Pest News   |   July 7, 2020

Product choice is the most important factor in successful mosquito control

 By: Dr. Kurt Vandock, Head of Public Health, Bayer

Protecting our customers from the world’s deadliest animal, the mosquito, is one of the most important jobs you’ll ever do. But between the unique biology of mosquitoes and environmental factors like rainfall, UV exposure, and unpredictable or untreatable resting sites, the challenge of controlling mosquitos often seems unbeatable. But it’s notI’m going to cover the most important component of effective mosquito control and debunk some common misconceptions along the way. 

First, let’s talk biology. That’s what makes mosquito control and general insect control profoundly different tasks.  

Think about it. Most of our target pests are crawlers – ants, roaches to name a few. Once an insecticide is applied in their path, crawling pests may have hundreds, maybe thousands of chances to interact and take up the product.

But with flying pests like mosquitoes, interactions with surface treatments are very different. Mosquitoes buzz around and then come to rest on surfaces, sometimes only for a fraction of a second. So unlike their crawling cousins, mosquitoes only have six possible chances at any one time to connect with a treated surface, and those contact points are pretty miniscule – at the tiny tips of their legs!  

This means that product availability at those likely resting surfaces is critical. Which means your choice of product is critical.Your best choice is a product that packs a punch from the get-go, that’s easy to use and is long lasting across a range of surfaces.

For outdoor mosquito control, Bayer Suspend® PolyZone® is a proven champion. Its proprietary polymer formulation provides up to 90 days of effective residual control. It’s easy to mix and has a broad label. Suspend PolyZone has no phototoxicity, so it won’t harm plants, and it does not require PPE unless spraying directly overhead. Plus, Suspend PolyZone doesn’t have wind speed or interval restrictions like bifenthrin. 

Residual pyrethroid adulticide products like Suspend PolyZone don’t need a tank-mix partner for extra control. They are designed to work all by themselves.

I’m often asked whether adding an Insect Growth Regulator (IGR) to a tank is necessary. The short answer is NO. An IGR prevents immature larval mosquitoes from growing into adults. But mosquito larvae live in water, and would you ever apply a tank-mixed pyrethroid-IGR combination to water? No! That’s strictly prohibited, as all pyrethroids carry a warning: do not allow pesticide to enter or run off into storm drains, drainage ditches, gutters or surface waters. Since you’re not spraying larval mosquito habitats with a pyrethroid-IGR combination anyway, the IGR is an unnecessary addition to the tank.

Another argument some manufacturers make is that an IGR can be carried by mosquitoes from sprayed surfaces to breeding sites where it subsequently kills mosquito larvae. But this argument is also flawed. For this claim to be true, by default, the manufacturer’s adulticide must not effectively kill adult mosquitos, since the female mosquito must have survived for several days and taken a blood meal before laying eggs. The entire theory, based on the failure of the adulticides in the tank-mix, hasn’t been scientifically proven in the field and has only been replicated in laboratory settings.  

Finally, some manufacturers claim IGRs cause female mosquitoes to lay fewer eggs, thereby reducing mosquito populations. Once again, this argument is based on the premise that adulticide has failed, and that the female mosquito has time to take a blood meal before the product has an effect – another problematic scenario.

In all these cases, the claim of needing an IGR-adulticide tank-mix is only true if the adulticide fails to do its job, which is NEVER good for customer satisfaction or for the elimination of disease carrying mosquitoes. 

I hope this explains the complexity of mosquito control and has shined a bright light on the most important factor in successful mosquito control – your product choice.  At the end of the day, your best bet is a high-quality, easy-to-use, long-lasting product like Bayer Suspend PolyZone, which is designed for mosquito control without unnecessary extras. 

Now for those three blue chip recommendations to quickly improve your service:

  1. Set customer expectations realistically with the first interaction.As we’ve covered, a mosquito must rest on a treated surface in order to die. This will take time as not all surfaces in a yard can be treated, and dense populations from untreated neighboring yards will naturally migrate into your customer’s yard. Adequate control with anyresidual mosquito control product is never achieved immediately, and the customer needs to understand that. Tell the customer that after the initial treatment it can take days to notice a difference and cite the need for these flying pests to interact with the treatment areas you’ve targeted.
  2. If you’re using a backpack mist blower, apply in an up and down manner,not side to side or circles. Up and down is most efficient for using the blower’s velocity to force the leaves of target foliage up, so the product can be applied to the underside of leaves where mosquitoes rest.
  3. Coverage is king.The more surfaces you treat, the fewer places a mosquito can hide.  Take your time and slow down. When you go fishing, you drop a line where the fish are. When you hunt mosquitoes, you’ll want to hunt the shade where they will be resting.  Places often overlooked are under decks, eaves of homes, tall tree canopies, and under elevated structures. Follow the label and your licensing to ensure you are permitted to treat these surfaces.

I wish you luck as you battle the world’s deadliest animal. For more need-to-know information on mosquito control, Suspend PolyZone, the Bayer product lineup or product support, visit the Bayer website.


Bayer Environmental Science, a Division of Bayer CropScience LP, 5000 CentreGreen Way, Suite 400, Cary, NC  27513. For additional product information, call toll-free 1-800-331-2867. Not all products are registered in all states. Bayer, the Bayer Cross, PolyZone and Suspend are registered trademarks of Bayer. ©2020 Bayer CropScience LP.