Susceptibility of Economic Dipteran Fruit Flies to Entomopathogenic Nematodes

Abstract

The present review article demonstrates laboratory and field evaluations of entomopathogenic nematodes (EPNs) against different developmental stages of fruit flies. The virulence of the EPNs differed clearly even on the same insect species and / or by the same nematode species. Such differences might be attributed to some reasons such as the method of treatment as well as the concentrations of the tested nematodes. Fruit flies are among the most important insect pests infesting vegetables and fruits causing considerable losses in the yields worldwide. In laboratory studies, the tested nematodes proved to be highly virulent to larvae as percentage of mortality may reach 100 %. As for treated pupae, at different ages, the results are variable and controversially; some studies revealed their moderate or high susceptibility to nematode infection and others indicated low susceptibility or resistance to infection .Treated adults, or those emerged from treated larvae or pupae, are also susceptible to infection. In semi-field and field trials, EPNs proved to be successful for reducing the populations of some fruit flies with up to 85 % at concentrations not less than 100 infective juveniles (IJs) / cm2 of soil. However, the field applications of commercial EPNs have been recommended to be 2.5 – 5 x 109 IJs / ha (25-50 IJs/cm2 of soil).