Novel larvicide tablets of Bacillus thuringiensis var. israelensis: Assessment of larvicidal effect on Aedes aegypti (Diptera: Culicidae) in Colombia

• Main Authors: Wilber Gómez-Vargas, Kelly Valencia-Jiménez, Guillermo Correa-Londoño, Faiber Jaramillo-Yepes
• Format: Article
• Language: English
• Published: Instituto Nacional de Salud 2018-08-01
• Series: Biomédica: revista del Instituto Nacional de Salud
• Subjects: Aedes; Bacillus thuringiensis; disease vectors; dengue; chikungunya virus; Zika virus; Colombia
• Online Access: https://www.revistabiomedica.org/index.php/biomedica/article/view/3940
• ISSN: 0120-4157; 0120-4157

Introduction: Aedes (Stegomyia) aegypti is the vector for dengue, chikungunya, and Zika arboviruses. Bti-CECIF is a bioinsecticide designed and developed in the form of a solid tablet for the control of this vector. It contains Bacillus thuringiensis var. israelensis (Bti) serotype H-14. Objective: To evaluate under semi-field and field conditions the efficacy and residual activity of Bti-CECIF tablets on Aedes aegypti larvae in two Colombian municipalities. Materials and methods: We tested under semi-field conditions in plastic tanks (Rotoplast™) four different Bti doses (0.13, 0.40, 0.66 and 0.93 mg/L) in the municipality of Apartadó, department of Antioquia, to assess Bti-CECIF efficacy (percentage of reduction of larval density) and the residual activity in water tanks containing A. aegypti third-instar larvae. The efficacy and residuality of the most lethal dose were subsequently evaluated under field conditions in cement tanks in the municipality of San Carlos, department of Córdoba. Results: Under semi-field conditions, the highest tested dose exhibited the greatest residual activity (15 days) after which larval mortality was 80%. Under field conditions, the highest tested Bti-CECIF doses showed 100% mortality and exhibited a residual activity of seven days in 90% of the tanks. Conclusion: Bti-CECIF tablets effectively controlled A. aegypti larvae under field conditions for up to seven days post-treatment.