【摘要】 <正> 在湘西土家族苗族自治州首府吉首及其交界的古文和保靖三县县治内发现一种沙螨,认为是一新种,订名为吉首纤沙螨。 吉首纤沙螨Leptotrombidium(Leptotrombidium)jishoum sp.n. 标本:正模与1副模,宿主黑线姬鼠Apodemus agrarius寄生部位耳轮边缘,采自湖南省吉首县岩界,1983.Ⅶ.29;13副模宿主黑线姬鼠(耳轮边缘),采自湖南更多还原

【Abstract】 A new sand mite from three neighboring counties, i. e. Jishou, Guzhang and Baojin, in the western part of Hunan Province is described.Leptotrombidium (Leptotrombidium) jishoum sp. n.Type data: Holotype and 23 paratypes. Hototype and 1 paratype ex Apodemus agrarius (surrounding the outer margin of the ears) , Jishou County, Hunan Province, 1983. Ⅶ. 29; 13 paratypes ex Apodemus agrarius, Guzhang County, Hunan Province, 1982. Ⅷ. 10, 1983. Ⅷ. 20, 1983. Ⅶ. 28-29, 1983. Ⅸ. 27; 8 paratypes ex Microtus fortis calamorum (in the ears) , Guzhang County, 1983. Ⅷ. 6, 1983. Ⅸ. 2; 1 paratype ex Rattus norvegicus (in the ears) , Guzhang County, 1983. Ⅷ. 4; Dr. Li Guangmi et al. coll.Records; Other than the type localities, the new species parasitized on all the three species of the hosts distributed in the district of Baojin County. The insectivorous species Suncus murinus is also a common host of the new mite (at perianal area) in the three neighboring counties. Only one collection was Rattus nitidus (in the ear) parasitized by the mite (1982. X) in Guzhang County. This mite appears from June to October with a peak at July and August every year. It is a predominant sand mite on these animals in that season and in that region.Repository: Holotype and 13 paratypes are deposited in the Medical Ac-arology Laboratory, Shanghai Medical University, the remaining 10 paraty- pes in the Sanitation and Anti-epidemic Station of Hunan Province.Diagnosis: This new species belongs to the deliense-imphalum-akamushi line in the systematics of Vercammen-Grandjean & Langston (1976) . The combination of the characters of fDS= 2 + 8.6.8...= 32 (30-37) , fDS=8.6. 4a6.2 = 26 (21-28) , NDV=58 (54-64) and IP = 668 (597-705) of the new species will easily be distinguished from those closely related species, such as L. (L. ) deliense sinense Wen et Chen, 1984, L. (L. ) deliense deliense (Walch, 1922) , L. (L. ) imphalum imphalum Vercammen - Grandjean et Langston, 1976, L. (L. ) imphalum sialkotense Vercammen-Grandjean et Langston, 1976. L. (L. ) delimushi delimushi Vercammen-Grandiean et Langston, 1976. The differentiation between L. (L. ) jishoum sp. n. and other closely related species are as follows:Furthermore, the new species with Snp=N, Snd= 15B (13-18B) , ti0d = 2-3B, t1=18. t2=l4 may be distinguished from others.Larval mite of small to medium size. Orange colored while alive, idios-oma oval and rounded up when fully engorged. Sc (scutum) short trapezoidal in shape with anterior margin slightly concave, lateral margins concave and posterior margin slightly biconvex. Sensilla (Sn) nude at its proximal 3/7 (only few individuals provided with sparse minute dilations) and branched at distal 4/7 (13-18 branches, 15 in average, up to 9 ,(im long) . 2/3 of the types with fDS= 2 + 8.6.8...= 32, rest of them being 2 + 8.6. 7.... or 2 + 8.7.6....., etc. And also 2/3 of the specimens with fVS=8.6.4a6.2 = 24-26. NDV =5 4-6 4, 58 in average. Gnathosoma of medium size. Chelost-yle with single apical recurved toothlet only. Galeal seta with 6 branches usually, verylong. Legs short, 2/3 of the IP being 653-685. Solenidia on tarsi short, t1 18-19UUUUUUUUUUUm, t2 13-15UUUUUUUUUm. Measurements Cum) (n=24):Bemarks. Although L. (L. ) jishoum sp. n. appears most similar to L. (L. ) deliense in having the same size of the scutum and almost equal lengths of the legs, the new mite differs from the latter in having more body setae. On the contrary, the formulae of dorsal and ventral setae of the new mite are somewhat like those of L. (L. ) imphalum, but they are different in the lengths of the legs.Due to the presence of 8 setae on the third row of the dorsal setae of L. (L. ) jishoum sp. n. , we prefer to classify it into the akamushi-group rather than deliense- or imphalum- group. The ecological data may support this point of view as well. The predominant rodents parasitized by L. (L.) jishoum sp. n. are Apodemus agrarius and Microtus fortis calamorum. They are congeneric respectively with Apodemus spp. and Microtus monte-belli parasitized by L. (L. ) akamushi, the vecto更多还原