Pathogenicity of entomopathogenic nematodes to dipteran leaf miners, house flies and mushroom flies

Abstract

Background: The entomopathogenic nematodes (EPNs), especially in the 2 families Steinernematidae and Heterorhabditidae, are important biocontrol agents against insect pests. The leaf miners (Fam.: Agromyzidae) are cosmopolitan insect pests. There are more than 330 Liriomyza spp. including more than 20 species that have been reported as economically important pests of field crops, ornamentals and vegetables. The house flies are serious insect pests for human and animals. More than 100 human and animal diseases have been associated with house flies. Mushroom flies (phorid and sciarid families) are among the main arthropod pests affecting the cultivation of mushroom throughout the world. Results: Virulence of EPNs differed clearly even on the same insect species and/or by the same nematode species. Such differences might be attributed to the method of treatment, the age of the stage of the insect as well as the concentrations of the tested nematodes. Laboratory studies revealed that the tested nematodes proved to be moderate to highly virulent to larvae as percentage of mortality reached 100%. As for pupae, some studies revealed their moderate or high susceptibility to nematodes, whereas others showed low susceptibility or resistance to infection. Treated adults, or those emerged from treated larvae or pupae, are also susceptible to infection. Conclusion: Laboratory studies proved the virulence of EPNs to larvae of the 3 dipteran families. Semi-field and field trials indicated that they could successfully reduce the populations of some treated insects without affect the others.