Otostigmus tricarinatus

Figs 1 B, D, 3, 4 Chinese name 三棱耳孔蜈蚣

Holotype (CMMI 20210316103) description. Body length 26 mm. Antennae and anterior 1 / 2 of the cephalic plate, tergites and legs have blue colouration; posterior 1 / 2 of the cephalic plate, forcipule segment, and sternites have yellow colouration. Antennae with 17 articles, 3 glabrous dorsally, 2.5 glabrous ventrally, apical article double the length of the penultimate, with a well-developed lateral depression (Fig. 3 A). Antennae reach the posterior margin of T 2 when reflexed. Forcipular coxosternite slightly wider than long and lacking sutures / sulci. Coxosternal tooth-plates wider than long, with four teeth. Trochanteroprefemoral process bears one apical and one lateral tubercle. T 1 lacks sutures and convex granules, T 2 has sparse convex granules, TT 3 - 21 has scattered convex granules. Tergites without paramedian sutures, TT 3 - 20 with three sharp longitudinal keels, T 21 with three incomplete longitudinal keels. Lateral margination at TT 3 - 21. SS 2 - 20 with paramedian sutures occupying anterior 80 - 100 % of sternites (Fig. 3 D). The left coxopleural process has one apical and one lateral spine and the right one has two apical and one lateral spine (Fig. 3 F, G). Pore-free median longitudinal strip in pore field from the posterior of sternite 21 to the end of coxopleural process. The ultimate legs are long and slender, with the left prefemur having one ventrolateral and one ventromedial spine. Right prefemur with one ventrolateral spine, one ventromedial spine, and one dorsomedial spine. Ultimate leg relatively long with dense setae (Fig. 3 H). Dorsal surface of ultimate prefemur with convex granules, lacking corner spine. Legs 1 - 5 with two and legs 6 - 20 with one tarsal spur. Legs 1 and 2 with one tibial spur: leg 1 with one prefemoral and one femoral spur.

Diagnosis. Antennae with 17 articles, basal three glabrous dorsally, the apical article with a well-developed lateral depression. TT 3 - 20 with three longitudinal keels. SS 2 - 19 (20) with paramedian sutures occupying anterior 20 - 100 % of sternites, a median depression, and two posterolateral depressions. Coxopleural process with 1 - 3 apical spines and none or one lateral spine, pore-free median longitudinal strip in pore field from the posterior of sternite 21 to the end of coxopleural process. The ultimate leg prefemur typically with 0 - 7 spines, lacking corner spine.

Distribution. Fig. 2. China: Guangxi Zhuang autonomous region, Yunnan Province, Guizhou Province; Vietnam (Schileyko 1992, 1995, 2007; Vu et al. 2020).

Etymology. The name refers to the characteristics of the tergites. The tri - compounded with the Latin Otostigmus carinatus refers to the three sharp keels on the tergites.

Material examined. Holotype. CMMI 20210316103, China: Guangxi Zhuang Autonomous Region: Guiping: Xishan Town, 23.1147 ° N, 109.5947 ° E, 16 March 2021, coll. Mengxuan Shi. Paratypes. 1 spm, CMMI 20210316161, same data as holotype; 4 spms CMMI 20200712008 - 011, same data as holotype, 12 July 2020; 1 spm, CMMI 20220327101, China: Guangxi Zhuang Autonomous Region: Nandan County, 27 March 2022, coll. Yongxiao Luo. 3 spms, CMMI 20220327102 - 104; Hezhou: Babu District, 24.3751 ° N, 111.9739 ° E, 27 March 2022, coll. Xusheng Zhou. Yunnan Province: Maguan county, 1 spm, CMMI 20200817001, 23.01 ° N, 104.39 ° E, 17 Aug. 2020, coll. Yanan Li. Pingbian Miao autonomous county, 1 spm, CMMI 20210315101, back mountain of Pingbian Memorial Park, 22.9884 ° N, 103.6931 ° E, 1380 m asl., 15 March 2021, coll. Chao Jiang. China: Guizhou Province: Libo County: Jiaou Township, 1 spm, CMMI 20220123101, 25.3017 ° N, 107.6708 ° E, 23 Jan. 2022, coll. Quanyu Ji.