穆勒没有想到,当时的人们也没有想到, 后来发生了那么多意外的事情。因为DDT的 毒性过强,在杀死害虫的同时把它的天 敌--益虫、益鸟也杀死了。而益虫、益鸟 少了,害虫就更加肆虐。因为频频使用DDT, 使得害虫的抗药性迅速增强。1945年以前, 能抵抗DDT的害虫有十几种,但到了1960年, 就达到了137种。人们只好增加DDT的浓度, Muller did not think, then people did not think of it, then there have been so many unexpected things. Because DDT is too toxic, killing its pests while killing its predators - beneficial insects, beneficial birds also killed. Beneficial insects, birds less, pests even more rampant. Due to the frequent use of DDT, pest resistance has rapidly increased. Before 1945, a dozen pests that could resist DDT were found, but by 1960 they had reached 137. People had to increase the concentration of DDT,