Attractive activity of plant extracts for the oviposition of aedes aegypti L. (diptera: Culicidae)

Abstract

Aedes aegypti is one of the most important culicidae species for public health, since it transmits the viruses for yellow fever, dengue fever, chikungunya and zika. With the purpose of analyzing the effect of plant extracts on the oviposition of this vector in ovitraps, 100 ovitraps were set containing an attractive plant substrate and a pressed wooden palette vertically installed on the pot for female oviposition. The traps were randomly distributed in 10 neighborhoods of Crato, Ceará, Brazil. To determine the best extract, water from the supply network, distilled water, sewage and aqueous extracts of plant leaves from guava (Psidium guajava L.), papaya (Carica papaya L), cassava (Manihot esculenta Grantz), cashew tree (Anacardium occidentale L.), sorghum (Sorghum bicolor L., Moench) and grass hay (Cynodon nlemfluensis Vanderyst) were used. The substrates were prepared at the Laboratory of Agricultural Entomology at the Center of Agricultural Sciences and Biodiversity of the Federal University of Cariri (UFCA). Leaves were collected from the plants and crushed using a blender and then mixed with water at a concentration of 50 g of each substrate per liter of water. The material was stored for seven days in a dark room to facilitate the reactions and avoid the photoinactivation of active compounds. To determinate the best concentration, guava leaves were used subject to the same treatment of the first experiment, at concentrations of 0.5, 1; 5, 10, 25, 50, and 75 g of substrate per liter of water. Traps with sewage water showed the highest attractiveness for the oviposition of A. aegypti and the extract of guava leaves showed the highest percentage of egg attractiveness for the vector mosquito. These results can be useful to guide the adoption of new entomological surveillance and control methods of A. aegypti.