Speakers - 2026

Title: In-Vitro Acaricidal Efficacies of the Essential Oils of Lemongrass and Citrus Peel on Egg, Larvae and Adult Amblyomma Variegatum

Abstract

Amblyomma variegatum is a major livestock ectoparasite in tropical regions, and reliance on synthetic acaricides has led to resistance, environmental contamination, and non-target toxicity. Plant-derived essential oils are being explored as safer alternatives. This study evaluated the in-vitro acaricidal activity of lemongrass (Cymbopogon citratus) and citrus peel (Citrus sinensis) essential oils on adult mortality, larval mortality and egg hatchability of A. variegatum. Ticks were collected, identified, and maintained under controlled laboratory conditions. Acaricidal activity was assessed using the Adult Immersion Test, Larval Packet Test, and egg hatchability assay at 10%, 20%, and 30% concentrations. Mortality and hatchability were analyzed statistically at p < 0.05. Both oils produced significant concentration and time dependent effects across all stages. Mortality increased with concentration and exposure time, with lemongrass oil showing consistently higher efficacy, particularly at 30% after 72 hours. Egg hatchability was significantly reduced by both oils, while the positive control confirmed assay validity. These findings demonstrate notable in-vitro acaricidal activity, with lemongrass oil showing superior efficacy and potential as an environmentally safer botanical acaricide for integrated tick management.