Nososticta salomonis (Selys, 1886)

Theischinger, Günther, Mitchell, Andrew, Richards, Stephen J. & Polhemus, Dan A., 2023, Systematics of the Nososticta salomonis complex (Odonata: Zygoptera: Platycnemididae), Zootaxa 5296 (2), pp. 101-146 : 110-114

Nososticta salomonis (Selys, 1886)

( Figs 7–16 , Map 1 , Pls 1, 7, 8)

Alloneura salomonis Selys, 1886: 188 .

Material examined. Solomon Islands: Holotype ♁ (photographs). Solomon Is, Mathew ( BMNH); the specimen probably comes from Ugi Is near San Cristobal. Other material. As listed below and described in Table 2 from the areas given under Known Distribution. Choiseul Is.: 13 ♁♁, 2 ♀♀, Choiseul Prov., Vangamole River, 3 km N of Mole , 25 m a.s.l., 6°48’40”S, 156°32’42”E, water temp. 28.5° C, 17-iii-2005, CL 7389 , D.A. Polhemus; 9 ♁♁, same locality and data as preceding, D.A. Polhemus and R.A. Englund; all in BPBM . 1 ♀, Kitipi River , 80 m a.s.l., 12-iii-1964, P. Shanahan; in RMNH. Guadalcanal: 7 ♁♁, 1 ♀, Guadalcanal Prov., Tenaru River at Tenaru Falls , SE of Honiara, 40 m a.s.l., 9°31’01”S, 160°00’59”E, water temp. 25° C, 21-xi-2004, flying along stream margins, CL 7337 , D.A. Polhemus; 8 ♁♁, Guadalcanal Prov., Lungga River gorge, SW of Mt Austen at proposed dam site , 25 m a.s.l., 9°23’44”S, 159°50’48”E, water temp. 25.5° C, 28-vii-2005, CL 7407 , D.A. Polhemus; 7 ♁♁, 1 ♀, Guadalcanal Prov., Charebuma River, above Gold Ridge mine , 390–460 m a.s.l., 9°36’00”S, 160°07’23”E, water temp. 23.5° C, 03-viii-2005, CL 7421 , D.A. Polhemus; all in BPBM. 1 ♁, Ilu farm , Rystveld, 30-x-1964, R. & G.S. Slooff; 1 f, Komugelea, 1200 ft, Ananastuintje , 23-ix-1965, R. Slooff; 2 m, rivier bij Tenaligi , 25-ix-1965, R. Slooff; 1 ♁, 3 ♀♀, Tenaligi-river, dicht bos , 25-ix-1965, R. Slooff; all in RNMH. Kolombangara Is.: 1 ♁, Western Prov., rocky forest stream 5.5 km N of Ringgi harbour, 120 m a.s.l., 7°12’03”S, 156°54’40”E, water temp. 26° C, 19-iii-2005, CL 7394 , D.A. Polhemus; in BPBM. Makira Is. (= San Cristobal): 1 ♁, Makira and Ulawa Prov., Tagataga Creek , 4 km S of Kirakira, 160 m a.s.l., 10°29’34”S, 161°55’58”E, water temp. 26° C, 11-iii-2005, CL 7375 , D.A. Polhemus; 1 ♁, Makira and Ulawa Prov., Tawaitara Creek , SE of Tawaitara , 30 m a.s.l., 10°27’35”S, 161°56’37”E; water temp. 26° C, 10-iii-2005, CL 7374 , J.T. Polhemus; 3 ♁♁, Makira and Ulawa Prov., Puepue River and trib. , 3 km S of Kirakira, 15–50 m, 10°28’40”S, 161°55’33”E, water temp. 26° C, flying along main river channel, 10-iii-2005, CL 7373 , D.A. Polhemus; all in BPBM. Malaita Is.: 4 ♁♁, Malaita Prov., Aluta River at bridge on Auki-Atori road , 75 m a.s.l., 8°41’46”S, 160°50’03”E, water temp. 25.5° C, 30-vii-2005, CL 7411 , D.A. Polhemus; 4 ♁♁, 4 ♀♀, Malaita Prov., Kwarea River at high bridge on road to Atori , 85 m a.s.l., 8°39’10”S, 160°45’33”E, water temp. 25° C, 29-vii-2005, CL 7408 , D.A. Polhemus; 4 ♁♁, 2 ♀♀; Malaita Prov., Kwaisele River at Kwaisele Falls, nr Anomasu , 180 m a.s.l., 8°41’53”S, 160°49’40”E, water temp. 25.5° C, 30-vii-2005, CL 7410 , D.A. Polhemus; 2 ♁♁, Malaita Prov., Malaita, Kapolo Creek , 7.5 km N of Auki , 10 m a.s.l., 8°42’09”S, 160°41’59”E, water temp. 26° C, 31-vii-2005, CL 7412 , D.A. Polhemus; all in BPBM. 1 ♁ Hojollo , schaduwryke bosbeek, 300 ft a.s.l., 13-x-1967, R. Sloof; 1 ♀, Anoasa Hill, 20 km S. Auki, 400 m a.s.l., 13-ii-1982, G. & T. Racheli; 1 ♁, Tanytalau, 26-ix-1957, J.L. Gressitt; all in RMNH. New Georgia: 2 ♁♁, Western Prov., Dadaloana River , NE of Munda, 20 m a.s.l., 8°08’58”S, 157°21’22”E, water temp. 26° C, 18-xi-2004, CL 7334 , D.A. Polhemus; 2 ♁♁, Western Prov., Sakumbare River, near former Sakumbare logging camp , 15 km E of Putagita, 190 m a.s.l., 8°24’30”S, 157°41’34”E, water temp. 26° C, 22-iii-2005, CL 7401 , D.A. Polhemus; all in BPBM. Ranongga Is.: 3 ♁♁, 3 ♀♀, Western Prov., Paoroe Creek, above Boroi village , 50–70 m a.s.l., 8°05’00”S, 156°35’51”E, water temp. 26° C, 14-iii-2005, flying along stream margins, CL 7381 , D.A. Polhemus; in BPBM. Rendova: 1 ♁, Western Prov., Toropi River headwater trib. , 5.5 km S of Kenole, 230–250 m a.s.l., 8°30’30”S, 157°18’45”E, water temp. 26° C, 21-iii-2005, CL 7399 , D.A. Polhemus; in BPBM. Santa Isabel: 5 ♁♁, Santa Isabel Prov., Laticie River, above Buala , 2–118 m a.s.l., 8.14212°S, 159.58585°E, 23-vii-2005, R. Englund & D. Boseto; 2 ♁♁, Santa Isabel Prov., Blahitada Stream and large waterfalls above hydropower plant, upstream of Buala , 8.15681°S, 159.59264°E, 280 m a.s.l., 22-vii-2005, R. Englund & D. Boseto; all in BPBM. Shortland Is: 4 ♁♁, in very bad condition, Lofung, 18-x-1936, R.A. Lever; in RMNH. Vella Lavella Is.: 7 ♁♁, 1 ♀, Western Prov., Bainapo Kasi Creek, trib. to Sireri River , 5–15 m a.s.l., 7°45’54”S, 156°36’17”E, water temp. 26° C, 15-iii-2005, hovering along stream margins, CL 7385 , D.A. Polhemus ; 1 ♀, same locality and data as preceding, R.A. Englund; all in BPBM .

Affinities. Although the COI distances of material from San Cristobal, from Guadalcanal and Malaita and from Santa Isabel, Choiseul, Vella Lavella, New Georgia and Rendova are sufficient to consider these three groups as different species, there are large gaps in sampling and the poor quality of some material has prevented adequate morphological comparisons. We have therefore taken a conservative approach and regard all Nososticta from the Solomons archipelago, except the population from Bougainville which is both morphologically and genetically very divergent, as a single geographically variable species, Nososticta salomonis , which is the sister taxon of N. hedigeri sp. nov. from Bougainville.

Differential diagnosis. The lack of a pale dorsal marking on segment 2 distinguishes the male of N. salomonis from N. africana and N. tagula sp. nov. and the lack of a narrow black basal stalk between the ante-humeral patches distinguishes it from N. hedigeri sp. nov. A straight anterior margin of the mostly not shortened metepimeral patch separates the male of N. salomonis from N. chrismulleri (anterior margin of the shortened metepimeral patch dorsally convex). The male of N. salomonis can be separated from N. boonei sp. nov. by the lack (vs. presence) of blue pattern elements on S7 and from N. stueberi sp. nov. by the markedly longer antehumeral patch.

However, as the ante-humeral patch of N. salomonis ranges from as long as, to markedly longer than, half the length of the mesanepisternum, and can even be absent in the female, and as the poststernum of N. salomonis ranges from yellow over bluish, variously patterned with brown to black patches to completely black in both sexes, it appears helpful to additionally define N. salomonis (in the present concept) also by distribution.

Distribution and habitats. Nososticta salomonis as defined in this work is restricted to the Solomon Islands archipelago between at least Choiseul island in the northwest and San Cristobal island in the southeast ( Map 1 , Pl. 1).

Figures

MAP 1.—Distribution of species of the Nososticta salomonis complex in the Solomon Islands.

FIGURES 7–10. Nososticta salomonis (Selys), Holotype male: (7) dorsal, plus labels; (8–10) synthorax: (8) frontal; (9) lateral, (10) part of watercolour painting by Selys (Ag194b, collection RBINS).

FIGURES 11–13. Nososticta salomonis (Selys). (11) male, from Makira, San Cristobal; (12, 13) from Guadalcanal: (12) male; (13) female.

FIGURES 14–16. Nososticta salomonis (Selys). (14, 15) from Vella Lavella: (14) male; (15) female; (16) female, from Ranongga.