Efficacy of Entomopathogenic Fungi Against Brown Planthopper Nilaparvata Lugens (Stal) (Homoptera: Delphacidae) Under Controlled Conditions

摘要

The current study was conducted to evaluate the efficacy of entomopathogenic fungi (EPF) as an alternative strategy for the sustainable control of Nilaparvata lugens. Three species of EPF, Beauveria bassiana, Metarhizium anisopliae and Lecanicillium lecanii, were tested against N. lugens with two suspensions of each tested EPF applied in different treatments. The observed mortality of N. lugens adults during the overall exposure period for the lowest and highest concentrations of each EPF ranged from 0-100%. At both highest and lowest concentrations of EPF, when sprayed on adult, the mortality of N. lugens was higher as compared to when sprayed on the stem pieces as food. A higher mortality rate was observed when the stem pieces were absent than when stem pieces were present. Maximum percent mortality of N. lugens was recorded due to the spray of highest concentration of M. anisopliae on only stem pieces (82.67%) and on adult N. lugens provided with stem pieces as food (93.33%) after 14 days of exposure interval. On the other hand, B. bassiana and L. lecanii were also responsible to cause more than 50% mortality of N. lugens in both treatments after 14 days of exposure interval. Results also indicated that maximum and minimum percent mycosis and sporulation from dead cadavers of N. lugens were recorded in both conidial suspensions of L. lecanii and M. anisopliae, respectively, in all treatments. The high efficacy levels recorded in the current study indicates that M. anisopliae can be effective biological control agents against N. lugens.