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

GERMANO, MÓNICA; PICOLLO, MARÍA INÉS

JOURNAL OF VECTOR ECOLOGY

SOC VECTOR ECOLOGY

Lugar: Idaho, EEUU; Año: 2015 vol. 40 p. 59 - 65

1081-1710

Effective chemical control relies on completely or strongly reducing vector population size. However, insecticide selection pressure is often associated to the development of resistant populations which endanger control success. In treated areas, these resistant individuals present an adaptive advantage due to enhanced survival. Though, resistance can also lead to negative effects when the insecticide pressure ceases. In this study, the biological effects of deltamethrin resistance were assessed in Chagas disease vector Triatoma infestans. Length of each developmental stage and complete life cycle, mating rate and fecundity 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 deltamethrin resistance is suggested as these effects were identified in resistant females and their progeny independently of the mated male´s deltamethrin response. The results described in this work suggest the presence of pleiotropic effects of deltamethrin resistance. Possible associations of these characters to other traits such as developmental delays and behavioral resistance are discussed.