O trabalho determinou a potência (UTI) e a eficácia de um formulado líquido de Bacillus thuringiensis israelensis desenvolvido pela Universidade Estadual de Londrina, designado como BioUel, em testes com larvas de quarto instar inicial de Aedes aegypti e Culex quinquefasciatus. A UTI/mg do Biouel foi de 960, a CL50 foi de 0,271 (± 0,39) ppm e a CL95, de 0,634 (± 0,099) ppm, em larvas de C. quinquefasciatus. Para larvas de A. aegypti, a CL50 foi de 0,332 (± 0,042) ppm e a CL95, de 0,694 (± 0,073) ppm. A potência do BioUel e os resultados de controle foram comparáveis à maioria dos produtos comerciais testados. A estabilidade foi de aproximadamente 90 dias, o que permite uma produção local.

The aim of this study was to determine the potency (ITU) and efficacy of a liquid formulation of Bacillus thuringiensis israelensis developed by the State University of Londrina named BioUel, against early fourth instar larvae of Aedes aegypti and Culex quinquefasciatus. The ITU/mg of BioUel was 960, the LC50 was of 0.271 (± 0.39) ppm, and the LC95 was 0.634 (± 0.099) ppm, in larvae of C. quinquefasciatus. In A. aegypti larvae, LC50 was 0.332 (± 0.042) ppm and LC95 was 0.694 (± 0.073) ppm. The ITU level of BioUel and its control results were similar to most commercial products tested. Stability was of approximately 90 days, which allows for local production.

The bacterial strain Bacillus cereus is closely related to Bacillus thuringiensis, although any genetic relationship between the two strains is still in debate. Using rep-PCR genomic fingerprinting, we established the genetic relationships between Brazilian sympatric populations of B. cereus and B. thuringiensis simultaneously collected from two geographically separate sites. We observed the formation of both B. thuringiensis and B. cereus clusters, as well as strains of B. cereus that are more closely related to B. thuringiensis than to other B. cereus strains. In addition, lower genetic variability was observed among B. thuringiensis clusters compared to B. cereus clusters, indicating that either the two species should be categorized as separate or that B. thuringiensis may represent a clone from a B. cereus background.