Larvicide activity of Bacillus thuringiensis var. israelensis. in simulated field condition/ Atividade larvicida de Bacillus thuringiensis var. israelensis. em condição simulada de campo

• Autor(a) principal: Viana, Juliete Lima
• Data de Publicação: 2021
• Outros Autores: Neta, Maria dos Remédios Araújo Vieira, da Silva, Joelma Soares, Andrade, Aylane Tamara dos Santos, Bezerra, Juliana Maria Trindade, Tadei, Wanderli Pedro, Pinheiro, Valéria Cristina Soares
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Revista Veras
• Texto Completo: https://ojs.brazilianjournals.com.br/ojs/index.php/BRJD/article/view/29026
• topic: Mosquito; Control; Bacterium; Biolarvicide

Bacillus thuringiensis var. israelensis (Bti) is the active ingredient most used in biolarvicides, due to its ability to produce toxins with insecticidal action against vector mosquitoes, however the effectiveness of the toxins can be affected by climatic conditions. The present study aimed to evaluate the factors involved in the efficiency of the formulated VectoBac® WG against immature Ae. aegypti in simulated field conditions. The experiments were carried out in two types of reservoirs (12 buckets and 12 tires) with or without direct exposure to sunlight during the dry and rainy season. Climatological data were obtained from the Instituto Nacional de Meteorologia, located in Caxias-MA. Treatments and control were performed in triplicates, and the difference in larval mortality between the treated and control reservoirs was estimated using the t-Student test, at a level of 5% significance. Weekly were placed 25 larvae of the Ae. aegypti of 3rd instar in each reservoir, and every 24 hours the larval count was performed, evaluating the recycling of Bti. The biolarvicide maintained efficiency for 42 days, killing 100% of the larvae in the reservoirs protected from weather conditions, unlike the reservoirs that were unprotected, its effectiveness lasted 14 days. The experiments were completed when mortality was below 20% in all reservoirs treated with Bti. Although climatic conditions influence the activity of the VectoBac® WG larvicide, it showed that Bti has a recycling capacity for 77 days, therefore, the persistence of the bacillus in the environment shows its efficiency in controlling Ae. aegypti larvae.