Larvicidal effect of Spinosad and Bacillus thuringiensis var. israelensis on Aedes aegypti (Linnaeus, 1762) (Diptera: Culicidae)

Abstract

The use of biological larvicide based on Bacillus thuringiensis var. israelensis (Bti) has stood out for its effectiveness in controlling mosquito Aedes aegypti. The larvicide Spinosad is used in the National Dengue Control Program. This study evaluated the effect of Spinosad and Bti larvicide at various temperatures in a laboratory environment. The assays were performed with 10 larvae in quintuplicate, at temperatures of 18° C, 25° C and 32° C, with 24-hour monitoring. The larvae exposed to Bti were eliminated within 0.5 hours at ambient and hot temperatures (32° C), while at colder conditions (18° C) it took 1.5 hours for complete elimination. Regarding Spinosad, 50% survived for 11 hours, but all larvae were killed after 24 hours. The results reinforce the indication of these products for larval control of the species under the conditions of temperature fluctuation.