The genus Sympetrum Newman, 1833 in Thailand, with description of S. thailandensis sp. nov. (Odonata: Libellulidae) Author Makbun, Noppadon text Zootaxa 2023 2023-05-30 5296 4 569 581 http://dx.doi.org/10.11646/zootaxa.5296.4.6 journal article 10.11646/zootaxa.5296.4.6 1175-5326 A667A27C-CBB4-432C-8901-8399950699B3 Key to species of the genus Sympetrum known from Thailand 1 Males .............................................................................................. 2 - Females............................................................................................. 3 2 Mesepisternum yellow to red; side of synthorax yellow with black stripes; dorsum of S8–9 unmarked; postfrons unmarked; ceri red or yellow with black apically................................................................ S. hypomelas - Mesepisternum reddish brown; side of synthorax red with black stripes; dorsum of S8–9 with black spots; postfrons with a black basal band; cerci black with red basally................................................... S. thailandensis 3 Dorsum of S8–9 unmarked; postfrons unmarked; cerci red with black apically; valvula vulvae slightly raised rounded bilobe with shallow and broad incision at middle........................................................ S. hypomelas - Dorsum of S8–9 with black middorsal spots; postfrons with a black basal band; cerci entirely black; valvula vulvae short, bluntly triangular-tip bilobe................................................................. S. thailandensis