Long-term impact of insecticide spraying against Triatoma infestans affects a non-target secondary vector of Chagas disease, Triatoma garciabesi

VAZQUEZ-PROKOPEC GM; GURTLER RE; CECERE MC; RODRIGUEZ-PLANES L; CANALE DM

JOURNAL OF MEDICAL ENTOMOLOGY

ENTOMOLOGICAL SOC AMER

Lugar: Lanham; Año: 2016 vol. 53 p. 144 - 151

0022-2585

The control of nondomiciliated triatomine species adapted to peridomestic habitats represents a challenge becausethey are connected to sylvatic colonies, and pyrethroid insecticides have limited effects outdoors. The effectsof residual insecticide spraying have rarely been assessed on secondary triatomines. Triatoma garciabesi20 (Carcavallo, Martinez, Cichero, Prosen & Ronderos, 1967) is a nontarget vector that inhabits the dry westernChaco region, and a member of the Triatoma sordida Sta˚l 1859 complex. Little is known on the capacity ofT. garciabesi to invade and establish viable domestic or peridomestic colonies, and on its response to residualAQ3 insecticide sprays directed against Triatoma infestans Klug 1834. The presence and abundance of triatomineswere assessed by timed manual collections annually or biannually (spring and fall) during 10 yr after a25 community-wide insecticide spraying campaign and selective insecticide sprays directed against T. infestans ina rural village of northwestern Argentina. T. garciabesi mainly occupied peridomestic habitats associated withchickens, and was unable to colonize human sleeping quarters. Trees with chickens occurred in nearly allhouses and were infested in >25% of the occasions. The abundance of bugs at house-compound level was bestexplained by a generalized estimating equation model that included selective insecticide sprays during the30 previous semester (negative effects), chicken abundance (positive effects), seasonality, and their interactions.Our results suggest that insecticide applications targeting T. infestans affected the abundance of T. garciabesi,and reduced the likelihood of future infestation