Rhinocypha monochroa (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 : 338-349

Rhinocypha monochroa (Selys, 1873)

( Figs 5, 6, 38–53 )

Libellago (Rhinocypha) monochroa. — SELYS (1873b): 614–615 (sep. 61–62) (origi- nal description, type locality Celebes).

Rhinocypha monochroa . — KIRBY (1890): 114 (catalogue, distribution Celebes); SELYS (1891): 215 (distribution Ceylon [lapsus], relationships); RIS (1916): 311– 312 (pro parte) (key species Celebes, material); LIEFTINCK (1935): 177 (compared with R. frontalis , distribution); COWLEY (1937): 6 (penis structure in group A); KIMMINS (1969): 309 (lectotype designated, in BMNH).

Diagnosis

Stripe over synthorax with a ventral projection on metepimeron against metakatepisternum ( Figs 41–42 ), which is diagnostic among the Sulawe- si Rhinocypha species. Males have more extensive brownish black opaque markings on the wings than other species on Sulawesi, leaving only the area anterior to the Arculus, or just distal to the Arculus, transparent. Frons black without blue markings. Mesopreepisternum black, not blue or pale yellow

as in other species on Sulawesi (except R. togeanensis ), although in some females this plate has a very small and indistinct pale marking. Synthorax ( Fig. 41 ) with upperside of transverse blue stripe more or less straight, usu- ally without conspicuous projection. Some specimens, however, may have such a projection ( Fig. 42 ). Abdomen black on dorsum, without pruinosity.

Description

Male

Head ( Fig. 39 ) — Labium brownish black, median lobe black; labrum swol- len, black; mandibles black, with a large blue mark, its base distinctly wider than near labrum, its lower side running parallel to border of mandible, leaving a narrow black margin; clypeus projected as in other Chlorocyphi- dae; anteclypeus shining black; postclypeus, frons, vertex, occiput and post- ocular lobe velvet-black, a paired cream spot behind lateral ocelli, and small cream post-ocular spots close to occiput; genae with large blue spot just above mandibles, extending dorsally with a narrow blue line along the eyes up to the level of the median ocellus.

Thorax — Pronotum ( Fig. 40 ) black, with pale-blue markings as follows:an- terior lobe with small spot in latero-posterior corner, continuing onto me- dian lobe, where it is wider anteriorly and tapers in a sharp point, reaching just the posterior half of the median lobe; spots on lateral lobe very variable, some large as in Fig. 40 , in other specimens small or even hardly visible; posterior lobe black, unmarked.

Synthorax ( Fig. 41 ). Mesopreepisternum black, Mesepisternum black, umarked; a wide, rather straight, blue stripe in lower half of synthorax, run- ning anteriorly from ventro-posterior corner of mesokatepisternum, continuing on ventro-anterior part of mesepimeron; dorsal side of stripe irregular, but usually without conspicuous projection, ending well before posterior border of mesepimeron; lower side of stripe runs from mesokatepisternum just under metathoracic spiracle to metepimeron, where it begins sharply in ventro-anterior corner, continuing at some distance from lower margin of metepimeron, reaching its posterior margin; dorsal side of stripe poste- riorly leaving metapleural suture and meeting the posterior margin of met- epimeron in the middle; metakatepisternum black.

Legs — Black, but distal ¾ on innerside of mid and hind tibiae white.

Wings — Black with metallic sheen; basal part to the level of Arculus transparent, posteriorly also to level of distal side of quadrangle; metallic blue iridescence on underside of hind wing to level of Px10, distal part of wing with deep, golden copper iridescence; pterostigma of fore and hind wings dark brown, nearly black against veins.

There are remarkable differences in the coloration of the wings between the males of different populations of R. monochroa ( Figs 45–53 ). This applies particularly to the iridescent colours of the undersides of the hind wings. Also, being strongly iridescent structural colour, both the colours and the extent of the coloured zones perceived are affected by the angle of reflection, with shallow viewing angles resulting in shorter wavelength reflected light (cf. Figs 46 and 47 ). The best overall colour impression is seen on photographs of living individuals. Reflective patterns of newly preserved specimens are fairly stable. However, the colours on the wings of pinned specimens can change or fade with time, especially in younger specimens.

The populations in the southern part of south-western Sulawesi and on Sa- layar Island show a metallic light blue to deep blue sheen in the proximal half of the underside of the hind wing (‘blue triangle’), distally followed by a narrow yellow band and a golden brown distal part ( Figs 5 and 45 ). Such coloration is also shown in the lectotype ( Fig. 38 ). In specimens from Palopo ( Fig. 47 ) and Madjene ( Fig. 48 ) the reflection of the basal ‘blue triangle’ is, depending on the angle of examination, more deep blue to blue violet, while the reflection of the distal parts is golden coppery brown, at slightly altered angle of incidence changing to green. Specimens from Malino and Watampone ( Fig. 46 ) have an intermediate coloration. The tripartite reflec- tion pattern with a basal ‘blue triangle’ is characteristic of populations from the south-western peninsula. Specimens of the south-eastern peninsula lack this clear zoning in the reflection patterns; the underside of the hind wings reflect bronzy brown with slightly golden sheen (Kolaka, Fig. 49 ), purple- brown to purple (Kendari, Fig. 50 ) or green to bluish with a greenish distal part of the wing (Moramo ( Fig. 51 ). A distinctly different reflection pat- tern is shown by specimens from Kabaena Island, off south-eastern Sulawesi ( Fig. 52 ). The main area of the wings reflects green, and towards the distal end one finds a colour gradient from gold to blue violet. The space between C and R1 reflects, depending on the view angle, steel blue to purple, and the space between R1 and R2 purple (see also the conclusions below).

Abdomen ( Fig. 43 ) — Dorsum black; side of tergites with extensive blue markings as follows: S1 large, sub-quadrangular, S2 rectangular, but ventro- anterior corner emarginate, S3–S8 with progressively smaller markings, that on S3 large and rectangular, those on S6–S7 tapering dorso-posteriorly, S8 with oblong triangular marking, pointed posteriorly, ending before poste- rior margin of segment; S9–S10 and anal appendages black.

Female

Head ( Fig. 44 ) — Mandible with squarish pale bluish-white marking in ba- sal part, distal part shining black; gena with similar marking to R. frontalis , extending along the eyes as a very narrow stripe up to the level of vertex; frons black without pale marking; a paired spot beyond the lateral ocelli, about the size of the ocelli; post-ocular spots of similar size.

Thorax — Pronotum velvet black with just a small irregular bluish white marking from the extreme lateral corner of anterior lobe to middle of me- dian lobe; marking widest in the middle.

Synthorax. Mesopreepisternum black.Synthorax velvet black with a longi- tudinal bluish white stripe from ventro-posterior corner of mesokatepister- num, over ventro-anterior part of mesepimeron, continuing over meta- thoracic spiracle on metepisternum, and over middle of metepimeron.

Legs — Black.

Wings — Basal part of fore wing opaque dark brown up to level of Px24; posterior part transparent white, the extreme tip opaque white; pterostigma white, basal corner brown; hind wing dark brown, with tip posterior to posterior side of pterostigma opaque white; pterostigma with significant variation in both fore and hind wings, from basal half dark brown and rest creamy white, to nearly fully dirty white.

Abdomen — Black, with small bluish white markings as follows: S1 with small oblong spot mediolaterally; S2 with longitudinal marking about length of segment mediolaterally, with sub-cylindrical spot in same line against posterior margin, ventrally a spot of ca ¼ of segment length, half as high as long; a series of similar spots at same level on S3–S7, large on S3–S5, smaller on S6–S7; anterior margin of S3–S6 with narrow stripe, very small on S7; rest of abdomen black.

Measurements

Males: Measurements of specimens from south-western Sulawesi [mm] — Hind wing length (n=5) x=24.5 (23.0–26.0); hind wing width (n=5) x= 6.0 (5.5–6.5); abdomen length (including appendages) (n=5) x=20.5 (19.5–22.0). Females: Measurements of specimens from south-western Sulawesi [mm] — Hind wing length (n =5) x= 26.0 (25.5–29.5); hind wing width (n =5) x=6.5 (6.0–7.0); abdomen length (including appendages) (n =5) x= 20.5 (19.0–21.5). Specimens from Salayar [mm] — Hind wing length (n =3) 24.0–25.0; hind wing width (n= 3) 5.5–6.0; abdomen length (including appendages) (n= 3) 18.0–20.0.

Material studied (290♂ 196♀)

Sulawesi (Celebes, without further locality)

1♂ (lectotype), Celebes. Before 1873 (in BMNH); 1♂ 3♀, Celebes , [before 1916] (ded. R. Martin; in SMFD); 1♂ 1♀, Celebes, [before 1916]. Leg. C. Ribbe (in SMFD). Sulawesi Selatan (South Sulawesi, including present-day Sulawesi Barat, West Su- lawesi)

28♂ 13♀, Celebes mer[idional]. 1896. Leg. H. Fruhstorfer, (in SMFD); 1♂, Lompa-Battau. 3000’. Mar. 1896. Leg. H. Fruhstorfer; 6♂ 1♀, Bonthain, 1897. Leg. H. Fruhstorfer; 1♀, Maros, 3–4 Sep. 1904. Leg. E. Lorenz Meyer; 2♂ 1♀, Maros. 28 Apr. 1914. Leg. L. Martin; 4♀, Surroundings Makassar, June 1929. Leg. G. Overdijkink; 1♂ 5♀, Bantimoeroeng, 3 Oct. 1930. Leg. J. van der Vecht; 1♂ 1♀, Bantimoe- roeng. Aug. 1931. Leg. G. Heinrich; 7♂ 6♀, Watampone. Lonrong. 150 m asl. 25 June 1936. Leg. L.J. Toxopeus; Maros; 1♂, Bantimoerong. 200 m. 27 June 1936. Leg. L.J. Toxopeus; 1♂ 1♀, Bonthain. Makassar-Malino Rd. – pl. 47 and pl. 46. 200 m. 24 July 1936. Leg. L.J. Toxopeus; 2♂, Maros. Bantimoerong. 24 July 1936. Leg. L.J. Toxopeus; 1♀, Bonthain, July 1938. J.P. Kalis; 23♂ 15♀, Eiland Saleier [Salayer Is- land]. Pariangan. 100 m. Oct–Nov 1938. Leg. J.P.A. Kalis; 6♂, Paloppo. 1939. Leg. M.E. Walsh-Held; 3♂ 2♀, Madjene. 8–10 Nov. 1939. Leg. J.J. van der Starre; 9♂ 2♀, Maros n/b M’sar [near Makassar]. 13–19 Nov. 1939. Leg. J.J. van der Starre; 1♂ 2♀, Madjene. 30 Nov. 1939. Leg. J.J. van der Starre; 1♂, Masimboe [Masimbu]. 18 Mar. 1940. 500 m. Leg. J.J. van der Starre; 1♀, Madjene, 20 Mar.1940. Leg. J.J. van der Starre; 1♂ 1♀, Loewoe. Masamba. S. [Sungai] Baeboenta [appr. 8 km W of Masamba]. 22–23 June 1940. Leg. L.L.A. Maurenbrecher; 1♀, Masimboe [Ma- simbu]. 20 Aug. 1940. Leg. J.J. van der Starre; 1♂ 1♀, Bantimoeroeng. CdR XXX. 11 Apr. 1941. Leg. L. Coomans de Ruiter; 2♀, Maros. Bantimoeroeng. Omgeving waterval [Surroundings waterfall] CdR XXX. 22 May 1941. Leg. L. Coomans de Ruiter; 1♂, Loewoe. Masamba. S. Baebunta. 25 May 1941. Leg. L.L.A. Maurenbre- cher; 2♂ 3♀, Maros. Bantimoeroeng. Omgeving waterval. CdR XXX. 11–12 June 1941. Leg. L. Coomans de Ruiter; 1♀, Luwu distr. Masamba. Lamasi. 12 June 1941. Leg. L.L.A. Maurenbrecher; 1♂, Maros. Bantimoeroeng. CdR XXX. 17 Aug. 1941. Leg. L. Coomans de Ruiter; 5♂ 1♀, km 47 road to Malino [from Makassar], CdR 36. 23 Aug. 1941. Leg. L. Coomans de Ruiter; 2♀, Maros. Bantimurung. 6 July 1949. Leg. W.A. van der Noordaa; 4♂ 2♀, Bantimurung. 10–18 Aug. 1949. Leg. A. Diakonoff; 6♂, Bantimurung area. Pattunuang Asue. 200 m. 29–31 May 1982. Leg. M.A. Lieftinck; 1♂, Mt. Lompobatang area. Malino. 1100 m. 5°15’S, 119°51’E. 2–10 Jun 1982. Leg. M.A. Lieftinck; 3♂ 2♀, Mt. Lompobatang area. Affl. Berang river. 400 m. 3–7 June 1982. Leg. M.A. Lieftinck; 8♂ 2♀, E of Maros. Bantimu- rung area. Surroundings of Bantimurung waterfall. QK94. 18 Sep–14 Oct 1983. Leg. S.S. Pariwono; 2♂ 1♀, E of Maros. Bantimurung area. QK94. Biseang Labboro. 275 m. 4–11 October 1983. Leg. S.S. Pariwono; 13♂ 4♀, E of Maros. Bantimurung area. QK 94. Pattunuang Asue. 250 m. 21 Sep–10 Oct 1983. Leg. S.S. Pariwono; 3♂ 3♀, E of Maros: rivulet in Bantimurung area. 5°02’S, 119°40’E. 16–23 June 1985. Leg. J. van Tol; 2♂ 3♀, E of Maros. 5°02’S, 119°40’E. Rivulet in Bantimurung area. Semi-cultivated. 23 June 1985. Sample A. Leg. J. van Tol; 4♂ 4♀, E of Maros: Ban- timurung area, Sg. Pattunuang Asue. 5°03’S, 119°41’E. Fast flowing stream through disturbed forest on limestone. Large boulders, ponded areas, clear water. Sample 91JvT07. 19 Apr. 1991. Leg. J. van Tol; 11♂ 2♀, Circa 10 km E of Maros: surround- ings of Bantimurung waterfall. River through disturbed forest on limestone, and ponds in semi-cultivated area, c. 200 m asl. 19–23 Apr. 1991 (91JvT09). Leg. J. van Tol; 6♂ 2♀, Bantimurung, Sungai Bantimurung (5°01’S, 119°41’E), 29–30 Mar. 1993. Leg. A. Günther (in AGPC); 2♀, Bantimurung, Sungai Bantimurung (5°01’S, 119°41’E), 21 Aug. 1993. Leg. A. Günther (in AGPC); 9♂ 2♀, Pattunuang Asue, Sungai Pattunuang Asue (5°04’S, 119°43’E), 23 Aug. 1994. Leg. A. Günther & F. Randow (in AGPC); 3♂ 3♀, Pattunuang Asue, Sungai Pattunuang Asue (5°04’S, 119°43’E), 12 Mar. 1997. Leg. A. Günther (in AGPC); 1♂, Pattunuang Asue, Sungai Pattunuang Asue (5°04’S, 119°43’E), 14 Sep. 2010. Leg. A. Günther (in AGPC); 1♂ 1♀, Sulawesi Selatan, Pattunuang Asue, Sungai Pattunuang Asue (5°04’S, 119°43’E), 31 July–1 Aug. 2011. Leg. A. Günther (in AGPC).

Sulawesi Tengah (Central Sulawesi)

1♂, Palu: Pekawa, 15 Sep. 1912. Leg. L. Martin; 1♂, Palu: Soeroemana, Feb. 1913. Leg. L. Martin.

Sulawesi Utara (North Sulawesi)

9♂ 17♀, Toli Toli [locality considered a lapsus, not on the map], [ca. 1897]. Leg. H. Fruhstorfer (in SMFD).

Sulawesi Tenggara (South-eastern Sulawesi)

1♂, Kolaka. T. Elbert. Ovt. 1909. [Partly handwritten] (in SMFD); 11♂ 2♀, 30 km WSW Kendari: Sg Amoito. Small stream and trickles through disturbed forest N of Pegunungan Boroboro. Clear water. Alt. 100 m. 5 Feb. 1989. Sample 89JvT09. Leg. J. van Tol; 5♂ 2♀, 18 km ENE Kolaka: Sg. Koloimba near crossing with road. Black- water stream with vegetation. 4°02’S, 121°47’E. Sample 89JvT11. 7 Feb. 1989. Leg. J. van Tol; 2♂, Pulau Kabaena. Tangkeno. 2–3 Nov. 1989. Leg. C. Lepelaar; 1♀, Pulau Kabaena. 4 km S of Tangkeno. Cave camp. S8928R. Open riverine forest along Sg. Lakambula. 5–8 Nov. 1989. Leg. R. de Jong & J. Huisman; 1♀, Pulau Kabaena. 1 km S of Tangkeno. Riverine forest, bamboo, grassy slopes (S8931). 550 m. 8–9 Nov. 1989. Leg. R. de Jong; 7♂, Pulau Kabaena. Batuawu. Cultivations, mainly coconut (S8933). Sea level. 11 Nov. 1989. Leg. R. de Jong; 1♀, Moramo. Sg. Sena. Forest with dense undergrowth along stream. 50 m. S 8938. Leg. R. de Jong.

Distribution and habitat

Widespread in south-western Sulawesi below about 400 m, northward up to Palopo. Some specimens were collected along the coast near Palu by L. Mar- tin (in SMFD); these records need confirmation.More local in other parts of

Sulawesi ( Fig. 85 ). The locality of specimens in RMNH labelled Gorontalo / Minahasa (northern arm of Sulawesi) is considered doubtful and as such in- cluded on the map. In south-eastern Sulawesi it is much rarer than R. frontalis . Although they occur in the same regions, R. monochroa has not been observed at the same sites as R. frontalis or R. phantasma. It is the only spe- cies of Rhinocypha recorded from the islands of Salayar and Kabaena, while it is not known from Buton, where both R. frontalis and R. phantasma occur.

Little has been recorded about the habitat requirements of this species, with the exception of the frequently visited streams at Bantimurung and Pattunuang Asue near Maros in SW Sulawesi ( Fig. 15 ). Our observations indicate that R. monochroa frequents more open streams than R. frontalis . The species was found in clear and fast flowing streams, mostly in areas of lowland primary or secondary forests. The species seems to be absent from muddy watercourses, e.g., near larger forest clearings and below paddy field or settlements. The streams in south-western Sulawesi have partially very large fluctuations in flow, caused by seasonal influences.

Behaviour

The behaviour was studied by GÜNTHER (2008a) in south-western Sulawesi. Oviposition sites were dead rotting logs, driftwood or other plant substrates lying in the water. Males defend territories around these sites with long- lasting threat displays. The patterns of these threat flights are unique among all Rhinocypha species described here. The synchronous wing beat is signifi- cantly modified. Single hind wings are presented forward and laterally to the rival male. During this display the wing beat of these wings pauses over 2–3 strokes. The strongly banded, contrasting colours of the hind wings, described above for the males, probably intensifies the signal effect in this style of presentation.

The presentation of the hind wings is of obvious importance during male courtship displays to females.It is conceivable that what we describe as Rhinocypha monochroa, actually consists of several genetically distinct populations that do not interbreed since they are isolated by their behaviour and male colour patterns, and should therefore be treated as separate species. Further behavioural and genetic studies are needed to help clarify this matter.

Remarks

As already mentioned above, RIS (1916: 310 ff.) treated the Rhinocypha specimens available at the time, now preserved in SMFD. Ris distinguished two forms of R. monochroa. ‘Form a’ (»typisch«) was mentioned from »Süd- Celebes«, Toli-Toli, Lombok [considered erroneous], and Maros. ‘Form b’ was mentioned from the Takala Mts and Suramana and Pekawa, both near Palu. From Suramana and Pekawa, also R. frontalis was reported. We have examined these specimens in SMFD, and conclude the following: all specimens of R. monochroa ‘Form a’ indeed belong to R. monochroa, al- though we have strong doubts whether the locality Toli-Toli is correct (not included on the map). There is a male specimen of a Euphaea (ex UMMZ) with a similar label in RMNH. It was identified as Euphaea lara Krüger by M. Hämäläinen (with question mark), and previously as Euphaea brunnea Selys by F. Förster. It may actually represent a specimen of the type series of Euphaea lara var. lombockensis McLachlan. No other specimen of the family Euphaeidae is known from Sulawesi. We conclude that labels of specimens collected by H. Fruhstorfer from »Toli Toli« are unreliable.

The specimens characterised as R. monochroa “Form b” are labelled by F. Ris as R. frontalis [sic!] “Form b” in the collection. We have identified these specimens as follows: the 3♂ 2♀ from the Takala Mts are R. virgulata sp. nov. (Ris no. 1441, 1442, 1446 and 1447), and R. flavipoda sp. nov. (Ris no. 1443, ♂). The specimens from Pekawa and Soeroemana / Suramana had been correctly identified: Pekawa: R. monochroa (Ris no. 1437, ♂) and R. frontalis (Ris no. 1438–1439, ♂ and Ris no. 1440, ♀), and Soeroemana: R. monochroa (Ris no. 1445), and R. frontalis (Ris no. 1444), both males. These specimens represent the only observations of sympatry of R. frontalis and R. monochroa.

Figures

Figure 15. Habitat of Rhinocypha monochroa, Libellago rufescens and L. asclepiades. Stream Sg. Pattunuang Asue in Bulusaraung National Park, Southwest Sulawesi. Photo: AG (31-vii-2011)

Figure 38. Rhinocypha monochroa. Male, lectotype [NHMUK 013324013]. Photo: B. Price, Natural History Museum, London

Figures 39–44. Rhinocypha monochroa. All specimens from Sulawesi Selatan. 39 – Male, head, frontal view. Bantimurung, 19­iv­1991 [JvT 05698]; 40 – Male, pronotum, lef lateral view. Bantimurung, 19–23­iv­1991 [JvT 05708]; 41 – Male, synthorax, lef lateral view. Bantimurung, 19­iv­1991 [JvT 05698]; 42 – Male, syn- thorax, lef lateral view. Madjene, 8–10­xi­1939 [JvT 05343]; 43 – Male, abdomen, lef lateral view. Bantimurung, 19­iv­1991 [JvT 06630]; 44 – Female, head, dorsal view. Bantimurung, 19­iv­1991 [JvT 05702]. Artwork by JvT

Figures 45–52. Rhinocypha monochroa. Male, hind wing, ventral view. 45 – Sulawesi Selatan. Bantimurung, Sg. Pat- tunuangAsue,05-ix-1999 (in life); 46 – Sulawesi Se- latan, Watampone, Lonrong, 25-vi-1936. Leg.L.J. Toxopeus [JvT 05452]; 47 – Sulawesi Selatan, Palopo, 1939. Leg. M.E. Walsh [JvT 05342]; 48 – Sulawesi Selatan, Madjene, 8–10­xi­1939. Leg. J.J. van der Starre [JvT 05345]; 49 – Sulawesi Tenggara, 18 km ENE of Kolaka: Sg. Koloimba. Leg. J. van Tol, 07-ii-1989 [JvT 06622]; 50 – Su- lawesi Tenggara, 30 km WSW of Kendari, Sg. Amoito, 05-ii-1989. Leg. J. van Tol [JvT 05503]; 51 – Sulawesi Tenggara, Moramo, Sg. Moramo, 16–17-xi-1989. Leg. R. de Jong [JvT 05507]; 52 – Sulawesi Tenggara, Pulau Kabaena, Batuawu, 11- -xi-1989. Leg. R. de Jong [JvT 05330]. Photos: AG

Figure 53. Rhinocypha monochroa. Simplified scheme of coloration of underside of hind wing. Artwork by AG

Figure 85. Distribution Rhinocypha monochroa.