Last year, the experts Lawn & Landscape interviewed about insects and pests almost uniformly said that a wet, warm winter made it unclear what problems LCOs would face over the spring and summer.
Some things never change – experts say there’s no way of knowing for sure what will be this year’s prominent problems. But those same experts instead point to a dry winter as the reason for this season’s unpredictability.
“I dropped my crystal ball this morning,” said Chris Williamson, a researcher with the PBI-Gordon team. It was a joke – he obviously doesn’t really have a crystal ball – but the point was that it’s difficult to say with any certainty how the weather affects pest pressures.
Williamson is also a former professor of 20 years, and he knows that a wet winter could either let pests fester or drown them. Meanwhile, a dry winter might mean that insects don’t get what they need to survive or it could mean that they thrive without snow or cold rain.
“All regions in the country are being impacted more than normal by turf pest pressures in great part due to the inconsistencies in weather patterns from season to season and year to year,” says Bayer’s Robert Golembiewski. “We are seeing the spread of diseases, insects and weeds into regions of the country that we have never seen before.”
“We are seeing the spread of diseases, insects and weeds into regions of the country that we have never seen before.” Robert Golembiewski, Green Solutions Specialist, Bayer
If you went to California right now, Reinie Drygala from Civitas says farmers started applying products to crops in January because of the mild winter. They wouldn’t normally start applying products until mid-March.
“We didn’t really have much of a winter,” Drygala says. “Most of the time, winter deals with a lot of unwanted pests, either fungal disease or some sort of insects.”
When looking more on the lawn care side of things, Drygala says the same principle applies as freezes or other winter events didn’t happen to wipe out populations of insects. He adds that mites and grubs will be more problematic this year across the country, but the larger issue at hand is what could happen long-term as LCOs try to fend off the insects.
Drygala says types of mites, honey locust, lace bug, leaf beetle larvae, leaf miner and leaf roller, among a whole slew of other insects like sawfly larvae, mealybugs and fruit worms, could be controlled with products that include petroleum or mineral oils as the active ingredients. It’s just hard to know which populations will be most prevalent.
“Unless we get a cold snap throughout the course of the year, I wouldn’t be surprised if the insect pressure is stronger throughout the entire spring, summer, going into early fall, probably more than normal,” Drygala says. “We’re going to be applying more (product) over the course of the year. Now, that causes some problems because… there are limitations on how many times (LCOs) can put them out. You’re going to get some issues with resistant populations, and you’re going to have to start finding different ways to deal with that.”
Take the annual bluegrass weevils, which are starting to pop up in the Midwest, not just the East Coast. Drygala says these are moving westward because they’re becoming resistant to the products as time wears on.
“Those are tough insects to deal with because a lot of them have become resistant to chemicals from overuse,” he says. “The options are becoming fewer and fewer in terms of how people are dealing with that.”
Golembiewski says there are five dominant turf species used for home lawns. Though each of them face their own pressures independent of one another, the main problems all face are doveweed and annual bluegrass.
He says doveweed is a low-growing, creeping summer annual that continues to proliferate and spread throughout the southeast. It’s difficult to control since traditional preemergence herbicides aren’t usually effective in a normal application timing. Bluegrass, meanwhile, is a winter annual that has developed resistance to most commercially available chemicals.
Meanwhile, tall fescue turf faces challenges like gray leaf spot and Pythium. “Under favorable environmental conditions, both diseases can strike very quickly resulting in significant turf death,” Golembiewski says. When you factor in the more traditional threat of brown patch, he says all three pathogens can affect the tall fescue turf at the same time, culminating in a triple threat that’s hard to combat.
For St. Augustinegrass, the southern chinch bug is especially problematic. He says it can have between five or six generations every year and some of those generations are pyrethroid insecticide resistant.
“The first thing to understand is that there is no elimination or eradication of any turfgrass pest,” Golembiewski says. “The best approach is to be proactive with an integrated management program that consists of both cultural and chemical strategies.”
He recommends reminding crews to maintain a proper mowing height, irrigation frequency, fertilizer rate and core aeration, which reduces soil compaction and promotes healthy air exchange. Meanwhile, for the gray leaf spot and Pythium, he suggests initiating a preventative fungicide program in summer through early fall when maximum daytime temperature and minimum relative humidity exceeds 140. The southern chinch bug remains active when it’s warm all year, so he recommends rotating chemical classes and avoiding using the same chemical multiple times.
For doveweed, the best approach is a split-application preemergence program combined with a postemergence program. He suggests a herbicide with the active ingredient indaziflam. Further, the annual bluegrass can be combated with a pre- and postemergence combination with different modes of action. He suggests using products with indaziflam, halosufuron-methyl and simazine.
He also says contacting your local state university’s turf program could provide specific insights on your area’s prominent turf type.
Williamson from PBI-Gordon says in areas with cool-season grasses, white grubs will likely be tricky to navigate for LCOs. There’s no cool-season grasses or hedges that naturally battle these grubs, so insecticides with active ingredients like dinotefuran, thiamethoxam or clothianidin should prove helpful this season.
“We’re limited on solutions because some things could be good for other insects, like keeping the grass cut short or irrigating overnight instead of in the morning,” Williamson says.
He also mentioned the spotted lanternfly, a recurring pest in the northern region of the U.S. that often afflicts ornamentals, trees and even fruit crops in the Northeast. Products with dinotefuran are recommended to combat this invasive species.
As a positive, Drygala from Civitas says mosquito pressures may be down as there won’t be as much standing water from a wet, humid winter season. Even up way north in Minnesota, the snowfall was closer to normal rates.
“Things could change very quickly if we start getting some major rainstorms, but we’re just looking at other sources of water,” he says. “It’s just not there.”