The efficacy of entomopathogenic nematode and fungi in controlling of Polyphylla fullo (Coleoptera: Scarabaeidae) and Curculio elephas (Coleoptera: Curculionidae) larvae

The efficacy of entmopathogenic nematodes and entomopathogenic fungi alone and their combinations were evaluated against chestnut fruit pest Curculio elephas and white grub Polyphylla fullo larvae which are known to be resistant to nematode infection. Experiments were conducted in two different experiemental arenas, plastic containers and flower pots for C. elephas. Entomopathogenic nematode Heterorhabditis bacteriophora and two isolates of entomopathogenic fungi Metarhizium anisoplia (4556 and V275) were used. The results showed that the both isolates of M. anisoplia were highly virulent against C. elephas larvae at plastic container and pot experiments with more than 90% mortality. There was an additif interaction at fungi and nematode combine application. Entomopathogenic fungus Beauveria brogniartii showed a very high pathogenicity against 1.instar P. fullo larvae with 90% mortality. The combine application of B. brogniartii and H. bacteriophora presented 100% mortality against first stage of P. fullo and the interaction between nematode and fungi was additif. As conclusion, M. anisoplia isolates 4556 or V275 for C. elephas in gomu places in chestnut field and B. brogniartii against first instar P. fullo larvae are recommended to use in biological control studies.