Ischnothyreus qiuxing Tong & Li, 2020

Tong, Yanfeng, Sun, Xiaochen, Li, Shuqiang & Bian, Dongju, 2021, Taxonomic study of the genus Ischnothyreus (Araneae, Oonopidae) from Xishuangbanna Rainforest, southwestern China, ZooKeys 1034, pp. 165-197 : 165

Ischnothyreus qiuxing Tong & Li, 2020 Figures 13 , 14 , 15 , 20M-O , 21F, G , 23I, J

Ischnothyreus qiuxing Tong & Li, 2020: 12, figs 7A-H, 16E, F.

Material examined.

4♂ 3♀: China, Yunnan, Menghai City, Mangun Stockaded Village, Xishuangbanna Natural Reserve , secondary forest; 22°02 ’12’’ N, 100°23 ’28’’ E; 1179 m; 20.III.2016; S. Li leg. (SYNU-372-378) .

Diagnosis.

This species is similar to I. balu Kranz-Baltensperger, 2011 in the circular atrium in the female, but can be distinguished by the finger-shaped sclerotized process of the male cheliceral fang (Fig. 13H-J ) (lacking in I. balu ; Kranz-Baltensperger 2011: fig. 1F-G), the size of the atrium (nearly 1/5 the length of postgastric scutum (Fig. 23I )) (vs more than 1/3 the length of postgastric scutum; Kranz-Baltensperger 2011: fig. 2F, H) and the greater sinuosity of the winding tube (Fig. 23J ) (vs the short, simple winding tube in I. balu ; Kranz-Baltensperger 2011: fig. 2G).

Redescription.

Male (SYNU-372). Body: habitus as in Fig. 13A-C ; body length 1.90. Carapace: 1.03 long, 0.81 wide; yellow, with egg-shaped patches behind eyes, surface of elevated portion of pars cephalica smooth, sides finely reticulate, lateral margin straight, smooth (Fig. 13D, E ). Clypeus: height about equal to ALE diameter (Fig. 13G ). Eyes: see Fig. 13D, G . Sternum: pale orange (Fig. 13F ). Mouthparts: chelicerae, endites and labium orange; chelicerae straight, base of fangs with finger-shaped sclerotized process, fang groove with a few small denticles (Figs 13H-J , 21F, G ); anteromedian tip of endites with one strong, tooth-like projection (Fig. 13F ). Abdomen: 0.95 long, 0.54 wide; dorsal scutum well sclerotized, pale orange, covering approximately 2/3 of the abdomen width and 3/4 of the abdomen length, fused to epigastric scutum; epigastric and postgastric scutum well sclerotized, pale orange, fused, postgastric scutum covering about 3/4 of the abdomen length (Fig. 13A-C ). Legs: pale orange, femur I with 2 prolateral spines, tibia I with 4 pairs, metatarsus I with 2 pairs of long ventral spines. Leg II spination similar to leg I except femur with only 1 prolateral spine. Legs III and IV spineless. Palp: trochanter with ventral projection, cymbium brown; bulb with one very small ventral protuberance, distal end of bulb elongated, with distal narrow membrane, and a retrolateral tuber-like projection (Figs 14 , 20M-O ).

Female (redescription, SYNU-378). Same as male except as noted. Body: habitus as in Fig. 15A-C ; body length 1.82. Carapace: 0.81 long, 0.66 wide. Mouthparts: chelicerae and endites unmodified. Abdomen: 1.24 long, 0.79 wide, dorsal scutum very small. Epigastric area: surface without external features (Fig. 15H ). Endogyne: from the middle of the slightly thickened margin of the postgastric scutum runs a dark, simple winding tube posteriorly, ending in a circular atrium (Fig. 23I, J ).

Distribution.

China, Myanmar.

Figures

Figure 13. Ischnothyreus qiuxing, male (SYNU- 372) A-C habitus, dorsal, lateral and ventral views D-G prosoma, dorsal, lateral, ventral and anterior views H-J left chelicerae, anterior, lateral and posterior views. Abbreviation: stp = strong, tooth-like projection. Scale bars: 0.4 mm (A-G); 0.1 mm (H-J).

Figure 14. Ischnothyreus qiuxing, male (SYNU- 372), left palp, SEM A-C prolateral, retrolateral and dorsal views D, E palpal bulb, prolateral and retrolateral views F-H distal part of palpal bulb, dorsal, prolateral and retrolateral views. Abbreviations: tlp = tuber-like projection; vpr = ventral protrusion.

Figure 15. Ischnothyreus qiuxing, female (SYNU- 378) A-C habitus, dorsal, lateral and ventral views D-G prosoma, dorsal, lateral, ventral and anterior views H epigastric region, ventral view. Scale bars: 0.4 mm (A-G); 0.2 mm (H).

Figure 20. Ischnothyreus spp., left male palp A-C I. cristiformis sp. nov. D-F I. mangun sp. nov. G-I I. mengyang sp. nov. J-L I. qidaoban sp. nov. M-O I. qiuxing A, D, G, J, M prolateral view B, E, H, K, N dorsal view C, F, I, L, O retrolateral view. Scale bars: 0.1 mm (A-F, M-O); 0.2 mm (G-L).

Figure 21. A-E I. xiaolongha sp. nov. F, G I. qiuxing A left male palp, prolateral view B left male palp, dorsal view C left male palp, retrolateral view D, F left male chelicerae, anterior view E, G left male chelicerae, posterior view. Abbreviations: fsp = finger-shaped process; tsp = tongue-shaped process. Scale bars: 0.2 mm (A-C).

Figure 23. Endogyne of Ischnothyreus spp., A, B I. cristiformis sp. nov. C, D I. mangun sp. nov. E, F I. mengyang sp. nov. G, H I. qidaoban sp. nov. I, J I. qiuxing A, C, E, G, I ventral view B, D, F, H, J dorsal view. Abbreviations: a = apodemes; bsa = bell-shaped atrium; cd = central oval depression; csa = circular atrium; nsa = nipple-shaped atrium; oa = opening of the atrium; rsa = rectangular-shaped atrium; wt = winding tube. Scale bars: 0.2 mm.