【摘要】 研究了4种生物农药、2种化学农药对宁夏南部山区苜蓿斑蚜(Therioaphis trifolii)及苜蓿地害虫-天敌群落的影响.结果表明,所有药剂处理对苜蓿斑蚜种群增长均有较好的控制作用,对照处理区的昆虫物种一直比较稳定,昆虫多样性指数最高;供试生物药剂Bt对天敌的安全性前期表现较好,植物源农药藜芦碱、鱼藤酮、苦参碱药后昆虫平均丰富度均较高,对天敌瓢虫的安全性也较好;化学药剂吡虫啉、啶虫脒对斑蚜的防治效果也较好,但对天敌杀伤力较大,且药后昆虫平均丰富度和生物多样性较低.因此,在防治苜蓿斑蚜时应尽量减少使用化学药剂,选用对天敌敏感性较低的生物药剂,如苦参碱、鱼藤酮、藜芦碱、Bt,并轮换使用不同类型的药剂,以免因害虫产生抗药性而加大使用量和增加施用次数导致对天敌最大的伤害.更多还原

【Abstract】 The effects of four biological pesticides and two chemical pesticides on Therioaphis trifolii and pest-natural enemy community in alfalfa fields were studied.The experiment results showed that the controlling of all pesticides on Therioaphis trifolii was better.Bacillus thringinensis was safe to predator at early stage,insect richness was higher after imposing Rotenone,Veratridine and Matrine,they were safe to predator.The effect of Imidacloprid and Acetamiprid on Therioaphis trifolii were better,but it damaged natural enemies,and what is more,insect richness and diversity were lower obviously after imposing them.Therefore,in order to control Therioaphis trifolii,chemical pesticides should not be used as far as possible,some bio-pesticides which have lower sensitivity on natural enemies,such as Rotenone,Veratridine,Matrine and Bacillus thringinensis.These pesticides should be used alternately,which can reduce the pests resistance and protect natural enemies.更多还原