臭氧对墨西哥豆瓢虫取食和生长的影响

本文报道在美国农业研究中心用臭氧在室内熏蒸和田间开顶熏蒸植物,用此饲养墨西哥豆瓢虫的实验,以及熏蒸后植物体内某些化合物含量变化的测定.结果表明,墨西哥豆瓢虫(Epilachna varivestis Mulsant)喜食臭氧(O₃)污染的植物,幼虫取食O₃污染植物后蛹显著重于取食未受污染植物所形成的蛹.根据豆瓢虫食性和植物体内糖含量的测定,可以认为,低浓度O₃污染导致植物体内糖含量的增加,是促使豆瓢虫取食量和蛹重增加的重要因素.

THE EFFECT OF OZONE ON FEEDING AND GROWTH OF THE MEXICAN BEAN BEETLE LARVAE

Experiments were carried out with larvae of Mexican bean beetle (Epilachna varivestis Mulsant) and their food plants grown in air polluted with ozone to test the effect of ozone on the insects as well as on the plants. The results showed that the larvae preferred the ozone-polluted plants to the unpolluted ones. Therefore, the effect of ozone on the insects seemed to be indirect. The pupal weights of the male and female larvae feeding on the ozone-polluted plants were significantly heavier than that of the controls. According to the results of feeding preference experiments and the determination of soluble sugars and starch of foliage of the soybean plants from open-topped fumigation fields, significant differences appeared when compared with the controls. The change of sugar content in the foliage was seen to correlate with the chlorophyll content; and the larvae consumed more foliage with higher sugar coment. It is concluded that ozone at lower concentration in the air would increase the content of soluble sugar and in turn promote food ingestion of the larvae feeding upon them.