Avaliação comparativa de diferentes formulações líquidas à base de bacillus thuringiensis var. israelensis no manejo de simuliidae no município de Erechim-RS

Abstract

Simulids (Diptera: Simuliidae), commonly known as black flies, are a group of insects of public health importance due to the blood-feeding habits of the females and the impacts of their bites on humans and animals. Biological control using Bacillus thuringiensis var. israelensis (Bti) stands out as a selective alternative with less environmental impact compared to conventional chemical insecticides. In this context, the present study aimed to compare the efficacy of two commercial Bti-based formulations, VectoBac 12AS and CRYSTAR XT, in controlling Simuliidae larvae in two streams in the municipality of Erechim, Rio Grande do Sul. Four experimental applications were conducted, and larval mortality was monitored at nine collection points distributed along each stream, 24 hours after exposure to the products. The results showed that VectoBac 12AS was more effective, achieving mortality rates of 53.4% and 72.4%, while CRYSTAR XT achieved mortality rates of 15.8% and 37.4%. Spatial analysis of the data indicated that hydrological factors, such as flow rate, the presence of tributaries, and water flow dynamics, influenced the distribution of the larvicide and the efficiency of control. It is concluded that VectoBac 12AS performed better under the evaluated conditions, demonstrating greater potential for use in simuliid management programs in the municipality of Erechim, Rio Grande do Sul.