Rhinocypha frontalis (Selys, 1873)

Jan van Tol & André Günther, 2018, The Odonata of Sulawesi and adjacent islands. Part 8. Revision of the genus Rhinocypha Rambur, 1842 (Chlorocyphidae), Odonatologica 47 (3), pp. 299-386 : 324-333

publication ID	https://doi.org/ 10.5281/zenodo.1481114
DOI	https://doi.org/10.5281/zenodo.6485248
persistent identifier	https://treatment.plazi.org/id/0395A91C-AC68-FFA4-95CB-FF52FEBFFA44
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scientific name	Rhinocypha frontalis (Selys, 1873)
status

Treatment

Rhinocypha frontalis (Selys, 1873) View in CoL

Rhinocypha frontalis frontalis (Selys, 1873) View in CoL

( Figs 3 View Figure 3 , 4 View Figure 4 , 24–33 View Figure 24 View Figures 25–29 View Figures 30–33 , 84 View Figure 84 )

Libellago (Rhinocypha) frontalis . — SELYS (1873a): 490–491 (sep. 26–27) (original description, type locality Moluques, Ménado); SELYS (1873b): 614–615 (sep. 61– 62) (compared with R. monochroa).

Rhinocypha frontalis View in CoL . — KIRBY (1890): 114 (catalogue, distribution Menado [Ma- nado], Luzon [lapsus]); SELYS (1891): 215 (compared with R. semitincta var. colorata [Philippines] and R. monochroa); RIS (1916): 310–313 (key, distribution); LIEFTINCK (1935): 175–177 (compared with R. phantasma, new material, re- description and variation); LIEFTINCK (1938): 49–55 (status and distribution dis- cussed, compared with other species of the R. tincta complex); KIMMINS (1969): 309 (lectotype designated BMNH, type locality »Moluques«); VAN TOL (1987a): 154 (record Dumoga-Bone National Park); ASKEW et al. (1989): 117 (records Dumoga-Bone National Park); DE JONG & VAN TOL (1994): 18 (colour picture of male); MALKMUS (2007): 16 (fig. 9) (colour picture of female).

Nec Rhinocypha frontalis View in CoL . — COWLEY (1937): 8, Fig. 20 View Figures 19–23 (penis of specimen from Shortland Island [Solomon Islands]).

Diagnosis

The males of Rhinocypha frontalis can be distinguished from the species of the R. monochroa complex within Sulawesi by the paired blue spot on its frons ( Figs 30–33 View Figures 30–33 ); a paired median spot on the anterior lobe of the pro- notum; the presence of a humeral stripe anteriorly on the mesepisternum ( Fig. 27 View Figures 25–29 ), and a short stripe posteriorly on the mesepimeron; the blue stripe over the synthorax with a distinct posterior projection over the metepister- num reaching to the wing base; S9 of the abdomen has a small, but clearly visible lateral blue spot ( Fig. 28 View Figures 25–29 ); the dorsum of the abdomen is black, with- out pruinosity; the bases of fore and hind wings are transparent.

We describe specimens collected in the southern part of Sulawesi Selatan as a new subspecies (see below), based on size and much more extensive opaque bluish black patches in the wings, and distinctly different wings in the females.

Description

Male

Head ( Figs 25 View Figures 25–29 , 30–33 View Figures 30–33 ) — Labium shiny black; labrum swollen, shiny black with stout setae; mandibles predominantly blue with narrow black border; anteclypeus and postclypeus black; frons, vertex, occiput and post-ocular area dull black, but frons with a pair of large sub-quadrangular blue spots, anteriorly with irregular margin, vertex with small oval spots next to the lateral ocelli; post-ocular spots small, creamy white.

Thorax — Pronotum ( Fig. 26 View Figures 25–29 ) black; median lobe black with purple sheen, anterior lobe with a paired, oval creamy spot, placed distinctly from lateral corner; lateral lobes with large crescent-shaped blue or bluish white mark; propleuron with oblong bluish white mark, anteriorly wider than posteri- orly.

Synthorax ( Fig. 27 View Figures 25–29 ). Mesopreepisternum with oval pale blue spot. Syn- thorax black, rather dull, but laterally shiny, with extensive blue markings as follows: mesepisternum anteriorly with sub-triangular marking, approximately three times as long as wide, covering approximately 1 /₅ of mesepister- num; blue marking of mesepimeron covering anterior third, shape irregu- lar, tapering anteriorly, wider posteriorly and connected to blue marking of metepisternum; blue marking covering most of metepisternum, just leav- ing sub-rectangular black marking dorso-posteriorly and triangular black marking ventro-posteriorly; metepimeron anteriorly black with large blue transverse marking, leaving small triangular black spot dorso-posterior- ly, which connects to the ventro-posterior spot on metepisternum; mesokatepisternum with small, triangular blue spot in posterior corner against coxa.

Legs — Dull black, but inner side of mid and hind tibiae white, covering ca the distal ⅔ of the mid legs, and the distal half of the hind legs; femora and tibiae with long stout setae; fore tibiae with a comb of about eight short setae.

Wings — Fore wing clear in basal part with brownish tinge up to level of nodus; hind wing with similar pattern up to level of Ax10; distal part of wings dark brownish black, dark parts of underside of fore wing anteriorly with blue metallic sheen, remainder with golden sheen; hind wing rather dull, tip with blue sheen; pterostigma of fore and hind wings brown.

Abdomen ( Fig. 28 View Figures 25–29 ) — Dorsally black, intersegmental annulae black, sides of tergites with large blue spots as follows: S1 with a posterior sub-quadrangu- lar spot, covering ¾ of segment, tapering anteriorly; S2 with large rectangu- lar spot, anteriorly somewhat elongate, leaving a narrow black border ante- riorly; S3 with large spot covering side of tergite almost completely, slightly tapering posteriorly; S4 with spot as on S3, but marking more strongly tapering posteriorly and not quite reaching the posterior margin; markings on S5–S9 increasingly smaller and more tapered posteriorly on dorsal side, marking on S9 about half the length of segment and sub-quadrangular, acute posteriorly; S10 and anal appendages black.

Female

Head ( Fig. 29 View Figures 25–29 ) — Labium shiny black, labrum swollen, shiny black with stout setae; mandibles with squarish creamy white spot with narrow black borders, the apex black; anteclypeus black, shiny; remainder of head dor- sally velvet black, genae with large squarish creamy white spot, extending dorsally along the eyes as a narrow creamy stripe to the level of the lateral ocelli; frons with small, yellowish, irregular paired spot; vertex with small yellowish spots latero-posteriorly of lateral ocelli; post-ocular spots small, creamy white.

Thorax — Pronotum black, rather shiny; anterior lobe laterally with cream- ish oval spot; median and posterior lobes black; lateral lobes with large, round creamish spot, dorsally tapered. Mesopreepisternum with rectangu- lar cream spot.

Synthorax black, rather dull and slight purple sheen; mesepisternum with very thin ante-humeral stripe, both ends somewhat wider; all pale markings on synthorax creamy white; mesepimeron with short pale stripe in dorsoposterior corner; long pale stripe from posterior corner of mesokatepister- num and ventro-anterior corner of mesepimeron, running over ventral part of metepisternum over metathoracic spiracle, continuing on posterior half of metepimeron; this stripe with irregular margins and approximately ten times as long as high.

Legs — Dull black, trochanters of mid and hind legs partly creamish.

Wings — With brownish tint on transparent parts. Fore wing with dark opaque distal patch, extending from Px15 to Px23, somewhat further dis- tad in the middle of wing; wing tip opaque white; pterostigma covering ca six underlying cells, proximal half brown, distal half white; hind wing also with brownish black distal patch, wider than in that in fore wing, with more distinct bluish metallic sheen, covering wing between level of Px12 to pterostigma; wing tip opaque white; pterostigma of fore wing basal ² /₅ grey- brown, distal part grey-white, but darker against the veins; pterostigma of hind wing basal ⅓ grey-brown, rest as in fore wing; we have observed sig- nificant variation in this character.

Abdomen — Black, with pale markings on sides of tergites as follows: S1 with small subcircular spot posteriorly, S2 with a short line medio-anteri- orly and an even shorter marking below it, and a larger oval spot close to posterior margin; S3–S4 with L-shaped marking running along anterior margin of segment, extending medially over tergite, and a sub-circular spot posteriorly (very small on S4), ventrally a short longitudinal mark- ing, ca 3–4 times longer than wide (these markings continue on S3–S7); narrow anterior stripes along anterior margin of S5–S7; rest of abdomen black.

Measurements

Males: Measurements of specimens from Dumoga-Bone National Park [mm] — Hind wing length (n = 5) x= 23.5 (22.5–24.5); hind wing width (n =5) x=6.0 (6.0–6.0); abdomen length (including appendages) (n =5) x= 20.0 (19.0–20.5). Specimens from Luwuk — Hind wing length (n =5) x= 24.5 (23.5–25.5); hind wing width (n =5) x= 5.5 (5.0–6.0); length abdomen (including appendages) (n = 5) 19.5 (19.0–20.5).

Females: Measurements of specimens from north-eastern Sulawesi [mm] — Hind wing length (n = 5) x= 25.5 (24.5–26.0); hind wing width (n = 5) x = 5.5 (5.5–6.0); abdomen (including appendages) (n = 5) x= 18.5 (18.0–20.0).

Geographical variation

Rhinocypha frontalis is quite a variable species, especially in size, but also in the size of the blue spots on the frons ( Figs 30–33 View Figures 30–33 ); both characters are geo- graphically correlated. We treat only the populations of the Sangihe Islands as a separate, new species. Specimens from the south-western peninsula dif- fer clearly from those of northern Sulawesi, and we describe these as a sepa- rate subspecies. We have also studied a few specimens with extensive blue markings on the synthorax, as in R. frontalis (see Fig. 42 View Figures 39–44 ), collected near Madjene [ca 3°33’S, 118°57’E), 08–10-xi-1939, by J.J. van der Starre. How- ever, they agree in all other characters with R. monochroa. For a further dis- cussion, see the remarks on variation of R. monochroa of these specimens.

Rhinocypha frontalis is absent from (geographical) central Sulawesi, where Rhinocypha is rather uncommon, particularly at higher altitudes, and replaced by R. phantasma, R. flavipoda sp. nov. and R. virgulata sp. nov. It is, however, locally abundant at some sites on the Banggai peninsula, in the south-eastern peninsula of Sulawesi, and on Buton (see also LIEFTINCK 1935: 177). As previously observed by Lieftinck (l.c.), specimens from Bu- ton do not differ from those of the northern peninsula. Specimens from Sabang (north of Palu) ( Fig. 31 View Figures 30–33 ), and also those collected in the Banggai peninsula ( Fig. 32 View Figures 30–33 ), have a tendency to smaller blue patches on the frons, which are anteriorly rather irregular. Specimens collected in the south-east- ern peninsula are closer to the typical form ( Fig. 33 View Figures 30–33 ).

Material studied (269♂, 49♀; all in RMNH, except indicated otherwise, localities in abbreviated form; Buton locality, November 1989, not included) Sulawesi Utara, including Province of Gorontalo.

1♂ (lectotype), »Moluques«, 1860. Leg. Lorquin (in BMNH); 2♂ 3♀, Noordkust, [1863]. Leg. C.B.H. von Rosenberg; 1♀, Ayer Pann.[as] [1863]. Leg. C.B.H. von Rosenberg; 1♀, Limbotto. Leg. C.B.H. von Rosenberg. 1863–1864; 2♂ 1♀, Pekawa, 15 Sep. 1912. Leg. L. Martin (in SMFD); 1♂, Soeroemana, Feb. 1913. Leg. L. Martin (in SMFD); 5♂ 2♀, Tondano [acq 11.vi.1935]. Leg. C. van Braekel; 5♂ 5♀ Ton- dano, Sept. 1938. Leg. C. van Braekel; 6♂ 2♀, Manado, Pandoe, 250 m, 26 May 1940. Leg. L. Coomans de Ruiter; 5♂ 4♀, Surroundings of Tondano, 600 m, 9 June 1940. Leg. L. Coomans de Ruiter; 4♂ 1♀, Gorontalo, Kwandang, 9 July 1940. Leg. L. Coomans de Ruiter; 4♂ 2♀, Manado, Pandoe, N. of road to Wori (brooklets with sandy bottom), Alt. 0–20 m. CdR VII. 1 Aug. 1940. Leg. L. Coomans de Ruiter; 2♂, Surroundings Ranotongkor, 300 m. CdR XVI. Fish ponds and fast running river. 2 Aug. [19]40. Leg. L. Coomans de Ruiter; 3♂, Tanahwangko-Ranotongkor, 4 Aug. [19]40. Leg. L. Coomans de Ruiter; 2♂, Modoinding, 27 June 1941. Leg. F. Dupont; 1♀, Kajoeroja [Kajuroja], Alt. 100–120 m, 10 Nov. 1941. Leg. F. Dupont; 2♂, Project Wallace. Dumoga Bone National Park: Tumpah River near Edward’s camp (Stat. 28). Alt. 900 m. 23 Feb. 1985. Leg. J. P. Duffels; 1♂, Same Park [Around Basecamp]. 225 m. Primary forest. 0°34’N 123°54’E. 25–31 March 1985. Leg. F. G. Rozendaal; 1♀, Same Park, Waterfall creek (tributary of river Tumpah). Fast running brooklet with ponded areas, through multistratal evergreen forest. Mainly shaded. Boulders and sand. Alt. 225–250 m. 21 Apr. 1985, sample B. Leg. J. van Tol; 2♂, Same site. 22 Apr. 1985, sample B. Leg. J. van Tol; 5♂, Same site. 23 Apr. 1985, sample B. Leg. J. van Tol; 8♂, Same NP. Tumpah river near Edward’s camp. River through undis- turbed multistratal evergreen forest. Alt. 540 m. 30 Apr. 1985, sample A. Leg. J. van Tol; 1♀, Same NP. c. 2 km W of Edward’s camp. Brooklet in undisturbed multi- stratal evergreen forest. Sandy bottom. Alt. 700m. 1 May 1985. Leg, J. van Tol; 5♂ 1♀, Same NP. Waterfall creek (tributary of river Tumpah) [further data as above]. 20 May 1985, sample B. Leg. J. van Tol; 2♂, Same NP. Trickles near Toraut river close to Base camp. Small, non-permanent brooklets in primary forest. Width c. 0.5 m and depth a few cm, with some deeper pools in the stream bed 22 May 1985, sample A. Leg. J. van Tol; 2♂, Same NP. Waterfall creek (tributary of river Tumpah) [further data as above]. 24 May 1985, sample A. Leg. J. van Tol; 2♂, Same NP. Tumpah river near Edward’s camp. UTM=WL9365. Alt. c. 600 m asl. River through undisturbed multistratal evergreen forest. 3 June 1985, sample A. Leg. J. van Tol; 2♂, Same NP. c. 2 km W of Edward’s camp. Brooklet in undisturbed multistratal evergreen forest. Alt. 700 m asl. Sandy bottom. UTM: WL 9265. 4–5 June 1985. Leg. J. van Tol; 1♂, Same NP. Gunung Poniki. Station 0 74. Alt. 1810 m asl. [presumably mislabelled], 2 Nov. 1985. Leg. R. Bosmans; 2♂, Same NP. River Tumpah. Alt. 200 m asl. [vari- ous dates Oct. 1985]. Leg. R. Bosmans & J. Van Stalle; 3♂, Same NP. Waterfall trail. 280 m. 14 Nov. 1985. Station 0 94. Leg. R. Bosmans & J. Van Stalle; 1♂, West of Ma- nado: brooklet at N side of Lake Tondano. 89JvT08. 1 Feb. 1989. Leg. J. van Tol; 4♂, Tomohon: stream below Air Terjun (1°23’35”N 124°50’22”E), 3–5 Aug. 2011. Leg. A. Günther (in AGPC); 6♂, Bogani-Nani-Wartabone (Dumoga-Bone) National Park, Sg. Tumpa kecil (0°34’35”N 123°54’01”E), 11 Aug. 2011. Leg. A. Günther (in AGPC); 2♀, Same NP, Sg. Tumpa (0°34’23”N 123°54’07”E), 12 Aug. 2011. Leg. A. Günther (in AGPC); 4♂ 2♀, Talawaan, small stream downstream of Air Terjun Tunan (1°34’08”N 124°58’43”E), 21 Aug. 2011. Leg. A. Günther (in AFPC); 1♂, Dumoga Bone National Park. River Tumpah near Waterfall creek. Middle-sized river, up to 40 m wide, current velocity up to 1 m/s. Large boulders, rapids. Edge of somewhat disturbed multistratal evergreen forest. 0°33’53”N 123°54’24”E. 11 July 2013. Leg. J. van Tol; 1♂, Same NP. Waterfall creek (tributary of river Tumpah). Fast running brooklet through multistratal evergreen forest. Mainly shaded. Boulders and sand. 225 m asl. 0°34’36”N 123°54’01”E. 12 July 2013. Leg. J. van Tol; 3♂, East of Manado. Talawaan. Waterfall, stream, small stream, seepages. Largely shaded by secondary vegetation. 1°34’08”N 124°58’42”E. 14 July 2013. Leg. J. van Tol.

Sulawesi Tengah

1♂ 1♀, Balantak. Luwuk-Pagimana road. CdR XXI. 26 Oct. 1940. Leg. L. Coomans de Ruiter; 6♂ 2♀, Sabang. Dampelas. 28–29 Nov. [19]40. Leg. J.J. van der Starre; 1♂, Meili [Meli]. 6 Dec. 1940. Leg. J. J. van der Starre; 3♂ 1♀, Sabang. Dampelas. 30 Jan. 1941. Leg. J. J. van der Starre; 4♂ 1♀, Sabang. Dampelas. 9 May 1941. Leg. J. J. van der Starre; 2♂, Sabang. Dampelas. 3 July 1941. Leg. J. J. van der Starre; 8♂ 1♀, 15 km NNE of Luwuk: Sg. Biak. Clear running water with rapids and pools. 0°49’S, 122°52’E. 150 m asl. 27 Jan. 1989. Leg. J. van Tol; 17♂ 6♀, 15 km NNE of Luwuk. Sg Biak at road Biak to Poh. River with ponded sites and currents. Nearly unshaded. Some emergent vegetation. Semi-cultivated area. 6 and 22 Oct. 1989 (89JvT13). Leg. J. van Tol; 1♂, 15 km NNE of Luwuk: Sungai Biak nr road Biak to Poh. River, in disturbed lowland rainforest. 6 Oct. 1989 (sample Duffels Sul. 1). Leg. J. P. Duffels; 12♂ 2♀, 20 km ENE of Biak: Sg. Takilalang. Stream 2–3 m wide in somewhat dis- turbed lowland evergreen rain forest. Clear water. Bottom sand and uplifted coral reef. Mostly shaded. 0°48’S, 123°00’E. 8 Oct. 1989 (sample 89JvT015). Leg. J. van Tol; 4♂ 1♀, 15 km NNE of Luwuk: Sg Biak at road from Biak to Poh, with ponded sites and currents. Completely shaded site. 11 Oct. 1989 (sample 89JvT18). Leg. J. van Tol; 1♂, SW of Luwuk. Batui river at Sinsing Camp. Middle-sized stream in lowland rainforest. Alt. 90 m asl. 14–17 Oct 1989. Leg. J. P. Duffels; 1♂, SW of Lu- wuk. Totop camp along Batui river. Lowland rainforest. (1°09’00”S, 122°31’30”E). Alt. 120 m asl. 19 Oct. 1989. (Sample Sul. 18). Leg. J. P. Duffels; 1♂, 20 km ENE of Biak: Sg. Takilalang. [Data as 8 Oct. 1989]. 20 Oct. 1989 (sample 89JvT015). Leg. J. van Tol; 1♂, 20 km NNE of Luwuk, between Salodik and Siuna. Brooklet and pond in semi-cultivated area. 22 Oct. 1989 (sample 89JvT29). Leg. J. van Tol; 2♂ 1♀, NE of Palu, road Tawaeli-Parigi, at ‘49 / 16’. West side mountain ridge. Small brooklet on steep slope. Coffee plantation. Alt. c. 500 m asl. 6 April 1997. Leg. J. van Tol.

Sulawesi Tenggara

1♂ 1♀, Boeton [Buton] Island. 2 Feb. [19]17, leg. [supposition] N.A.L. Krans; 1♂, S of Sanggona. Foot of Watuwila Mts. : Mokowu river near Mokowu camp. Rivulet with ponded areas, clear water, bottom with boulders, some sand. Alt. 150 m asl. 19–20 Oct. 1989 (sample S89020 View Materials J). Leg. J. Huisman; 18♂, S of Sanggona: Mokowu river near Mokowu camp. Foot of Watuwila Mts. Rivulet with ponded areas, clear water, bottom with boulders, some sand. Largely shaded. Alt. 150 m asl. 3°48’S, 121°39’E. 89JvT031. 29–31 Oct. 1989. Leg. J. van Tol; 3♂, NE of Kolaka: Mokowu camp along Mokowu river near Gng Watowila. (3°49’S, 121°40’E). Rivulet, in dis- turbed lowland rainforest. Alt. 200 m. 29–31 Oct. 1989 (sample Duffels Sul. 24). Leg. J. P. Duffels; 6♂ 1♀, S of Sanggona: Mokowu river near Mokowu camp [further data as 29–31 Oct. 1989]. 4–6 Nov. 1989 Leg. J. van Tol; Numerous ♂ and ♀, North- ern Pulau Buton. A few kms inland from Labuhan Tobelo. Jismil camp along Sg. Labuhan Tobelo. Rivulet through hardly disturbed primary evergreen rain forest. Boulders covered with calcareous deposit. Alt. 150 m asl. 4°26’30”S, 122°59’00”E. 12–17 Nov. 1989. sample 89JvT040. Leg. J. van Tol.

Sulawesi Selatan

1♂, Onan[g], Sg. Parabaya, 58 km N of Majene. Strongly disturbed rain forest. 19 Nov. 1993. 3°07’S, 118°46’E. Leg. J.P. & M.J. Duffels.

Distribution and habitat

Rhinocypha frontalis is a common species in the northern arm of Sulawesi ( Fig. 84 View Figure 84 ). It is further recorded from most parts of the islands, and also from Buton (off south-eastern Sulawesi). In several of these regions of south- western and south-eastern Sulawesi, R. monochroa is the more common species. We have never observed both these species at the same site, but

R. frontalis and R. phantasma have been recorded from the same streams, especially on the Banggai peninsula.

At least in northern and south-eastern Sulawesi it is a lowland species and prefers smaller streams in forested habitats or at least streams with gal- lery forests, shady streams within plantations or in steep gorges. It was also found in quiet sites in rivers and tolerates a certain level of water pollution. It is absent from polluted as well as from very sunny streams and larger riv- ers. The highest population densities were observed on small, deeply shaded streams in undisturbed primary forest ( Fig. 13 View Figure 13 ).

Behaviour

Males remain by the water most of the day, even on cloudy days. By con- trast, the females appear at the streams only on sunny days and mostly in late morning hours or about noon. Oviposition takes place in dead, rotting logs, driftwood or other plant substrates lying in the water. Males establish small territories around these sites, usually in small sunny spots. They de- fend these territories against rivals with aerial threat displays that can oc- cupy most of the daily activity schedule. The main flight style is a relatively simple frontal display in which males face head to head and with synchro- nous stroking wing beat, turning all wings forward simultaneously. As typi- cal for the R. tincta -complex, male courtship behaviour includes a display of the white-coloured inner faces of the tibiae of mid and hind legs.

Remarks

Rhinocypha frontalis shares several characters with R. colorata (Philippines) and R. semitincta (Halmahera) , e.g., in the coloration of the pro- and syn- thorax, which are not present in R. monochroa and related species on Su- lawesi. SELYS (1891: 215) already discussed the relationships of these three species (R. colorata as R. semitincta colorata). As explained above, our analy- sis of molecular characters indicates that R. tincta and R. colorata are sister- species, while the Sulawesi species form another clade that is sister to tincta plus colorata. A more detailed reconstruction of the historical biogeography of this so-called R. tincta -group must await further analysis of the molecular characters of this group.