CHEMICAL COMPOSITION AND OVICIDA ACTIVITY OF THE ESSENTIAL OIL OF CROTON ARGYROPHYLLUS (EUPHORBIACEAE) LEAVES ABOUT AEDES AEGYPTI (DIPTERA: CULICIDAE

Abstract

The control of Aedes aegypti, which transmits several arboviruses of importance to public health, has as strategies the use of synthetic insecticides, integrated with environmental control. Its control is mainly directed to the larvae and adult phases. The egg phase is difficult to control, as it has great resistance to environmental conditions. The objective of this work was to evaluate the ovicidal potential of the essential oil obtained from the leaves of Croton argyrophyllus, on Aedes aegypti, as well as to determine the moisture content, the yield, and its chemical composition. The eggs were exposed to the aqueous solution of the essential oil in 10% Tween 80, in the concentration of 12 mg mL-1, for a period of 15, 30, 60, and 120 minutes. Subsequently, the eggs were washed and, after 180 hours of observation, the feed was added. The analysis of the chemical composition of the essential oil was performed by Gas Chromatography coupled to Mass Spectrometry. It was found that up to 180 hours of observation, the highest percentage of larval hatching occurred in eggs exposed to essential oil for 15 min (30%) and the lowest percentage in eggs exposed for 120 min ( less than 10%). After 180 hours, there was an increase in hatching in all treatments. The moisture content was 58.69%, the oil yield was 0.35%, and the main chemical constituents found were bicyclogermacrene and b-cariophylene. It was observed that the essential oil of Croton argyrophyllus, at the concentration evaluated, affects the hatching of Aedes aegypti larvae only in the absence of food.