中国趋流摇蚊属记述(双翅目:摇蚊科)

NOTES ON THE GENUS RHEOCRICOTOPUS FROM CHINA (DIPTERA: CHIRONOMIDAE)

本文记述了中国产趋流摇蚊属Rheocricotopus4新种及1新纪录种:长胫趋流摇蚊R.tibialis sp.nov.四川,金佛山。二带趋流摇蚊R.bifasciatus sp.nov.四川,金佛山。短足趋流摇蚊R.brachypus sp.nov.广东,封开。白山趋流摇蚊R.baishanensis sp.nov.吉林,长白山。铺展趋流摇蚊R.effusus(Walker)四川,金佛山。

In this paper four new species of Rheocricotopus are described and R. effusus (WaJker) is recorded for the first time from China. The type specimens are deposited in the Biology Department of Nankai University.Rheocricotopus tibialis sp. nov. (fig. 1)Imago male: Darkbrown, body length about 3 mm. AR 0.46. Antepronotum with 3-4 lateral setae. Humeral pits large and ovoid. LR1 0.9, LR2 0.65, LR3 0.6. Wing length 2mm, anal lobe strongly reduced. Squama with 1 setae. Costa extension long 104 urn. R with 9 setae.Abdomen with segments Ⅰ and Ⅴ yellow, the other segments black. Anal point slender, with 5 lateral setae (each side), apical half bare. Superior volsella nearly rightangled. Crista dorsalis of gonostylus absent,Holotype ♂: Sichuan Province (Mt. Jinfo, 29.0°N, 107.1°E, 1800 m.), 9-Ⅴ-1986.Allies to R. godavarius Lehmann, 1969 in Nepal in having bicolored abdomen and un-usual LR (LR3 LR2), but differs in: larger AR, with squama fringe, without crista dorsalis and larger humeral pits. Also allies to R. nepalensis Lehmann, 1969 in Nepal in similar hy-popygium structure, but the latter have single black abdomen coloration and much shorter C extension.Rheocricotopus bifasciatus sp. nor (fig. 2)Imago male: Total length 2.7 mm. AR 0.9. Antepronotum with 5 lateral setae. Humeral pit distinct and ovoid. LR1 0.85, LR2 0.63, LR3 0.64. Wing length 1.9 ram. Costa extension 83 μm. long Squama with 2 setae, R with 8 setae.Abdomen black, with segment Ⅰ, Ⅱ and Ⅳ yellow. Anal point rather slender, each side with 5 lateral setae. Superior volsella comparatively large, subrectanglar, apex pointed slightly bending inward. Gonostylus with a small ovoid preapical crista dorsalis.Holotype ♂: Sichuan (Mt. Jinfo, 29.0°N, 107.1°E, 1800 m.), 9-Ⅴ-1986. Paratype 1♂, same as holotype.Allied to R. godavarius Lehmann, 1969 and R. nepalensis Lehmann, 1969 in having very long Costal extension and narrow anal area. Showing more close affinity with godavarius on account of the structure of gonostylus and bicolored abdomen, but with larger humeral pit, larger AR, the shape of superior volsella, the anal point and the squama fringe also diffrentRheocricotopus brachypus sp. nov. (fig. 3)Imago male: Darkbrowm. Total length 2.1 mm. AR 0.43. Apex of last antennal segment expanded. Legs with shorter length. LR1 0.69, LR2 0.47, LR3 0.56. Antepronotum with 1 setae. Dorsocentrals 6. Humeral pit absent. Wing length about 1.4mm. Anal lobe distinct, squama with 5 setae, Costal extension 45 μm. long. R with 2 setae. Apex of anal point blunt, each side with 2-3 lateral setae. Superior volsella broad with rounded apex. Gonostylus with a large triangular crists dorsalis, megasetae long.Holotype ♂: Guangdong Province (Fengkai County, 23.4°N, 111.4°E) 12-Ⅳ-1985.Allies to R. tamabrevis Sasa, 1983 in Japan in AR, LR, squama fringe, but differs in lak-ing humeral pit, the shape of anal point and crista dorsalis.Rheocricotopus baishanensis sp. nov.(fig. 4)Imago male: Darkbrown insects with pale abdomen. AR 1.1. Antepronotum with 2 setae. Dordocentrals 7. Humeral pit large and ellopsoid. LR1 0.74, LR2 0.53, LR3 0.57. Wing length 1.84mm. anal lobe distinct, with 7 squama setae. C extension 40 μm. long. R with 5 setae.Anal point blunt with 2 lateral setae. Gonocoxite with well developed tooth-like caudo-mesal projection. Superior volsella simple without apex projection. Gonostylus laking crista dorsalis.Holotype ♂: Jilin Province (Mt. Changbai, 42.0°N, 128.1°E), 23-Ⅵ-1986.Allied to R. effusus in AR, LR, but laking crista dorsalis and the shape of anal point, superior volsella, caudomesal projection and humeral pit also different.Rheocricotopus effusus (Walker) (fig. 5)New record from China. Locality: Sichuan Province (Mt. Jinfo, 29.0°N, 107.1°E), 9-Ⅴ-1986.