New water mites of Torrenticolidae (Acari, Hydrachnidia) from Jiangxi Province, P. R. China Author Gu, Xinyao Institute of Entomology, Guizhou University, Guizhou Provincial Key Laboratory for Plant Pest Management of the Mountainous Region, the Scientific Observing and Experimental Station of Crop Author Jin, Daochao Institute of Entomology, Guizhou University, Guizhou Provincial Key Laboratory for Plant Pest Management of the Mountainous Region, the Scientific Observing and Experimental Station of Crop Author Guo, Jianjun Institute of Entomology, Guizhou University, Guizhou Provincial Key Laboratory for Plant Pest Management of the Mountainous Region, the Scientific Observing and Experimental Station of Crop text Acarologia 2020 2020-06-11 60 2 488 500 http://dx.doi.org/10.24349/acarologia/20204381 journal article 10.24349/acarologia/20204381 2107-7207 5402615 Monatractides trilaminatus sp. nov. Zoobank: 912FE8BD-2C65-4854-9D06-6279CDB557B1 ( Figures 1–4 ) Material examined — Holotype male, No. JX-TO-20190701, Guanshan National Nature Reserve , Jiangxi Province , P. R . China ( 28°35′16′′N , 114°33′14′′E , 471 m a.s.l. ), collected by Haitao Li and Min Ao, 3 July 2018 . Paratype : 2/4/0, No. JX-TO-20190702 – JX-TO-20190707, same data as holotype . Diagnosis — Dorsal plate 1+2: shoulder platelets on each side fused with frontal platelets to form a pair of elongated platelets ( Figure 1A ). Infracapitular bay U-shaped, extremely deep and narrow, the tip of Cx-I with a small rectangle extension; genital field elongated and oval, L/W ratio 1.2, genital flaps with 13 pairs of setae at the margins. Description Male (n = 3) – Idiosoma elliptical, L 1143 (916–1160), W 940 (830–940), L/W ratio 1.2 (1.1–1.3). Dorsal plate 1+2 ( Figure 1A ), dorsal shield L 1010 (887–1010), W 932 (760–932), dorsal plate L 911 (775–911), anterior plate (shoulder + frontal platelets) L 506 (506–596), W 167 (167–198). The tip of Cx-I with a small rectangle extension; infracapitular bay U-shaped, extremely deep and narrow, depth 278 (278–293); Cx-I L 470 (425–470), mL 165 (148–165), Cx-II+III mL 29 (29–59); genital field elongated and oval, L 237 (236–249), W 184 (158–188), L/W ratio 1.3 (1.3–1.5), distance between genital field and Ap 237 (174–247), genital flaps with 13 pairs of setae at the margins; E 4 at the same level as the 4 th pair of acetabula; Ap away from the line of primary sclerotization and anterior to V 2 , posterior to V 1 ( Figure 1B ). P-1 with one dorsal seta; P-2 with five dorsal and one ventral setae; P-3 with two dorsal and one large thick ventral setae; P-4 with one small dorsal, two ventral and one mediodistal setae ( Figure 1D ). Gnathosoma vL 224 (224–272), dL 179 (179–198); chelicera bs L 249 (242–256), claw L 32 (29–32); dorsal apodeme long, twice of ventral apodeme ( Figure 1E ). Ejaculatory complex ( Figure 1C ), L 320 (291–320), aL 207 (185–208). L of palp segments: P-1, 35 (34–37); P-2, 74 (74–84); P-3, 52 (52–57); P-4, 72 (71–73); P-5, 33 (33–34). dL of leg segments: I-L-1–6: 96 (92–96), 132 (99–132), 104 (104–112), 131 (130–132), 128 (113–128), 117 (105–119); II-L-1–6: 93 (77–105), 143 (143–156), 94 (94–98), 147 (141–151), 161 (137–165), 163 (152– 163); III-L-1–6: 99 (78–102), 166 (139–182), 116 (110–125), 167 (158–175), 183 (165–191), 170 (163–170); IV-L-1–6: 138 (138–151), 171 (171–179), 171 (171–175), 211 (211–220), 216 (212–223), 217 (216–217). Female (n = 4) – Body features same as the male except: E 4 at the same level as the 6 th pair of acetabula; Ap away from the line of primary sclerotization and closed to the line of V 1 ( Figure 3B ). The ventral apodeme longer (almost twice of male) ( Figure 3D ). Idiosoma L 1275 (826–1275), W 1061 (758–1061), L/W ratio 1.3 (1.2–1.3). Dorsal shield L 1137 (773–1137), Figure 1 Monatractides trilaminatus sp. nov. , male: A = dorsal view; B = ventral view; C = ejaculatory complex; D = palp; E = infracapitulum and chelicera. Scale bars = 100 μm. Figure 2 Monatractides trilaminatus sp. nov. , male: A = Leg-I; B = Leg-II; C = Leg-III; D = Leg-IV-1–3; E = Leg-IV-4–6. Scale bars = 100 μm. Figure 3 Monatractides trilaminatus sp. nov. , female: A = dorsal view; B = ventral view; C = palp; D = infracapitulum and chelicera. Scale bars = 100 μm. W 969 (700–969), dorsal plate L 1046 (674–1046), anterior plate (shoulder + frontal platelets) L 580 (489–612), W 193 (167–193). Infracapitular bay depth 308 (245–308); Cx-I L 466 (377–466), mL 141 (122–165), Cx-II+III mL 28 (16–40); genital field L 253 (243–271), W 231 (213–231), distance between genital field and Ap 269 (136–269). Gnathosoma vL 259 (230–274), dL 190 (169–190); chelicera bs L 251 (245–272), claw L 32 (31–35). L of palp segments: P-1, 38 (34–38); P-2, 94 (79–94); P-3, 58 (50–63); P-4, 79 (72–81); P-5, 31 (31–33). dL of leg segments: I-L-1–6: 95 (86–95), 141 (104–150), 114 (97–115), 139 (124–156), 136 (118–164), 119 (105–157); II-L-1–6: 110 (97–110), 155 (133–165), 99 (92–115), 162 (130– Figure 4 Monatractides trilaminatus sp. nov. , female: A = Leg-I; B = Leg-II; C = Leg-III; D = Leg-IV-1–3; E = Leg-IV-4–6. Scale bars = 100 μm. 162), 175 (129–175), 151 (111–164); III-L-1–6: 110 (86–110), 169 (144–185), 137 (111–146), 188 (162–188), 196 (179–196), 190 (160–193); IV-L-1–6: 168 (78–168), 195 (148–195), 199 (165–199), 230 (201–230), 236 (208–236), 196 (132–221). Habitat — Streamlet, about 2–3 m wide, 0.3 m depth, with many small stones at the bottom and opulent sunlight. Remarks — Monatractides trilaminatus sp. nov. can be distinguished by the shoulder and frontal platelets fused together and forming a pair of platelets but separated from the large dorsal plate. This character is also found in other species of Monatractides , i.e. M . hesperia ( Lundblad, 1941 ) ( Lundblad 1941 ) , M . veracruzensis ( Cook, 1980 ) ( Cook 1980 ) , M . sahuli Pešić & Smit, 2011 ( Pešić and Smit 2011 ), and M. acutiscutatus (K. Viets, 1914) ( Pešić and Smit 2014 ) . But M . hesperia and M . veracruzensis can be easily distinguished by: infracapitular bay V-shaped in these two species, U-shaped in the other species. M . sahuli differs from M. trilaminatus and M. acutiscutatus by Ap on the line of primary sclerotization. At the same time, M. trilaminatus differs from M. acutiscutatus in E 4 at the same level as the 4 th pair of acetabula in male, the 6 th pair in female (the 5 th pair in M. acutiscutatus ). Etymology — The specific epithet is masculine in gender and derived from Latin words, triplex (we used tri -) = three and laminae = platelets, in reference to three dorsal platelets. Distribution — China ( Jiangxi ).