Liu S, Wang X, Guo S, He J, Shi Z
Department of Plant Protection, Zhejiang University, Hangzhou, China.
Bull Entomol Res. 2000 Jun;90(3):221-31. doi: 10.1017/s0007485300000341.
An investigation of insect parasitoids of the diamondback moth, Plutella xylostella (Linnaeus), in brassica vegetable crops in the suburbs of Hangzhou was conducted during five periods from 1989 to 1997. Eight species of primary parasitoids were recorded: Trichogramma chilonis Ishii, Cotesia plutellae Kurdjumov, Microplitis sp., Oomyzus sokolowskii Kurdjumov, Diadromus collaris (Gravenhorst), Itoplectis naranyae (Ashmead), Exochus sp. and Brachymeria excarinata Gahan. Seven species of hyperparasitoids were also collected. Rates of parasitism of eggs of P. xylostella were usually very low. However, rates of parasitism of larvae and pupae were substantial and showed two peaks each year, around June-July and September-November respectively. Rates of parasitism during peaks were usually 10-60% and reached over 80% on a few occasions. Cotesia plutellae, O. sokolowskii and D. collaris were the major larval, larval-pupal and pupal parasitoids respectively. In the field, C. plutellae was active throughout the year. Oomyzus sokolowskii was active from May to October, entered a quiescent pupal stage in October-November to overwinter and did not emerge until next April-May. Diadromus collaris was recorded from April to July and October. Rates of parasitism of P. xylostella in radish and mustard fields were usually higher than those in cabbage and Chinese cabbage fields in the same locality. Negative correlations of parasitism rates between C. plutellae and O. sokolowskii indicate a competitive relationship for host larvae between these two larval parasitoids.
1989年至1997年期间,分五个阶段对杭州郊区十字花科蔬菜作物上小菜蛾(菜蛾,鳞翅目菜蛾科)的昆虫寄生蜂进行了调查。记录到8种主要寄生蜂:螟黄赤眼蜂、小菜蛾绒茧蜂、微蛾绒茧蜂、菜蛾啮小蜂、环斑猛寄蝇、日本追寄蝇、外茧蜂属和短角长腹寄蝇。还采集到7种重寄生蜂。小菜蛾卵的寄生率通常很低。然而,幼虫和蛹的寄生率相当高,且每年出现两个高峰,分别在6 - 7月和9 - 11月左右。高峰期的寄生率通常为10% - 60%,少数情况下超过80%。小菜蛾绒茧蜂、菜蛾啮小蜂和环斑猛寄蝇分别是幼虫、幼虫 - 蛹和蛹的主要寄生蜂。在田间,小菜蛾绒茧蜂全年活跃。菜蛾啮小蜂5月至10月活跃,10 - 11月进入静止蛹期越冬,直到次年4 - 5月才羽化。环斑猛寄蝇在4月至7月以及10月有记录。同一地点萝卜和芥菜田中小菜蛾的寄生率通常高于甘蓝和大白菜田。小菜蛾绒茧蜂和菜蛾啮小蜂的寄生率呈负相关,表明这两种幼虫寄生蜂在寄主幼虫方面存在竞争关系。