5种生物农药对水稻褐飞虱的防治效果

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 d后，以0.5%藜芦碱WP 3000 mL/hm2和4.0×1010孢子/g球孢白僵菌WP 1800 g/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WP 600 mL/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 d达到65.0%，药后7 d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。

The Efficiency of 5 Biological Pesticides against Nilaparvata lugens

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.