Repellent and insecticidal effects of essential oils on Colorado potato beetle (Leptinotarsa decemlineata (Say, 1824))

Krumpirova zlatica (Leptinotarsa decemlineata Say, 1824) jedan je od najvažnijih štetnika krumpira u Hrvatskoj i svijetu. Štetu čine ličinke i odrasli oblici hraneći se lisnom masom i time uzrokuju uništenje cime. Suzbijanje krumpirove zlatice znatno je otežano zbog nedostatka učinkovitog kemijskog sredstva za zaštitu, a i zbog problema razvoja rezistentnosti čime su proizvođači primorani upotrijebiti drugačije metode zaštite. Cilj rada je utvrditi reakciju odraslih jedinki krumpirove zlatice na različite vrste eteričnih ulja te učinkovitost eteričnih ulja na mortalitet odraslih jedinki. Tijekom svibnja 2022. godine prikupljeni su odrasli oblici krumpirove zlatice s dva lokaliteta na netretiranim poljima na području Sisačko-moslavačke županije. U laboratorijskim uvjetima provedeno je utvrđivanje atraktivnosti/ repelentnosti uz pomoć olfaktometra i učinkovitosti eteričnih ulja na odrasle oblike prema IRAC test metodi 007. Rezultati su pokazali kako eterično ulje zvjezdastog anisa ima najveću učinkovitost dok eterično ulje bosiljka ima najveću repelentnost, no između eteričnih ulja nema značajnih razlika kod utvrđivanja atraktivnosti odnosno repelentnosti. Zbog problema rezistentnosti krumpirove zlatice na kemijske insekticide, eterična ulja imaju dobre karakteristike i mogla bi biti učinkovita zamjena za kemijske insekticide, no potrebno je provesti još istraživanja kako bi se to potvrdilo.The Colorado potato beetle (Leptinotarsa decemlineata Say, 1824) is one of the most important pests of potatoes in Croatia and worldwide. Larvae and adults are causing damage by feeding on the leaf mass causing the destruction of the cyme. Suppression of Colorado potato beetle is much more difficult due to the lack of effective chemical protection, and also due to the problem of the development of resistance, which forces producers to use different methods of protection. The aim of the work is to determine the reaction of adult individuals of the Colorado potato beetle to different types of essential oils and the effectiveness of essential oils on the mortality of adults. During May 2022, adult forms of the Colorado potato beetle were collected from two localities on untreated fields in the area of Sisačko-moslavačka County. In laboratory conditions, attractiveness/ repellency was determined with an olfactometer and the effectiveness of essential oils on adult forms according to IRAC test method 007. The results showed that star anise essential oil has the highest effectiveness, while basil essential oil has the highest repellency, but there are no significant differences between the essential oils, when determining attractiveness or repellency. Due to the problem of resistance of the Colorado potato beetle to chemical insecticides, essential oils have good characteristics and could be an efficient substitute for chemical insecticides, but more research is needed to confirm this