Slugs are economically important pests in agriculture, as their feeding damages parts of plants and consequently affects the reduced yield, ornamental and market value of plants, and increases the risk of infection with microorganisms. There are 10 species of slugs from the Arionidae family known in Slovenia, of which as many as 8 species are economically important. Various non-chemical practices, molluscicides based on iron (III) phosphate and metaldehyde, and biological control with the parasitic nematode Phasmarhabditis hermaphrodita are used to control slugs. Abroad, the latter has been used for this purpose for several years, but in Slovenia it is still on the list of non-native organisms, which prohibits its use. In 2018, Slovenian researchers confirmed the representation of its relative, the parasitic nematode Phasmarhabditis papillosa. In this study, the effectiveness of the P. papillosa on feeding and mortality of slugs from the Arionidae family at different temperatures (15 and 20 °C) and at different concentrations of nematode suspension were evaluated. The results are promising and indicate the potential of P. papillosa in suppressing slugs from Arionidae family. The temperature shows the biggest impact – the higher the temperature (20 °C) the sooner the slugs stopped feeding and died. There is also a strong emphasis on the interaction of the factors, as the concentration affected the slugs only at a higher temperature (20 °C). At 20 °C there were also no differences in nematode efficacy between the highest (500 IL/slug) and lowest (10 IL/slug) concentration. The peculiarity of the infected slug was in their 360° twisting around their axis and in the mantle that collapsed.
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