SO2污染对农业害虫的间接影响

用开顶式熏气罩研究了SO2污染对粘虫、黄地老虎、小菜蛾、桃蚜、萝卜蚜和豆蚜等农业害虫的影响．结果表明，适度SO2污染显著地促进了这些昆虫的生长和／或繁殖，但高浓度SO2污染对它们有明显的不良影响，这种作用是通过食料植物间接发生的．这些昆虫对适度SO2污染的反应因种类而异：3种鳞翅目昆虫表现为幼虫的平均相对生长速率（MRGR）明显加快，成虫繁殖力变化不大；3种蚜虫主要表现为成蚜的繁殖力大幅度提高．若蚜（除豆蚜外）的MRGR也显著增加．对被处理食料植物营养成分的分析表明，SO2污染诱导的蛋氨酸相对含量变化可能是它产生这些间接影响的重要原因．

INDIRECT EFFECT OF SO_2 POLLUTION ON AGRICULTURAL INSECT PESTS

Influences of SO2 pollution on agricultural insect pests, Mythimna separata, Agrotis segetum,Plutella xylostella,Myzus persicae,Lipaphis erysimi and Aphis craccivora were investigated using open-top fumigation chambers. The results showed that moderate SO2 pollution significantly enhanced the growth and / or reproduction of these insects, while heavy SO2 pollution exhibited obvious adverse effect on them. Such effects indirectly occurred via their food plants. The response to moderate SO2 pollution varied,depending on the insect species tested. There were significantly increase in larval mean relative growth rate (MRGR) with little change in adult fecundity for the three species of lepidopterous insects and great enhance of adult fecundity with marked increase in MRGR of the nymphs for the aphid species except A. craccivora,compared with control ones. The analyses of nutritional composition of the food plants suggested that the changes in methionine relative content induced by SO2 pollution might be the major reason for such indirect effects.