Larvicidal and pupicidal activity of combination of two plant essential oils against Aedes aegypti

Abstract

The larvicidal and pupicidal effects of six mixtures of cinnamon (Cinnamomum verum J. Presl.) and nutmeg (Myristica fragrans Houtt.) essential oils (EOs) and major compositions (geranial, α-pinene and trans- cinnamaldehyde) were tested against early fourth instar and pupal stages of Aedes aegypti. The combinations (2% cinnamon EO + 1% geranial, 2% cinnamon EO + 1% trans-cinnamaldehyde and 2% cinnamon EO + 1% α-pinene) showed high toxicity against early 4th instar larvae, with 100% mortalities at 24 hours and LT50 between 1.4 and 2.4 hours. Additionally, 2% nutmeg EO + 1% α-pinene showed >99% mortality at 24 hours with LT50 = 4.6 hours. 2% nutmeg EO + 1% geranial and 2% nutmeg EO + 1% α-pinene were highly toxic against pupae, with 100% mortality at 48 hours and LT50 values of 5.8 and 7.8 hours. On the other hand, temephos showed LT50 for larval and pupal stages at 9.8 and 94.1 hours. It showed that 2% nutmeg EO + 1% α-pinene was able to control immature stages and was more effective than temephos. However nutmeg extracts need to be checked for human and valuable species toxicity.