Abstract:
The larvicidal and pupicidal effects of six mixtures of cinnamon (Cinnamomum verumJ. 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 4thinstar larvae, with 100% mortalities at 24 hours and LT50between 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 LT50values of 5.8 and 7.8 hours. On the other hand, temephos showed LT50for 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.
