Behavioral responses of Aedes aegypti and Culex quinquefasciatus (Diptera: Culicidae) to four essential oils in Thailand

The behavioral effects of four essential oils extracted from orange peel (Citrus aurantium L.), cinnamon leaf (Cinnamomum verum J. Presl), citronella grass (Cymbopogonwinterianus Jowitt), and clove flower [Syzygium aromaticum (L.) Merrill & Perry] were evaluated against two medically important species of mosquitoes, Aedes aegypti (L.) and Culex quinquefasciatus Say, using an excito-repellency test system. Ae. aegypti was collected from a small village in Kanchanaburi Province and Culex quinquefasciatus was captured from an urban area of Bangkok. Mosquitoes from the F1–F3 generations were tested in the excito-repellency test chamber for contact excitation and non-contact spatial repellency. Results showed that both species demonstrated varying levels of behavioral escape responses to different essential oils, showing a clear dose response depending on percent w/v concentration used. Orange oil produced the least response in both mosquito species, while citronella and clove the greatest. In general, Cx. quinquefasciatus exhibited much stronger behavioral responses to all four essential oils than Ae. aegypti. From this study, we conclude that the essential oils from various botanical sources should continue to be screened for protective properties against mosquitoes and other biting arthropods.