Abstract

Terrestrial gastropods are economic pests of horticultural crops, vegetables and nurseries in Egypt. Biological control using slug parasitic nematodes is one of the alternatives of chemical control to avoid the hazards of pesticides. This paper describes the finding of a new species of nematode parasite in Limax flavus slug in Egypt. It was identified as Rhabdetella axei using molecular (18s r DNA sequencing) technique, however, its nucleotide sequencing exhibited 97.7% homology with this species of nematode. Pathogenicity of these nematodes was tested against three species of land gastropods, two species of land snails, Monacha cartusiana and Eobania vermiculata, and one species of land slug, L. flavus. Results revealed that nematode gave highly significant effect against M. cartusiana snail, whereas higher concentration of nematodes (12000 IJ/3 ml) caused mortality rate reaching 80% after seven days of treatment, but there was no effect on other two species of land gastropods, E. vermiculata and L. flavus. Also, the results investigated that R. axei can live a dual life (free living life and parasitic life) i. e. they could be pathogenic only adult species of small size gastropods like M. cartusiana snail (parasitic life) and they can live necromenically on large size species of land gastropods. Finally, it can be concluded that the nematode R. axei can be used in integrated pest management as a biological control agent against M. cartusiana land snail species.