生物测定虫种——小菜蛾的人工饲养及冷藏

Artificial rearing and low temperature keeping of Plutella xylostella

用不同菜苗饲养的小菜蛾发育历期基本相同（世代历期为２２～２３ｄ），但以芥蓝菜和甘蓝型油菜饲养的发育状况较好，其平均蛹重均在４．５ｍｇ以上，蛹羽化率为９７．８％～９８．７％，每雌产卵量在２００粒以上．在低温（５～６℃）条件下，卵冷藏１０ｄ孵化率为９０％左右，蛹冷藏２０ｄ羽化率为８０％～９０％．

The development periods of Plutella xylostella were almost consistent (generation duration 22￣23 d) reared with different vegetable seedlings. However both the cabbage and Brassica napus were most suitable for the insect′s development: mean pupa weight was over 4.5 mg; pupa emergence percentage was 97.8%￣ 98.7 % ; the quantity of oviposition was more than 200 grains. The vitality of its eggs and pupae was measured by different time lengths of low temperature keeping. The egg hatch percentage was about 90% kept for 10 d, pupa emergence percentage 80%￣90% for 20 d, at low temperature of 5￣6 ℃.