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

Key Words：biological insecticides, Nilaparvata lugens, Sogatella furcifera, control effect

Abstract：        The effectiveness of four biological and two man-made pesticides, and mixtures of these compounds, in controlling sympatric populations of Nilaparvata lugens (Stal) 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.