Utilização de óleos essenciais como tecnologia alternativa aos inseticidas sintéticos para o controle do Aedes aegypti

Abstract

Aedes aegypti is the main vector of dengue and yellow fever. The control, made with the use of synthetic insecticides caused the insect to develop resistance to these products, leading to demand for new products with insecticidal properties, effective, affordable and environmentally viable to an alternative control, with, for example, essential oils. The objective was to evaluate the effects of essential oils of Foeniculum vulgare and Cymbopogon witerianus on the different stages of the life cycle of A. aegypti. The experiments were performed in a room conditioned to 26 ° C ± 2 º C and a photoperiod of 12 hours, applying concentrations ranging from 0.0025 to 0.0085 ml/200ml of oil in 3rd stage larvae in late (L3) and / or 4th young stage. A sample population of Aedes aegypti collected in Campina Grande-PB was used. We evaluated larvicide, adulticide, ovicidal effect and oviposition repellency of essential oils for different concentrations. Mortality data were submitted to Probit analysis to determine the (LC 50 and LC ). Ovicidal and oviposition repellency of essential oils tests were carried out using the lethal concentrations of the larvicide test (CL 90 e CL ).The evaluation of the adulticide effect was performed using doses of 0.5 and 1 ml of plant products. The average for the preference for oviposition in multiple choice questions were compared by Friedman test (P <0.05) and no choice by the KruskalWallis test (P <0.05). Vegetable oils of F. vulgare and C. witerianus demonstrated high potential for larvae control with CL 90 50 = 0,0038ml e CL 90 = 0,0046ml e CL = 0.0070 e CL = 0,0125ml, respectively. However, the essential oil of F.vulgare required a lower concentration of the product to cause 50% and 90% of larval mortality. To the adulticide effect, the concentration of 1ml oil of C. witerianus showed the highest percentage of mortality. All the products showed repellent action on oviposition of A. aegypti through the IOA values. There was a very low hatching rate, indicating a very significant ovicidal activity. The essential oils of F. vulgare and C. witerianus demonstrated great potential in controlling the different stages of the life cycle of this vector.