杀虫剂对桔全爪螨自然种群动态的影响

本文应用生命表方法研究了两种类型杀虫剂，即广谱性的拟除虫菊类杀虫剂速灭杀丁和具有一定选择性的杀虫（螨）剂尼索朗对桔全爪螨种群动态的影响。结果表明，大量杀伤天敌是使用广谱性杀虫剂导致桔全爪螨种群数量大发生的主要原因，使用对天敌作用较小的选择性杀虫剂，可达到控制桔全爪螨种群数量的效果。

EFFECTS OF TWO PESTICIDES ON POPULATION DYNAMICS OF CITRUS RED MITE

The effects of selective and wide-spectrum pesticides on the population dynamics ofcitrus red nite,Panonychus citri McGregor were studied by means of the methods oflife table in this paper.Treatment with the wide-spectrum pesticide(fenvalerate)incitrus orchards brought about the reemergence of citrus red mite in a short time be-cause of killing a lot of natural enenues.Meanwhile,the density of the pestdecreased in the orchards treated by the selective pesticide(hexythiazox).The intrin-sic capacity of increase rates(rm)of the mite population were 0.0625 and-0.0118after treatments of fenvalerate and hexythiazox,respectively.The densities of naturalenemies were very low in the orchards treated by fenvalerate while the reverse resultswere observed in the orchards where hexythiazox was applied.