四种杀菌剂对智利植绥螨定居和繁殖的影响

化学杀菌剂粉锈宁、甲基托布津、多菌灵对智利植绥螨有不良影响。粉锈宁有忌避作用,智利螨定居率为21.7％,对照为53.3％。在同一植株上,经粉锈宁处理的叶片上,智利螨有80.8％转移至未处理叶上;而对照组则80％停留在原接虫叶上。经甲基托布津和多菌灵处理过的植株上的叶螨,智利螨捕食后有抑制产卵的作用。试验证明:这种抑制产卵的物质可通过叶螨雌成螨传递至其子代卵内,并对智利螨起影响。智利螨的繁殖力受抑制后不能恢复,且缩短寿命。经多菌灵处理叶片,7天后,抑制智利螨产卵的作用未见减弱。农抗120对智利植绥螨雌成螨未表现有不良影响。

EFFECT OF FOUR FUNGICIDES ON THE SETTLEMENT AND REPRODUCTION OF PHYTOSEIULUS PERSIMILIS [ACA.:Phytoseiidae]

Laboratory studies showed that three common fungicides, Bayleton, Cercobin-M and Derosal had adverse effects on Phytqseiulus persimilis, a predator of red spider mites. Bayleton showed a repellent effect on the predator. The percent settlement of P. persimilis was 21.7% on the fungicide treated plants of snap bean (Phaseolus vulgaris), comparing to 53.3% on the untreated one. When P. persimilis was placed onto a treated leaf with the other leaf untreated on the same plant, 80.8% of the predator escaped to the untreated leaf, only 19.2% remained on the treated. On the plants with both leaves untreated, 80% of the predators stayed. Cercobin-M and Derosal were found to be inhibitory to egg-laying of P. persimilis. After preying upon the spider raitss or even " the eggs laid by the mites fed on the treated plants, the predator suffered non-recoverablly reduced longevity and reproductivity. The inhibitory effect by Derosal remained active 7 days after the treatment. No harmful effect to P. persimilis was found by a bio-fungicide Agricultural Antibiotic 120.