Avaliação da eficácia de inseticidas naturais sobre Lutzomyia longipaldis (Diptera, Psychodidae), colonizada em laboratório

Abstract

A closed colony of L. iongipaipis was established with material collected in the indian area of Raposa-Serra do sol, one of the main foci of visceral leishmaniasis in the state of Roraima.The ptant species Antonia ovata and Derris amazonica were collected in the same area. Observations were made on the biology of the colony of Lutzomyia longipalpis, with emphasis on productivity. During five generations the colony had a yield of between 64,2%(F3) and 90,3%(F2).of females that fed and oviposited. From the total of 10.088 eggs laid, 5.791 adult insects were obtained; 2750 males and 3.041 females. Some of these insects were used in tests of plant extracts. The extracts were prepared fron leaves of A. ovata (leaves) and roots of D. amazonica dried in the shade at ambient temperature. 300 g. of the dry material was processed in 51. of water for each species, using an eletric coffee-maker. The inkrsion were filtered and evaporated, and the solid extract weighed for use in the bioassays with extracts at diiutions of 150, 200 and 250 rng dry extract per ml of water. Mortality was record during 72 hours of exposure. At 48 hours the mortality was up to 56,6% on extracts of A. ovata, and up to 70% for D. amazonica. At 72 hours the percentage of dead insects was up to 70% and wp to 83.3%, respectively. Maximum control mortality was 10%.