Two beneficial entomopathogenic nematodes including Heterorhabditis bacteriophora (Fig.1) and Steinernema carpocapsae (Fig. 2) have showed a potential to control cucurbit flies, Dacus ciliatus (Kamali et al., 2013). These nematodes are considered as beneficial nematodes because they have been used as biological control agents to control insects that are damaging to crops and harmful to animals