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Biological Control of the Chagas Disease Vector Triatoma infestans with the Entomopathogenic Fungus Beauveria bassiana Combined with an Aggregation Cue: Field, Laboratory and Mathematical Modeling Assessment.

Forlani L, Pedrini N, Girotti JR, Mijailovsky SJ, Cardozo RM, Gentile AG, Hernández-Suárez CM, Rabinovich JE, Juárez MP - PLoS Negl Trop Dis (2015)

Bottom Line: We developed a stage-specific matrix model of T. infestans to describe the fungal infection effects on insect population dynamics, and to analyze the performance of the biopesticide device in vector biological control.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 here shown supported by mathematical modeling.

View Article: PubMed Central - PubMed

Affiliation: Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP, CONICET, CCT-La Plata, UNLP), Facultad de Ciencias Médicas, La Plata, Argentina.

ABSTRACT

Background: 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.

Methodology and findings: We have already shown that the entomopathogenic fungus Beauveria bassiana has the ability to breach the insect cuticle and is effective both against pyrethroid-susceptible and pyrethroid-resistant T. infestans, in laboratory as well as field assays. It is also known that T. infestans cuticle lipids play a major role as contact aggregation pheromones. We estimated the effectiveness of pheromone-based infection boxes containing B. bassiana spores to kill indoor bugs, and its effect on the vector population dynamics. Laboratory assays were performed to estimate the effect of fungal infection on female reproductive parameters. The effect of insect exuviae as an aggregation signal in the performance of the infection boxes was estimated both in the laboratory and in the field. We developed a stage-specific matrix model of T. infestans to describe the fungal infection effects on insect population dynamics, and to analyze the performance of the biopesticide device in vector biological control.

Conclusions: 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 here shown supported by mathematical modeling.

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Related in: MedlinePlus

Field box.A: Picture showing a fifth instar nymph entering into the box. B: Scheme showing the inner box design; the upper side of the racks and the internal sides of the box were covered by the exuviae suspension (brown); the fungal formulation (white) was applied over the exuviae-painted rack surfaces.
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pntd.0003778.g001: Field box.A: Picture showing a fifth instar nymph entering into the box. B: Scheme showing the inner box design; the upper side of the racks and the internal sides of the box were covered by the exuviae suspension (brown); the fungal formulation (white) was applied over the exuviae-painted rack surfaces.

Mentions: The device consisted in a 3-mm medium density fiberboard (MDF) box of 16×11×4 cm, with five lateral holes placed at the same level than that of five internal racks (3 cm width) containing the conidia:DE mixture (2:1) (A scheme is shown in Fig 1). Before incorporating the fungal mix, the upper side of the racks and the internal sides of the boxes were covered with the exuviae suspension.


Biological Control of the Chagas Disease Vector Triatoma infestans with the Entomopathogenic Fungus Beauveria bassiana Combined with an Aggregation Cue: Field, Laboratory and Mathematical Modeling Assessment.

Forlani L, Pedrini N, Girotti JR, Mijailovsky SJ, Cardozo RM, Gentile AG, Hernández-Suárez CM, Rabinovich JE, Juárez MP - PLoS Negl Trop Dis (2015)

Field box.A: Picture showing a fifth instar nymph entering into the box. B: Scheme showing the inner box design; the upper side of the racks and the internal sides of the box were covered by the exuviae suspension (brown); the fungal formulation (white) was applied over the exuviae-painted rack surfaces.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4430541&req=5

pntd.0003778.g001: Field box.A: Picture showing a fifth instar nymph entering into the box. B: Scheme showing the inner box design; the upper side of the racks and the internal sides of the box were covered by the exuviae suspension (brown); the fungal formulation (white) was applied over the exuviae-painted rack surfaces.
Mentions: The device consisted in a 3-mm medium density fiberboard (MDF) box of 16×11×4 cm, with five lateral holes placed at the same level than that of five internal racks (3 cm width) containing the conidia:DE mixture (2:1) (A scheme is shown in Fig 1). Before incorporating the fungal mix, the upper side of the racks and the internal sides of the boxes were covered with the exuviae suspension.

Bottom Line: We developed a stage-specific matrix model of T. infestans to describe the fungal infection effects on insect population dynamics, and to analyze the performance of the biopesticide device in vector biological control.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 here shown supported by mathematical modeling.

View Article: PubMed Central - PubMed

Affiliation: Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP, CONICET, CCT-La Plata, UNLP), Facultad de Ciencias Médicas, La Plata, Argentina.

ABSTRACT

Background: 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.

Methodology and findings: We have already shown that the entomopathogenic fungus Beauveria bassiana has the ability to breach the insect cuticle and is effective both against pyrethroid-susceptible and pyrethroid-resistant T. infestans, in laboratory as well as field assays. It is also known that T. infestans cuticle lipids play a major role as contact aggregation pheromones. We estimated the effectiveness of pheromone-based infection boxes containing B. bassiana spores to kill indoor bugs, and its effect on the vector population dynamics. Laboratory assays were performed to estimate the effect of fungal infection on female reproductive parameters. The effect of insect exuviae as an aggregation signal in the performance of the infection boxes was estimated both in the laboratory and in the field. We developed a stage-specific matrix model of T. infestans to describe the fungal infection effects on insect population dynamics, and to analyze the performance of the biopesticide device in vector biological control.

Conclusions: 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 here shown supported by mathematical modeling.

Show MeSH
Related in: MedlinePlus