Yunnanosticta wilsoni Dow & Zhang 2018, sp. nov.
Creators: name: Dow, Rory A.
name: Zhang, Hao-Miao
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Odonata
Platystictidae
Yunnanosticta
Yunnanosticta wilsoni

description: Yunnanosticta wilsoni sp. nov.
(Figs 1, 3, 5, 7, 9, 10, 12, 14, 16, 18, 20, 22, 24, 25)
Drepanosticta sp. 3;— Zhang 2017: Fig. 24c (photograph of male in life).
Holotype. ♂ Tongbiguan National Nature Reserve (24.5833 N, 97.5856 E, ca 1220 m), Yingjiang County, Dehong Dai & Jingpo Autonomous Prefecture, Yunnan, China, 23 vi 2015, leg. H.M. Zhang, to be deposited in BMNH.
Paratypes. A total of 39 ♂♂. 10 ♂♂, data as holotype; 13 ♂♂, same site and collector as holotype, 22 vi 2015; 6 ♂♂, same site and collector as holotype, 0 1 vi 2016; 2 ♂♂, same site and collector as holotype, 0 1 vi 2016; 6 ♂♂, same site and collector as holotype, 31 v 2016; 2 ♂♂, Tongbiguan National Nature Reserve (24.6636 N, 97.5883 E, ca 740 m), Yingjiang County, Dehong Dai & Jingpo Autonomous Prefecture, Yunnan, China, 0 6 vii 2014, leg. H.M. Zhang. Paratypes in the collections of the authors, some to be deposited at RMNH.
Etymology. The species is named wilsoni, a noun in the genitive case, after Keith Duncan Peter Wilson, who erected the Sinostictinae, in honour of his work on Chinese Odonata.
Description of holotype. Head (Fig. 1). Labium brown. Labrum, mandible bases whitish in basal ca twothirds, black below. Anteclypeus whitish, postclypeus, genae, frons shining black. Vertex, occiput black, small whitish sub triangular marking in front median ocellus, very small whitish marks at outer sides lateral ocelli. Underside of head shining black. Ratio of width of compound eye to width of vertex measured at level of lateral ocelli ca 0.6. Transverse occipital carina not very prominent. Ocelli whitish. Antenna with scape black, whitish at top, pedicel pale grey, rest missing; pedicel slightly expanded apically.
Thorax. Prothorax (Figs 3, 5) dark brown and black with pair of pale brown areas laterally on anterior pronotal lobe, pair small blue dorsal marks on middle lobe, much of dorsal surface posterior pronotal lobe blue. Anterior pronotal lobe with anterior carina lower than highest part of raised part, this shallowly divided centrally. Posterior pronotal lobe short, simple, collar-like. Synthorax (Fig. 7): mesepisternum and antealar triangles entirely bronzy black. Laterally almost entirely dark brown, small, faint pale spot just below interpleural suture, near antealar carina on metepisternum on right side only (Fig. 7 shows the left side), mesokatepisternum pale yellowish just above coxae, metakatepisternum pale yellowish. Venter of synthorax cream. Legs (left anterior leg absent below trochanter): almost entirely yellowish, narrowly black around joint of femur and tibia, with poorly defined greyish ring around femur at ca two-thirds of its length. Wings: 16 Px in all wings. Vein Ab present, joined to Ac to form Y with short stalk. Arculus arising slightly distal to Ax2. Postcubital vein present in all wings, one supplementary postcubital vein in left Hw. CuP meets wing margin at ca level of Px 6 in Fw, between levels of Px 10 and Px 11 in Hw. R4 arising proximal to subnodus, IR3 distal to subnodus, joined to R4 by short stalk. R4 meets the wing margin beyond level of distal end of Pt in Fw, ca at level of distal end of Pt in Hw. R3 arising at ca level of Px 6 in Fw, Px 5 (left) or Px 6 (right) in Hw; IR2 one Px further distal in all wings. R3 and IR2 both meet the wing margin at the tip, which is slightly falcate. Pterostigma almost rhomboidal, black with narrow pale border, covering slightly more than one underlying cell.
Abdomen. S1 brown. S2 brown with narrow but diffuse basal annulus, interrupted dorsally, continued along lower margin tergite for basal ca two-thirds. S3–7 largely brown, becoming darker apically and on successive segments, after S3 with diffuse basal annulus, continued along lower margin of tergite for some distance, on S7 this reduced to faint brown mark dorsally. S8 similar but basal marking restricted to lower lateral part in basal ca one quarter (Figs 14, 16), pale blue dorsal marking in apical ca one quarter (Fig. 16). S9 pale blue except black lower laterally, S10 black (Figs 14, 16). Anal appendages (Figs 18, 20, 22) dark brown and black. Cerci in lateral view (Fig. 18) curved down, then up, then down again at apex, whole narrowing only slightly from base to apex, small subapical internal ventral spur present, also visible in dorsal view. In dorsal view (Fig. 20) simple, approximately conical. Paraprocts ca as long as cerci. Basal ca two thirds paraprocts subtriangular in lateral view (Fig. 18), at ca two thirds length shallowly bifurcated into very short, rounded outer part and long inner branch, directed upwards and to rear, in ventral view (Fig. 22) expanded slightly to almost square-ended tip.
Genital ligula (Figs 10, 12). Terminal segment narrower than penultimate segment, long, narrowing from base, apically divided into two long slender, curled arms lying on either side of shaft, tapering to sharp point (Fig. 10); peculiar narrow spur arising just above origin of arms, running parallel to main part terminal segment. Internal fold very small, barely visible.
Measurements (mm). Abdomen without anal appendages ca 28, cercus ca 0.5, Hw ca 18.75.
Female. Unknown.
Variation in paratypes. Aside from small differences in pale markings, there is considerable variation in the blue markings on the prothorax and S8. In some individuals the blue marks on the middle pronotal lobe are larger than in the holotype and the posterior pronotal lobe is almost entirely blue, in others these markings are reduced compared to the holotype, with the marks on the middle pronotal lobe entirely absent on one specimen. The S8 marking occupies the apical ca one quarter to ca three quarters of the segment. None of the paratypes has a supplementary postcubital vein in any wing. Vein ab is occasionally absent or incomplete in one or more wings, as is the case in the Fw of the paratype are shown in Figure 9. Sometimes IR3 arises at the subnodus, in one individual R4 and IR3 are fused or nearly fused at origin in all wings and arise at the subnodus. CuP meets the wing margin at the level of Px 5–8 in the Fw, Px 9–13 in Hw (10–11 typical). In several paratypes R4 meets the wing margin beyond the level of the distal end of Pt in the Hw or Fw. R3 arises at level of Px 6–7 in Fw, Px 5–6 in Hw, IR2 typically arises one Px further distal, but occasionally up to 2 Px further distal. There is also considerable variation in size (see below).
The genital ligula was examined in three paratypes. The only significant variation observed is in the narrow spur on the terminal segment, in one paratype this is present, but narrower than in the holotype, in another only a short part of the spur is present and in the last it is not visible at all (see Remarks below).
Measurements (mm). Abdomen without anal appendages ca 23.5–28.5, Hw ca 17–19.5.
Diagnosis. The male is easily separated from all other known members of the Platystictidae except Y. cyaneocollaris by the characters defining the genus. It is separated from Y. cyaneocollaris by the pale venter of the synthorax, the very small internal fold and differently shaped terminal arms of the genital ligula, the longer cercus of approximately the same length as the paraproct and with only a small subapical interior ventral spur present, and the longer inner branch of the apex of the paraprocts.
Remarks. The colour pattern of the prothorax and of abdominal S8 are sufficiently variable that they may not provide reliable means of separating this species from Y. cyaneocollaris, although the extent of blue on the pronotum in Y. cyaneocollaris is greater than in any of the type series of Y. wilsoni. The spur on the genital ligula might also provide a useful character; although it is only partially present or not present in some of the paratypes, this might be because this seemingly fragile structure was broken during extraction of the genital ligula, during which it would certainly have been subjected to stress because of its position. However it is also possible that the spur is simply a variably developed structure, not always present.
Yunnanosticta wilsoni is found in shady, dark forests, where it occurs at seepages, usually with a high gradient, at altitudes in the range ca 700-1200 m. These habitats are found in the best tropical rain forests throughout the Tongbiguan National Nature Reserve. Males perch low on leaves or hang on branches. When disturbed they fly for a very short time, hovering, and then perch back again at the same spot. Individuals have been observed from early morning until late in the afternoon, suggesting that they seldom travel far from the habitat. Yunnanosticta wilsoni was found co-occurring with Coeliccia Kirby, 1890 and Echo Selys, 1853 species at the type locality.
description: Published as part of Dow, Rory A. & Zhang, Hao-Miao, 2018, Yunnanosticta gen. nov., from Yunnan, a new genus from the Sinostictinae, with the description of two new species (Odonata: Zygoptera: Platystictidae), pp. 567-577 in Zootaxa 4375 (4) on pages 568-570, DOI: 10.11646/zootaxa.4375.4.6, http://zenodo.org/record/1161001