Turf Reports: Inside the quest to control insects

Envu is proud to sponsor the following report on some of the most problematic golf course insect pests.

The golf industry continues to struggle with annual bluegrass weevil (ABW) as probably the toughest insect pest to control in cool-season turf. ABW continues to spread west and south from the Northeast United States into previously undetected areas. The major contributing factor is ABW contamination in creeping bentgrass sod shipped from out of state. Be careful with selecting a sod company for renovations or winter damage repair, favoring the closest source possible. Once ABW is in a location, it is virtually impossible to eliminate it because of its reproductive capacity. Furthermore, the longer ABW resides in a particular area, the chances increase for both insecticide resistance and multiple overlapping generations, making control more difficult. Control of ABW revolves around season-long, multipronged programs with multiple insecticide applications targeting primarily overwintering adults and first-generation larvae as well as later-generation larvae. Rotating insecticide modes of action is critical to limit the chance of resistance development in ABW populations at your course.

Though white grubs traditionally have been more problematic in the eastern half of the country, turf managers in the Rockies and all the way to the West Coast are now accounting for these insect pests. Unlike ABW, insecticide resistance has not been documented in white grubs and likely will not occur since they have only one generation per year. However, we are seeing population shifts in white grub species. Where Japanese beetles and northern or southern masked chafers were the most predominant species, we are now seeing more oriental beetles, Asiatic garden beetles and May/June beetles. The white grubs themselves rarely cause significant damage; it’s actually the raccoons, skunks, feral hogs and other vertebrates foraging for the larvae that cause the most problems. Controlling larvae in late summer with long-lasting soil insecticides should minimize the damage from the foraging animals.

Envu officially launched Tetrino® insecticide two years ago — an exciting new tool in the fight against ABW and white grubs. Featuring the active ingredient tetraniliprole, Tetrino is a new diamide insecticide that joins the ranks of other Envu favorites like Merit® and Dylox® insecticides. This new active ingredient is taken up quickly into the turf plant, providing knockdown within days of application. It offers unrivaled control of white grub and ABW larvae as well as billbugs, black turfgrass ataenius and caterpillars like fall armyworm that destroy turf throughout the Midwest and North Central United States. As is the case with all insecticides targeting soil larvae, optimum application timing of Tetrino is when adults are present in order to control the larvae appearing shortly thereafter. Tetrino offers tremendous flexibility to the golf course superintendent with two rates and up to four applications per year depending on your geography and pest pressure. Results over the last two years on ABW, white grubs, billbugs and fall armyworms were impressive.

Again, Envu is honored to support the following insecticide report based on a survey administered by Golf Course Industry. If you have questions regarding controlling these pests or others on your course, our Green Solutions Team of turfgrass technical specialists is just a phone call, email or text message away as is our nationwide team of area sales managers.

Let us know if we can help!

Zac Reicher, Ph.D.

Jesse Benelli, Ph.D.

Green Solutions Team, Envu

The smallest animals lurking on golf courses are the centerpiece of a big business within the business of preparing high-valued playing surfaces for recreation.

Turfgrass insects are the subjects of books. Major universities employ researchers to study their tendencies and vulnerabilities. Dozens of insecticides possessing proven and emerging active ingredients are designed and positioned to halt their spread.

Tiny creatures. Immense potential problems.

For the third straight year, Golf Course Industry asked superintendents, directors of agronomy and assistant superintendents about all things insect control. The results of the survey are published on the following pages.

We collaborated with New Jersey-based research firm Signet to collect data based on responses from individuals on our list of print and/or digital subscribers in the United Staes, Canada and other countries. The survey was distributed via email from July 25 to Aug. 14. Results are based on 170 completed responses and the confidence level is 95 percent with a sampling tolerance of approximately +/- 7.5 percent.

In addition to the survey results, we explored the personal side of turfgrass insect control. Here are a trio of stories humanizing the business of preventing insects from harming the extensive work executed by superintendents and their teams.

Like most superintendents, Matthew Partridge looks down to find the insects he needs to corral and control. White grubs are probably his biggest nemesis at Country Club of Rancho Bernardo, a William F. Bell design later updated by Ted Robinson situated about 25 miles north of downtown San Diego. European chafers are a challenge too, and armyworms, cutworms, billbugs. But to find his most surprising struggle, Partridge needs to look up.

“Crows have been a huge issue for us this whole summer,” says Partridge, who arrived at Rancho Bernardo in February after almost six years at nearby Miramar Memorial Golf Course. “We’ve tried everything. Nothing works. The crows keep pecking away at things.”

Crows, like elephants, have long memories. If they find an insect they like in a certain spot, they will return to that spot again and again and again, even if their food goes elsewhere. Unfortunately for Partridge, local crows have found good grub on his Poa greens and kikuyugrass.

“It looks like about 50 ball marks exploded on the green and they’ve pulled out some chunks bigger than a cup cutter,” he says. “They really do cause some damage. And it’s repairable, but if it happens during play it’ll mess up the green. They don’t do every green. They work their way around. It’s frustrating. The crows have caused more damage than any insects the entire year.”

Compounding the aerial problem, San Diego has endured a series of storms — including Tropical Storm Hilary in August — that have dumped about double the average annual amount of rain.

“Used to be late spring, early summer was the time you would start to look for different things,” Partridge says. “This year, April was way too cold. Soil temps were still in the low 50s. We had a frost at the end of March. The rain continued, overall temps were lower, soil temps were lower, which prolongs our wintertime. … From an insect standpoint, that’s the biggest thing: soil temperatures staying lower later in the year.”

Partridge has worked at a handful of courses around San Diego since returning to the industry in 2009 following six years in the U.S. Marine Corps. He knows the area. He knows the turf and the soil. He knows insects. But the crows and the weather have altered his approach.

“It’s making enough of a change to affect us and everything that we do,” he says. “And I think it’s changed enough that we have to pay a little closer attention to it. It’s going to make a difference in the timing of the products we use. We’re going to have to go to a technology-, soil temperature-, air temperature-, growing degree day-based system and stick to it, versus the old tried-and-true (calendar) approach.

“And if these stupid crows keep pecking away at the greens, we might go hardcore into all sorts of different things just to figure out what the heck it is they’re trying to find down there.”

Near the country’s other coast, Pat Quinlan deals with white grubs, too.

The Fairmount Country Club superintendent considers the annual bluegrass weevil to be a bigger challenge, but with New Jersey fast approaching its statewide elimination of neonicotinoids on golf courses, white grub control is about to become more expensive for Quinlan and his Garden State peers. Quinlan estimates that because a post-patent version of a popular insecticide will not be available before Nov. 1 — when the new legislation goes into effect — each white grub application will increase from about $700 to about $6,300.

“Unfortunately, we lost that battle,” says Quinlan, who has worked in the Tri-State area for about a quarter of a century and arrived at Fairmount six years ago. “Our grassroots efforts were doing the best they could in Trenton and they didn’t win.” Now not only can New Jersey superintendents no longer purchase neonicotinoids, “we have to have everything applied by Oct. 31.

“But you can still apply it to your dog, your cat, or inside your house. I’m not a politician, but let’s just say they don’t know what they’re talking about.”

Quinlan will at least be able to maintain his current annual bluegrass weevil plan, though those applications aren’t getting any cheaper, either. “We’re only applying that on greens and approaches currently,” he says. “We’re not treating for adults anymore on fairways or tees, and larvaecides are fairly pricey. We do two larvaecide apps at pretty high cost, but we’re controlling it with those two applications.”

Quinlan scouts for adults throughout the 140-acre property — which is located entirely within the Great Swamp National Wildlife Refuge — by checking forsythia plants around the middle of April. That process started a little later this year, “because it was cool and a little dry,” he says. “We scout for the adults and that’s helped us with the application. Since we’re not treating the adults elsewhere, we don’t get too excited, but once we see the adults in large numbers we know when to start looking for larvae.”

As for scouting for larvae, “we just wait to see some off-color turf or dig in some of the hotspot areas we’ve had. We’re seeing moisture plays a huge role. We’ve been very, very wet the second half of the season and we have not put out our second larvaecide, and we might not. It’s been so wet that even if there’s larvae present, we’re not seeing any damage. So it seems as far as the larvae goes, I’m not saying that the moisture is preventing the larvae, but it’s keeping the damage at very, very acceptable levels for us.”

Quinlan and his 15-person crew spotted a mole cricket not long ago, “but that’s nothing to get worried about for us,” he says. “They’re kind of interesting for us to see because we’re pretty far north, but weevils continue to be our biggest issue.”

White grubs are the primary turfgrass insect concern in the Central states. Ninety-eight percent of superintendents in the region indicated white grubs have the potential to cause turf damage, with 96 percent reporting they use an insecticide for control.

Mike Tichenor can relate to what his peers experience. Tichenor is in his fourth season as the superintendent at Island Hills Golf Course, a 24-year-old layout on a 275-acre property bordering Lake Templene in southern Michigan.

Fortunately, Tichenor hasn’t observed turfgrass insect problems related to the course’s proximity to the 1,000-acre lake. Unfortunately, he’s noticed white grub activity and damage on fairways.

“It is frustrating, especially when you have the rodents come in and do the damage on top of the damage that the grubs do,” Tichenor says. Skunks and raccoons are the most opportunistic rodents Tichenor encounters.

The damage becomes noticeable in late summer and early fall. Tichenor treats Island Hills’s 30 acres of bentgrass fairways with an insecticide in June or July. He treats the surfaces for white grubs once per year. He’s considering altering his approach in 2024.

“I kind of use what they have used in the past with some input from some of our sales reps,” Tichenor says. “I use what they recommend. Next year I’m going to change products so hopefully we can get better control.”

Ants are the only other insects Tichenor uses an insecticide to control. He says he treats portions of Island Hills’s 5½ acres of greens on an “as-needed” basis to curtail ant activity.

Annual bluegrass weevil, according to Tichenor, hasn’t reached Island Hills, a course equidistant from Detroit and Chicago. “I’m keeping an eye on it,” he adds. “We’re watching to see how far it’s coming. I have been reading up on it and trying to prepare myself for it."

Controlling one perplexing turfgrass insect presents enough challenge.

“If it gets any worse than it is now,” Tichenor says of his white grub tussles, “it will rank right up there with the disease pressure. It’s not quite there … yet.” 