Susceptibility of Rhagoletis cerasi to entomopathogenic fungi

Summary

The effects of six fungus strains (Deuteromycotina: Hyphomycetes) on the mortality of different life stages of the European cherry fruit fly, Rhagoletis cerasi Loew (Diptera: Tephritidae), were assessed in a series of laboratory experiments. All fungus strains were able to cause mycosis to larvae and adults of R. cerasi. However, virulence varied considerably among the strains. Effects on
L3-larvae were negligible. In contrary, adults were highly susceptible to fungus infection. Beauveria bassiana and Paecilomyces fumosoroseus caused 90 to 100% mortality and had a strong influence on fecundity. Metarhizium anisopliae also showed reliable effects. The pathogenicity of Paecilomyces farinosus was low. Higher conidia concentrations lead to higher mortality, whereas B. bassiana was most efficient at low concentrations. Young flies showed lower mortality rates than older flies but,
sub-lethal effects on eclosion rate off eggs were greater in young than in older flies.