Drepanosticta vietnamica Asahina, 1997

Phan, Quoc Toan, Yokoi, Naoto, Makbun, Noppadon, Joshi, Shantanu, Subramanian, K. A., Ngo, Quoc Phu & Dow, Rory A., 2021, A review of the Drepanosticta carmichaeli-group, with the description of D. wildermuthi sp. nov. from the Central Highlands of Vietnam (Odonata: Zygoptera: Platystictidae), Zootaxa 5067 (2), pp. 187-210 : 202

Drepanosticta vietnamica Asahina, 1997

( Figure 8a–f )

Drepanosticta vietnamica: Asahina (1997) : Original description from Lai Chau Province, North Vietnam, pp. 107–108, Figs 1–2 (head & thorax and appendages); Dow et al. (2018): pp. 279–280, Figs 17–20 (figures of head, thorax and appendages based on paratype).

Specimens examined. 3 ♂♂, Ta Thom Village (19.0329 N, 103.5950 E, altitude 355 m), Muangngan District, Xiang Khuoang Province, Laos, 29.v.2017, Naoki Yokoi leg. ( ZCDTU) ; 1 ♂, 11km southeast Muang Xay (20.6079 N, 102.0540 E, altitude 1053 m), Oudomxay Province, Laos, 11.v.2004, Naoki Yokoi leg. ( ZCDTU) .

Notes. Drepanosticta vietnamica is a new addition to the Laotian fauna. This species was originally described from northern Vietnam by Asahina (1997) based on two male specimens with one figure of the head and thorax (in lateral view) and one figure of the anal appendages ( Figs 1–2 in Asahina 1997). Recently Dow et al. (2018) provided figures of D. vietnamica based on the paratype male (with the same collection date and location as the holotype). The body coloration and structure of the Laotian specimens match well with the original description of D. vietnamica ( Asahina 1997) . This species differs from all other species in the D. carmichaeli –group by the yellowish markings dorsally on S9–10 ( Fig. 8c ), as opposed to these segments black or with blue markings in other members of the group. However this difference may well not be reliable since the yellow marking in dorsal S9–10 of male D. vietnamica might be due to the preservation (for instance, see the case of the paratype males of D. wildermuthi sp. nov.). Within the D. carmichaeli -group the structure of the anal appendages of D. vietnamica is most similar to D. carmichaeli and D. emtrai with a distinct ventral heel on the cerci (compare Figs 3d , 5b ) ( Fig. 8d ). The female of D. vietnamica remains unknown.

Distribution. Vietnam (Lai Chau Province) & Laos (Oudomxay & Xiang Khuoang Provinces) ( Fig. 13 ).

Figures

FIGURE 1. Drepanosticta annandalei ♂ [a, c, e, g, h, i] & ♀ [b, d, f, j], Bamboo Teri,Andaman Island, India (NZC). (a, b), head & thorax, lateral view; (c), head, dorsal view; (d), synthorax, dorsal view; (e, f), terminal segments of abdomen, lateral view; (g–i) appendages in lateral, dorsal and ventral view; (j), pterostigma, ♀.

FIGURE 2. Drepanosticta brownelli ♂, Nankushan Mountain, China (KPMNH). (a), head and thorax, lateral view; (b), prot- horax, lateral view; (c–e), appendages in oblique dorsal, lateral and ventral view.

FIGURE 3. Features of Drepanosticta carmichaeli ♂ [a–f], Darjeeling, India (NMNS) & ♀ [g–j], Arunachal Pradesh, Seijosa, India (NCBS). (a, g), head and thorax, lateral view; (b), abdominal tip, lateral view; (c, d), appendages in dorsal and lateral view; (e), genital ligula; (f), pterostigma; (h, i), prothorax in lateral & dorsal view; (j), abdominal tip, lateral view.

FIGURE 5. Drepanosticta emtrai ♂, Ta Thom, Laos (ZCDTU). (a), head and thorax in lateral view; (b), tip of abdomen; (c), genital ligula; (d), pterostigma.

FIGURE 8. Features of male Drepanosticta vietnamica ♂, Ta Thom, Laos (ZCDTU). (a), head & thorax, lateral view; (b), prothorax, lateral view; (c), abdominal tip, lateral view; (d), appendages, oblique dorsal view; (e), genital ligula; (f), pterostigma.

FIGURE 13. Distribution map of Drepanosticta carmichaeli group. D. vietnamica (yellow circle); D. annandalei (red circle); D. brownelli (white circle); D. carmichaeli (red square); D. emtrai (blue square); D. hongkongensis (pink square); D. jurzitzai (red triangle); D. wildermuthi sp. nov. (yellow triangle); D. sumatrana (pink triangle); D. tenella (red diamond).