科学家最近发现,从楝树(Melia.sp.)中提取的某些物质,可能是很理想的杀虫剂。美国农业部的一位化学家已经从楝树中分离出几种物质,其中一种叫苦楝素,它甚至能阻止昆虫接触植物体。其他几种,昆虫接触后便不吃东西而死亡。研究人员发现,日本瓢虫宁愿饿着肚皮而不敢吃 Scientists recently discovered that certain substances extracted from Melia sp. May be ideal pesticides. A chemist at the U.S. Department of Agriculture has isolated several substances from the neem tree, one of which is called toosendanin, which can even stop insects from touching plants. Several other species of insects will die after they have not eaten. Researchers found that Japanese ladybugs rather hungry and afraid to eat