| abstract | This paper gives descriptions of two new species of chigger mites parasitic on rats from Shaanxi Province. All type specimens are deposited in the Health and Anti-Epidemic Station of Shaanxi Province. Measurements in micron.
1, Helenicula myospalacis sp. nov. (figs: 1-4)
Idiosome of engorged larva elongated oval, length 426, width 254. Cheliceral claw with a tricuspic cap. Geleal setae nude. Formula of palpal setae B-B-BBB/5B; claw 3-forked. Scutun punctate, nearly rectangular, with concave anterior margin, posterior margin sinuous; ratio of AW to SD approximately l:1. Scutal standard measure-ments of holotype: AW 48, PW 65, SB 11, ASB 34, P8B 17, AP 29, AM 37, AL 68, PL 56, Sens 21x18+11, Eyes 2/2, without ocular plate. Dorsal setae arranged as 2-8-6-8... =50. Two pairs of sternal setae. Ventral setae 59 in number. Legs all 7-segmented. Coxal setae 1-1-8. Length of legs: I 254, II 230, III 233. SIF=5B-N-3-2111.0000.
Holotype and a paratype, larvae, collected off Myospalax smithi Thomas in Oct. 26, 1984, from Pinghe Liang (33°28’N. 108°30ʼE., alt. 2,400 m), Ningshan County, Shaanxi.
This new species is allied to H. simena (Hsu et Chen, 1957), but differs in the formula of coxal setae 1-1-8 instead of 1-1-6; the ratio of PW to SD 1.27 instead of 1.49; IP=747 not 935.2.
Shunsennia scabmetosa sp. nov. (figs. 5-8)
Color in life milky white. Idiosome of unengorged oval, with slightly constriction behind coxae III, 354 long and 244 wide, Chelicera claw with a single row of atoot 15 small teeth. Formula of palpal setae B-B-BNB/7B, claw bifurcate. Scutum punctate, roughly trapezoid shaped; anterior margin with slightly convexity, posterior margin concave. Sensilla flagelliform, and very long. Scutum standard measurements: AW 94, PW 119, SB 38, ASB 48, PSB 20, AP 46, AM 74, AL 75, PL 88, Sens>89. Eyes 2/2, on ocular plate. Dorsal setae 92 in number, arranged in irregular. Sternal setae one pairs. Ventral setae 66. All legs with six segmente. IP=1,113. Coxal setae 2-1-1, Tilbiae I-III with 10-8-8B. Microgenuala present. SIP=7B-N-2-2111.0000.
Holotype, larva, collected off Rattus niviventer Hodgson in May 22, 1984, from Huanghua Ling (33°47’N. 108°50’E., alt 1,800m), Zhashui County, Shaanxi.
The new species is similar to S. harunaensis (Kumada, 1956), but can be easily distinguished from the latter by the formula of coxal setae (2-1-1, 2-2-2 for S. harunaensis), present of eyes, less of body setae. |