2024 was arguably the most challenging year in the past decade for Florida chinch bug management. Phone call after email after meeting, I was hearing pest control professionals describe their struggles to control chinch bugs in lawns. None of the insecticides they were applying seemed to provide adequate control, although they have in past years. I was optimistic that this was a fluke. Perhaps the products weren’t working because we had unusual weather patterns with extreme drought conditions followed by extreme rain events. Maybe the weather was helping the bugs and making the insecticides less effective. Unfortunately, 2025 is shaping up to be worse.
What is this bug?
The southern chinch bug, Blissus insularis, has long been the most economically important insect pest of turfgrass lawns in Florida. This native sap-feeding insect thrives in St. Augustinegrass, but attacks zoysiagrass and bermudagrass as well. Once a population builds in a lawn, chinch bugs can rapidly kill large areas. There are no commercially available St. Augustinegrass, zoysiagrass, or bermudagrass varieties known to be resistant to the southern chinch bug. Properly irrigating, fertilizing, mowing, and managing turfgrass is the starting point for effective chinch bug management, but that is easier said than done.
What is resistance?
Insecticide resistance is the increased ability of an insect to survive exposure to an insecticide and reproduce, passing on that ability to survive. Due to our reliance on insecticides to manage this pest, it has a strong track record of developing resistance to them. For example, we have documented cases of southern chinch bug resistance to five insecticide classes, including those most relied upon by the pest control industry, pyrethroids and neonicotinoids. This doesn’t mean all chinch bugs are resistant to these chemistries, but it does mean it happens. The most recent research evidence of this was over 15 years ago, meaning they have had plenty of insecticide exposure and time to continue developing resistance. While we do not yet have confirmed research evidence of resistance in 2025, there is an overwhelming amount of in-the-field evidence of failed control when populations are treated with multiple insecticides within the same chemical classes.
Patience, understanding, and diligence
If you’ve hired a pest control company to manage your lawn, I encourage you to have patience and understanding when it comes to managing the southern chinch bug. In many cases, their hands are tied and they are doing their best to provide a quality service. Changing companies is not necessarily the solution, as most have access to the same tools. Although there are over 100 insecticide products available to control chinch bugs in lawns, there are really five (chemical classes) from a resistance perspective. And not all are equally effective, even before resistance is in the picture.
If you are a pest control professional, I feel for you and encourage you to remain diligent and responsible. Try to expand your programs beyond the two main classes we rely on if you can. Consider IRAC Groups 1A, 15, or 28. Even try branching out into biologicals like azadirachtin or Beauveria bassiana, if possible. But continue to comply with the label restrictions.
Looking ahead
In the coming months and years, my lab at UF is committed to addressing this issue and continuing to work towards developing more sustainable solutions to southern chinch bug management. This is a long game, but I am confident we can identify solutions to help the pest control industry and the many millions of FL residents with turfgrass lawns.
Adam G. Dale, Phd
Turfgrass & Ornamental Entomologist
Associate Professor & Associate Chair for Extension
UF IFAS Entomology & Nematology Dept.
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