Control of triatomines with entomopathogenic fungi combined with an aggregation cue

N. PEDRINI

Teresópolis

Simposio; 14 Siconbiol; 2015

Current Chagas disease vector control strategies, based on chemical insecticide spraying, are growingly threatened by the emergence of pyrethroid-resistant Triatoma infestans populations in the Gran Chaco region of South America. As an alternative tool, the entomopathogenic fungus Beauveria bassiana is effective both against pyrethroid-susceptible and pyrethroid-resistant T. infestans, in laboratory as well as field assays. B. bassiana has the ability to breach the triatomine cuticle; once into the hemolymph, the fungus secretes toxic or immunosuppressive compounds that facilitate the invasion process.T. infestans cuticle lipids play a major role as contact aggregation pheromones. The effect of insect exuviae as an aggregation signal in the performance of infective boxes containing B. bassiana spores to kill indoor bugs will be here discussed. A stage-specific matrix model of T. infestans was developed to describe the fungal infection effects on insect population dynamics, and to analyze the performance of the biopesticide device in vector biological control.The pheromone-containing infective box is a promising new tool against indoor populations of this Chagas disease vector, with the number of boxes per house being the main driver of the reduction of the total domestic bug population. This ecologically safe approach is the first proven alternative to chemical insecticides in the control of T. infestans. The advantageous reduction in vector population by delayed-action fungal biopesticides in a contained environment is supported by mathematical modeling.