日本食蚧蚜小蜂对橡副珠蜡蚧的致死作用

为探明日本食蚧蚜小蜂（Coccophagus japonicus Compere）对橡副珠蜡蚧（Parasaissetia nigra Nietner）致死作用的影响因子,在不同接蜂时间、接蜂比例、补充营养及寄主龄期等条件下,研究了日本食蚧蚜小蜂对橡副珠蜡蚧的致死能力。结果表明：寄主在2龄-初期成虫范围内,繁殖致死率随寄主龄期增加而上升,在初期成虫-黑色期成虫范围内,繁殖致死率则随寄主龄期上升而下降,繁殖致死率以初期成虫最高（67.8%）,黑色期成虫最低（2.2%）;非繁殖致死率随寄主龄期的增加而下降,2龄最高（60.0%）,黑色期成虫最低（0）。日本食蚧蚜小蜂对橡副珠蜡蚧的致死率受接蜂时间影响明显,随着接蜂时间延长,该蜂对橡副珠主蜡蚧的繁殖致死率下降,非繁殖致死率和总致死率上升。成虫期补充6类糖类物质后,小蜂对橡副珠蜡蚧的总致死率为：蔗糖（96.5%）>葡萄糖（95.0%）>果糖（91.3%）>蜂蜜（82.1%）>松三糖（80.0%）>海藻糖（70.8%）。接蜂比例为蜂∶蚧=1∶5~1∶15范围内,随蜂虫比下降,繁殖致死率上升,非繁殖致死率和总致死率均下降。综合分析,日本食蚧蚜小蜂对橡副珠蜡蚧的致死作用随接蜂的蜂虫比例、时间增加而增强,随寄主龄期增加而减弱,成虫期补充蔗糖等营养物质有利于增强该蜂对橡副珠蜡蚧的致死作用。

Lethal Effects of Coccophagus japonicus Compere on Parasaissetia nigra Nietner

To determine the factors affecting the lethal effect of Coccophagus japonicus Compere on Parasaissetia nigra Nietner, the lethality of C. japonicus Compere was studied under different conditions including different parasitoid introducing time, ratio of parasitoid number to host number, supplementary nutrition and host stage. The results showed that when host stage was between the 2 ^nd larva and early adult, the reproductive host-mortality increased with host stage, and when host stage was between early adult and black adult, the mortality decreased with host stage. The reproductive host-mortality of early adult was the highest (67.8%) and the mortality of brown adult was the lowest (2.2%). The non-reproductive host-mortality decreased with host stage. The highest mortality was the 2 ^nd larva (60.0%) and the lowest at black adult (0). The lethality of C. japonicus was significantly affected by parasitoid introducing time. The reproductive host-mortality decreased with parasitoid introducing time, but the non-reproductive host- mortality and the total mortality increased with parasitoid introducing time. After being supplemented with six sugar substances, the total lethality of C. japonicus to P. nigra was ranked as from high to low: sucrose (96.5%) > glucose (95.0%) > fructose (91.3%) > honey (82.1%) > melezitose (80.0%) > trehalose (70.8%). When the ratio of parasitoid number to host number was between 1∶5 and 1∶15, the reproductive host-mortality decreased with ratio of parasitoid number to host number, but the non-reproductive host-mortality and the total mortality increased with ratio of parasitoid number to host number. In total, the lethality of C. japonicus to P. nigra increased with parasitoid introducing time and ratio of parasitoid number to host number, but decreased with host stage. Supplementary nutritions as sucrose would strengthen the lethal effect of C. japonicus.