Polyphylla olivieri (Col.,Melolonthidae) is the most destructive white grub in the Iran.This Scarabaeid has a wide host range including different fruit trees in most part of Iran. Chemical pesticides is the common for controlling this pest. Considering side effects of this method, application of biocontrol agent has been considered in management programmes. Among the natural pathogens, several isolates of entomopathogenic nematodes from both genus of Steinernema and Heterorhabditis were isolated from third and second larval stages of this pest in Iran. This isolates belonged to Heterorhabditis bacteriophora, Steinernema carpocapsae and Steinernema glaseri.Laboratory assay showed that the last species, S.glaseri had the highest mortality potential .The prevalent pathogen of this melolonthid in Tehran province was Metarhizium anisopliae and after this Beauveria bassiana.Compatability studies on application of entomopathogenic nematodes and fungi indicated that application of entomopathogenic nematodes and M.anisopliae can reduce population of this white grub considerably. In addition to natural pathogens as naturalbiocontrol agents, some isolates of nematodes were isolated from soil habitats of this pest. Among this, Steinernema feltiae and Heterorhabditis megidis had the highest virulence compaed with other species .A survey for characterization and introduction of isolates with high virulence can provid a good alternative in integrated management of Polyphylla olivieri in future.

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