Chemical analysis, repellent, larvicidal, and oviposition deterrent activities of plant essential oils against Aedes aegypti, Anopheles gambiae, and Culex quinquefasciatus

Plant-based essential oils have gained attention as a natural alternative for controlling mosquitoes due to their repellent, larvicidal and oviposition deterrent properties. We tested repellent, larvicidal, and oviposition deterrent effects of essential oils (EOs) of <i>Mentha</i> sp<i>icata</i> (L.), <i>Ocimum basilicum</i> (L.), and <i>Abutilon indicum</i> (L.) against three mosquito species (Diptera: Culicidae) including <i>Aedes aegypti</i> (L.), <i>Anopheles gambiae</i> s. l. Giles, and <i>Culex quinquefasciatus</i> Say by using contact-based technique. In screening bioassays, <i>M.</i> sp<i>icata I</i>, <i>M.</i> sp<i>icata II</i>, <i>O. basilicum I</i>, <i>O. basilicum II</i>, and <i>A. indicum</i> EOs showed higher repellency against <i>Cx. quinquefasciatus</i> as compared to <i>Ae. aegypti</i> and <i>An. gambiae</i> when tested at 33.3 μg/cm². In time-span bioassays performed at 33.3 μg/cm², EO of <i>M.</i> sp<i>icata I</i> exhibited 100% repellence up to 45, 30, and 75 min against <i>Ae. aegypti</i>, <i>An. gambiae</i>, and <i>Cx. quinquefasciatus</i>, respectively. Interestingly, at this tested dose, <i>M.</i> sp<i>icata I</i> and <i>M.</i> sp<i>icata II</i> showed higher repellence compared to DEET against <i>Ae. aegypti</i> and <i>Cx. quinquefasciatus</i> after 45 and 75 min, respectively. Their repellency was observed up to 150 and 210 min against <i>Ae. aegypti</i> and <i>Cx. quinquefasciatus</i>, respectively. In larvicidal bioassays, <i>M.</i> sp<i>icata I</i> EO proved more toxic against 2^nd instar larvae of <i>Ae. aegypti</i>, <i>An. gambiae</i>, and <i>Cx. quinquefasciatus</i> (LC₅₀ = 11.0, 42.9, and 12.6 mg/L, respectively) compared to other tested EOs. In oviposition bioassays, <i>M.</i> sp<i>icata I</i> exhibited the highest activity, showing 60%, 46%, and 79% oviposition deterrence against <i>Ae. aegypti</i>, <i>An. gambiae</i>, and <i>Cx. quinquefasciatus</i>, respectively, tested at a dose of 600 µg/cm². Major compounds of <i>M.</i> sp<i>icata I</i>, <i>M.</i> sp<i>icata II</i>, <i>O. basilicum I</i>, and <i>O. basilicum II</i> EOs were piperitenone oxide (38.8%), piperitone oxide (35.4%), estragole (55.3%), and linalool (43.8%), respectively. In conclusion, <i>M.</i> sp<i>icata</i> EO could be used to control mosquitoes and their bites.