Occurrence and Distribution of Entomopathogenic Nematodes in Termite Prone Areas of Eastern and Western Ethiopia

Abstract

Entomopathogenic nematodes (EPNs) are simple roundworms that naturally kill insects and are abundantly present in the soil. A survey of EPNs was conducted in selected agroecologies of eastern and western Ethiopia with termite problems aiming to assess the species’ diversity and distribution. From a total of 80 soil samples collected, 20% of them were positive for EPNs. They were found in all of the habitats where the study was conducted, but they were more abundant in soil samples collected from tree litters than in any others. Molecular analysis of the recovered EPNs of the internal transcribed spacer ITS region and D2\D3 expansion segments of the 28SrRNA gene were conducted. The results of the molecular analysis revealed the presence of three types of PNs viz., Oscheius tipulae, Heterorhabditis indica and Caenorhabditis briggsae. Among the recovered nematodes, Oscheius spp. are obtained from eight, II. indica from six, and C. briggsae from two soil samples. Oscheius spp. belong to the gronp of insectivores whereas Heterorhabditis belongs to the obligate parasite group of nematodes. All the three species recorded in the study were reported for the first time from Ethiopia. Further surveys should be conducted in the future to ensure the untouched sites of the country.