Rhysida immarginata

Figs 1, 6, 7

Diagnosis. Body with 21 leg-bearing segments. LBS 7 th with spiracles. Antennae (Fig. 6 A) composed of 18 – 20 articles, of which three basal ones glabrous dorsally. Cephalic plate without lateral and posterior marginations; posterior edge straight, and covered by tergite 1 (Fig. 6 A). Tooth-plates with 4 (5) + 4 (5) teeth prominently; trochanteroprefemora of forcipular strong, with 3 + 4 prominent teeth (one apical and two-three lateral teeth )); coxosternite with short median suture starting from toothplate (Fig. 6 C). Tergites (Figs 6 B, 7 C) without punctate and short median sulcus; lateral margination absent (except for tergite 21, complete); tergites 6 – 20 with complete paramedian sutures and incomplete on tergites 3 – 5. Sternites 2 – 19 with incomplete (only 10 – 15 % length of sternites) paramedian sutures on anterior and posterior parts (Fig. 6 D). Coxopleural process with 1 (2) apical and 1 (2) subapical spine, lateral and dorsal spines absent (Fig. 7 B). Leg 1 with 1 fermoral, 1 tibial, and 2 tarsal spur (s) (Fig. 7 A). Ultimate leg (Fig. 7 D) prefemora with 1 – 2 VL, 0 – 1 VM, 0 – 1 M, and 0 – 2 DM spines.

Distribution. This species occurs in Africa (Congo, Sudan), South America (Bolivia, Cuba, El Salvador, Guatemala, Peru, Venezuela, and Uruguay), and South and Southeast Asia (Taiwan, Cambodia, Indonesia, Kalimantan, Maluku, Myanmar, the Philippines, Singapore, Sri Lanka, Sumatera, Papua New Guinea, Malaysia, India, Nepal, Thailand, and Laos) (Bonato et al. 2016; Schileyko and Stoev 2016; Siriwut et al. 2018). In Vietnam it was recorded in Quang Ninh Province (Ha Long Archipelago) and Nghe An Province (Vinh city) by Attems (1938), and Ha Giang, Dien Bien, Son La, Hoa Binh, Phu Tho, Vinh Phuc, Hai Phong, Thai Binh, Ha Noi, and Dong Thap in this study. The distribution of R. immarginata was further updated (Fig. 1).