Will we see the same record numbers as 2021?
The turf world is a constantly changing environment and being really good at what you do also requires change. Over time, our approach to turf management has evolved and practices have been modified. Changes in weather patterns and climate further complicate matters.
I will avoid spending a lot of time on this topic to avoid alienating anyone, but from my perspective, climate change is very real. We can measure it, see it, and it is reflected in our pest problems.
When I first started at North Carolina State University, sod webworms on bermudagrass were a problem. Through the late ‘80s, though, I never really saw webworm problems and rarely received any calls. However, in the past few years, sod webworms seem to be returning. (For advice, see content.ces.ncsu.edu/sod-webworm-in-turf.)
Fall armyworms can be a handful. (Photo: Provided by Dr. Brandenburg)
As drought conditions worsen in some areas, it could impact insects that like it hot and dry—such as southern chinch bugs and bermudagrass mites—which may increase dramatically. Others that require soil moisture for egg laying, such as white grubs, may become less abundant. This can also vary annually depending upon weather. Pest problems we’re seeing throughout the country, in both warm and cool-season turf, are not consistent, but things are ultimately changing.
Pest Trends
So what transitions in insect pest populations have I observed in the past few years? I could start with an ever expanding range of fire ants, more chinch bug problems, new white grub species, more bill- bugs, annual bluegrass weevil expansion, mites, and in 2021 – fall armyworms. We also have seen strange outbreaks including sugarcane beetles that cause problems for two to three years and then go away.
Many factors allow or promote these pest changes. In some cases, invasive pests are simply adapting and expanding their range. It may also be the result of changing turf and landscape management practices that create more favorable conditions. Finally, it could be related to transitions to warm-season turf types and climate warming (fall armyworm). It isn’t as simple as outlined here, but pest changes are happening and we have ways to manage them. All turfgrass insect pests can be effectively managed (except ground pearls), but awareness, monitoring, and timely applications of proper products are the key to success.
While chinch bugs, billbugs, mites, and others have increased in abundance and frequency in recent years, I want to focus on one observed at record levels last year: fall armyworms. They occurred in locations where no one had ever experienced them before. Once the battle was over, everyone was asking: Why did it happen and was it going to happen again in 2022?
Fall Armyworms
First, let’s take a look at fall armyworm biology. They do not overwinter in the majority of the U.S. They are tropical insects that overwinter in extreme southern Texas, along the Gulf Coast. Therefore, any infestations outside of these warmer areas must start all over again annually with the migration of moths to the North. In other words, what happened in 2021 is going to have very little impact on 2022. Any given year’s outbreak is dependent upon the northward migration—and that migration is impacted by weather. I have seen moths arrive in NC and start causing problems as early as May and as late as July. The timing of their arrival impacts the potential for serious outbreaks. In fact, in some years, outbreaks in NC don’t occur until late August.
Fall armyworm outbreaks are always sporadic—even in NC where we see our fair share. However, it appears we are seeing more and more each year as compared to 10-20 years ago. In my area of NC, they are more problematic on hybrid Bermuda, but I have seen them cause serious damage in both warm and cool-season turfgrass.
