Prommi, L-785b, 1 male, 1 female ( UMC) . Kanchanaburi Province: 30 km N Thong Pha Phum , 14°58'11"N 98°38'35"E, 160 m a.s.l., 13.XII.2010, leg. H. Freitag, 22b, 1 spec. ( NHMW) ; Thong Pha Phum Reforestation Station, Mae Nam Noi, Sai Yok District 14°31'N 98°37'E, 204 m a.s.l., 12.IV.2002, leg. UMC & CMU teams, L-335, 4 males, 8 females ( UMC) ; Heuy Kob, Sangkhla Buri District , 15°13'N 98°22'E, 289 m a.s.l., 13.IV.2002, leg. UMC & CMU teams, gravel stream, 1 male, 10 females ( UMC) ; same locality except for, gravel stream, L-339, 1 spec. ( UMC) ; Heuy Ka Yaeng, at Ban Pracham Mai, 19.I.2015, leg. R.W. Sites, gravel riffles, L-1871, 1 female ( UMC) ; Heuy Ou Long, opposite Keong Ka Wia Reforestration Station , 14°33.199'N 98°34.238'E, 326 m a.s.l., 19.I.2015, leg. R.W. Sites & A. Vitheepradit, gravel and vegetated margins, L-1872, 1 male, 4 females ( UMC) . Loei Province: Dan Sai , "Lomie Mt.", 17°16'47.4"N 101°09'01.5"E, 1.III.1955, leg. R.E. Elbel, ZML. 2010/356, 1 spec. ( MZLU) ; Loei River, Ban Non Phatthana, Loei Wang Sai Subdistrict, Phu Luang District , 17°06'24.1"N 101°28'43.1"E, 20.V.2017, leg. P. Sapewisut, C. Jaitamart & T. Paotajai, 1 male, 2 females ( THNHM) ; same locality except for, Ban Wang Yao, Wang Yao Subdistrict, Dan Sai District , 17°07'40.5"N 101°28'14.5"E, 20.V.2017, leg. P. Sapewisut, C. Jaitamart & T. Paotajai, 2 males, 2 females ( THNHM) ; Na Haeo, River bank, 17°28'40.4"N 100°58'56.4"E, 15.V.2003, leg. P. Grootaert, J. Constant & K. Smets, Light trap, 3 spec. ( IRSB) ; Phu Luang Wildlife Sanctuary , 17°13'51.2"N 101°30'06.5"E, 700–900 m a.s.l., 8–14.X.1984, leg. Karsholt, Lomholdt & Nielsen, 8 spec. ( NHMD) ; Phu Rua Natl. Park, Huay Pai Waterfall , 17°28'52.7"N 101°21'06.5"E, 10.VI.1998, leg. R.W. Sites, K.B. Simpson & A. Vitheepradit, L-175, 1 spec. ( UMC) . Mae Hong Son Province: " Ban Si Lang", 19°19'N 97°59'E, 1200 m a.s.l., 23–31.V.1991, leg. L. Dembicky, 1 spec. ( NHMW) ; Huai Sua Tao , 19°15'34.9"N 97°54'12.6"E, V.1992, leg. L. Dembicky, 1 spec. ( NHMW) ; Huay Pha , stream <1 km N of Ban Huay Pha, 19°25'50.8"N 97°59'49.6"E, 360 m a.s.l., 19.IV.2009, leg. R.W. Sites, A. Vitheepradit & T. Prommi, L-1049, 1 male ( UMC) . Mukdahan Province: Phu Pa Yon Natl. Park, Keang Pho Waterfall , 16°45.368'N 104°14.736'E, 314 m a.s.l., 23.IV.2004, leg. A. Vitheepradit, margin, L-634, 3 males, 5 females ( UMC) . Nakhon Nayok Province: Khao Yai Natl. Park , ca. 700 m, 29.IX– 6.X.1984, leg. Karsholt, Lomholdt & Nielsen, 6 spec. ( NHMD) ; same locality except for, 200 m E of Heaw Narok Waterfall , 14°17'N 101°23'E, 397 m a.s.l., 5.IV.2004, leg. R.W. Sites & A. Vitheepradit, L-602, 1 male, 1 female ( UMC) . Nakhon Ratchasima Province: Khao Yai Natl. Park, Heaw Su Wat Waterfall, 14°25.963'N 101°24.948'E, 380 m a.s.l., 6.IV.2004, leg. R.W. Sites & A. Vitheepradit, L-605, 3 females ( UMC) ; same locality except for, 700–800 m, 31.IV.1990, leg. E. Fuller, 3 spec. ( NHMW) ; pooled margins of slow stream behind the Youth Camp buildings, 4.I.2011, leg. R.W. Sites, L-1268, 4 males, 1 female ( UMC) ; Lam Takong Stream, Musi Subdistrict, Pak Chong District , 14°30'41.6"N 101°22'49.6"E, 378 m a.s.l., 9.IV.2018, leg. B. Suksai, O. Pornsophon, T. Jantaranakee & S. Phengsalung, 2 females ( THNHM) ; Thap Lan Natl. Park, Khok Krachai Subdistrict, Khon Buri District , 14°19'52.0''N 102°14'05.0''E, 224 m a.s.l., 24.XI.2013, leg. K. Piraonapicha, 1 male, 1 female ( KKU) ; same locality except for, 27.IV.2014, leg. K. Piraonapicha, 2 males, 4 females ( KKU) ; same locality except for, 14°20'13.6''N 102°14'48.0''E, 224 m a.s.l., 27.IV.2014, leg. K. Piraonapicha, 2 males, 3 females ( KKU) ; same locality except for, 5.III.2017,leg. K. Piraonapicha, 1male, 1female ( KKU) . Nan Province: Ban Pha Khap, 19°07'28.2"N 101°08'54.2"E, 15–20.V.1992, leg. P. Pecholatko, 2 spec. ( NHMW) ; Mae Charim Natl. Park, Nam Wa River , 18°36'N 100°59'E, 335 m a.s.l., 13.III.2002, leg. CMU Team, 2 spec. ( UMC) ; Tat Man Waterfall , 19°17.187'N 100°47.312'E, 352 m a.s.l., 17.IV.2009, leg. R.W. Sites, A. Vitheepradit & T. Prommi, stream with waterfall, L-1045, 2 females ( UMC) ; Yao River, Du Pong Subdistrict, Santi Suk District , 18°56'44.3"N 100°48'37.7"E, 251 m a.s.l., 13.V.2017, leg. B. Suksai, S. Kullasoot & C. Yatfung, 3 males, 5 females ( THNHM) . Phetchabun Province: Nam Nao Natl. Park, stream front of Tum Yai Nam Nao, Lak Dan Subdistrict , Nam Nao District , 16°56'48.2"N 101°30'24.5"E, 27.III.1998, leg. N. Sangpradub, 2 males, 1 females ( KKU) ; same locality except for, Yakruae Stream, Nam Nao Subdistrict, Nam Nao District , 16°44'19.7"N 101°34'26.4"E, 840 m a.s.l., 17.VIII.2014, leg. N. Sangpradub & R. Somnak, 1 female ( THNHM) ; same locality except for, 21.IX.2014, leg. N. Sangpradub & R. Somnak, 1 female ( THNHM) ; same locality except for, 13.XII.2014, leg. N. Sangpradub & R. Somnak, 1 male ( THNHM) ; same locality except for, 16°44'19.7"N 101°34'36.2"E, 827 m a.s.l., 16.XII.2013, leg. N. Sangpradub & R. Somnak, 1 female ( THNHM) ; same locality except for, 15.VI.2014, leg. N. Sangpradub & R. Somnak, 1 female ( THNHM) ; same locality except for, 18.X.2014,leg. N. Sangpradub & R. Somnak, 1 male, 1 female ( THNHM) ; same locality except for, 16°44'27.9"N 101°34'46.5"E, 807 m a.s.l., 18.I.2014, leg. N. Sangpradub & R. Somnak, 1 female ( THNHM) ; same locality except for, 5 km E Sila, " Mae Nam Pa Sak ", 17°04'20.3"N 101°22'31.1"E, 2.III.1994, leg. W. Shephard, WDS A 1025, 1 spec. ( NHMW) ; Khao Kor Non-Hunting Area, Sridit Waterfall , 16°37'N 100°56'E, 702 m a.s.l., 11.V.2004, leg. A. Vitheepradit & T. Prommi, L-677, 1 spec. ( UMC) . Phang Nga Province: Bang Won Subdistrict, Khura Buri District , 8°59'N 98°26'E, 45 m a.s.l., 27.IV.2002, leg. A. Vitheepradit & K. Kirawanich, gravel stream, L-375, 13 males, 9 females ( UMC) ; Khao Lak Stream , 8°37'08.4"N 98°14'51.5"E, 10.I.2003, leg. H. Forster, 6 spec. ( NHMW) ; Si Phang Nga Waterfall, Ban Tamnang, Khura Buri District , Si Phang Nga Natl. Park , 29.XI.2006, leg. H. Zettel, 48, 4 spec. ( NHMW) ; Tam Nang Stream, Bang Wan Subdistrict, Khura Buri District , 8°59'50.3"N 98°26'55.4"E, 110 m a.s.l., 24.V.2017, leg. B. Suksai & C. Yatfung, 1 female ( THNHM) ; Trem stream, Khura Subdistrict, Khura Buri District , 9°19'54.5"N 98°25'02.8"E, 110 m a.s.l., 24.V.2017, leg. B. Suksai & C. Yatfung, 2 males, 2 females ( THNHM) . Phatthalung Province: Lam Sin Stream, Kong Ra Subdistrict, Kong Ra District , 7°30'39.8"N 99°56'06.3"E, 150 m a.s.l., 23.V.2017, leg. B. Suksai & C. Yatfung, 2 males, 3 females ( THNHM) . Prachin Buri Province: Khao Yai Natl. Park , 14°20'N 101°30'E, 1000 m a.s.l., 26.III.1992, leg. E. Hüttinger, 10 spec. ( NHMW) ; same locality except for, Kaeng Wang Thong , 14°10.077'N 101°43.420'E, 8.IV.2004, leg. R.W. Sites & A. Vitheepradit, L-608, 8 males, 10 females ( UMC) . Rayong Province: Khao Chamao-Khao Natl. Park (" Khao Chamao Natl. Park "), 12°57'54.0"N 101°43'55.2"E, 12.XII.1990, leg. M.A. Jäch, Sites codes14, 1 spec. ( NHMW) . Sakon Nakhon Province: " 11 km NE Kham Poem ", " Huai Ya ", 16°56'35.5"N 104°02'31.2"E, 5.III.1994, leg. W. Shephard, WDS A 1027, 4 spec. ( NHMW) ; " Keek poo", 9.XI.1954, leg. R.E. Elbel, Bar codes and specimen numbers ZML.2010/357, 1 spec. ( MZLU) ; Phu Phan Natl. Park, Huay Wian Prai, Phu Phan District , 16°57'49.9"N 103°46'38.9"E, 23.V.1998, leg. N. Sangpradub, 1 male ( KKU) . Saraburi Province: Khao Yai Natl. Park., Lam Takong Stream , 2.I.2008, leg. R.W. Sites, L-1025, 3 males, 6 females ( UMC) . Satun Province: Ma Lao Stream, Wang Prachan Subdistrict, Khuan Don District , 6°47'44.5"N 100°08'41.9"E, 159 m a.s.l., 25.V.2017, leg. B. Suksai & C. Yatfung, 1 male, 2 females ( THNHM) . Songkhla Province: Khao Nam Chang Natl. Park , SW Nathawee, 13.I.1995, leg. R.W. Sites & B. Nichols, 1 male, 4 females ( UMC) ; same locality except for, 102 km SE Hat Yai District, Na Thawi District , 6°36'N 100°36'E, 100 m a.s.l., 15.VI.2001, leg. R.W. Sites, L-246, 1 male, 4 females ( UMC) ; Khoa Nam Khang (" Khao Nam Chang "), SW Na Thawi ("SW Nathawee "), 13.I.1995, leg. R.W. Sites & B. Nichols, 5 spec. ( UMC) ; Ton Nga Chang Natl. Park, stream at Buddhist temple, 30.I.1995, leg. B.J. Nichols, L-81, 1 male, 2 females ( UMC) ; same locality except for, 6.VI.2001, leg. R.W. Sites, L-127, 9 males, 15 females ( UMC) ; 9.VI.2001, leg. R.W. Sites, L-236, 23 males, 31 females ( UMC) . Sa Kaeo Province: Pang Sida Natl. Park, Khlong Huay Nam Yen , 14°02.399'N 102°15.955'E, 218 m a.s.l., 16.IV.2004, leg. R.W. Sites & A. Vitheepradit, L-630, 3 males, 12 females ( UMC) ; same locality except for, Pang Sida Waterfall , 13°59.634'N 102°12.408'E, 209 m a.s.l., 15.IV.2004, leg. R.W. Sites & A. Vitheepradit, L-627, 3 males, 2 females ( UMC) . Suphan Buri Province: Bang Pla Ma District, Tumbon Salee, Moo Sarm , 14°18'N 100°14'E, 11 m a.s.l., 4.VII.2004, leg. A. Vitheepradit, L-784, 2 females ( UMC) . Surat Thani Province: Ban Chong Lom; Khlong Sok, Phanom District , 8°52'N 98°40'E, 43 m a.s.l., 23.V.2003, leg. M.L. Ferro & A. Vitheepradit, L-563, 3 males, 7 females ( UMC) ; Khao Sok Natl. Park , 8°53'45.2"N 98°38'34.0"E, 15.I.2003, leg. H. Forster, 5 spec. ( NHMW) ; same locality except for, 5–9.VI.1999, leg. D. Šanc, Jiří Hájek Collection, 5 spec. ( NMPC) . Ubon Ratchathani Province: Huay Luang Stream, Na Chaluai Subdistrict, Na Chaluai District , 14°26'55.7"N 105°12'34.4"E, 173 m a.s.l., 24.XII.2017, leg. B. Suksai, 2 males, 1 female ( THNHM) ; Huay Sae Stream, Na Pho Klang Subdistrict, Khong Chiam District , 15°32'05.2"N 105°31'06.7"E, 131 m a.s.l., 23.XII.2017, leg. B. Suksai, 1 male ( THNHM) ; Phu Chong Na Yoi Natl. Park, Huay Kan Din Dum Stream, Na Chaluai Subdistrict , Na Chaluai District , 14°25'40.3"N 105°16'34.3"E, 390 m a.s.l., 23.XI.2012, leg. K. Rattanachan, 1 male ( KKU) ; same locality except for, Huay Laung , 14°26.513'N 105°16.449'E, 172 m a.s.l., 11.IV.2004, leg. R.W. Sites & A. Vitheepradit, L-616, 5 males, 14 females ( UMC) ; same locality except for, UV pan trap, 14°26.125'N 105°15.360'E, 231 m a.s.l., 11.IV.2004, leg. R.W. Sites & A. Vitheepradit, L-615, 1 male ( UMC) . Yala Province: Betong , "Gunung Cang dun vill.", 5°47'09.4"N 101°02'08.9"E, 25.III–22.IV.1993, leg. J. Strnad, 1 spec. ( NHMW) .

Diagnosis. Male ( Fig. 1H ): Size: 15.6–18.6 mm. Body form broadly oval; dorsally olive-green to bronzybrown; labrum long and triangular; elytral apices with parasutural and epipleural spines, sutural angle present; lateral margin of orbital ridge, pronotum and elytron yellow or white, with dark spot near basal third of length of lateral margin of elytron ( Fig. 1H ), apicolaterally half of length of lateral margin of elytra with sawtooth-like spines reaching almost epipleural spine; protrochanter apically with small cluster setae at apex of ventral surface ( Figs. 4E–F ); protibia club-shaped, apex with spines; venter and epipleura yellow; aedeagus ( Figs. 6E–F ) with median lobe shorter than parameres, parallel-side in basal half, expanded in apical half, apex acuminate in apical 1/6 length of median lobe, apex with tip truncate ( Fig. 6E ), curved dorsally in lateral view ( Fig. 6F ).

Female: Similar size to male: 15.4–17.4 mm; protrochanter apically without small cluster of setae at apex and without setae on ventral surface; gonocoxae short, lateral margin straight weakly angled toward apex, apex obliquely truncate ( Fig. 6G ).

Differential diagnosis. Porrorhynchus marginatus is the only Porrorhynchus found in Thailand. It can be easily recognized from the other Thai Gyrinidae by its large body size and long, triangular labrum for which it derives its common name in English, the snouted whirligig beetle. Porrorhynchus marginatus is also unique in having the lateral margin of the orbital ridge yellow or white in color.

Distribution. This species has been recorded as far northwest as Zayü Co. China ( Jäch et al. 2012) and south and east through Myanmar, Thailand, Laos, Vietnam, Malaysia, and Indonesia far as Java and Borneo ( Ochs 1927, 1930; Gustafson & Miller 2016).

Habitat. It has been found in small, forested streams with elevations above 100 m a.s.l. and up to 1,000 m a.s.l. ( Ochs 1927; Gustafson & Miller 2016). Ochs (1927) reported that P. marginatus was found in unpolluted localities and always near the water’s edge in the shallower parts of the streams. We found this species only in streams with shaded areas and slow current with substrates including pebble, gravel and sand ( Fig. 7H ), at elevations ranging from 11 to 1,800 m a.s.l., but most often at 100–900 m a.s.l.

Discussion. Porrorhynchus marginatus is a common, attractive species of Gyrinidae in Thailand, and as suggested by Ochs (1927), was the most common species encountered in several streams. Our survey revealed that P. marginatus occurs in all major regions of Thailand ( Fig. 8B ). This study adds many additional Thai localities to those presented by Gustafson & Miller (2016).

Figures

FIGURE 1. Habitus of Gyrinini and Dineutini species: (A) Gyrinus sericeolimbatus, dorsal view, female; (B) G. smaragdinus, dorsal view, male; (C–D) Dineutus australis, dorsal view: (C) male; (D) female; (E) D. sitesi, dorsal view, male; (F) D. spinosus, dorsal view, male; (G) D. unidentatus, dorsal view, male; (H) Porrorhynchus marginatus, dorsal view, male; (I) D. sitesi, ventral view, male; (J) D. spinosus, ventral view, male. Scale bars = 3 mm.

FIGURE 4. SEM photographs of protochanters in species of Dineutus and Porrorhynchus (males): (A) D. australis, patch of thick setae (arrow), scale bar = 100 μm; (B) D. sitesi, protrochanter without setae (arrow), scale bar = 1 mm; (C) D. spinosus, setae (arrow), scale bar = 100 μm; (D) D. unidentatus, setae (arrow), scale bar = 100 μm; (E–F) P. marginatus, cluster setae (square and arrow): (E) scale bar = 500 μm; (F) scale bar = 100 μm.

FIGURE 6. Elytral apex, aedeagus and gonocoxae: (A–D) D. unidentatus: (A) male elytral apex, scale bar = 2 mm; (B–C) aedeagus, scale bar = 0.5 mm: (B) dorsal view; (C) lateral view; (D) gonocoxae, ventral view, scale bar = 0.5 mm; (E–G) P. marginatus: (E–F) aedeagus, scale bars = 1 mm: (E) dorsal view; (F) lateral view; (G) gonocoxae, ventral view, scale bars = 1 mm.

FIGURE 7. Habitats of species of Gyrinini and Dineutini: (A–B) G. smaragdinus: (A) stream at Siriphum Waterfall, Doi Inthanon Natl. Park, Chiang Mai Province; (B) pond at Ban Buak Thoei, Chiang Mai Province; (C) D. australis, D. spinosus and D. unidentatus, pond at Sakaerat Environmental Research Station, Nakhon Ratchasima Province; (D) D. sitesi, Tum Din Stream, Thung Salaeng Luang Natl. Park, Phitsanulok Province; (E) D. spinosus, Huay Sae Stream, Ubon Ratchathani Province; (F–G) D. unidentatus, ponds at Ban Kho, Khon Kaen Province; (H) P. marginatus, Lam Takong Stream, Nakhon Ratchasima Province.

FIGURE 8. (A–B) Distributions of species of Dineutini and Gyrinini in Thailand.