Effect of Temperature on Insecticide Susceptibility in knockdown resistant Aedes aegypti

Aedes aegypti are vectors for common arthropod-borne-diseases (arboviruses) such as Zika, yellow fever, dengue, and chikungunya, which are of significant public health concern. The management of vectors is critical to mitigating the incidence, reemergence, and expansion of these diseases. Vector control has been complicated by the emergence of insecticide resistance within vectors, which threatens the effectiveness of control efforts. Furthermore, vector management is also complicated by the interaction between insecticide susceptibility and abiotic factors, such as temperature. While it is well-documented that environmental factors affect insecticide susceptibility, it is poorly understood how insecticide resistant vectors with different genetic backgrounds respond to insecticides at different temperatures. This study aims to establish the relationship between deltamethrin susceptibility at varying temperatures across Ae. aegypti lines that differ in their susceptibility due to knockdown resistance (kdr) mechanism. This was done through exposures using the “WHO tube test method” using simulated climate environments (22°C, 27 °C, and 32 °C) on mosquitoes of varying resistance at 1016 and homozygous resistance at 1534. This experiment is still ongoing. This study found that IICC was the most resistant genotype, VVCC the least resistant, and VICC and intermediate. There was found to be no statistically significant relationship between temperature and insecticide susceptibility across kdr genotypes.