Residual effect of two Bacillus thuringiensis var. israelensis products assayed against Aedes aegypti (Diptera: Culicidae) in laboratory and outdoors at Rio de Janeiro, Brazil Efeito residual de duas formulações de Bacillus thuringiensis var. israelensis sobre Aedes aegypti (Diptera: Culicidae) em condições de laboratório e em simulado de campo, no Rio de Janeiro, Brasil

• Published in: Revista do Instituto de Medicina Tropical de São Paulo
• Main Authors: José Bento Pereira Lima, Nilson Vieira de Melo, Denise Valle
• Format: Article in Journal/Newspaper
• Language: English
• Published: Universidade de São Paulo (USP) 2005
• Subjects: Aedes aegypti; Bacillus thuringiensis var. israelensis; Insecticide; Biological control; Arctic medicine. Tropical medicine; RC955-962; Infectious and parasitic diseases; RC109-216; Arctic
• Online Access: https://doi.org/10.1590/S0036-46652005000300002; https://doaj.org/article/9eb261eb22ce46cda58b9f8cabaf8fcc

Resistance of the dengue vector to temephos stimulated its substitution for Bacillus thuringiensis var. israelensis (Bti) since 2001 in Brazil. The persistence of the two Bti formulations employed at that time by the Health Ministry, Vectobac G and Aquabac G, was assayed under laboratory and outdoor conditions. Both formulations were tested at 0.2 g/10 liters of water, the same concentration applied in the field for vector control. The tests were done against Ae. aegypti third instar larvae (Rockefeller strain). In the laboratory, Vectobac G and Aquabac G caused at least 95% mortality until 101 and 45 days after treatment, respectively. In the outdoor assays, test containers of different materials were treated with either formulation and placed in a shaded area. Larvae were introduced each 3-6 days and mortality was recorded 24 and 48 hours later. In the first set of assays, performed in June 2001, mortality levels of 70% or more were attained for 2-5 weeks for both formulations in all containers. The exception was for the iron one that rusted, resulting in low mortality after seven days. In the second set of assays (August 2001), 70% mortality was attained for just 1-2 weeks for all the containers and both formulations. RESUMO Resistência do vetor de dengue, Aedes aegypti, a temephos estimulou sua substituição por Bacillus thuringiensis var. israelensis (Bti) desde 2001 no Brasil. A persistência de duas formulações de Bti empregadas naquele ano pelo Ministério da Saúde, Vectobac G e Aquabac G, foi testada em condições externas e de laboratório. Ambas formulações foram testadas a 0,2 g/10 litros de água, a mesma concentração recomendada para o controle do vetor no campo. Os testes foram realizados com larvas de Ae. aegypti de terceiro estádio (linhagem Rockefeller). No laboratório, Vectobac G e Aquabac G induziram pelo menos 95% de mortalidade até 101 e 45 dias depois do tratamento, respectivamente. Nos testes externos, recipientes de diferentes materiais foram tratados com cada formulação e colocados em local ...