小金蝠蛾Hepialus xiaojinensis Tu.是小金县冬虫夏草主要寄主之一。在小金县海拔3 850 m的自然条件下，完成1代需要4年，以各龄幼虫休眠越冬。每年5月初—7月上旬为蛹期。6月中旬—7月下旬为成虫期，成虫羽化时间多出现在16∶00—20∶30，羽化当晚或次日交配，在18∶30和20∶00有2个交配高峰；交尾后20 min可产卵，以当晚至次日晨产卵最多，平均每雌产卵为428粒。6月中旬至8月下旬为卵期。幼虫6龄，主要分布于5～40 cm的土层中；取食嵩草等植物的根或茎的幼嫩部分；最适宜生长的温度为8～12℃，土壤含水量为45%～50%。在自然条件下，各虫态发育历期：卵期为45～60 d；幼虫期1 370～1 385 d，其中幼虫休眠期为580～695 d；蛹期为50～65 d；成虫期为4～6 d。

        Hepialus xiaojinensis Tu., the main host insect of Cordyceps sinensis in Xiaojin County, has one generation every four years at 3 850 m altitude under natural conditions and hibernates in the soil as larvae during winter. Pupae occurred from early May to early July each year. The adults occurred from middle June to late July. Adults usually emerged from 16: 00 to 20: 30. Adults mate on the same, or the next, day after emergence, and have two mating peaks at 18:30 and 20:00. Oviposition begins 20 minutes after mating. The average number of eggs laid by each female is 428. Eggs appeared from midJune to late August. The larval stage has six instars. Larvae are generally distributed in the soil at a depth of from 5 to 40 cm, and feed on the tender parts of the roots and stems of plants such as Kobresia spp. The optimum temperature for larval growth is 8—12℃, and the optimum soil moisture is 45%—50%. Under natural conditions, developmental duration was 45—60 days for the egg stage, 1 370—1 385 days for the larval stage (including 580—695 days of dormancy) 50—65 days for the pupal stage and 4—6 days for the adult stage.