隐助甲螨属在我国的发现及─新种记述（蜱螨亚纲：甲螨亚目，滑珠甲螨科）

DISCOVERY OF THE GENUS COSTEREMUS FROM CHINA, WITH DESCRIPTION OF A NEW SPECIES (ACARI:ORIBATIDA, DAMAEOLIDAE )

隐助甲螨属在我国的发现及─新种记述（蜱螨亚纲：甲螨亚目，滑珠甲螨科）王慧芙，崔云琦（中国科学院动物研究所北京１０００８０）Ａｏｋｉｌ’］－－Ｔ１９７０年建立隐肋甲螨属Ｃｏｓｔｅｒｅｍｕｓ，模式种为产于日本对马岛的Ｃ．ｏｒｎａｔｕｓ。Ｆｕｊｉｋａｗａ等...

Aoki (1970) erected the genus Costeremus with C.ornata Aoki asthe type species. Fujikawa and Fujita (1985)described the second species C.yezoensis.The present paper deals with a new species of Costeremus from China.The genus is recorded for the first time from China,as well as from the outsidearea of Japan.The type specimen is deposited in the institute of Zoology,Academia Sinica.Costeremus cornutus Wang, sp. nov.(figs.1-5, pl. I: 1,2 )Dimensions.Length 330μm,width 146. 5 μm.Diagnosis. Prodorsum with a pair of longitudinal,widely separated ridgesand two transversal ridges between bothridia. Sensillus flagellate,withoutexpansion on the proximal portion. Notogaster having 3 pairs of ridges on theanterior part and 11 pairs of notogastral setae which mostly are pilose.Prodorsum and notogaster with a pairs of conspicuous,rounded tubercles on thelateral margin respectively. On the ventral aspect,a pair of triangular tubercleswith acute point located between coxae Ⅰ andⅡas well as between coxae Ⅲ andⅣ. Each tubercle covered by dark colour cerotegument.Material examined Holotype (W-89-29, on slide), April 30,1989,Mt.Wuyi in Fujian Province,ex litter under China fir tree.Remarks 1. This new species resembles type species C.ornata Aoki 1970,in the shape of body, struncture of ridges on prodorsum and notogaster andpilose dorsal setae.But it differs from the latter in the following characters: (l)Sensillus not forming distinct expansion, (2) the second transversal ridge onprodorsum without rounded small projections, (3) the second ridges onnotogaster semi-rounded, and not connected each other;(4) on the ventral as poet,there are small triangular tubercles betWeen coxae Ⅰand Ⅱ, as well as between coxae Ⅲ and Ⅳ,(5) rostral setae smooth, lamellar setae only with a fewpectinations proximally,setae da,dp not having strongly pilose,being bi-ortrifurcated. 2. In the original description,Aoki described:'pedotecta Ⅰ and Ⅳwell developed, each with a darkcolored ear-like appendage'. According to theobservation on the new species, the authors consider that' dark-colored earlikeappendage' may be cerotegument which can be found frequently in the FamilyDamaeidae (pl. I: 3,4). 3. Four pairs of distinct tubercles can be observed onthe lateral margine of C. cornutus sp .nov. From dorsal view, there is a pair ofrounded tubercles located on lateral side of prodorsum and notogaster respectivelywhich covered by deep colour cerotegument, they appear the same outline withbutercles. From ventral aspect, another pair of triangular with acute tip tubercleslocated between coxae Ⅰ and Ⅱ as well as between coxae Ⅲ and Ⅳ which coveredby cerotegument showing the same contour with triangular tubercles. The latternot been mentioned in Aoki's description. 4. Aoki (1970) described f a notogasterhas 10 pairs of notogastral setae' in the genus definition and the description ofC. ornatus, but 11 pairs of notogastral setae were drawn in fig. 35. The newspecies C. cornutus has 11 pairs of notogastral setae, therefore, the definition ofthe genus Costeremus should be corrected.