Fig. 3

The effect of heat shock on the malathion- and deltamethrin-resistant phenotypes of insecticide-resistant Anopheles arabiensis. Adult SENN DDT individuals that emerged from larvae reared at a constant temperature of 30 °C showed a significant decrease in deltamethrin induced mortality compared to controls that had been reared at 25 °C and received no heat shock during their lifetime. Similarly, adults that were reared at 25 °C but received a heat shock prior to exposure (3-h heat shock at 37 °C with a 1-h recovery period) showed a similar decrease in deltamethrin-induced mortality. These findings were observed in both males and females. This effect was not observed for the malathion resistance phenotype. All exposures were performed under standard WHO bioassay conditions [26]