PERTANIKA JOURNAL OF TROPICAL AGRICULTURAL SCIENCE

Melaleuca cajuputi crude extract in four different solvents viz dichloromethane, ethyl acetate, hexane, and methanol were evaluated for their insecticidal properties against Aedes aegypti and Aedes albopictus mosquito. Bioassay against larva and adult mosquito was done following World Health Organization’s guidelines. Late 3rd and/or early 4th instar of Aedes larvae were assayed for different concentrations ranging from 10 to 120 mg/L of M. cajuputi crude extract. Larvicidal effects were observed in dichloromethane, hexane, and methanol. Dichloromethane gave the highest of mean mortality, against Ae. Aegypti (12.6 ± 0.98) and Ae. Albopictus (10.2 ± 0.37) with LC₅₀ of 104.8 mg/L and 106 mg/L, respectively. The adulticidal bioassay was tested against 3 - 5 days old of female mosquitoes with the range concentrations from 0.04 to 6.21 mg/cm2. Amongst solvents used, extracts of dichloromethane and hexane showed effects against the adult mosquito. Extract in hexane gave 100% mortality against both Aedes with LC₅₀ of 0.015 mg/cm² (Ae. aegypti) and 0.022 mg/cm² (Ae. albopictus). In conclusion, the extract of M. cajuputi could be exploited in the development of potential plant-based products in controlling dengue Aedes vectors, particularly in the adult mosquito.