Demographic effects of deltamethrin resistance in the Chagas disease vector Triatoma infestans. Medical and Veterinary Entomology

GERMANO M; PICOLLO M.I.

MEDICAL AND VETERINARY ENTOMOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2016

0269-283X

Abstract. Triatoma infestans (Heteroptera: Reduviidae) Klug is the main vector ofChagas disease in Latin America. Resistance to deltamethrin was reported in Argentinaand recently associated with reproductive and longevity trade-offs. The objectives of thepresent study were to describe the demographic consequences of deltamethrin resistancein T. infestans and to establish possible target stages for chemical control in susceptibleand resistant colonies. A stage-classified matrix model was constructed based on theaverage stage length for susceptible, resistant and reciprocal matings? progeny. Thedifferences between colonies were analysed by prospective and retrospective analysis.The life table parameters indicated reduced fecundity, fertility and population growthin resistant insects. The retrospective analysis suggested the latter was associated withlower reproductive output and increased fifth-instar nymph stage length. The prospectiveanalysis suggested that the adult stage should be the main target for insecticidecontrol. Although, fifth-instar nymphs should also be targeted when resistance has beendetected. The presented results show demographic effects of deltamethrin resistance inT. infestans. While the older stages could be the main targets for chemical control, thisapproach is impeded by their higher tolerance to insecticides. It is concluded that thedifferent mode of action insecticides would be more effective than a dose increase forthe control of deltamethrin-resistant T. infestans.