Avaliação do efeito residual e da mortalidade de larvas de Aedes aegypti expostas ao Bacillus thuringiensis var. israelensis e ao temephos

Abstract

The residual effect of Temephos (commercial applications A, B e C) and Bacillus thuringiensis israelensis (D and E) on Aedes aegypti larvae was evaluated, in recipients with water renewal. 44 beakers of l,000ml each (8 for each application and 4 Controls) were used. In each beaker, 25 larvae were introduced daily. After 24 hours, the dead larvae were counted, the beakers emptied to 200ml and refilled to original volume, with addition of new larvae. The duration of the maximum residual effect (100% of mortality) was: A-19; B-39; C-40; D-8; E-19 days. The mortality ratio (MR) of all applications remained equivalent for 25 days; B, C and E maintained MR equivalent up to 45 days; B and C showed MR 2.40 times greater than E, between 46-95 days; B, compared with A, showed MR 1,90-7,51 times greater between 26-95 days. The conclusion was greater effectiveness of two presentations of Temephos, even in an epidemiological situation with long exposure to the product and renewal of water in recipients.