Resistance of Aedes aegypti (Diptera: Culicidae) to temephos in Parana State, Brazil

The number of dengue cases has increased drastically the state of Parana since 1995 without a consistent explanation. In order to contribute to this subject, the susceptibility of A. aegypti to the insecticide temephos was evaluated in several municipalities in Parana, along with seasonal variation of oviposition of Aedes spp. in Maringa and Jacarezinho. Comparison of mortality and resistance rates RR95 (CD = 0.0060 mg/L) of the Rockefeller temephos strain (Rock) on individuals from these locales showed that vector populations from Foz do Iguacu (67.5 +/- 7.7; RR95 = 3.9), Paranavai (58.1 +/- 14; RR95 = 3.4), Maringa (57.8 +/- 5.2; RR95 = 6.9), Ibipora (68.75 +/- 3.9; RR95 = 6.6), and Jacarezinho (73.3 +/- 7.5; RR95 = 3) were resistant; while those from Cambe (81.56 +/- 10; RR95 = 2.6) had an incipient change in susceptibility. The vector populations in Maringa and Ibipora displayed average resistances (RR95 > 5 and < 10), while the others showed low resistance (RR95 < 5). In Maringa and Jacarezinho, oviposition fluctuation was lower in winter.