Screening seven commercial essential herb oils for larvicidal activity against the mosquito Aedes aegypti (Linnaeus), a vector of the dengue virus

Mosquitoes are tiny flying insects of great importance as vectors to many pathogenic organisms, including viruses.Aedes aegypti is a primary vector of the dengue virus that causes dengue fever, which is a globally important disease,threatening people in developing countries. In this research, we screened seven commercial herb essential oils,including ‎cassia, cinnamon, East Indian lemongrass, bay, sweet basil, holy basil, and ginger for larvicidal activityagainst larvae of the dengue virus vector A. aegypti. The results revealed the efficacy of seven commercial pureessential oils against mosquito larvae. The cinnamon oil had the highest larvicidal activity (LC50 = 0.03 ppm and LC90= 0.04 ppm), followed by cassia, holy basil, bay, sweet basil, East Indian lemongrass, and ginger essential oils. Theseresults are important from the public health perspective since they relate to a dengue vector that requires alternativeorganic substances for its control and elimination.

Comparison of the larvicidal and adult mosquito attractant efficacy between straw mushroom Volvariella volvacea extract and octenol (1-octen-3-ol) on mosquito vectors (Diptera: Culicidae)

Mosquito-borne diseases are a major public health issue, especially in tropical and subtropical regions. In this study, wecompared the efficacy of Volvariella volvacea (Bull. ex Fr.) mushroom, an edible, commercially available mushroomspecies grown in Thailand with octenol (1-octen-3-ol) as a standard substance to kill larvae and attract adult, includingAedes aegypti Linnaeus and Culex sitiens Wiedemann, mosquitoes. Five concentrations of extract, including 120,12, 1.2, 0.12, and 0.012 mg/l were selected to test the effectiveness of killing mosquito larvae. Three concentrationsof extract, including 100, 10, and 1 mg/l were selected to test the effectiveness of adult female mosquito attraction.The result of the comparison of the larvicidal efficacy between V. volvacea extract and octenol in each concentration,showed that there were differences in number of dead larvae in almost all the concentrations in testing with octenol(p < 0.05), while in the adult mosquito attraction bioassay, V. volvacea extract attracted the highest number of adultfemale A. aegypti and C. sitiens at the 10 mg/l concentration followed by 1 and 100 mg/l, as well as the effect ofoctenol. The statistical comparison found that the efficiency of attracting A. aegypti and C. sitiens mosquitoes in allthe concentrations of V. volvacea extract was different from octenol (p < 0.05).