## 7 Activities in the Past 15 Years  
### Entomopathogenic Nematodes  
Research on entomopathogenic nematodes at the Biotechnical Faculty intensified in 2004, when we became responsible for the national research project \"Usage of entomopathogenic nematodes in plant protection-method optimisation\", in which we began carrying out the first research into the efficiency of these biological control agents under laboratory conditions. Entomopathogenic nematodes were still considered alien organisms at that time in Slovenia, and their outdoor use was not permitted. In the first laboratory study, we thus confirmed the effects of entomopathogenic nematodes on adult specimens of the granary weevil (_Sitophilus granarius_ [L-]) and the sawtoothed grain beetle (_Oryzazophilus surinamensis_ [L-]) [37; 38] and then against the rice weevil (_Sitophilus oryzae_ [L-]) [39], cabbage flea beetles [40], the cereal leaf beetle (_Oulema melanogaster_ [L-]) [41], thrips _Hercinothrips femoralis_ [[PERSON]] [42], larval and adult specimens of the Colorado potato beetle (_Leptinotarsa decminenta_ [[PERSON]]) [43], and larvae of the common cockchafer (_Melolontha melolontha_ [L-]) [44], while in greenhouses, we identified satisfactory effects of these biological control agents on the western flower thrips (_Franklinella occidentalis_ [Pergandel]) [45] and the greenhouse whitefly (_Trialeurodes vaporarium_ [[PERSON]]) [46]. Under laboratory conditions, we also confirmed nontarget effects of entomopathogenic nematodes on natural enemies, namely, with the example of the two-spot ladybird (_Adalia bipunctata_ [L-]) and common green lacewing [47].  
By sampling soil in different regions of Slovenia, we confirmed the presence and autochthonous of five species of entomopathogenic nematodes, four of which (included on the EPPO positive list) were added to the list of indigenous species of organisms for biological control on the basis of published scientific articles indicating their detection. Among the species that can now be used in Slovenia to control harmful insects are _Steinerema feliae_ ([PERSON]) [48], _Steinerema carpocapsae_ ([PERSON]) [49], _Steinerema raussei_ ([PERSON]) [50] and _Heterorhabditis bacterioplora_ ([PERSON]) [51]. The development from modest beginnings in the field of entomopathogenic nematodes to their implementation in food production systems was described in a monograph [52].  
The establishment of the autochthonous of the mentioned entomopathogenic nematode species enabled their testing for the control of harmful insects in the field; they were initially fairly successful against the Colorado potato beetle in a potato field [53] and the cereal leaf beetle in a wheat crop [54], while their use did not prove particularly efficient for controlling white grubs (Scarabaeidae) in grassland soils [55; 56]. We also carried out a separate set of research projects addressing the simultaneous application of entomopathogenic nematodes and plant protection products, which was intended to save time and money in application, increase the efficiency of both plant protection products and entomopathogenic nematodes, and reduce the risk of developing resistance to plant protection products. In connection to this work, we tested the ability of entomopathogenic nematodes to survive when mixed with fungicides [57], insecticides [58], acaricides [59] and herbicides [60]; the results of all our research projects and numerous related studies were published in a monograph chapter [61].  
After 2013, we also focused our research on the chemotactic responses of entomopathogenic nematodes to volatile substances released by plants damaged by herbivores. We thus assessed the reactions of nematodes to substances released from damaged roots of maize [62], potato tubers [63], roots of _Brassica nigra_ [64], and roots and leaves of hemp [65]. Some interesting multitrophic interactions among plants, harmful soil insects and entomopathogenic nematodes have been recently presented in review papers [66; 67].