干旱区生态环境知识资源中心

Biweekly soil samples were collected from fruit orchards located at Cairo-Alexandria desert road during January-June 2014 and 2015. The orchards included citrus, pomegranate, figs, grapes, date palms, annona, olive, mango, guava, pear, peach and apple. Both entomopathogenic nematodes (EPNs) Steinernema and Heterorhabditis genera could be isolated. Rate of nematode existence varied according to the nematode genus and sampling date. Out of 180 soil samples, EPNs were isolated 30 times (28 Heterorhabditis and 2 Steinernema). Steinernema was found in January and March, while Heterorhabditis was found along the whole season with higher abundance in April-June. No clear relationship could be detected between the nematode abundance and the fruit type. Four isolates were selected for testing their virulence against the wax moth larvae Galleria mellonella L. All tested isolates were virulent to the larvae with differences among them. This study may contribute to understand abundance of EPNs populations in the studied region and the possibility of utilizing the native isolates of EPNs in insect pest management in that region and others of similar climatic conditions.