Larvicidal, Ovicidal and Repellency Properties of the Indigenous Plants Ocimum Basilicum L Leaves Essential Oil against Aedes Aegypti Mosquitoes

Mya MM, Maung ACP, Aye Win Oo, Htay TM, New CT, Mu TZN, Aung ZZ, Myint YY and Thaung S

Published on: 2023-01-28

Abstract

Mosquito-borne diseases are mostly harmful to children being and it is a public health problem in Myanmar. Laboratory reared Dagon Myothit strain of Aedes aegypti larvae were used for testing larvicidal, ovicidal and repellency properties of Ocimum basilicum leaves essential oil from June 2019 to May 2020 according to WHO. Fresh Leaves 300 grams from Mingalardon was extracted by stream distillation at 100°C for 3hours and 1.41g of essential oil. Different concentrations of Ocimum leaves essential oil was prepared obtained freshly in 100ml each of distilled water in 150ml plastic cups. Fifty each Aedes larvae were exposed 24hrs for each replication in different concentrations in laboratory. Acute toxicity and allergenicity tests were done in laboratory according to OECD Guidelines. Repellency test was done by laboratory reared 5-7 days old adult female Aedes mosquitoes with Ocimum leaves essential oil and BPI made repellent as Rapito (0.1g solution) was used as control. Results revealed that the highest dose 0.1g of Ocimum leaves essential oil produced 98.6% knockdown within 60minute and 98.4% mortality within 24hrs respectively and 100% ovicidal effect for 3 days as well as persistency was observed 100% mortality of larvae for 4 days. The effective lethal concentrations LC₅₀ and LC₉₀ values were found to be 0.017g and 0.0576g of leaves essential oil. There was not found any acute toxicity on mice and allergenicity on the rabbits. 100% protection of Aedes mosquito landing to probe the skin was found 0.1g/ml or 0.000267g/cm² of essential oil. Repellency activity of complete protection time was observed over 80% protection for 240minutes, over 90% prevention for 180 minutes, and 100% prevention for 60mins. Semi field trial observed that it can prevent 4 hours of Aedes mosquito bite on oil applied areas of insect collectors in household in the daytime. The essential oil is not toxicity, no allergenicity and no irritation of skins of animal. Therefore, the Ocimum basilicum leaves essential oil can be used in public sector as insecticide and repellent of mosquitoes.