Utilisation of repellents for the control of western corn rootworm (Diabrotica virgifera virgifera leconte, 1868)

Abstract

The aim of the study was to find the level of repellent effect of two chemical substances (DEET and 2-Undecanone) and two essential oils (from Allium sativum and Eucalyptus oil) on the Western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte, 1868 in field conditions. Repellents were used in the area of 5 x 4 meters with four replications. They were applied as a solution of 700 μl chemical/essential oil in one litter of water. TWEEN 80 was used as a surfactant. After 24 and 48 hours, the repellent effect was checked by visual observation. After 24 hours, yellow sticky traps were installed in each plot and checked after the next 24 hours for the detection of the WCR adult beetles. The experiment was carried out during two years (2019 and 2020) in a maize field in Mojmírovce (48.199284°N, 18.038637°E), Slovakia. The results showed significant repellent effect of chemicals DEET and 2-Undecanone on WCR adults. After 48 hours the number of beetles per plant was significantly higher compared to the control for both DEET and 2-Undecamone. This was confirmed by yellow sticky traps in 2020, but not in 2019, probably due to the lower catching of WCR adults. The results indicate that repellent substances can influence the number of the WCR adults in maize fields.