菜蚜茧蜂对取食不同蔬菜桃蚜的选择性

目的]探明不同寄主植物上桃蚜对菜蚜茧蜂生物学特性的影响。方法]选取在萝卜、白菜、菜心、芥菜和芥蓝等寄主植物上繁殖的幼年桃蚜各30头,引入1头已交配的菜蚜茧蜂雌蜂,使其寄生1 h,再将挑蚜转移到原寄主植物上饲养,直到桃蚜僵化。定期更换寄主植物并移除新产生桃蚜。记录僵蚜出现的时间和数量及菜蚜茧蜂的羽化数和性比。结果]取食不同蔬菜桃蚜对菜蚜茧蜂世代发育历期的影响依次为芥蓝〉白菜〉萝卜〉菜心〉芥菜。菜蚜茧蜂在取食萝卜的桃蚜上寄生率和羽化率最高,分别为50.00%和92.97%。取食菜心桃蚜的菜蚜茧蜂后代雌性比最大,为82.81%,取食芥蓝桃蚜的菜蚜茧蜂后代雌性比最小,为45.29%。结论]菜蚜茧蜂的世代发育历期、寄生率、羽化率、后代性比等因桃蚜寄主植物的不同而差异显著。

Selectivity of Diaeretiella rapae M'Intosh on Myzus persicae Eating Different Vegetables

Objective] The aim was to investigate the influence of Myzus persicae in different host plants on the biological characteristics of Diaeretiella rapae M′Intosh.Method] Thirty heads of young M.persicae bred on host plants,such as radish,Chinese cabbage,Brassica campestris,mustard and Chinese kale,were selected resp.,one mated female D.rapae and them were introduced,and parasitizing one hour,then the M.persicae were reared on the original host plant till the M.persicae became stiff.The host plant was replaced periodically and the newly produced M.persicae were removed.The occurrence time and quantity of stiff M.persicae and the emergence number and sex ratio of D.rapae were recorded.Result] The influence of M.persicae eating different vegetables on developmental duration of generation of D.rapae was as follows: Chinese kale > Chinese cabbage > radish > B.campestris > mustard.The parasitizing rate and emergence rate of D.rapae eating M.persicae in radish were highest,being 50.00% and 92.97% resp.The female ratio of later generations of D.rapae eating M.persicae in B.campestris was highest,being 82.81% and that of D.rapae eating M.persicae in Chinese kale was lowest,being 45.29%.Conclusion] The developmental duration of generation,parasitizing rate,emergence rate and sex ratio of later generations of D.rapae showed significant difference due to the difference of host plants of M.persicae.