非致死浓度农药对智利植绥螨繁殖和定居的影响

用6种农药的非致死浓度(LC_(n-13)),在实验室内处理菜豆叶的结果说明,对智利螨的繁殖有显著的影响。三氯杀螨醇(84ppm)、氧化乐果(1ppm)、速灭杀丁(0.2ppm)、氯氰菊酯(0.1ppm)、溴氰菊酯(0.025ppm)和灭扫利(0.026ppm)使智利螨的产卵量比对照分别减少35.3％,41.2％、20.8％,65.1％、49.4％和74.7％。用上述农药在温室处理菜豆植株的结果说明,当对照植株上的智利螨定居率为96.7％时,上述农药处理植株上的智利螨定居率依次为48.4％、50.0％、25.0％、11.7％,3.3％和6.7％。菊酯类农药对智利螨定居率的影响明显大于氧化乐果和三氯杀螨醇。植株上残留的微量农药不仅能影响智利螨繁殖能力,而且严重影响其定居率,在螨类的综防工作中值得引起重视。

IMPACT OF SUBLETHAL CONCENTRATION PESTICIDES ON THE SETTLEMENT AND REPRODUCTION OF PHYTOSEIULUS PERSJMILIS [ACARI: PHYTOSEIIDAE]

Six commonly used pesticides were sprayed at sublethal concentrations (LC0-13) on common .bean (Phaseolus vulgaris) leaves in the laboratory to test their effect on the predacious mite. The results showed that the pesticides were baneful to the reproduction of P. persimilis. Applications of dicofol at 84 ppm, omethoate at 1 ppm, fenvalerate at 0.2 ppm, cypermethrin at 0.1 ppm, deltamethrin at 0.025 ppm and meothrin at 0.026 ppm resulted in a fecundity reduction of 35.3%, 41.2%, 20.8%, 15.1%, 47.4% and 74.7% of the predator, respectively, comparing to those in the control treatment. Treatment of bean plant with these pesticides at the sublethal concentrations in the greenhouse further demonstrated harmful effects on the settlement of P. persimilis. The settlement rate of the predator on the plants treated with the forenamed six pesticides at the above concentrations was 48.4%, 50.0%, 25.0%, 11.7%. 3.3%. and 6.7%, respectively, while that in the control was 96.7%. The detrimental impact of the pyrethroids on the settlement of P. persimilis was significantly greater than that of omethoate and dicofol.