Header Image Volume 4

Integrated Pest Management Overview: Part 4

Mosquito Adulticiding in the Modern Era

Modern Integrated Mosquito Management (IMM) in the United States is a decision-driven program that incorporates surveillance, public education, habitat source reduction, larval control, and, when appropriate, adult control through the targeted use of adulticides. Adulticides are an important component of an effective mosquito management program that are typically reserved for situations when mosquito surveillance indicates high adult population abundance, where vector species are present and biting, or where there is an increased risk of vector-borne disease transmission and rapid knockdown is needed. This type of highly visible, large area mosquito management operation requires informing the public about treatment times and locations as well as answering questions and alleviating concerns. Additionally, comprehensive surveillance and resistance management strategies are necessary to evaluate these operations and ensure the most effective mosquito control is achieved.

 

Incorporating adulticides into IMM

The foundation of an effective IMM program is surveillance. Adult trapping, landing rates, larval dipping, GIS data management and mapping, sentinel data, and arbovirus testing all provide information that is used to determine what control methods are best suited to a program’s goals and budget. Typically, source reduction and larval control activities are the first control measures an IMM program conducts, but when needed, adulticide operations are planned to both maximize impact and minimize non-target exposure.

The choices of adulticide product, application times (often at dawn or dusk when key vector species are active), equipment type (truck mounted Ultra Low Volume (ULV), aerial ULV, or handheld ULV), and treatment zones, are based on the collected surveillance data, with mosquito activity, disease risk and the probability for mosquito/human interactions being the primary decision-drivers. The goal is not to spray everywhere, but to treat strategically and effectively, when and where it matters, often when previous prevention methods such as source reduction and larviciding need an additional step to lower the threat of vector-borne disease and reduce adult mosquito populations.

 

Chemical classes used for Public Health adult mosquito control

In the U.S., the major adulticide classes used by mosquito control programs include organophosphates, natural pyrethrins, and pyrethroids.

Organophosphates are primarily used for rapid adult mosquito knockdown and often deployed when programs need an alternative mode of action to pyrethroids. Malathion and Naled are commonly used OP adulticides for ULV applications.

Pyrethrins are botanical insecticides derived from chrysanthemum flowers and are used for contact knockdown. They are commonly paired with synergists, such as piperonyl butoxide (PBO) to improve efficacy.

Synthetic pyrethroids (and pyrethroid-like adulticides) such as permethrin and etofenprox are widely used adulticides due to their effectiveness at low use rates and compatibility with ULV technology. Because pyrethroid resistance can occur in localized populations, programs increasingly emphasize mode-of-action rotation, quality assurance of droplet size, and post-treatment evaluation to ensure the product was delivered to the intended target sites and population reduction has occurred.

 

IMM relies on mosquito adulticiding for program effectiveness

Adulticide applications are a critical component to a complete IMM program and adulticides are most effective when programs implement clear parameters for their use. The following details are keys to success:

  • Clear thresholds and documentation – why the application was triggered, what data supported the action, where the application took place, and what outcomes were measured.
  • Application optimization – determine time of day, confirm correct droplet size, calibrate equipment, monitor environmental conditions (wind, temperature, inversions, precipitation), and follow label instructions.
  • Resistance management – rotate chemical classes where possible, avoid unnecessary repeat applications, ensure effective application rates are used, and incorporate local resistance monitoring.
  • Communication – notify communities about schedules, emphasize that adulticides are part of a larger prevention program (surveillance + source reduction + larvicide), and educate about the importance of vector control (disease risk and prevention) and the methods used to minimize risk (timing, ULV application rates, low product toxicity, environmental stewardship).
  • Geographic Information Systems (GIS) – GIS data management and mapping are a critical component of modern mosquito control programs and play a role in all of these keys to success. In fact, GIS has become so important that we will feature the subject as a keynote article in a future edition of Vector Vision, so stay tuned!

Under these conditions, adulticides remain a vital rapid response component of modern IMM by helping communities reduce biting pressure and disease risk while maintaining a disciplined, data-led approach to pesticide use.

 

Central Life Sciences as an IMM solution

Central Life Sciences positions mosquito adulticides as a complement to a broader IMM strategy, particularly when paired with larval control and surveillance-based decision making.

Zenivex® mosquito adulticides give you three alternatives for adult mosquito control. They are high-efficacy, reduced-risk adulticides that provide quick, permanent knockdown and reliable control of adult mosquito populations in any mosquito habitat.

Zenivex® E20 and Zenivex® E4 are oil-dilutable formulations for use in Ultra Low Volume (ULV) applications and do not require dilution. Aqua Zenivex™ E20 has the efficacy and toxicity profile of Zenivex® products, in a water-dilutable formulation. All Zenivex® formulations are ready-to-use for ground or aerial applications, require no aquatic setbacks and have crop approval so you can spray throughout urban and rural settings.

Zenivex and Aqua Zenivex are trademarks of Wellmark International.