毛食蚜蝇属二新种(双翅目:食蚜蝇科)

TWO NEW SPECIES OF THE GENUS DASYSYRPHUS (DIPTERA:SYRPHIDAE) FROM CHINA

本文记述毛食蚜蝇属Dasysyrphus 2新种,雄性外生殖器命名采用Vockeroth(1969)系统。模式标本保存于上海农学院昆虫标本室。1.曲毛食蚜蝇Dasysyrphus licinus He,新种(图 1) 雄体长10.5mm。眼毛褐色,长约0.2mm。头顶三角区的高度约等于复眼接合缝的长度,覆淡色粉被及黑毛。单眼黄褐色,排成短的等腰三角形。额黑色。

Two new species of the genus Dasysyrphus are described. The terminology of genital structures is based on Vockeroth (1969) system. All the type specimens are deposited in the Insect Collection of Shanghai Agricultural College.1. Dasysyrphus licinus He, sp.n.(Fig. 1)Male. Length 10.5mm. Hairs on eye long (about 0.2mm). Eye suture about as long as vertical triangle. Angle of frons at approximation of eyes about 115°? Face occupying about 50% head width. Ratio of width of wing membrane beyond upper marginal cross-vein to length of this vein 1: 4.2-5.1. For abdominal color pattern, see Fig.1,A.This species is rather similar to D. rotundiventris (Peck), but may be distinguished from it by the following characters: facial median stripe short, extending up to a little above the central prominence; hairs on eye brown; all tibiae without a dark median annulation, genitalia different (see Fig. 1, B-E). It differs from D. postclaviger (Stys et Moucha) by: antennae unicolorous black; yellow spots on abdomen not reaching lateral margin of tergite; genitalia different.Holotype (?) , Mt. Qilian, Gansu, 2700m, Ⅶ-1982, coll. Sun Xinquan.2. Dasysyrphus lituiformis He, sp. n. (Fig.2)Male. length 9.5mm. Hairs on eye rather short, about 0.12mm long. Eye suture shorter than vertical triangle. Angle of frons at approximation of eyes about 90°?. Face rather narrow occupying about 48% of head width. Ratio of width of wing membrane beyond upper marginal cross-vein to length of this vein 1 : 2.7-4.4, For genitalia, see Fig. 2, B-E.This new species is similar to D. venustus(Meigen), but differs from the latter as follows: face totally yellow-haired, median stripe not extending to base of antennae; genae yellowish-brown, mainly yellow-haired; abdominal yellow spots different (Fig. 2, A).Holotype (?) , Shihezi, Xinjiang, 28-Ⅵ-1986, paratypes 3 (?) (?) , Korgas, Xinjiang, 2000m, 11-Ⅶ-1986, coll. Gao Jianrong.