Pyrethroid-Resistant and Susceptible Triatoma infestans (Klug, 1834) (Hemiptera, Triatominae): Analysis of Their Vectorial Characteristics by Metacyclogenesis, Feeding/Defecation Patterns, and Parasite Load

Populations of Triatomas infestans with different susceptibility to pyrethroid insecticides were reported have distinct evolutionary and epidemiological characteristics. We aimed at evaluating metacyclogenesis parasite load as measures vector competence feeding/defecation patterns vectorial capacity estimates a group resistant (“R”) susceptible (“S”) T. infestans. Third instar nymphs each fed on mice infected Trypanosoma cruzi (Tulahuén strain, DTU VI). Parasite concentration in blood was quantified by real-time PCR (qPCR) for mouse. The time which feeding started, the span feeding, volume consumed, taken defecate measured. At 30 days post-feeding, feces analyzed parallel optical microscopy (percentage metacyclic trypomastigotes, % MT), qPCR (total DNA). ratio parasites consumed/defecated used estimate parasites’ survival multiplication inside triatomines’ gut. It estimated that trypomastigote 6.6 obtained “R” nymphs, 7.9 “S”. consumed higher blood, had lower MT their (lower competence), took longer capacity) than