The essential oil of Cymbopogon citratus is generally used against mosquitoes. The aim of this study was to evaluate the larvicidal and histological effects of C. citratus essential oil against Aedes aegypti larvae. Third larval stages were exposed at 0.2 to 1 μl/ml doses, and mortality was recorded at 4, 12, and 24 h. The histopathological study was assessed for the control and treated larvae at 4, 12, and 24 h using light and electronic microscopies. The results show that larval mortalities were 19.4 ± 2.3%, 43.2 ± 3.7%, 70.3 ± 2.6%, 92 ± 4.5%, and 100 ± 0.0% for respectively 0.2, 0.4, 0.6, 0.8, and 1 μl/ml doses 24 h after treatment compared to the control (01.4 ± 0.0%). Histological studies with light microscope revealed disruption of the cellular structures of midgut, damaged of apical surface toward the gut lumen, disorganization of muscle and fat body compared to the control. Electron microscopy revealed that the product acts by destroying intestinal microvilli, with cytoplasm being highly vacuolated. The sarcoplasmic reticulum, mitochondria, and genetic material were also disorganized. At the same time, the muscular tissue was progressively disorganized, and the actin and myosin filaments were transformed into vacuoles. Thus, as a biological product, preparation-derived extract of Cymbopogon citratus could be used as an effective botanical larvicide in mosquito control such as Aedes aegypti, Anopheles, and Culex species.
