In addition, anytime a control application does not obtain the desired efficacy, they will also do a bioassay to assess if resistance could have been a factor. For typical rotational management throughout a season, they will rotate products on approximately a month-to-month basis. Over successive control years, using synthetic pyrethroids with and without synergists and organophosphates is another means of implementing rotational management. If resistance is suspected in a population, either they will change the active ingredient, mode of action, or increase the application rate.
Operational Application of Resistance Management Program
With all the resistance management techniques that TASD uses, I wanted to understand how it translates into operational use in Paul’s program.
“In terms of our mosquito population composition and susceptibility, we identified some low-level resistance to organophosphates that helped guide a change to more pyrethroid use in certain areas of the county when targeting Culex mosquitoes. This is a change we may not have identified without resistance testing and was important for our efforts to protect our citizens from West Nile Virus.
Overall, our program has changed a great deal since 2014, when we started resistance testing. Technology advancements and increased surveillance sites along with trapping frequency have allowed us to gain a much better understanding of what is happening within our mosquito populations in response to our treatment efforts. Resistance testing provides additional information for us to consider when making product selections, application rates, or when evaluating the overall efficacy of control applications.”