Pathogenicity of Metarhizium anisopliae var acridum strains on pink hibiscus mealy bug (Maconellicoccus hirsutus) affecting cotton crop

摘要

Metarhizium anisopliae var. acridum (Metschnikoff) Sorokin strains Ma1912, Ma1729 and Ma3605 were found to be pathogenic to the pink hibiscus mealy bug, Maconellicoccus hirsutus Green (Homoptera: Pseudococcidae) affecting cotton crop. Effects of these strains on survival of adults, instars and egg hatching were assessed. The strains were able to infect adults within 2 days after inoculation and showed 90 rnortality by 8(th) day, whereas, 100 mortality of instars was observed by 4(th) day of inoculation when females were inoculated. Metarhizium anisopliae strain Ma1912 reduced the egg hatching of M. hirsutus by up to 60 and other two strains reduced egg hatching less than 30, whereas, direct inoculation of eggs on glass slides by all strains resulted in more than 70 reduction in egg hatching.