冬虫夏草的寄主昆虫—虫草蝠蛾

THE HOST INSECT OF THE CORDYCEPS SINENSIS FUNGUS-HEPIALIDS

冬虫夏草的寄主涉及鳞翅目蛹蛾科的蝙蝠蛾属(Hepialus)、类蝠蛾属(Hepialiscus)、二岔蝠蛾屑(Forkalus)和双节蝠蛾属(Bipectius)37种昆虫,其中蝙蛹蛾属的虫草蝙蝠蛾(H.armortcartus)、斜脉蝠蛾(H.oblifurcus)、德钦蝠蛾(H.deginensis)、白马蝠蛾(H.baimaensis)以及五龙蝠蛾(H.yulongensis)是冬草夏草的主要或优势寄主昆虫。虫草蝠蛾地理分布具有区域性、地带性,主要分布于我国的四川、青海、云南、西藏和甘肃等地,除虫草蝙蝠蛾为广域分布种外,其余种类均为狭域分布种。虫草蝠蛾生长在雪线以下3000m以上的海拔高度,垂直分布的上限为5080m,在高山草甸土中分布最多,高山寒漠土次之,再次是高山棕色针叶林土,其他类型土壤中未发现。虫草蝠蛾幼虫期长,一般2～3年,最长的4～5年,营地下生活主食高山草甸中的蓼属、黄芪属、柳属、无心属及杜鹃属等植物嫩根芽相地下茎,耐寒性强,过冷却点在-18.2℃～-21.5℃之间,无真正的滞育特性。虫草蝠蛾被冬虫夏草菌('ordyceps sinensis(Berkely)Saccards寄生是在幼虫一年中第二次蜕皮(7～8月),感染寄生率为2.6～16.1％,以4～5龄期幼虫的寄生感染率最高,约占90％。

37 species of insect which belong to 4 genera of Hepialidae (Lepidaptera), which are Hepialus, Forkalus, Hepialiscus and Bipectilus, are found to be the host of Chinese insect herb Cordyceps sinensis, Among these species, Hepialus armoricanus, H. oblif-urcus. H. deqi-nensis, H. baimaensisand, H.yulongensis are major host insect.The geographical distribution of Hepialid moths has obvious regional and geograph-ical band characteristic. It distributes mainly Sichuan, Qinhai, Yunnan, Xizang and Gan-su Provinces. Except for Hepialus armouricanus which is the species distributed exten-sively, the others are narrowerly distributed. The insect herb moths live in the place below alpine snow line and upper 3000 meters of altitude. Its distribution upper limit is 5080 meters. Most of the larva are found in alpine meadow-hume soil. some are in alpine frigorideserta soil, a little are found in brown conifer forest soil and few is found in other type of soil.The larval stage normally lasts for 2-3 years, and the longes.t one reachs to 4-5 years. The larvae live in tunnel beneath soil surface and feed on tender root or rhizoma of Polygonum, Astrgalus, Salix, Arenaria, Rhodoendron, and have greater cold toler-ance. The supercooling points range from-18.2℃ to -21. 5℃. Diapause is not found until recent day in these species.Larvae are more easy to be parasitized by fungus Cordyceps sinensis (Berkely) sac-cards on second exuviation time (during July to August) than on other time in a year. The rate of parasitism is about 2. 6%-16.1%. the fourth and fifth instar larvae are in-fected more easily than other instar, the infected rate is about 90%.