Gestroiella limnocoroides Montandon, 1897

Dan, Polhemus, John, Polhemus & Sites, Robert, 2008, A Revision Of The Indochinese Genera Cheirochela And Gestroiella Heteroptera Naucoridae And A Review Of The Tribe Cheirochelini, Raffles Bulletin of Zoology 56 (2), pp. 255-279 : 268-270

Gestroiella limnocoroides Montandon

( Figs. 19–25 , 27, 29 , 32 , 34, 36–38 )

Gestroiella limnocoroides Montandon, 1897: 371 .

Gestroiella schoutedeni Montandon, 1909: 45 . Syn. by Horváth, 1918: 142.

Gestroiella perfecta Montandon, 1911: 86 . Syn. by Horváth, 1918: 142.

Supplemental redescription. – Brachypterous male: General colouration medium brown, with dark brown hemelytra, dark yellow markings on head, pronotum, scutellum and lateral hemelytra; head dark yellow with darker, posteriorly opening V-shaped mark centrally on frons, eyes black; pronotum dark yellow, narrowly margined with brown laterally, symmetrically mottled with brown centrally at muscle attachment scars; scutellum dark yellow, with pair (1 + 1) of small, roughly circular brown spots to either side of midline on basal half; hemelytra dark brown, with claval suture, entire embolium, outer margin of corium dark yellow, extreme lateral margin narrowly black; visible sections of abdominal tergites dark yellow. Overall form elongate-ovate ( Figs. 19, 22 ), size large for genus, body length 18.60, maximum width (across basal abdomen) 14.80; head length/ width 4.00/5.60, anterior/posterior interocular 3.50/3.70, eye length/width 2.00/1.10; pronotum length (midline)/width 2.70/12.90; scutellum length/width 3.20/6.00. Hemelytra brachypterous, not attaining tip of abdomen, reaching to abdominal tergite VII ( Fig. 19, 22 ); venation obscure; corium finely and shallowly rugose; membrane absent; hemelytral apices acutely rounded.

Brachypterous female: Similar to brachypterous male in general size and colouration; body length 17.40, maximum width (across basal abdomen) 12.70.

Macropterous female: Similar to brachypterous female in general structure and colouration but slightly narrower in form ( Fig. 25 ); body length 17.40, maximum width (across basal abdomen) 11.10. Pronotum with posterolateral angles less produced, obtuse ( Fig. 25 ); scutellum enlarged, tumid; hemelytra with clavus well defined ( Fig. 25 ), claval vein evident, membrane present and well defined, lacking evident venation.

Discussion. – The male holotype of G. limnocoroides is a brachypterous male specimen ( Figs. 19–21 ) in the Genoa Museum from Asciuii Cheba, Burma bearing the following labels (from top to bottom, commas indicate line breaks, slashes indicate separate labels): “Carin, Asciuii Cheba, 1200–1300 m, L. Fea I-88 (black, printed)/TYPUS (red, printed)/ Gestroiella , limnocoroides, Mont. (script in Mondandon’s hand)/ Gestroiella , limnocoroides, gen. n. sp. n., es. tip. (script in Mondandon’s hand)/ Gestroiella , limnocoroides, Montand. , type (script in Gestro’s hand).” Another brachypterous male specimen in The Natural History Museum, London is also labelled as the holotype, and bears the same locality data as the Genoa specimen above, but lacks the type notations by Montandon and Gestro. The Genoa specimen is therefore designated as the lectotype to avoid further confusion.

The holotype of G. schoutedeni is a brachypterous female ( Figs. 22–24 ) in the Paris Museum from Phuc Son, Annam (in the current Nghê An Province of Vietnam) bearing the following labels (from top to bottom, commas indicate line breaks, slashes indicate separate labels): “Phuc Son, Annam XI. XII, H. Rolle Berlin S. W. 11 (black, printed)/Museum Paris, A. L. Montandon 1909 (black, printed)/ Gestroiella , schoutedeni, type 1909 Montandon (black script in Mondandon’s hand, with type notation in red).” Another brachypterous male from Phuc Son in The Natural History Museum , London is also labelled as the holotype; it bears the same locality data as the specimen above, but lacks the red type notation by Montandon. Still another brachypterous female specimen from Phuc Son in the University of Kansas collection bears a script label below the locality label reading: “ Gestroiella schoutedeni Mont. Spec. with type from same local.” The Paris specimen is herein designated as the lectotype, in order once again to avoid further confusion .

The holotype of G. perfecta has not been located. The specimen came from “ Tonkin, Than-Moi” and was considered by Horváth (1918) to be the macropterous form of G. schoutedeni .

Gestroiella limnocoroides exhibits a wide degree of intraspecific morphological variation across its range in Indochina, similar to the situation seen with the variable naucorid species Ambrysus mormon in western North America. The type specimens from Burma have the pronotal angles broadly produced laterally ( Fig. 19 ), much more so than other specimens from Thailand or Vietnam ( Fig. 22 ). Initially it was thought that this could be a useful character for separating these populations, since the narrower morphs had been given the name G. schoutedeni Montandon. Examination of a large amount of material from across Indochina, however, has revealed that no consistently reliable morphometric measurements can be found to separate these supposed taxa across what appears to be a continuous range of variation, possibly linked to varying degrees of incipient submacroptery in populations, or sexual dimorphism. Since the internal genitalic characters of the males do hold constant across all of these populations, as do the external characters of the female abdomen, it is concluded herein that Horvath was correct in his synonymy of G. schoutedeni and G. perfecta under G. limnocoroides .

As interpreted herein, G. limnocoroides may be separated from G. siamensis by its larger overall size (body length less than 15 mm in G. siamensis versus over 17 mm in G. limnocoroides ), and by its more robust male paramere shape (compare Figs. 27, 28 ). Although similar in size to G. insignis , it may be separated from that species by the angular, nonbifurcate tip of the dorsomedial process in the male genital capsule, and by the pattern of medial hair tufts on female abdominal venter and the shape of the female subgenital plate (compare Figs. 31, 32 ).

Gestroiella limnocoroides is widely distributed in Indochina ( Fig. 34), with the type locality lying east of modern Toungoo, in the western foothills of the Shan Plateau draining to the Sittang River. In Vietnam, this is a species of lower elevation rivers below 1,000 m, with beds of gravel and cobbles ( Figs. 36–38 ), and is not generally found in the higher, colder, more rushing streams favored by Cheirochela tonkina . By contrast, on the swift Nam Chai River near Fang, in northern Thailand, this species was found syntopically with Cheirochela thailandana .

Material examined. – BURMA [ MYANMAR], Kayah Division: 1 brachypterous male, Carin, Asciuii Cheba, 1,200 –1,300 m, L. Fea, Jan.1888 (type, MSNG); 1 brachypterous female, Carin Ghecu, 1,300 –1,500 m, L. Fea, Feb.–Mar.1888 ( MSNG). Kachin Division: 1 macropterous male, 2 brachypterous females, Ma Kyaw Wa River, 3.8 km SW of Putao, 480 m, 27°18.90'N 97°22.93'E, 30 May 1999, H. Schillhammer ( USNM). Kayin Division: 1 brachypterous male, Dawna [Dawna Range], April 1992 ( USNM). CHINA, Yunnan: 1 brachypterous male, Ningpo, Le Moult ( SEMK); 1 macropterous male, Yunnan, Le Moult ( RMNH); 1 brachypterous male, 2 brachypterous females, Simao, Mekong Basin, THH0078, H. H. Tan ( NUS); 1 brachypterous male, 4 brachypterous females, 7 nymphs, Xishuangbanna, Manchang stream, 63 km fr Jinghong to Menglun; CM Yan & P. Chew, 30 May 2002, YCM 0300 ( NUS); 2 brachypterous males, Xishuangbanna, Mengxing River, CM Yang & P. Chew, 1 Jun.2002, YCM 0308 ( NUS); 1 brachypterous male, 1 brachypterous female, 1 nymph, Xishuangbanna, Nanla River, CM Yang, 2 June 2002 YCM 0312 ( NUS); 2 brachypterous males, 1 brachypterous female, 1 macropterous female, 5 nymphs, Xishuangbanna, Mengyuan, nr. Village, fast flowing stream, CM Yang, 2 Jun.2002 YCM 0315 ( NUS); 1 brachypterous female, 2 nymphs, Xishuangbanna, Mangle Stream, next to rubber plantation, CM Yang & Gao Lei, 4 Jun.2002, YCM 0320 ( NUS). LAOS, Houaphan Prov.: 1 brachypterous male, Ban Saleui, 1350 m, Xamneua [Xam Nua], 21–24 Jun.2003, M. Sato ( JTPC). Louang Phrabang Prov.: 1 brachypterous male, Luang Prabang, Ban Nam Mo, 3 Apr.1918, R. V. de Salvaza ( RMNH); 1 brachypterous male, 1 brachypterous female, Luang Prabang, Ban Na Hai, 10 Mar.1920, R. V. de Salvaza ( BMNH); 1 brachypterous male, Luang Prabang, Ban Houei Ngai, 8 Mar.1918, R. V. de Salvaza ( BMNH); 4 brachypterous males, Annam, Laos ( JTPC); 1 brachypterous female, Pak Teu, 11 Nov.1917, R. V. de Salvaza ( BMNH). Xiang Khoang Prov.: 3 brachypterous females, Haut Mekong, Nam Mat, 15 Apr.1918, R. V. de Salvaza ( BMNH). Province uncertain: 1 brachypterous female, Haut Mekong, Muong Sing, 18 Apr.1918, R. V. de Salvaza ( BMNH). THAILAND, Chiang Mai Prov.: 29 brachypterous males, 19 brachypterous females, Fang Dist., Nam Chai River above hydro station intake at Fang Horticultural Research Station, 550 m, 15 Nov.1985, CL 2197, D. A. and J. T. Polhemus ( JTPC); 23 brachypterous males, 51 brachypterous females, 18 immatures, Fang Dist. , Mae Mao River, S. of Fang Horticultural Research Station, 500 m, 16 Nov.1985, D. A. and J. T. Polhemus ( JTPC); 1 brachypterous male, 1 macropterous male, 5 immatures, Doi Inthanon National Park, Mae Pan Noi at Ban San Pathana, 18°31'N 98°25'E, 750 m, gravel in bedrock stream, 7 May 2002, UMC & CMU teams, L-393 ( UMC); 4 brachypterous males, 1 macropterous female, 2 immatures, Doi Inthanon National Park, Mae Klang River at Sob Ab Waterfall, 18°31'N 98°36'E, 543 m, gravel, 8 May 2002, UMC & CMU teams, L-397 ( UMC); 1 brachypterous female, Doi Inthanon Nat. Park, Mae Pan Waterfall, 18°31’N 98°27’E, 1,100 m, gravel, 8 Jun.2002, CMU team ( UMC); 1 brachypterous male, 4 brachypterous females, Doi Inthanon Nat. Park, Mae Klang River at Ecolodge, 18°32'N 98°32'E, 1,000 m, gravel, 8 May 2002, UMC & CMU teams, L-399 ( UMC); 1 brachypterous male, 1 brachypterous female, Fang Horticulture Exp. Farm, Nam Mae Chai, 19°57'N 99°09'E, 600 m, 17 Mar.2002, R. W. Sites, L-301 ( UMC); 3 brachypterous males, 13 brachypterous females, ca. 10 km E of Samoeng at River, 18°51'40.2"N 98°38'49.5"E, 11–2 Apr.2000, W. Ullrich ( USNM); 3 brachypterous males, 13 brachypterous females, ca. 10 km E of Samoeng at River, 18°51'40.2"N 98°38'49.5"E, 11–2 Apr.2000, W. Ullrich ( USNM). Kampaeng Phet Prov.: 1 immature, Khlong Lan National Park, 16°07'N 99°16'E, stream at Nam Tok Klong Lan, 8 Mar.2002, CMU team, L-272 ( UMC). Kanchanaburi Prov.: 20 brachypterous males, 20 brachypterous females, 4 macropterous males, 2 macropterous females, Amphur Sai Yok, Thong Pha Phum Forest Restoration Station, Mae Nam Noi, 14°31'N 98°37'E, 204 m, 12 Apr.2002, UMC & CMU teams, L-335 ( UMC); 6 brachypterous males, 9 brachypterous females 3 macropterous males, 12 immatures, Amphur Thong Pha Phum, Heuy Ou Long, 14°46'N 98°40'E, stream, 139 m, 11 Apr.2002, UMC & CMU teams, L-332 ( UMC); 1 brachypterous male, 1 brachypterous female, river at Pong Phu Rawn, 14°38'N 98°31'E, 24 Mar.2002, G. W. Courtney ( UMC); 1 brachypterous male, 1 brachypterous female, Amphur Sangkhla Buri, Heuy Li Jia, 15°04'N 98°33'E, gravel stream, 169 m, 13 Apr.2002, UMC & CMU teams, L-338 ( UMC); 2 brachypterous males, 1 brachypterous female, Amphur Sangkhla Buri, Heuy Song Ka Lia, 15°13'N 98°26'E, gravel stream, 204 m, 13 Apr.2002, UMC & CMU teams, L-340 ( UMC); 20 brachypterous males, 20 brachypterous females, Amphur Thong Pha Phum, Huey Pak Kog, 14°39'N 98°32'E, 184 m, gravel stream, 12 Apr.2002, UMC & CMU teams, L-336 ( UMC). Lampang Prov.: 1 immature, Jae Sawn National Park, Nam Tok Jae Sawn, 18°50'N 99°28'E, 650 m, 16 Mar.2002, R. W. Sites, L-297 ( UMC). Mae Hong Son Prov.: 1 brachypterous male, 3 km SE of Mae Hong Son, 13 Nov.1995, H. Zettel ( NHMW); 20 brachypterous males, 20 brachypterous females, Huai Pha, 18 km N. of Mae Hong Son, 19°25'N 97°59'E, 340 m, 19 Mar.2002, Sites, Vitheepradit, Kirawanich, L-306 ( UMC); 1 brachypterous male, 4 brachypterous females, Nam Tok Mae Surin National Park, Mae Nam Pai, 19°21'N 97°59'E, 310 m, 19 Mar.2002, Sites, Vitheepradit, Kirawanich, L-307 ( UMC); 1 macropterous male, 1 macropterous female, 1 brachypterous female, Mae Kong River, ca. 25 km N of Mae Hong Son, Ban Na Pla Chia at Mae Nam Sangel River, 19°30'31.0"N 98°00'05.7"E, 9 Aug.1997, W. Ullrich ( USNM); 2 brachypterous females, Tam Pla River, ca. 20 km N of Mae Hong Son, Tam Pla Resort, 19°25'34.2"N 97°59'16.7"E, 8 Aug.1997, W. Ullrich ( USNM). Nan Prov.: 1 brahypterous male, Mae Charim National Park, Nam Wa River, 18°36'N 100°59'E, 335 m, 13 Mar.2002, Sites, Vitheepradit, Kirawanich, L-293 ( UMC). Phayao Prov.: 2 macropterous males, Doi Nangka [= Doi Phu Lang Ka], N. Siam, 29 Apr.1931, H. M. Smith ( USNM). Prachuap Khiri Khan Prov.: 3 brachypterous males, 4 brachypterous females, 1 macropterous male, 1 macropterous female, 5 immatures, Amphur Bang Saparn, Tumbon Tong Mongkol, Moo Ban Tong Mongkol, 11°14'N 99°22'E, 73 m, 23 Apr.2002, Vitheepradit & Kirawanich, L-362 ( UMC); 1 brachypterous female, Amphur Bang Saphan, Tumbon Tong Mongkol, creek from Nam Tok Sai Koo, 11°14'N 99°20'E, 73 m, 23 Apr.2002, Vitheepradit & Kirawanich; L-364 ( UMC). Tak Prov.: 1 brachypterous female, Mae Nam Moi, Salween basin, 19 Mar.1996, S. H. Tan and N. Sivasothi ( ZRC). VIETNAM, Cao Bang Prov.: 9 brachypterous males, 22 brachypterous females, rocky stream 5 km E. of Cho Ra, 210 m, water temp. 70°F (21°C), 21 Mar.2000, CL 4370, J. T. Polhemus and P. Nguyen ( USNM); 1 brachypterous male, Le Nin stream at Pac Bo cave, 370 m, water temp. 64°F (18°C), 22 Mar.2000, CL 4371, J. T. Polhemus and P. Nguyen ( USNM); 1 brachypterous male, 2 brachypterous females, Ban Doc waterfall area, 365 m, water temp. 68°F (20°C), 23 Mar.2000, CL 4372, J. T. Polhemus and P. Nguyen ( USNM). Bac Thai Prov. : 2 brachypterous males, 3 brachypterous females, Cuc Bo stream, 37 km S. of Bac Canh, 80 m, water temp. 70°F (21°C), 24 Mar.2000, CL 4374, J. T. Polhemus and P. Nguyen ( USNM). Lào Cai Prov.: 4 brachypterous males,9 brachypterous females, river 31 km NE of Sa Pa on Lào Cai road, 105 m, 22°27'33"N 103°57'44"E, water temp. 22°C, 9 Apr.2000, 0945–1145 hrs., CL 4405, D. A. Polhemus, J. T. Polhemus and P. Nguyen ( USNM); 1 macropterous female, Tonkin, Lao Kay, E. Le Moult ( RMNH); 1 brachypterous female, Tonkin, Ban Nam Coum, Aug.1917, R. V. de Salvaza ( RMNH); 1 brachypterous female, Tonkin, Ban Nam Coun., Aug.1917, R. V. de Salvaza ( BMNH); 1 brachypterous male, Tonkin, Bao Ha [along Red River, SE of Lao Cai], Sept.1901, Ardouin; label below with notation “ Gestroiella limnocoroides comp. au type Montandon de Mus. Civ. de Genoa, J. Martin, det. 1902” ( MHNP). Hòa Bình Prov.: 1 brachypterous female, Tonkin, Hoabinh, Aug.1918, R. V. de Salvaza ( JTPC); 2 brachypterous females, Tonkin, reg. de Hoa Binh, A. de Cooman, 1928 ( MHNP); 6 brachypterous males, 5 brachypterous females, Tonkin, Hoa Binh, Aug.1918, R. V. de Salvaza ( BMNH). Nghê An Prov.: 1 brachypterous female, Annam, Phuc Son, XI. XII, H. Rolle, Berlin, S. W. 11 (holotype, MHNP); 2 brachypterous females, same data as preceeding ( SEMK); 6 brachypterous males, 4 brachypterous females, Pu Mat Nature Reserve, SW of Con Cuông, Khe Moi stream, 235 m, water temp. 71°F (22°C), 1 Apr.2000, CL 4382, J. T. Polhemus and P. Nguyen ( USNM); 5 brachypterous males, 1 brachypterous female, Choang River, nr. edge of Pu Mat Nature Reserve, 165 m, water temp. 78°F (26°C), 2 Apr.2000, CL 4387, J. T. Polhemus and P. Nguyen ( USNM). Quang Ngai Prov.: 1 macropterous male, 1 macropterous female, 3 brachypterous males, 3 brachypterous females, Nuoc Xi stream, 123 km NE of Kontum on Hwy. 24, 120 m, 14°43'10"N 108°35'48"E, water temp. 26°C, 18 Mar.2001, CL 4299, D. A. Polhemus, J. T. Polhemus and P. Nguyen ( USNM). Kontum Prov.: 1 brachypterous female, stream in dry forest hills 29 km NE of Kontum on Hwy. 24, 565 m, 14°27'01"N 108°09'12"E, water temp. 69°F (21°C), 7–9 and 19 Mar.2001, CL 4284, D. A. Polhemus, J. T. Polhemus and P. Nguyen ( USNM); 1 brachypterous female, Ialing Rapids, 64 km SW of Kontum, 4 km W. of Ialy, 500 m, 14°12'02"N 107°48'42"E, water temp. 76°F (24°C), 8 Mar.2001, CL 4285, J. T. Polhemus and P. Nguyen ( USNM); 1 brachypterous male, 3 brachypterous females, rocky stream 84 km NE of Kontum on Hwy. 24, 1145 m, 14°39'03"N 108°25'14"E, water temp. 22°C, 20 Mar.2001, CL 4305, D. A. Polhemus, J. T. Polhemus and P. Nguyen ( USNM). Lâm Dông Prov.: 4 brachypterous males, 5 brachypterous females, Pongour Falls, 62 km SW of Dalat, 915 m, water temp. 78°F (26°C), 13 May 1998, CL 3091, J. T. Polhemus ( JTPC). Province uncertain: 1 brachypterous male, Tonkin, E. le Moult, 1910; label below with notation in Montandon’s hand “ Gestroiella limnocoroides var? Montandon, det. Montandon 1910” ( MHNP). COUNTRY UNCERTAIN: 1 brachypterous male, 1 brachypterous female, Indo-China [det. as G. limnocoroides by Hoberlandt] ( JTPC); 1 brachypterous male, 1 brachypterous female, Kouy-Tcheou, reg. de Pin-Fa, Père Cavalerie, 1908 ( MHNP); 1 macropterous female, Keng Trap, May 1917, R. V. de Salvaza ( BMNH).

Figures

Figs. 19–24. Gestroiella limnocoroides, structural details: 19, Dorsal habitus, legs omitted; 20, Embolium of hemelytra, ventral view; 21, Foreleg; 22, Dorsal habitus, legs omitted; 23, Embolium of hemelytra, ventral view; 24, Foreleg. Figs. 19–21: Gestroiella limnocoroides, brachypterous male (holotype of G. limnocoroides); Figs. 22–24: Gestroiella limnocoroides, brachypterous female (holotype of G. schoutedeni).

Figs.25. Gestroiella limnocoroides, macropterous female.Specimen from Lao Cai, Tonkin (= northern Vietnam).

Figs. 26–30. Gestroiella species, male genitalia, structural details: 26, G. insignis, paramere; 27, G. limnocoroides, paramere; 28, G. siamensis, paramere; 29, G. limnocoroides, phallotheca; 30, G. siamensis, dorsomedial process of genital capsule.

Figs. 31–33. Gestroiella species, apex of abdomen of female, ventral aspect: 31, G. insignis; 32, G. limnocoroides; 33. G. siamensis.

Figs. 36–38. Typical habitats for Gestroiella limnocoroides in central Vietnam (for detailed locality information see text): 36, Nuoc Xi stream, 120 m elevation, Quang Nai Province; 37, Stream 29 km northeast of Kontum, 565 m elevation, Kontum Province; 38, Stream 84 km northeast of Kontum, 1,145 m elevation, Kontum Province.