Attractiveness of bioinsecticides caffeine and used coffee grounds in the choice of oviposition site by Aedes aegypti (Diptera: Culicidae)

Data in the literature have shown that treatment with caffeine (CAF) blocks development and causes death of Aedes aegypti (Ae. aegypti), in the larval stage. Since adults are not produced, CAF was considered a potential bioinsecticide, useful for controlling these mosquitoes that transmit human viral diseases. Similar results were obtained in tests with used coffee grounds (UCG). Considering the importance of the oviposition site in the reproductive success, in the present study, two experiments were carried out aiming to verify if CAF aqueous solution and UCG suspension might interfere in the choice of the oviposition site by Ae. Aegypti, competing with water, the attractive medium in their normal breeding sites. Four glasses were put into a cage, two containing CAF solutions in different concentrations, one containing UCG and other water. The oviposition behavior was verified by counting the number of eggs. CAF solutions showed a number of eggs greater than that in the other mediums. During the experiments, many mosquitoes died immersed in the mediums, being their number higher in UCG. These observations are discussed, reinforcing the possibility of using CAF and UCG as auxiliaries in the control of Ae. Aegypti.