Abstract
Aedes aegypti can transmit dengue fever, yellow fever, Chikungunya fever, Zika virus disease and vector density control is the most effective way to prevent these infectious diseases. However, the extensive use of chemical pesticides has caused a series of problems, such as environmental pollution, killing non-target organisms and so on. In this study, a parasitic nematode, Romanomermis wuchangensis was used in the larviciding evaluation of Ae. aegypti, while the activity of four chemical insecticides and biological control agents were tested. Besides, Mentha haplocalyx essential oil was isolated and its olfactory physiological function with OBP1 protein of Ae. aegypti antenna was measured by the prokaryotic expression and fluorescence competitive binding assay. Compared with the control group, R. wuchangensis indicated high efficiency and environmental friendliness in the control of Ae. aegypti. After the second instar larvae were parasitized, the mortality of two treatment groups exceeded 75%. Compared to control group, the quantitative real-time PCR analysis results demonstrated that SOD, POD and CAT genes had obvious high expression levels in the nematodes parasitic groups. The antioxidant enzyme test results also exhibited obvious difference of SOD, CAT and POD during the nematode parasitic period. Besides, Bacillus thuringiensis (Bti) and chemical insecticide experimental results also showed great insecticidal efficacy against mosquito larvae. Five chemical components including Menthol, Pinene, Limonene, Isopulegol and Pulegone were identified from M. haplocalyx and exhibited great binding ability with AaegOBP1 protein. Present results illustrated that the integrated application of these various mosquito vector control methods in the future has broad prospects.