title: The effects of cypermethrin pour-on and piperonyl butoxide on Triatoma infestans under laboratory conditions.
abstract: The effect of exposing Triatoma infestans to chickens treated with cypermethrin pour-on combined with piperonyl butoxide (PBO) was studied. Four groups of treated chickens and one control group were used. Each treatment received 1 or 2 ml of the cypermethrin formulation with and without PBO. Independent groups of nymphs were fed 1, 7, 15, 30, and 45 d after the treatment application. Blood intake was estimated after each feeding occasion. Up to 15 d after the pour-on application, high mortality was observed in all nymphs fed on treated chickens (> 93% +/- 12), and lower than the nymphs of the control group (< 33% +/- 15). After 30 d of the pour-on application, there was significantly different mortality between the treatment with 1 ml (80% +/- 9) and 2 ml (> 96% +/- 5); no difference was observed between groups with or without PBO addition. After 45 d of the pour-on application, the treatments did not show significant differences (77% +/- 7), although all treatments showed higher mortality than the control group (10% +/- 9). Up to 45 d after the pour-on application, blood intake by nymphs exposed to treated chickens (0.85 +/- 0.96 mg/nymph) was lower than blood intake by nymphs exposed to control chickens (6.7 +/- 5 mg/nymph). This study shows that cypermethrin pour-on produces high mortality and reduces the blood intake of third-instar nymphs of T. infestans up to 45 d after the insecticide application to chickens. PBO did not produce a detectable effect.
authors.affiliation: Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja, Argentina. iamelotti@crilar-conicet.com.ar
authors.forename: Ivana
authors.initials: I
authors.lastname: Amelotti
authors.forename: Silvia S
authors.initials: SS
authors.lastname: Catalá
authors.forename: David E
authors.initials: DE
authors.lastname: Gorla
mesh_terms: D000287:Administration, Topical; D000818:Animals; D002645:Chickens; D004359:Drug Therapy, Combination; D007299:Insect Bites and Stings / Q000517:prevention & control; D018978:Molting; D009758:Nymph / Q000187:drug effects / Q000502:physiology; D010882:Piperonyl Butoxide / Q000008:administration & dosage / Q000494:pharmacology*; D011722:Pyrethrins / Q000008:administration & dosage / Q000494:pharmacology*; D014224:Triatoma / Q000187:drug effects* / Q000502:physiology
chemical_list: D011722:Pyrethrins; C017160:cypermethrin; D010882:Piperonyl Butoxide