This study aimed to determine the efficacy of biological control of the Colorado potato beetle (Leptinotarsa decemlineata) through Entomopathogenic nematode (EPNs) Steinernema carpocapsae in both laboratory and field conditions. Before starting the experiment, Entomopathogenic nematodes (EPNs) were isolated from the soil, which were obtained at different locations of Samtskhe-Javakheti region, in particular, soil samples were taken for the experiment from borough Bakuriani, village Timotesubani, borough Dviri, borough Tsaghveri (from the agricultural plots of land, various parts of Arjevanidze forest). The experiments conducted in the laboratory conditions determined, that all insects participating in the experiment died, including Imago (95%), while the mortality of larvae reached 99,5%, which undoubtedly indicates the efficacy of entomopathogenic nematodes. This experiment showed, high efficacy of Steinernema carpocapsae towards imagos and larvae of Colorado potato beetle. Accordingly, the determination of the efficacy of Entomopathogenic nematode (EPNs) in the field conditions became necessary, particularly in the plot of land of the potato. This experiment also showed, the efficacy of Steinernema carpocapsae. Almost all Metamorphic forms of adult Colorado potato beetle and final stage larva died, as a result of suspension treatment of entomopathogenic namatodes of potato bush. Of which, adult beetle mortality reached (75 %), while the mortality of final stage larvas amounted to 88,5%. As a result of filtrate inspection and microscopic examination, it was determined, that nematode suspension showed good results even in field conditions. It is also noteworthy, that the target insect for entomopathogenic nematode is only an insect-pest and at the same time it does not influence the growth and development of the plant and its fruit (tuber), which is a quite effective method in terms of ecology, because it does not require the use of pesticides and other poisonous chemical products and therefore it is an environmentally safe natural process.

Keywords : Entomopathogenic nematode, Steinernema carpocapsae, Leptinotarsa decemlineata