Susceptibility of Triatoma infestans to deltamethrin in Rio Grande do Sul, Brazil

Residual effect of a micro-encapsulated formulation of organophosphates and piriproxifen on the mortality of deltamethrin resistant Triatoma infestans populations in rural houses of the Bolivian Chaco region

“…In several cases, the phenomenon seems nearer to insecticide tolerance than insecticide resistance, in other words, not strictly a consequence of the repetitive use of insecticides in a particular area. Pyrethroid resistance in triatomines shows a patchy spatial distribution, not necessarily associated with the intensity of pyrethroid use for triatomine control, as shown by Sonoda et al (2009). Although there are no previous reports concerning T. infestans pyrethroid resistant populations in the studied region, this work indicates that it is effectively a deltamethrin resistant area.…”

Susceptibility and resistance to deltamethrin of wild and domestic populations of Triatoma infestans (Reduviidae: Triatominae) in Bolivia: new discoveries

“…At least three hypotheses can be put forward: (i) the existence of natural resistance in wild populations, (ii) resistance developed by contact with insecticides used in agriculture and/or in malaria control and (iii) the existence of a contact between these populations and resistant populations of a nearby village. The presence of natural resistance to deltamethrin in Triatominae has never been demonstrated and most of our wild strains were susceptible to deltamethrin, including some domestic populations of T. infestans (Sonoda et al 2009, Lardeux et al 2010). Nevertheless, Roca Acevedo et al (2011) hypothesised that wild populations of T. infestans from different geographical areas would have different toxicological profiles.…”

Susceptibility of Triatoma brasiliensis from state of Ceará, Northeastern Brazil, to the pyrethroid deltamethrin

“…More details of the bioassays are described in Sonoda et al (2009). The following numbers of T. brasiliensis specimens were obtained from each locale: Cachoeira do Julio (I) (8 adults and 9 nymphs), Cachoeira dos Pedrosas (I) (2 adults and 5 nymphs), Dormideira (I) (0 adults and 2 nymphs), Mutuca (I) (14 adults and 24 nymphs), Cachoeira dos Pedrosas (P) (18 adults and 18 nymphs), Morada Nova do Thomas (P) (0 adults and 3 nymphs), Mutuca (P)…”

“…T. infestans from RS presented the smallest RR value, 7.0 for deltamethrin, considered the initial resistance. Recently, Sonoda et al (2009) studied samples of T. infestans from four locations in RS and found RR values that classified the samples as susceptible to deltamethrin.…”