Deltamethrin pyrethroid susceptibility characterization of Triatoma sordida Stål, 1859 (Hemiptera: Reduviidae) populations in the Northern Region of Minas Gerais, Brazil
Pessoa, Grasielle Caldas DÁvila, Dias, Letícia Sena, Diotaiuti, Liléia
Rev. Soc. Bras. Med. Trop.
DATA DE PUBLICAÇÃO
Introduction Triatoma sordida is the most captured Triatomine species in the Brazilian artificial environment. In 2008, the discovery of three Triatomine populations with altered susceptibilities to deltamethrin highlighted the importance of investigating the genetic potential for resistance in triatomines. The purpose of this study was to characterize the susceptibility to deltamethrin of peridomestic T. sordida populations in Minas Gerais, Brazil. Methods A susceptibility reference lineage derived from Uberaba, Minas Gerais, Brazil was used. Serial dilutions of deltamethrin were prepared and applied to the dorsal abdomen of first instar nymphs. The control group received only pure acetone. Mortality was evaluated after 72h. Qualitative tests assessed mortality in response to a diagnostic dose of 1xLD99 of the susceptibility reference lineage. Results Susceptibility profile characterization of T. sordida populations revealed resistance ratios (RR50s) ranging from 0.42 to 3.94. The percentage mortality in response to the diagnostic dose varied from 70% to 100%. A comparison of the results obtained in the quantitative and qualitative assays demonstrated a lack of correspondence for some populations. Conclusions We demonstrated that only T. sordida populations that present a RR50>1.0 have altered susceptibility, and the execution of simultaneous field and laboratory tests is required to understand the actual effect of vector control. A possible cause of the observed resistance ratios might be the continuous use of pyrethroids in Brazil since the 1980s.
- Susceptibility of Triatoma sordida Stal, 1859 (Hemiptera: Reduviidae) to alpha-cypermethrin under natural climatic conditions
- Susceptibility characterization of residual Brazilian populations of Triatoma infestans Klug, 1834 (Hemiptera: Reduviidae) to deltamethrin pyrethroid
- Monitoramento da suscetibilidade de populações de Triatoma sordida Stål, 1859 (Hemiptera: Reduviidae) ao inseticida deltametrina, na região Centro-Oeste do Brasil
- Morfologia da espermateca de Triatoma lecticularia (Hemiptera: Reduviidae) (Stal, 1859)
- First report of Triatoma sordida Stål, 1859 (Hemiptera, Reduviidae, Triatominae) in the State of Acre and Brazilian Western Amazon