Isolation and identification of Metarhizium anisopliae from natural infections of Coconut hispid beetle Brontispa longissima (Gestro) (Coleoptera: Chrysomelidae) , and preliminary studies on against this pest in Hainan island, China
海南椰心叶甲病原菌金龟子绿僵菌的分离、鉴定及其生防潜力

Coconut hispid beetles,Brontispa longissima(Gestro)(Coleoptera:Chrysomelidae) have been prevalent all over Hainan Island in China,and millions of coconut palms were attacked by this pest.The objective of this work was to isolate and identify strains of entomopathogenic fungi from natural infections of B.longissima collected from coconut palms.Conidia or mycelia collected from the surface of beetle cadavers were cultured and the colonies were screened on dodine oatmeal agar medium(DOA).The colony morphology,mycelia growth rate and conidial production were further studied on various agar media: PPDA,OMA,V8A and PDA.In order to confirm whether these isolates were pathogenic to B.longissima,their virulence to the beetles were also tested in laboratory.The results showed two different kinds of strains MA and MB were all identified as Metarhizium anisopliae(Metschnikoff) base on the macromorphological and micromorphological characteristics,and PPDA was the optimal culture medium for vegetative growth and conidial production.Several high virulent strains were screened in vitro,and application on controlling coconut hispid beetles was carried out preliminarily in vivo.The results showed a significant reduction in adult population was caused by the isolate.It was proved that M.anisopliae isolated from the natural infected cadavers of B.longissima have great potential as a means of biocontrol against this serious pest.