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Comparison of two sampling methods for domestic populations of Triatoma infestans in north‐west Argentina
Author(s) -
GURTLER RICARDO E.,
SCHWEIGMANN NICOLAS J.,
CECERE MARIA C.,
WISNIVESKYCOLLI CRISTINA,
CHUIT ROBERTO
Publication year - 1993
Publication title -
medical and veterinary entomology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.028
H-Index - 82
eISSN - 1365-2915
pISSN - 0269-283X
DOI - 10.1111/j.1365-2915.1993.tb00683.x
Subject(s) - triatoma infestans , reduviidae , deltamethrin , biology , toxicology , instar , nymph , hemiptera , triatoma , veterinary medicine , ecology , pesticide , parasite hosting , larva , medicine , trypanosoma cruzi , world wide web , computer science
Abstract. In mud‐and‐thatch houses of Santiago del Estero Province, northwest Argentina, where no insecticides had been sprayed officially to control domestic infestations of the Chagas disease vector Triatoma infestans (Klug) (Hemiptera: Reduviidae), two knockdown (KD) insecticidal collection procedures were compared with the standard flush‐out (FO) method for sampling T. infestans. Bugs were collected by FO using 0.2% tetramethrin in bedrooms of (1) 41 houses of Amama village employing 1 man‐hour of capture effort per house, and (2) 19 houses of Trinidad and Mercedes villages employing 4 man‐hours/house. From the same houses, 2‐5 days after the manual FO collection, bugs were collected by KD indoor‐spraying of deltamethrin 25mga.i./m 2 in Amama, or burning of one γ‐HCH (=γ‐BHC) fumigant tablet 3.1g of γ‐isomer) per bedroom in Trinidad and Mercedes. The majority of infestations were detected by both methods, the proportion of positive houses being 81% at Amama and 95% at the other villages. Although the FO method was more sensitive, at least because it was applied first, the KD method detected infestations in 25% of houses where bugs were not found by FO. Bug densities estimated by FO or by subsequent KD in each house were significantly correlated: r = 0.795 for deltamethrin; r = 0.882 for y‐HCH. Compared with FO collections of T.infestans large stages, i.e. adults plus fourth and fifth instar nymphs, the KD catch averaged 0.88x with deltamethrin and 0.57× with γ‐HCH, regardless of the apparent population density of bugs per house. However, the KD method has practical advantages of speed and standardization.