To mitigate the intrusion of insect pests, behavioral modifications using repellents are commonly employed. Among their active ingredients, plant essential oils have gained prominence as safer alternatives to synthetic repellents. However, the absence of rigorous scientific efficacy testing have been undermined the reliability of these essential oil based repellent products. Previous studies have highlighted that the observed repellency in bioassays are strongly influenced by the testing environment. Our research introduces three distinct laboratory-scaled repellency test methods – spatial repellency, choice repellency in a closed and opened environment – to evaluate prevalent insect repellent products. Notably, we observed significant variations in repellency percentages among products. The most effective product from each method was identified, and its active ingredients were analyzed both quantitatively and qualitatively, by GC-MS analyses. To determine the applicability of these methods in selecting active ingredient concentrations, individual active ingredient components underwent dose-response testing. Our findings suggest that, when selected appropriately, these three methods can be applied for the development and evaluation of potent essential oil based repellent products.

• Taeheon Yun(Department of Applied Biology and Chemistry, Seoul University) Corresponding author
• Junho Yoon(Department of Agricultural Biotechnology, Seoul National University)
• Jun-Hyung Tak(Department of Agricultural Biotechnology, Seoul National University, Research Institute for Agriculture and Life Sciences, Seoul National University)