5种生物农药对水稻褐飞虱的防治效果

The Efficiency of 5 Biological Pesticides against Nilaparvata lugens

为了明确5种生物农药对水稻褐飞虱的控制效果,以喷雾施药法进行了防治五(3)代褐飞虱低龄若虫的田间试验,结果表明:单用7天后,以0.5%藜芦碱WP3000mL/hm2和4.0×1010孢子/g球孢白僵菌WP1800g/hm2制剂用量的杀虫效果较好,分别为78.6%和79.0%,与对照药剂2.5%噻嗪酮WP600mL/hm2的防效接近,但单用的速效性较差。而以单用的剂量减半两两混合使用,以球孢白僵菌+噻嗪酮防效最高,药后1天达到65.0%,药后7天达到87.6%。因此,球孢白僵菌和藜芦碱可以部分替代高毒、高残留的化学农药,用于防治褐飞虱低龄若虫。

To understand the control effects of 5 biological insecticides against the younger nymphae of Nilaparvata lugens, the field trials were made in rice through field spray. The results showed that, 7 days after single spray respectively at a dosage of 3000 mL/hm~ and 1800 g/hm2, the control effects of veratridine 0.5% WP and Beauveria bassiana 4.0 x 101~ spores/g WP were better, i.e. 78.6% and 79.0% respectively, and the efficacy of the two biological insecticides was similar to that of buprofezin 25% WP at a dosage of 600 g/hm~, but these biological insecticides took effect more slower than chemical insecticides. When the two pesticides were mixed at a half dosage of the recommended dosage for spraying alone, the control efficacy of B. bassiana-t- buprofezin was the best, i.e. 65.0% in 1 day and 87.6% in 7 days after treatment. Therefore B. bassiana and veratridine can substitute partly for chemical insecticides to control younger nymahae of N. lugens.