Control effects of four biological pesticides and two chemical pesticides and their mixtures against mixed population of Nilaparvata lugens and Sogatella furcifera

The effectiveness of four biological and two man-made pesticides,and mixtures of these compounds, in controlling sympatric populations of Nilaparvata lugens (Stl) and Sogatella furcifera (Horvath),was tested in rice fields. The results show that,of four biological pesticides tested; matrine ( 0. 36% AS 1 500 mL / hm2 ),veratridine (0. 5% WP 3 000 g /hm2 ),abamectin (1. 8% EC 900 mL / hm2 ) and Beauveria bassiana (4. 0 × 1010 spores/ g WP 1 800 g/ hm2),abamectin was the most effective with control efficiencies 7 and 14 days after spraying of 73. 3% and 82. 3% respectively. These results were significantly higher than those achieved by the man-made pesticides; chlorpyrifos (48% EC at 1 500 mL / hm2 ) and buprofezin (25% WP at 750 g / hm2 ). The control efficiencies of six combinations of the above biological and chemical pesticides; ① matrine + chlorpyrifos,② veratridine + chlorpyrifos,③ avermectin + chlorpyrifos,④ Beauveria bassiana + chlorpyrifos,⑤ matrine + buprofezin,⑥ veratridine + buprofezin,were 81. 8% - 89. 2% ,88. 2% - 96. 5% ,95. 6% - 98. 1% ,and 86. 0% - 97. 8% ,respectively,1,3,7 and 14 days after application. We conclude that these combinations of biological and man-made pesticides and dosages are more effective their constituents for controlling younger nymphs of N. lugens and S. furcifera.