Abstract

GONZALEZ RIZO, Aileen et al. Evaluation of the larvicidal efficacy of Rapidall NP3 (Bacillus thuringiensis) against Aedes aegypti (Linnaeus) (Diptera: Culicidae) in laboratory conditions. Rev Cubana Med Trop [online]. 2019, vol.71, n.1  Epub June 30, 2019. ISSN 1561-3054.

Mosquitoes are vectors of human diseases such as dengue, zika and chikungunya. Biological control is a viable alternative to be taken into account in control programs. Bacillus thuringiensis is the microorganism most commonly used in public health. Its effectiveness as a larvicide against culicides depends to a great extent to the production process. The objectives of the study were to evaluate and compare the larvicidal efficacy against Aedes aegypti of the Rapidall NP3 powder formulation with Bactivec®, a liquid formulation used in Cuba. Laboratory bioassays were conducted to determine efficacy following WHO protocols. Larvae were exposed to the concentrations recommended by Rapidall NP3 and Bactivec® manufacturers. The water in the containers used in the study was replaced once a week: half, whole and no replacement. At 24 hours mortality was estimated and statistically analysis were done by one-way ANOVA. When significant differences were found, post-hoc analysis was performed with Tukey's test. Rapidall NP3 caused 100% larval mortality for 11 weeks, regardless of the water replacement proportion, whereas Bactivec® caused 100 % mortality for only 6 weeks after the start of the experiment. When compared with Bactivec®, biolarvicide Rapidall NP3 displayed better efficacy and more prolonged residual activity. We therefore recommend its field evaluation for larval control of containers constituting habitual breeding sites which cannot be physically eliminated.

Keywords : Bacillus thuringiensis; Aedes aegypti; biological control; efficacy.

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