Eco-friendly contro strategies against the asian tiger mosquito, Aedes albopictus (Diptera: Culicidae): repellency and toxic activity of plant essential oils and extracts.

The economic and health problems related to the Asian tiger mosquito, Aedes albopictus (Diptera: Culicidae), are due to its ectoparasitic behaviour and to the transmission of many diseases, particularly arbovirus and parasites. The difficulty to control the larval instars of A. albopictus, the reduced effectiveness and high environmental impact of adulticide treatments, highlight that the most effective solution to protect against A. albopictus is the use of repellent products for personal use such as DEET (N, N-diethyl-3-methylbenzamide). This compound showed a high repellent power in time but also some disadvantages including toxic effects on humans, especially on children and elderly. On this purpose, natural substances acting as repellent, such as plant essential oils and extracts, are considered very promising. Here we reported a critical review of our researches on repellence exerted by six different essential oils. The most effective essential oil was C. sativum. Furthermore, we discussed our research work conducted on ten essential oils tested as alternative larvicidal compounds. Following the dedicated WHO method, we proved that R. chalepensis EO was the most effective larvicidal among ten tested essential oils. Moreover, as regards to plant extracts, here we conducted bioassays to evaluate if the methanolic neem cake extract and its fractions of increasing polarity exhibit good mortality rates against A. albopictus larvae. We believe that the chance to use natural products such as essential oils and neem cake extracts, effective at lower doses when compared to synthetic products currently marketed, could be an advantageous alternative to build newer and safer mosquito control tools.