title: Control of experimental Triatoma infestans populations: effect of pour-on cypermethrin applied to chickens under natural conditions in the Argentinean Chaco region.
abstract: Among peridomestic structures, chicken coops are sites of major importance for the domestic ecology of Triatoma infestans (Hemiptera: Reduviidae). The aim of this study was to evaluate in an experimental context the effects of a cypermethrin pour-on formulation applied to chickens on blood intake, moulting and mortality in T. infestans, under the natural climatic conditions of a region endemic for Chagas' disease. Experimental chicken huts were made of bricks and covered with plastic mosquito nets. Ninety fourth-instar nymphs were maintained in each hut. The study used a completely random design in which chickens in the experimental group were treated with a cypermethrin pour-on formulation. Five replicates (= huts) of the experimental and control groups were conducted. The number of live T. infestans, blood intake and moults to fifth-instar stage were recorded at 1, 5, 20, 35 and 45 days after the application of cypermethrin. Cumulative mortality was higher in nymphs exposed to treated chickens (> 71%) than in control nymphs (< 50%) (P < 0.01). Blood intake and moulting rate were lower in nymphs fed on treated chickens than in control nymphs (P < 0.05). Pour-on cypermethrin was able to cause significant mortality, although it did not eliminate the experimental population of T. infestans.
authors.affiliation: Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja (CRILAR), La Rioja, Argentina.
authors.forename: I
authors.initials: I
authors.lastname: Amelotti
authors.forename: S S
authors.initials: SS
authors.lastname: Catalá
authors.forename: D E
authors.initials: DE
authors.lastname: Gorla
mesh_terms: D000818:Animals; D001118:Argentina; D014355:Chagas Disease / Q000517:prevention & control*; D002645:Chickens; D005247:Feeding Behavior / Q000187:drug effects; D007303:Insect Vectors; D007306:Insecticides / Q000494:pharmacology; D008136:Longevity / Q000187:drug effects; D018978:Molting / Q000187:drug effects; D009758:Nymph; D011722:Pyrethrins / Q000494:pharmacology; D011897:Random Allocation; D013997:Time Factors; D014224:Triatoma / Q000254:growth & development
chemical_list: D007306:Insecticides; D011722:Pyrethrins; C017160:cypermethrin
keywords: Chagas' disease; Triatoma infestans; cypermethrin; pour-on; vector control