Rhysida immarginata (Porat, 1876)

Rhysida immarginata (Porat, 1876) View in CoL

Figs 1 View Figure 1 , 6 View Figure 6 , 7 View Figure 7

Rhysida immarginata Pocock, 1891 - Kraepelin 1903: 143; Lewis 2001: 45; Siriwut et al. 2018: 1022, figs 9–11. View in CoL

Rhysida nuda immarginata Attems, 1930: 190. View in CoL

Rhysida nuda Attems, 1930: 189, figs 236–237; Attems 1938: 337; Tran et al. 2013: 227. View in CoL

Examined materials.

Vietnam • 1 specimen; Ha Giang Province, Tay Con Linh NR , natural forest; 22.78121°N, 104.85867°E; 1,113 m a. s. l.; 2019; col. A. D. Nguyen leg; HG.TCL.02 GoogleMaps . • 3 specimens; Dien Bien Province, Muong Nhe Natural Reserve ; residential area, 21.21278°N, 103.39833°E; 610 m a. s. l.; May 2018; S. X. Le & H. D. Nguyen leg.; DB 019 , DB 013 , DB 018 GoogleMaps ; • 2 specimens; same location, residential area; 22.30056°N, 102.39833°E; 558 m a. s. l.; Nov. 2017; S. X. Le leg.; MN 018.1 , MN 106 GoogleMaps . • 1 specimen; Son La Province, Ta Xua NR , residential area, 21.35972°N, 104.66972°E; 673 m a. s. l.; 11 Oct. 2017; S. X. Le and H. T. Vu leg.; HNUE.TX.D4.001 GoogleMaps • 1 specimen; same location, bamboo forest; 21.33833°N, 104.69139°E; 429 m a. s. l.; 14 Oct. 2017; L. K. Ha leg.; HNUE.TX.142 GoogleMaps . • 2 specimens; Hoa Binh Province, Thuong Tien NR , residential area; 20.66127°N, 105.46142°E; 175 m a. s. l., Jul. 2020; H. D. Nguyen leg.; HNUE.TT.202 to 203 GoogleMaps . • 4 specimens; Phu Tho Province, Xuan Son NP , natural forest; 21.11426°N, 104.95845°E; 511 m a. s. l.; 13 Jun. 2014; S. X. Le leg.; VRTC.XS.015 to 016, VRTC.XS.018 to 019 GoogleMaps • 4 specimens; same location, natural forest; 21.118219°N, 104.95159°E; 492 m a. s. l.; 10 Jun. 2014; S. X. Le leg.; VRTC.XS.006 , VRTC.XS.009 to 010, VRTC.XS.021 GoogleMaps • 4 specimens; same location, mixed wood – bamboo; 21.136413°N, 104.95244°E; 524 m a. s. l.; 12 Jun. 2014; S. X. Le leg.; VRTC.XS.011 to 014 GoogleMaps • 1 specimen; Xuan Son NP , natural forest; 21.12622°N, 104.92145°E; 556 m a. s. l.; 14 Jun. 2014, S. X. Le leg.; VRTC.XS.025 GoogleMaps . • 1 specimen; Vinh Phuc Province, Tam Dao NP , residential area; 21.45627°N, 105.64222°E; 1.001 m a. s. l.; Oct. 2022; A. D. Nguyen leg.; IEBR.VP.132 GoogleMaps . • 1 specimen; Hai Phong city, Duong Kinh , residential area; 20.82540°N, 106.68219°E; 5 m a. s. l.; 16 May 2021; S. X. Le leg.; VRTC.HP.01 GoogleMaps . • 8 specimens; Thai Binh Province, Tien Hai NR , coniferous forest; 20.25306°N, 106.59306°E; 8 m a. s. l.; 2021; H. D. Nguyen leg.; HNUE CHI 1066 to 1067 , HNUE CHI 1081 , HNUE CHI 1088 , HNUE CHI 1092 , HNUE CHI 1096 , HNUE CHI 1098 , HNUE CHI 1100 GoogleMaps . • 1 specimen; Ha Noi city, Ba Vi NP , natural forest; 21.08191°N, 105.35786°E; 487 m a. s. l.; Aug. 2016; S. X. Le leg.; VRTC.BV.104 GoogleMaps • 5 specimens; same location, residential area; 21.04000°N, 105.13389°E; 13 m a. s. l.; 8 Jan. 2019; H. D. Nguyen leg.; VRTC.HN.004 to 008 GoogleMaps • 1 specimen; same location, Cau Giay district , residential area; 21.04673°N, 105.80093°E; 9 m a. s. l.; 10 Sep. 2018; H. T. Vu leg.; IEBR.SP.01 GoogleMaps . • 4 specimens; same location, Ha Dong district , residential area; 20.946386°N, 105.78258°E; 8 m a. s. l.; 5 Dec. 2021; S. X. Le leg.; VRTC.KH.001 to 004 GoogleMaps • 1 specimen; same location, Thanh Xuan district , residential area; 20.99984°N, 105.81969°E; 9 m a. s. l.; 6 Jun. 2021; A. D. Nguyen leg.; VRTC.TX.001 GoogleMaps • 7 specimens; same location, Tay Ho district , agricultural area; 21.075970°N, 105.83600°E; 12 m a. s. l.; 12 Jan. 2022; S. X. Le and T. T. Do leg.; VRTC.HN.003 , VRTC.HN.005 to 008, VRTC.HN.015 , VRTC.HN.020 GoogleMaps • 1 specimen; same location, Cau Giay district , residential area; 21.069060°N, 105.79577°E; 15 m a. s. l.; May 2023, D. X. Le leg.; VRTC.HN.021 GoogleMaps . • 1 specimen; Nghe An Province, Pu Mat NP , natural forest; 18.93889°N, 105.23344°E; 437 m a. s. l.; 17 Apr. 2018; S. X. Le leg.; VRTC.PM.033 GoogleMaps • 1 specimen; same location, Pu Mat NP , natural forest; 18.95917°N, 104.18347°E; 254 m a. s. l.; 23 Apr. 2018; S. X. Le leg.; VRTC.PM.034 GoogleMaps . • 4 specimens; Dong Thap Province, Tram Chim NP , natural forest, 10.71746°N, 105.52186°E, 7 m a. s. l., 6 Oct. 2018, D. H. Lam leg.; VRTC.TrC.007 to 009, VRTC.TrC.011 GoogleMaps • 1 specimen; same location, Tram Chim NP , natural forest; 10.69942°N, 105.52884°E; 11 m a. s. l.; 18 Mar. 2023; S. X. Le and H. D. Nguyen leg.; VRTC. TrC 012 GoogleMaps • 1 specimen; same location, Tram Chim NP , natural forest; 10.71075°N, 105.53567°E; 7 m a. s. l.; 20 Mar. 2023; S. X. Le and H. D. Nguyen leg.; VRTC.TrC 033 GoogleMaps .

Diagnosis.

Body with 21 leg-bearing segments. LBS 7 th with spiracles. Antennae (Fig. 6 A View Figure 6 ) 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 View Figure 6 ). 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 View Figure 6 ). Tergites (Figs 6 B View Figure 6 , 7 C View Figure 7 ) 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 View Figure 6 ). Coxopleural process with 1 (2) apical and 1 (2) subapical spine, lateral and dorsal spines absent (Fig. 7 B View Figure 7 ). Leg 1 with 1 fermoral, 1 tibial, and 2 tarsal spur (s) (Fig. 7 A View Figure 7 ). Ultimate leg (Fig. 7 D View Figure 7 ) prefemora with 1–2 VL, 0–1 VM, 0–1 M, and 0–2 DM spines.

Remarks.

R. immarginata is clearly distinguished from other Rhysida species in Vietnam by the absence of lateral tergite margination, except for tergite 21. This is also the characteristic supporting the division of Rhysida species into two main groups, the longipes group and the immarginata group, as mentioned in the study of Joshi et al. (2019).

Our examined specimens were consistent with the description in Siriwut et al. (2018) in most characteristics. However, the descriptions by Siriwut et al. (2018) do not mention the presence of a median suture on the coxosternite, which we observed to be present, albeit very briefly (Fig. 6 C View Figure 6 ).

Additionally, the length of the antennae reaches the boundary between tergites 5 and 6, which aligns with Siriwut et al. (2018) and is confirmed by Schileyko and Stoev (2016). This differs from Attems (1930) and Waldock and Lewis (2014), where the antennae are shorter, reaching only the posterior margin of tergite 3, and even shorter in Koch (1985).

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 View Figure 1 ).