title: Secondary kill effect of deltamethrin on Triatoma infestans.
abstract: Control of the Chagas disease vector, Triatoma infestans, relies on the application of pyrethroid insecticides, especially deltamethrin. We performed laboratory studies to determine whether a T. infestans nymph that comes into contact with a deltamethrin-treated surface horizontally transfers the insecticide to subsequent triatomines. We found that a triatomine that walks on a deltamethrin-treated surface for a short period of time has the ability to transport the insecticide in concentrations sufficient to kill other triatomines with which it comes into contact. The effect was limited to high-density environments, and mortality as a result of secondary exposure was greater among second-instar nymphs compared with fifth-instar nymphs. Our results suggest that deltamethrin could be killing triatomines through both direct and indirect contact, although it remains unclear whether the phenomenon occurs in natural conditions.
authors.affiliation: Department of International Health and Development, Tulane University School of Public Health and Tropical Medicine, 1440 Canal Street, Ste 2200, New Orleans, LA 70112, USA. kmalonel@tulane.edu
authors.forename: Kathleen M
authors.initials: KM
authors.lastname: Maloney
authors.forename: Jenny
authors.initials: J
authors.lastname: Ancca-Juarez
authors.forename: Renzo
authors.initials: R
authors.lastname: Salazar
authors.forename: Katiy
authors.initials: K
authors.lastname: Borrini-Mayori
authors.forename: Danitza
authors.initials: D
authors.lastname: Pamo-Tito
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Keating
authors.forename: Michael Z
authors.initials: MZ
authors.lastname: Levy
mesh_terms: D000818:Animals; D014355:Chagas Disease / Q000517:prevention & control; D007303:Insect Vectors; D007306:Insecticides; D009570:Nitriles; D009758:Nymph / Q000187:drug effects; D011156:Population Density; D011722:Pyrethrins; D014224:Triatoma
chemical_list: D007306:Insecticides; D009570:Nitriles; D011722:Pyrethrins; C017180:decamethrin