Platysticta secreta Bedjanič & van Tol, 2016

Tol, Van, 2016, Taxonomy and molecular phylogeny of the Platystictidae of Sri Lanka (Insecta: Odonata), Zootaxa 4182 (1), pp. 1-80 : 39-42

21. Platysticta secreta Bedjanič & van Tol sp. nov.

Figs 116−123, 170−171 ; Map 8.

Platysticta sp. nov. B—Bedjanič et al. (2014): 145 [differential characters, biology, distribution, photograph of Ƌ]. SPECIES DIAGNOSIS IN THE KEY → 20b; NUMBER OF KNOWN LOCALITIES— Bedjanič et al. (2014): 11 [corrected to 13 localities by listing known faunistic records in the present paper].

Type material. Holotype: 1Ƌ (mature male), Hasalaka; Kandy District , Central Province ; N7.3535, E80.9509; alt. 100m; 31-v-1975; D.H. Messersmith & G.L. Williams leg. (in USNM, reg. no. USNM ENT 00359736); Paratypes: 2Ƌ (in USNM, reg. nos USNM ENT 0 0 359734, 00359735), 2♀ (in USNM, reg. nos USNM ENT 0 0 359737, 00359738), 2Ƌ, 1♀, (in RMNH, ex coll. USNM., reg. nos. JvT 19883-19885), locality data the same as for holotype; 2 juv. Ƌ, Gurulupotha, Gurulupota Oya; Kandy District , Central Province; N7.3431, E80.9275; alt. 270m; 1-iv-1973; R. Baumann & J. Cross leg. (in USNM, reg. nos USNM ENT 0 0 359664, 00359665); 1Ƌ, Ugelkaltota ; Ratnapura District , Sabaragamuwa Province; N6.6522, E80.8807; alt. 140m; 24-vi-1978; K.V.

Krombein leg. (in USNM, reg. no. USNM ENT 00359746 ); 1Ƌ, 6km NE Buttala ; Moneragala District , Uva Province; N6.8048, E81.2722; alt. 270m; 5-vi-1975; S.L. Wood & J.L. Petty leg. (in USNM, reg. no. USNM ENT 00359744 ); 2Ƌ (mature males, one ex alcohol), Monaragala, stream in the hills 1km NE of Monaragala ; Moneragala District , Uva Province; N6.8753, E81.3599; alt. 220m; 4-viii-2009; M. Bedjanič leg. (one ex alcohol to be deposited in CNMS, one in alcohol in RMNH, reg. no. RMNH.INS.229758).

Etymology. The species epithet, a Latin adjective, relates to the long but undetected presence of this species in collections.

Diagnosis. Large Platysticta , closely allied to P. apicalis . With the latter species it shares the white median lobe of the prothorax and is thus easily separated from its other two congeners, P. serendibica sp. nov., described below, and P. maculata . Males have the posterior parts of the inferior anal appendages moderately curved, with a shallow notch before their upturned point and not distinctly hook-shaped, with a deep notch before their upturned point, like in P. apicalis . In females of P. secreta sp. nov. the elevated and thickened anterior lobe of the prothorax is evenly rounded, while in P. apicalis it is medially compressed posteriorly, slightly convex and with small notch medially. In both sexes, S4–6 of abdomen show characteristic pale rectangular dorsolateral basal markings on each side, prolonged and thinned posteriorly along the ventral side. These basal markings are triangular and smaller in P. apicalis . Females of both species are further distinguished by the dorsal coloration of the last abdominal segments, which are uniformly sky blue in P. secreta sp. nov., while in P. apicalis S9 is sky blue dorsally with a black longitudinal middorsal stripe. Wings of P. secreta sp. nov. are tipped dark on apices of mature adults of both sexes. Females can be distinguished from all other Platysticta species by this feature.

Description of holotype male [dried specimen, USNM ENT 00359736]. Head.—Labium dark brown, bases of mandibles dark brown, with grey dorsolateral portions towards labrum and anteclypeus. Labrum greyish white, its anterior part broadly very dark brown, with rather long brown setae. Anteclypeus white, genae, postclypeus and frons shiny black. Anterior border of postclypeus with two long brown setae on each side, some shorter setae above postclypeus on frons laterally on each side. Vertex, occiput and epicranium glossy black. Occiput behind ocelli with two closely situated light setae on each side below lateral ocellus. Rear of head black. Transverse postoccipital ridge developed, angulated but with rather inconspiucous edges. Paraorbital carina well developed. Antennae dark brown. Eyes in preserved specimen brown. ( Fig. 116).

Thorax. —Median lobe of prothorax white on dorsum and its sides. Anterior lobe white, elevated, evenly rounded, but broadened posteriorly in middle, with upturned and slightly thickened brownish anterior margin. Posterior lobe of prothorax dark brown, evenly rounded, its posterior margin only gently upturned ( Figs. 116–117). Dorsum of synthorax black, as are sides of thorax laterally until the metapleural suture. Metepimeron with an oblique pale blue stripe. Ventrally towards legs and on metepimeron black ground colour gradually fades into brown. Ventroposterior part of metepimeron pale blue. Legs yellowish white on coxae and trochanters, ochreous distally, with dark brown bristle-like setae.

Wings. —Clear, venation dark brown. Apices of wings enfumed dark brown proximally to level of proximal side of pterostigma. Left forewing with 19½ and hindwing with 18½ Px, right forewing with 19½, and hindwing with 19 Px. Arculus distal to Ax2, R4+5 well proximal of subnodus. IR3 separates from R4+5 at the level of first crossvein distal to arculus. Vein R3 originates in right forewing slightly proximally to level of Px 7 and in hindwings at level of Px 6. Vein IR2 zigzagged but not strongly so. Y vein sessile. CuP reaching hind margin of all wings at level of Px 6. Number of cells between Arc and place where CuP meets hind margin of hindwing 11. Pterostigma brown, encircled by narrow lighter line and surrounded by thick dark brown veins, proximal side oblique, distal side rounded, more than two times wider than high.

Abdomen.—Slender, long, ground colour dark brown dorsally and laterally, light ochreous ventrally. S2 with basal triangular lateral ochreus marking pointed posteriorly and nearly reaching the segment end. S4−S6 with pale rectangular dorsolateral basal markings on each side, prolonged and thinned posteriorly towards ventral side. Dorsum of S8–10 dark grey due to preservation ( Fig. 118). Anal appendages dark brown. Superior anal appendages clearly longer than inferiors and nearly twice as long as S10. Superiors narrow to the middle, then broadened, laterally flattened and spatulate, curved ventrally and medially. On inner side of dorsum beyond their middle a very blunt protuberance. Inferiors with expanded basal portion, which has small medial projection, then narrowed, twisted and curved in form of very shallow hook. ( Figs. 118–119).

Measurements [in mm]. Ƌ—head width: 5; abdomen length: 47.98; fore- and hindwing length: 35.5, 35.3; fore- and hindwing pterostigma length: 1.58, 1.68; superior appendages: 1.2.

Description of paratype female [dried specimen, USNM ENT 00359737]. General habitus very similar to male ( Fig. 120). Venation similar to male. Apices of wings distal to middle of pterostigma enfumed dark brown. Both forewings with 18½ and hindwings with 17½ Px. Vein R3 originates in right forewing slightly proximally to level of Px 7 and in hindwings slightly proximally to level of Px 6. Anterior lobe of prothorax white, elevated, evenly rounded, not broadened posteriorly in middle, with upturned and slightly thickened brownish anterior margin. Median lobe white on dorsum and its sides. Anterior portions of posterior lobe narrowly grey, rest brown ( Fig. 121). Vertex of synthorax black, rest of thorax very dark brown fading to brown ventrally and on metepimeron. S4−7 of abdomen with pale rectangular dorsolateral basal markings on each side, prolonged and thinned posteriorly towards ventral side, basal marking on S3 smaller and triangular. Dorsum of S9−10 greyish blue, as is intersegmental membrane between S9 and S8 and lateral portions of posterior margin of S8. Cerci dark brown. Ovipositor not reaching tip of cerci, styli broken ( Fig. 122).

Measurements [in mm]. ♀ —head width: 4.4; abdomen length: 40.5; fore- and hindwing length: 32.8, 32.1; fore- and hindwing pterostigma length: 1.7; ovipositor: 2.5.

Remarks. Variation in paratypes. Wings of paratype male from Monaragala depicted in Fig. 123. Left forewings with 21½ and hindwings with 19½ Px. Y vein shortly stalked. Number of cells between Arc and place where CuP meets hind margin of hindwing 12. Vein R3 originates in left forewing at the level of Px 7 and in hindwings at the level of Px 6. In other paratypes the nodal index ranges from 18½ to 21½ Px in forewings and from 16½ to 20½ Px in hindwings. Second female paratype in forewings with 18½ and 18 and in hindwings with 16½ and 17 Px. Apices of wings tipped dark brown in female paratype and all male paratypes, except in two males from Gurulupotha, which are evidently juvenile. Coloration in life. Eyes of both sexes in life black, with contrasting whitish-grey posteroventral portions. Ground colour of synthorax black, with slight metallic shine on dorsum. Lateral blue band and light-coloured portion of metepimeron bluish white. Dorsum of last abdominal segments sky blue in both sexes. ( Figs. 170–171 ). Habitat.—As far as habitat and distribution is concerned, P. secreta sp. nov. is peculiar and distinct from its congeners in inhabiting much drier eastern parts of the island. Here the appropriate habitats, like smaller shaded streams and seepages along rivulets in forest or at least in a forested corridor, are rather scarce. The known populations of P. secreta sp. nov. are widely scattered. Adults can be found from March to August, so its flight season appears to be rather long. Most of the records originate from lower altitudes at up to 300 metres, and an old record from Madulsima at over 1,300 metres might just be due to inexact labelling. Conservation. —Despite the fact that eastern parts of Sri Lanka are far less densely populated, the rather dry climate results in high pressure on flowing water for irrigation and domestic use. Consequently, and due to its small range, this new endemic Platysticta is globally threatened, and its habitats deserve special conservation attention.

Measurements [in mm, paratypes]. Ƌ—abdomen length: 41.16−50.6; fore- and hindwing length: 30.97−42.53, 30.11−41.54; ♀ —abdomen length: 41.3; fore- and hindwing length: 34, 33.7.

Faunistic records [localities listed north to south]: —(1) Ritigala, Lower elevation of Ritigala ; Anuradhapura District , North Central Province; N8.1088, E80.648; alt. 300m; - v-2010; V. Weeratunga. —(2) Dabagahapitiya, two forested streams between paddy fields 8,5km NNE of Ududumbara ; Kandy District , Central Province; N7.3881, E80.8945; alt. 670m; 7-vii-2012; M. Bedjanič; 2Ƌ.—(3) Gurulupotha, Gurulupota Oya ; Kandy District , Central Province; N7.3431, E80.9275; alt. 270m; 1-iv-1973; R. Baumann & J. Cross; 1Ƌ.—(4) Hasalaka ; Kandy District, Central Province; N7.3535, E80.9509; alt. 100m; 31-v-1975; D.H. Messersmith & G.L. Williams; 1Ƌ.—(5) Makulmada, Pallegama, Kalu Ganga area ; Matale District , Central Province; N7.5451, E80.8217; alt. 185m; 25-xii-2010; A. Chandana. —(6) Wasgamuwa, stream habitat ; Matale District , Central Province; N7.684, E80.9304; alt. 115m; 21-vii-2013; A. Chandana. —(7) Wasagamuwa ; Matale District , Central Province; N7.7157, E80.9678; alt. 70m; 13-iv-2004; G. de Silva Wijeyeratne; 1♀.—(8) Ugelkaltota ; Ratnapura District , Sabaragamuwa Province; N6.6522, E80.8807; alt. 140m; 24-vi-1978; K.V. Krombein; 1Ƌ.—(9) Madulsima ; Badulla District , Uva Province; N7.0339, E81.1651; alt. 1350m; 15-viii-1932; T.B. Fletcher; FRASER (1933a, 1933b); 2Ƌ.—(10) Wellawaya, Kadapola Oya W of Wellawaya ; Moneragala District , Uva Province; N6.7337, E81.1094; alt. 190m; 17-iv-1976; G. von Rosen; 1Ƌ juv.—(11) Bibile ; Moneragala District , Uva Province; N7.1448, E81.222; alt. 250m; 16-vii-1929; G.M. Henry; 1♀.—(12) 6km NE Buttala ; Moneragala District , Uva Province; N6.8048, E81.2722; alt. 270m; 5-vi-1975; S.L. Wood & J.L. Petty. 1Ƌ.—(13) Monaragala, stream in the hills 1km NE of Monaragala ; Moneragala District , Uva Province; N6.8753, E81.3599; alt. 220m; 4-viii-2009; M. Bedjanič; 5Ƌ.

Figures

FIGURES 166 – 170. Coloration in life: Platysticta apicalis — (166) male; (167) female; Platysticta maculata — (168) male; (169) female; Platysticta secreta sp. nov. — (170) male [photos: M. Bedjanič].

FIGURES 171 – 173. Coloration in life: Platysticta secreta sp. nov. — (171) female; Platysticta serendibica sp. nov. — (172) male; (173) female [photos: M. Bedjanič, fig. 171 photo: G. de Silva Wijeyeratne].