Reproductive and developmental costs of deltamethrin resistance in the Chagas disease vector Triatoma infestans

GERMANO M; PICOLLO M.I.

JOURNAL OF VECTOR ECOLOGY

SOC VECTOR ECOLOGY

Lugar: Idaho, EEUU; Año: 2014 vol. 40 p. 59 - 65

1081-1710

Abstract Chagas disease vector Triatoma infestans is regularly controlled with deltamethrin house spraying, which has been associated with the development of resistant populations in the treated geographic areas. Although resistance provides an adaptive value in the context of insecticide spraying, its influence on other biological characters can lead to negative effects when the insecticide pressure ceases. The biological effects of deltamethrin resistance were assessed in T. infestans. Length of each developmental stage and complete life cycle, mating rate and fecundity of susceptible and resistant insects were evaluated. Susceptible and resistant insects presented similar mating rate. A reproductive cost of resistance was expressed as a lower fecundity in the resistant colony. Developmental costs were present in the resistant colony in the form of a shortening of the second and third nymph stage duration, and an extension of the fifth stage. A maternal effect of insecticide is suggested as these effects were identified in resistant females and their progeny independently of the mated male´s deltamethrin response. The findings of resistance costs suggest a pleiotropic effect of this character associated to deltamethrin selection pressure. A possible relationship between adaptive developmental delays and insecticide resistance is suggested, and further effects on vector control are discussed.