【摘要】 <正> 近从四川省阿坝州卫生防疫站一批待攀定的蚤类标本中,发现茸足蚤属Geusibia Jordan, 1932(蚤目:细蚤科)一新种,兹记述如下: 半圆茸足蚤Geusibia hemisphaera,新种 鉴别特征 本新种接近结实茸足蚤G. torosa Jordan, 1932,但在形态上有几个独有的特征,易与近缘种或本属其它种区别:(1)♂性可动突呈半圆形(不呈梨形、长梨形、或三角形),其后缘中段附近,密布小毛,其中有3～4根为短小亚刺鬃。(2)抱器后缘更多还原

【Abstract】 Geusibia hemisphaera, sp. n.Diagnosis. The new species is related to G. torosa Jordan, 1932 but differs from all members of the genus by the following unique characters: (1) movable process hemispherical in shape, the middle portion of its posterior margin bearing a row of marginal hairs, among which are 3-4 short sub-spiniforms; (2) posterior margin of clasper with a thumb-like projection having five apical bristles; (3) process of clasper broad and short, being wider at base than high; (4) spermatheca U-shaped reminiscent of that of Amphalius Jordan, 1933, which is gradually decreasing in diameter from bulga towards the apex of hilla; bulga with a very short conical projection. Type data. Holotype ♂, 3 mm, long, allotype ♀, 2.7 mm. collected in May, 1973. ex Apodemus syhaticus, probably an occassional host, from the National Livestock Farm situated on a mixed forest steppe at Nanping Xian (about 33.6° N, 104.3° E), North Sichuan, China. 1 ♂ and 2♀♀ paratypes taken in June, 1979 ex Ochotona cansa from the locality mentioned above and another batch of 3 ♀♀ paratypes taken in July, 1979 ex O. cansa and A. sylvaticus from Songpan Livestock Farm. Holotype, allotype and 2 ♀♀ paratypes deposited in the Academy of Military Medical Sciences, the remaining ♂ and ♀ paratypes in the Health and Epidemic Disease Prevention Station, Aha Zang Autonomous District, Sichuan Province.Taxonomic discussion. The new species furthers our understanding of the genus. Structurally speaking, it is an intermediate between the very primitive G. aprominus Liu, Tsai & Wu, 1980, and the two much specialized species G. torosa & G. intermedium (Liu, Tsai & Wu, 1974)-intermediate in the sense that the conical prominence of the spermatheca of female is very short and the Ⅷ St. of male lacks the fine structures (a row of flattened lanceolate spiniforms and a group of tiny mushroom-like spiniforms) near the apex.In view of the semicircular shape of the movable process, as well as the primitive Ⅷ St., both of which are rather common in the hirticrus-group of Ctenophyllus, it seems that Geusibia is supposed to be derived from Ctenophyllus. However, as the genus is unique in that the tibia and the first (sometimes including the second) tarsal segment of all legs are covered with tiny hairs near the dorsal margin and is growing larger during the recent years, we think it might be reasonable to recover its original status as a genus instead of a subgenus as done by Hopkins & Rothschild 1971.Traub (1972) after a study of the genitalia of fleas proposed a hypothesis of compensative structures. It is applicable in most cases, but the new species seems to be an exception since its fixed process and movable process, its Ⅷ T. and Ⅷ St. are both large and well developed.The U-shaped spermatheca of the new species is reminiscent of that of Amphalius of Ceratophyllidae and both genera are ectoparasites of Ochotona. It indicates that this is a case of parallelism.更多还原