Screening of high virulent strain of Metarhizium spp. against the brown planthopper, Nilaparvata lugens
褐飞虱高毒力绿僵菌菌株的筛选

Nine strains of different species of Metarhizium,including strain of M.flavoviride(Mf82) newly isolated from Nilaparvata lugens(Stl),and eight M.anisopliae strains from lab collection,were tested against the adults of N.lugens.The chitinase activities of these strains were also assayed.The results showed that both the cumulative mortality(82.1%) and the chitinase activity(9.78U/mg) of strain Mf82 were the highest among all tested strains.Scanning electron microscope(SEM) observations showed the germinating conidia of the strain Mf82 penetrated the cuticle not only via the intersegmental membranes and folded regions,but also through the pronotum which contained a large quantity of chitin.The biological characteristics of these strains,including growth rate,sporulation,germination rate and timing of sporulation,were further investigated.The results showed Mf82 was the best strain having strong pathogenicity and exhibited a great potential for sustainable control of N.lugens.