Resistance Management Program at St. Lucie Mosquito Control District

You may feel like the topic insecticide resistance is dynamic, complex, and ever evolving. In many ways, you’re right. As a vector control professional, you are challenged operationally every day to overcome resistance and successfully control mosquitoes. While this may be a new topic to some of us in vector control, it is a common theme across several entomological fields (such as agriculture and apiculture). To support you in your efforts to control mosquitoes, ADAPCO works to gather information and resources to better support your program’s needs for resistance monitoring and management.

So, what do you do if you think there is insecticide resistance in your area? How do you monitor for it and respond to it when it’s detected? With such an important topic, we wanted to take the opportunity to highlight programs in various regions throughout the US that have developed a resistance monitoring and management program to help them better control mosquitoes.

resistance management st. lucie

In the Southeast region, we interviewed Roger Jacobsen, Director of St. Lucie Mosquito Control District. Roger began his career in mosquito control as a seasonal fog truck driver.  He spent years learning everything he could about the district and the mosquito control industry and now manages a district that covers 301 square miles and includes both the city of Ft. Pierce and Port St. Lucie.  The district is overseen by its board or commissioners and the Florida Department of Agriculture and Consumer Services, Bureau of Entomology and Pest Control.   The five County Commissioners also serve as the District Board members.  St. Lucie Mosquito Control consists of three divisions: Administration, Inspection, and Impoundment Operations.

St. Lucie’s Approach to Monitoring and Managing Resistance

“Our resistance management plan is still in it’s infancy. We hope to be able to do much more of our own testing in the future. Before the resistance management plan, there was far less product rotation. This definitely could have contributed to the pyrethroid resistance that we are working against now.”

The insecticide resistance management plan at St. Lucie is primarily focused on three species:

  • Culex quinquefasciatus, the southern house mosquito
  • Aedes aegypti, the yellow fever mosquito
  • Aedes albopictus, the Asian tiger mosquito

These species are important from both a nuisance and public health perspective. To monitor the resistance in these populations, staff collects eggs and larvae from several sites and survey areas throughout the county. Resistance testing is managed by the Florida Medical Entomology Laboratory.

St. Lucie MCD currently partners with FMEL to have their resistance testing conducted. They test the above species at least twice per year, and most recently the high levels of pyrethroid resistance throughout the county has led to adding malathion to their rotation via Fyfanon EW. Their trucks are set up with Etofenprox (Zenivex), Permethrin (Biomist 3+15), and Malathion (Fyfanon EW) ensuring that the various adulticides utilized are rotated throughout the zones within the district.

When asked what changes had been observed as a result of starting a resistance management program through product rotation and what the biggest benefit was, Roger responded:

“Since implementing resistance management, data driven decision making has been implemented to include the rotation of chemicals to combat resistance. Resistance Management Plans enhance the overall effectiveness of Integrated Mosquito Management programs. This core competency enhances our control efforts, ultimately helping us control mosquitoes and other arthropods of public health importance.”

Challenges to Resistance Monitoring

In Roger’s opinion the biggest hurdle he has faced is funding.  Roger says,

“One of the obvious hurdles is funding. Having the staff and infrastructure to perform this type of testing is expensive. Internal support may be another obstacle.”

As you can see, there is not just one right answer when it comes to tackling and responding to insecticide resistance. Let the capabilities of your vector control program, your local mosquitoes, and the needs of your constituents drive what your insecticide resistance management plan looks like. Identifying the problem and taking even a small step to combat it is better than no attempt at all.

~Written by Katie Williams
Technical Development Specialist, ADAPCO

ADAPCO would like to note that the CDC is currently offering free bottle assay kits: Programs in the continental United States and its territories can order free Insecticide Resistance Kits by sending an email to USBottleAssayKit@cdc.gov and requesting an order form. Kits include bottles, insecticide, and manual.

Resistance Monitoring Resources

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