Slugs are economically important pests in agriculture. Their control is most often carried out using pesticides. Biological control using slug parasitic nematodes can offer an alternative in slug control. The presence of the parasitic nematode Phasmarhabditis papillosa was recently confirmed in Slovenia. The first results showed that this species of nematode also has a very high potential in biological control of slugs. As knowledge about this species is currently very limited, studies is needed that will allow us to better understand the workings of this parasitic nematode. Plants have the ability to use a variety of defensive ways to reduce damage when attacked by pests. To reduce the damage, one of the indirect ways is to eliminate volatile substances. Volatile substances can have an attractive / deterrent effect on several groups of organisms. This phenomenon has been confirmed in the use of entomopathogenic nematodes, and only a few studies have been done to date on the use of parasitic nematodes of slugs. In our study, we examined the response of the species P. papillosa to volatiles; terpinolene, ocimen, α-humulene, linalool and ß-caryophyllene at three temperatures (18, 20, and 24 °C). Linalool has been shown to be a repellent, while terpinolene and α-humulene have shown a weak repellent effect. Substances ocimen and ß-caryophyllene did not affect the direction of movement of the nematode P. papillosa. Temperature has been shown to be a very important factor influencing the movement. The P. papillosa species was most mobile at 20 °C, while the movement was less pronounced at 18 and 24 °C. The results of our study suggest the possibility of optimizing the use of P. papillosa in biological control.
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