Fitness of pyrethroid resistance in Triatoma infestans, a vector of Chagas disease

M.I. PICOLLO

Orlando, Florida

Congreso; International Congress of Entomology (ICE 2016) 64th Annual Meeting of the Entomological Society of America (ESA).; 2016

Entomological Society of America (ESA)

Triatominesare large blood-sucking bugs that occur mainly in Latin America countries andare vectors of Chagas´ disease. Chemical control by using pyrethroidinsecticides has been successful for the elimination of domestic infestation.However, at the beginning of the 2000s a decrease in the effectiveness ofpyrethroids was detected in Argentina and Bolivia, particularly in the GranChaco eco-region. Actually, it is known the wide widespread and mechanisms ofresistance in Triatoma infestans and the expression of deltamethrinresistance thoroughout the embryonic development. In thiswork, the fitness of resistant T. infestans from Aguaray, Salta,Argentina (22°14?S 63°43?W), an area of the Gran Chaco eco-region, was measuredin comparison to susceptible insects by using a demographic approach based onmatrix population models. The length of each developmental stage and completelife cycle, mating rate, and fecundity were evaluated. A survival life tablewas constructed and parameters were calculated to achieve a stage-structuredmodel of population growth. The resultsshowed that the total fecundity of susceptible females resulted significantlyhigher than resistant and crossed ones and was expressed as the highestreproductive value. Moreover, the proportion of individuals in the youngerstages was lower in the resistant than in the susceptible colony, and theopposite was found for the older stages (IV to adult). Thedescribed differences in reproductive output and development were associatedwith lower growth rates in the resistant insects, which could delay resistanceevolution or allow its reversion in heterogeneous populations. TopicSelection:Ecology ofPesticides, Resistance, Toxicology and Genetically Modified Crops