Behavioral responses to five essential oils by Aedes albopictus (Skuse) (Diptera: Culicidae)
The behavioral responses using an excito-repellency test system were investigated of the laboratory strain of Aedes albopictus (Skuse) to four concentrations of different essential oils (0.5%, 1%, 2.5%, 5%) extracted from citronella (Cymbopogon nardus [L.] Rendle), eucalypt (Eucalyptus camaldulensis Dehnh), kaffir lime (Citrus hystrix DC.), guava (Psidium gaujava L.) and betel vine (Piper betle L.). DEET (N, N-diethyl-3-methylbenzamide) was used as a standard mosquito repellent. The escape and knockdown percentages were recorded of test mosquitoes in noncontact and contact chambers. The results showed that two oil extracts (from guava and betel vine) produced very promising test results. Higher escape responses of Ae. albopictus were observed in the contact and noncontact trials at 2.5% guava (100% and 90.92%, respectively) and 0.5% betel vine (96.49% and 84%, respectively). It was concluded that both these essential oils were very promising and further study is needed to identify the active ingredients from Ps. gaujava and Pi. betle for future development as plant-based repellents in commercialized products.