Tick repellent activities of supercritical fluid extract from Perilla frutescens against Haemaphysalis longicornis

Abstract Supercritical fluid extraction (SFE) is a rapid, selective, and convenient method for sample preparation prior to the analysis of compounds in a volatile product of plant matrices. In this study, insecticidal activity and repellency were examined in a laboratory study to determine the active constituent of Perilla frutescens and a supercritical fluid extract from Perilla frutescens against hard tick Haemaphysalis longicornis. The repellency of P. frutescens oil extract was evaluated in comparison with two commercial repellents (Icaridin and DEET) against H. longicornis. Filter-paper diffusion assay revealed that P. frutescens oil (3.2 µg/cm²) had a 100% repellency and icaridine (3.2 µg/cm²) had a 96.1% repellency at 120 min. Repellencies of 4 compounds and microcapsule P. frutescens of against H. longicornis were compared with the repellency of Icaridine and DEET at 3.2 µg/cm². Responses varied according to the test compound and exposure time. Repellencies of Perillaldehyde and microcapsule P. frutescens were 100% at 30 min post-treatment. P. frutescens oil merit further study as potential fumigants or lead compounds for the control of H. longicornis.