title: Is imidacloprid an effective alternative for controlling pyrethroid-resistant populations of Triatoma infestans (Hemiptera: Reduviidae) in the Gran Chaco ecoregion?
abstract: The prevention of Chagas disease is based primarily on the chemical control of Triatoma infestans (Klug) using pyrethroid insecticides. However, high resistance levels, correlated with control failures, have been detected in Argentina and Bolivia. A previous study at our laboratory found that imidacloprid could serve as an alternative to pyrethroid insecticides. We studied the delayed toxicity of imidacloprid and the influence of the blood feeding condition of the insect on the toxicity of this insecticide; we also studied the effectiveness of various commercial imidacloprid formulations against a pyrethroid-resistant T. infestans population from the Gran Chaco ecoregion. Variations in the toxic effects of imidacloprid were not observed up to 72 h after exposure and were not found to depend on the blood feeding condition of susceptible and resistant individuals. Of the three different studied formulations of imidacloprid on glass and filter paper, only the spot-on formulation was effective. This formulation was applied to pigeons at doses of 1, 5, 20 and 40 mg/bird. The nymphs that fed on pigeons treated with 20 mg or 40 mg of the formulation showed a higher mortality rate than the control group one day and seven days post-treatment (p < 0.01). A spot-on formulation of imidacloprid was effective against pyrethroid-resistant T. infestans populations at the laboratory level.
authors.affiliation: Consejo Nacional de Investigaciones Científicas y Técnicas, Centro de Investigaciones de Plagas e Insecticidas, Instituto de Investigaciones Científicas y Técnicas para la Defensa, Buenos Aires, Argentina.
authors.forename: Guillermo
authors.initials: G
authors.lastname: Carvajal
authors.affiliation: Consejo Nacional de Investigaciones Científicas y Técnicas, Centro de Investigaciones de Plagas e Insecticidas, Instituto de Investigaciones Científicas y Técnicas para la Defensa, Buenos Aires, Argentina.
authors.forename: María Inés
authors.initials: MI
authors.lastname: Picollo
authors.affiliation: Consejo Nacional de Investigaciones Científicas y Técnicas, Centro de Investigaciones de Plagas e Insecticidas, Instituto de Investigaciones Científicas y Técnicas para la Defensa, Buenos Aires, Argentina.
authors.forename: Ariel Ceferino
authors.initials: AC
authors.lastname: Toloza
mesh_terms: D000818:Animals; D001118:Argentina; D001838:Bolivia; D014355:Chagas Disease / Q000517:prevention & control / Q000635:transmission; D010856:Columbidae / Q000469:parasitology; D005247:Feeding Behavior; D007093:Imidazoles / Q000737:chemistry / Q000494:pharmacology*; D007303:Insect Vectors / Q000378:metabolism; D007305:Insecticide Resistance; D007306:Insecticides / Q000737:chemistry / Q000494:pharmacology*; D000073943:Neonicotinoids; D009574:Nitro Compounds / Q000737:chemistry / Q000494:pharmacology*; D009758:Nymph / Q000187:drug effects; D011722:Pyrethrins / Q000494:pharmacology*; D014224:Triatoma / Q000145:classification / Q000187:drug effects* / Q000378:metabolism
chemical_list: D007093:Imidazoles; D007306:Insecticides; D000073943:Neonicotinoids; D009574:Nitro Compounds; D011722:Pyrethrins; C082359:imidacloprid