Telosticta dayak, Dow & Orr, 2012

Dow, R. A. & Orr, A. G., 2012, Telosticta, A New Damselfly Genus From Borneo And Palawan (Odonata: Zygoptera: Platystictidae), Raffles Bulletin of Zoology 60 (2), pp. 361-397 : 386-388

publication ID	https://doi.org/ 10.5281/zenodo.5348617
persistent identifier	https://treatment.plazi.org/id/03DD87E5-FFF7-6149-FC3B-FC56FCF89E16
treatment provided by	Tatiana
scientific name	Telosticta dayak
status	sp. nov.

Treatment

Telosticta dayak View in CoL , new species

( Figs. 9B View Fig , 10B, C View Fig , 11B, C, I View Fig , 12B View Fig , 13B, C View Fig , 14B View Fig , 20 View Fig )

Protosticta feronia View in CoL – Thompson & van Tol, 1993: 59, 64, 69; Orr, 2001: 190; 2003: 38, 69 (part)

Protosticta species cf. feronia View in CoL – Dow & Reels, 2010: 16–18 (note)

Protosticta aff. feronia View in CoL – van Tol et al., 2009: 26–28, 30–33, 64, 67

Material examined. — Holotype: male (SAR07_8_PST20), Sarawak, Miri division, Lambir Hills National Park, tributary to stream crossed by Inoue Trail, 22 Dec.2007, coll. RAD, to be deposited in RMNH.

Paratypes. Sarawak (all coll. RAD and in collection RAD unless otherwise noted, examples to be deposited in BMNH and ZRC): 7 males (SAR07_8_PST133–135, 137–140), Bintulu Division, Similajau National Park, small stream on Circular Trail , ca 20–30 m, 2 Feb.2008 ; 2 males (SAR07_8_PST206–207), same location and date, coll. GTR; male (SAR07_8_PST192), same location, 4 Feb.2008 , coll. GTR; male (SAR07_8_PST53), same national park, small stream on Selunsur Trail , 3 Feb.2008 ; 5 males (SAR09_10_ PST8–12), Bintulu Division, SPFP, Kakus district, Bukit Jugam , small stream in disturbed Kerangas forest , ca 90 m, 24 Aug.2009 ; male (SAR09_10_PST15), same location and date, coll. OT; 2 males (SAR09_10_PST14, other in ethanol), same district, tributaries to stream at Camp C acacia nursery, ca 50 m, 25 Aug.2009 ; male (SAR09_10_PST397), same location, 20 Jun.2010 ; 2 males (SAR09_10_PST314–315), same location, 21 Jun.2010 ; 12 males (SAR09_10_PST324–325), same location, 25 Jun.2010 ; 9 males (SAR09_10_PST338–346), female (SAR09_10_PST347), same district, steep tributary to stream ‘A’ in block K2L, ca 100 m, 26 Jun.2010; male (SAR09_10_PST310), same location and date, coll. S. Stone; 3 males (SAR09_10_PST311–313), same district, tributary to stream ‘B’, ca 130 m, 23 Jun.2010 ; 2 males (SAR09_10_PST320, other in coll. OT without number), same district, stream at Kapur Camp , ca 90 m, 29 Jun.2010 ; male (SAR09_10_PST308), same location, 1 Jul.2010 ; 5 males (SAR05_PST19–23), Miri Division, Lambir Hills National Park, small steep trickles in vicinity of Pantu waterfall, 11 May 2005 ; 2 males, same location, 15 May 2005 ; 6 males (SAR06_PST42, 112–116), female (SAR06_PST165, in tandem with male SAR06_PST42), same location, 1 Feb.2006 ; 3 males (SAR06_PST87–89), same location and date, coll. GTR; 2 males, same national park, small stream in Latak valley , 13 May 2005 ; 2 males (SAR06_PST117–118), same national park, tributaries to stream crossed by Main Trail beyond Pantu waterfall stream, 2 Feb.2006 ; 2 males (SAR06_PST90–91), same location and date, coll. GTR; male (SAR07_8_PST21), same national park, tributary to stream crossed by Inoue Trail , 22 Dec.2007 ; 6 males (SAR11_12_ PST30–35), same national park, small hill stream, 21 Apr.2011; 3 males, 2 females (SAR11_12_PST5–9), same national park, stream on Oil Well Trail , 22 Apr.2011 ; 3 males (SAR07_8_PST163–165), Gunung Mulu National Park, foot of Gunung Mulu, small stream near Camp 1, ca 200 m, 4 Jan.2008 ; female (SAR07_8_PST125), same area, trailside on Summit Trail near Camp 1, 11 Jan.2008 ; 1 female (SAR07_8_PST267), same area, stream on old trail to Sarawak Chamber, ca 80 m, 13 Jan.2008 ; 2 males, same national park, Sg. Putut, tributary of Sg. Melinau , 10 Oct.2009 , coll. SB. Brunei (all in RMNH, all coll. D. Thompson): 4 males (JvT 5062–5), female (JvT 5074), Ulu Belait, between Ingai and Topi rivers, stream in tropical heath forest, 28 Sep.1992 ; male, female (in tandem, JvT 5027–8), same area, tributary of Ingai river with stony substrate in mixed dipterocarp forest, 30 Sep.1992 .

Others : male, Sarawak, Kapit division, Dulit Range, western face of main Dulit ridge, side of broad rocky stream, ca 965 m, 29 Sep.2009, coll. RAD ; female, same area, in forest by steep tributary to broad rocky stream, 29 Sep.2009, coll. RAD; 2 males , same area, near head of rocky stream, ca 1020 m, 30 Sep.2009, coll. RAD .

Diagnosis. — The male of T. dayak is readily distinguished from other species of Telosticta except for T. berawan , T. kajang , T. ulubaram , and T. paruatia by the form of its superior anal appendage, with a distinct cleft in the tip, easily visible in lateral view. It is easily distinguished from T. paruatia by having a much shorter interior projection on the superior appendage. It is distinguished from T. berawan , T. kajang , and T. ulubaram by the having the arms of the cleft of the tip of the superior appendage of the same length in typical lateral view.

Etymology. — dayak , a noun in apposition; named for all the Dayak races. Dayak is a collective term used for Borneo’s indigenous inhabitants.

Description of holotype male. — Head: Labium pale. Basal 1/2 of labrum blue, black along free margin. Anteclypeus blue, postclypeus shining black. Mandible bases blue in corner by clypeus, black below. Vertex and frons bronzy black, occiput shining black. Ratio of width of compound eye to width of vertex measured at level of lateral ocelli ca 9/10. Transverse occipital carina with lateral extremities angulated and prominent. Ocelli whitish. Antenna with top of scape and basal 3/4 of pedicel greyish, rest dark brown, flagella missing.

Thorax: Prothorax, largely yellowish white except in upper rear of propleuron, rear part of middle pronotal lobe and whole posterior pronotal lobe, where black. Lateral pronotal processes well formed, smoothly rounded and moderately long ( Fig. 9B View Fig ) with the tip falling short of the level of the lower margin of the propleuron. Synthorax: Mesepisternum bronzy black, with a pair of pale blue antehumeral markings, occupying ca 1/2 of the length ( Fig. 10B View Fig ). Antealar triangles largely blue. Mesepimeron bronzy black. Metepisternum largely occupied by a pale band, becoming blue towards wing bases, with a bronzy black wedge below, this extending from the wing bases to the metinfraepisternum but only well defined over the upper ca 1/3 of this distance. Metepimeron mostly pale, with an indistinct brownish area below the metepleural suture. Venter of synthorax pale. Legs: each with coxa and trochanter cream, femur dirty cream with a dark stripe along extensor surface, another on flexor surface of anterior femur only, black above joint. Tibia black immediately below femur, then mostly pale, brown just above tarsus, which is mostly pale but dark at joints end and with pale brown claws. Wings: 11 Px in Fw, 10 Px in Hw. Vein ab absent. R 4 arising distal to subnodus in Fw, at subnodus in Hw, IR 3 joined to it by a short stalk. Pterostigma approximately trapezoidal with costal side shorter than anal side, and proximal side slightly shorter than distal side, greyish brown with prominent white border, covering slightly more than one underlying cell.

Abdomen: Largely brown, darker dorsally after S1 and darkening to rear. S1 yellowish cream, dark brown behind posterior carina. S2 with a pale basal annulus, broadly interrupted dorsally, laterally this extending to the posterior carina as a pale wedge, otherwise brown. S3–7 brown with a narrow pale basal annulus interrupted dorsally, becoming less distinct on successive segments; each segment becoming darker apically. S8–10 black with a large sub rectangular pale blue dorsal marking centrally on S8 ( Fig. 11B, I View Fig ) and a tiny pale mark dorsally on S9. Appendages ( Figs. 12B View Fig , 13B View Fig , 14B View Fig ) brown, this dark basally and towards tip of superior pair. Superior appendage ca 2.5 times the length of S10, with interior projection at just over 1/3 length directed inwards and downwards so clearly visible in lateral view, but with a sharp upward and distally directed spur. Dorsal projection poorly developed as a rounded upward directed swelling. Expanded dorsal-ventrally in distal ca 1/3, with a ‘U’ shaped cleft at tip, with the lower arm of the cleft the same length as the upper, the two arms separated by a hollow after the cleft on the interior side. Inferior appendage almost as long as superior, stem robust, scoop expanded and upturned at tip, spine robust and directed inwards, upwards and to rear.

Measurements (mm): Abdomen without anal appendages 36, superior appendage ca 1, Hw 20.

Description of female paratype. — Based on SAR06_ PST165. As male except as noted.

Head: antenna with top of scape and most of pedicel cream coloured.

Thorax: Antehumeral stripes slightly longer than in male, extending more than half the length of the mesepisternum. Dark mesepisternal stripe better defined than in male. Wings: 12 Px in Fw, 11 in Hw.

Abdomen: brown colouration generally slightly lighter than in male. Dorsum of S8 largely occupied by pale blue mark, S9–10 entirely dark brown and black. Superior anal appendages shorter than S10. Ovipositor long, valves extending well beyond tips of superior appendages, mottled cream, dark brown and black.

Measurements (mm): Abdomen without appendages or ovipositor 33.5, Hw 20.5, ovipositor ca 2.

Variation in paratypes. — There is quite considerable variation in size in both sexes. There is significant variation in the male paratypes in the pale marking on the dorsum of S9; in some individuals it is larger than in the holotype, in others it is smaller and in many, especially in the western part of the species range, it is entirely absent. The S8 mark is also variable in shape, sometimes triangular with apex pointing to the base of the segment, sometimes rather irregular, and occasionally joined to the segment base by a narrow stalk. Some individuals have antehumeral stripes that are slightly shorter or longer; in one individual from Lambir Hills the antehumeral markings are reduced to a pair of faint asymmetrically placed patches. The lateral processes of the posterior pronotal lobe are longer in many individuals, reaching the level of the lower margin of the propleuron. The dorsal projection of the superior appendage is more evident in many of the paratypes. There is some small variation in the depth and openness of the cleft in the tip of the superior appendage; this does not appear to be correlated with populations across most of the known range of the species. The orientation of the interior projection is constant. The spine on the inferior appendage frequently has a short distally directed spur near the tip.

The known population in Brunei appears to differ consistently from the norm in having a shallower cleft in the tip of the superior appendages ( Fig. 13C View Fig ) and shorter antehumeral stripes ( Fig. 10C View Fig ). The short antehumeral stripes are shared with specimens from Sungai Putut at Gunung Mulu National Park, the closest of the Sarawak populations to the Brunei population, but the Sungai Putut specimens have typical superior appendages. The intermediate nature of the Sungai Putut population suggests that the Brunei population merely represents an extreme of geographical variation.

Females show variation in the lateral processes of the posterior pronotal lobe, in the female taken in tandem in Brunei the lateral processes are entirely absent, as they are in females from Mulu; however in another female from Brunei they are present. The ovipositor is also shorter in the females from Gunung Mulu, reaching barely beyond the tips of the superior anal appendages.

Measurements (mm): Males: Abdomen without anal appendages 32–39, Hw 18–21. Wings with 10–14 Px in Fw, 10–12 in Hw. Females: Abdomen without appendages or ovipositor 30–35, Hw 18–23. Wings with 12–14 Px in Fw, 11–13 in Hw.

Remarks. — The material from Mount Dulit excluded from the type series differs in a number of respects: they are longer (male abdomen without anal appendages 40.5–44, Hw 23–25; female abdomen 39.5, Hw 25) with a more robust build, vein ab is present and the males all have a large blue marking on the dorsum of S9 ( Fig. 11C View Fig ). The male anal appendages do not differ in any significant way, suggesting that these specimens represent a local, montane form of T. dayak . However the female specimen, associated with the males by reasonable supposition based on near co-occurrence and similarity of markings, does differ from typical female T. dayak in the length of its ovipositor, the tip of which barely extends beyond the tips of the superior appendages, as in females from Gunung Mulu also associated with T. dayak by reasonable supposition, compared with well beyond in typical dayak from Lambir Hills.

Biological notes. — T. dayak has been found in a variety of forest types, at small streams usually, but not always, in hilly terrain. At Lambir Hills and one of the sites at Gunung Mulu it is found in mixed dipterocarp forest; at most other locations the habitat can be classified as kerangas forest but the Gunung Dulit population occurs in montane forest. At Similajau, a costal location, it occurs on low gradient streams. Males perch at the side of the stream and are often plentiful.

Distribution. — This species is quite widely distributed in Brunei and Sarawak as far west as Bintulu Division ( Fig. 20 View Fig ).