Entomopathogenic nematodes (EPNs) can be used as one of the measures for the purpose of biological control. In our experiment we studied influence of some ethanol extracts (EE) of the hemp tissues (leaf, tips, roots) on the individual types of EPNs Steinernema carpocapsae, S. feltiae and Heterorhabditis bacteriophora. Our hypothesis was that different factors can have an effect on the chemotaxis of individual types of EPNs: species of EPNs, selected EE, temperature and the foraging strategy. Our experiment was carried out in Petri dishes, which contained agar at two different temperatures (20 and 25 °C) and 70 % relative humidity. The movement of infective juveniles (IJ) was observed after 24 hours. Based on our results we calculated the chemotaxis index of different EE. On the H. bacteriophora EE FC was at 25 °C very attractive. On the S. feltiae EE FC at 20 °C acted as repellent, EE 11/37C and 707/10C at 25 °C acted very attractive. On the S. carpocapsae EE TC and FC at 20 °C acted as repellent, at 25 °C EE TL was very attractive. On the H. bacteriophora EE FC was very attractive at 25 °C. In our experiment H. bacteriophora was the most mobile species, the least mobile species was S. carpocapsae. We proved that those EPNs which have an active foraging strategy are more mobile than those who have a passive foraging strategy. The temperature also turned out as an important factor, because higher temperature caused significantly different movement of the EPNs which could be one of the specific characteristics of EPNs.
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