Bayadera serrata Davies & Yang, 1996

(Fig. 10a–i)

Bayadera serrata: Davies & Yang (1996), pp. 145–146, Figs 1–5; Hämäläinen (2013), p. 47–48, Fig. 1c, f, g, [Male specimen from Pia Oac Nature Reserve, Cao Bang Prov., first record from Vietnam]; Yokoi & Souphanthong (2014), pl. 8; Hämäläinen (2017), Figs 5, 9–10.

Materials examined. [Vietnam] 1♂, Pia Oac Nature Reserve, Cao Bang Prov., 30.VII.2014, T. Kompier leg. (TKC); 2♀, Pia Oac Nature Reserve, Cao Bang Prov., 18–27.VI.2015 (TKC); 2♂, Pia Oac Nature Reserve, Cao Bang Prov., 23.V.2015 (TKC); 7♂ 1♀, Pia Oac Nature Reserve, Cao Bang Prov., 19.V.2015, Q.T. Phan leg. (PQTC).

Female specimen used for description: 1♀, Pia Oac Nature Reserve, Cao Bang Prov., 18–27.VI.2015, T. Kompier leg.

Other materials confirmed by field observations. [Vietnam] Some individuals, Cao Bang Prov., V, VI.2015, VI.2016, T. Kompier; Some individuals, Yen Bai Prov., VI.2015, VII.2016, T. Kompier; 1♀, Xuan Son National Park, Phu Tho Prov., 29.VI.2015, T. Kompier; 1♀, Yen Bai Prov., 10.VII.2017, T. Kompier.

Notes. Bayadera serrata was described by Davies & Yang (1996) on the basis of a single mature male, collected in Dali, Yunnan, and recently recorded in northern Vietnam and northern Thailand (Hämäläinen 2013, 2017). This species resembles Bayadera kinnara Hämäläinen, 2013 from Myanmar. Both species are characterized by their complex anal appendages with strongly downward curving cerci bearing a large dorsal spine (Fig. 10c–e). The female of Bayadera serrata is described here for the first time.

Description of female. Body color pattern of the female superficially resembles the male. In the head (Fig. 10f–g), labrum and bases of mandibles are yellow, excluding a black band at anterior margin mandible base. Anteclypeus is entirely black (but yellowish in the male). Postclypeus is yellow, excluding black anterior margin. Genae yellow, which extends upward along margin of compound eyes and inward across the antefrons, but not connecting over the postclypeus as in the male. (Fig. 10b). The first segment of antennae is black with an oval yellow spot, and second and third segments are entirely black. Ocelli are amber with two small yellow spots positioned between lateral ocelli and central ocellus. Occipital ridge is black, without the two oval spots of the male (Fig. 10a–b). The blackish prothorax has two large yellow markings on the median lobe. Synthorax is black with yellow stripes similar to the male, but the stripes over mesepisternum and metepimeron form an S-shape (Fig. 10a). Legs are black with yellow stripes internally. Wings are hyaline with black venation (Fig. 10i). Abdomen is black with yellow stripes as follows: S1 with a small lateral marking; S2–7 with a lateral stripe which is broad at anterior margin but quickly narrows and tapers off posteriorly; S8 with a large posterolateral spot and S9 with a large dorsolateral spot; S10 with a semicircular lateral marking (Fig. 10h). Ovipositor structure as in Figure 10h.

Measurement (in mm). HW 40–41; abdomen (incl. appendages) 40–41.

Distribution. Vietnam (Cao Bang, Yen Bai and Phu Tho Provinces), China (Yunnan Province) (Davies & Yang 1996), Laos (Vientiane Province) (Yokoi & Souphanthong 2014), Thailand (Chiang Mai and Phetchabun Provinces) (Hämäläinen 2017).