Few pests have plagued superintendents in the Northeast, Mid-Atlantic and Midwest regions more than Listronotus maculicollis: the dreaded annual bluegrass weevil (ABW).
This voracious beetle can cause massive amounts of damage due to its appetite for very short grass, particularly Poa annua, but the pest was largely contained in the Northeast from the time of its discovery in the U.S. in 1931 until the early 2000s, when it began to spread south and west.
“I really didn’t know much about ABW before I first became a superintendent in 2012,” says David J. McGregor, golf course superintendent for Westwood Country Club in Vienna, Virginia. “We managed it by word of mouth – mostly through people sharing horror stories because if someone had ABW, they probably lost a lot of turf.”
It was a similar situation for Andrew Robertson, superintendent at Manor Country Club in Brockville, Maryland, who first began managing ABW when he took the job in 2014. “When I started at Manor, I heard they had ABW, so I started asking other superintendents about what they used to help them through all the different stages. Most superintendents suggested using WeevilTrack, as it was successful at their courses,” Robertson says.
McGregor adds, “It was a scary time because there really weren’t any proven management strategies available for us. People shared their experiences and what steps they took to address the problem, but there was no established plan that we could follow.”
That changed when Syngenta introduced WeevilTrak and the Optimum Control Strategy. Originally developed by DuPont in 2009 and acquired by Syngenta in 2012, it’s a free online tracking tool that provides local guidance based on real-time field scouting, and a treatment program consisting of up to seven carefully timed applications incorporating a rotation of four unique types of insecticides with varying class and mode of action differences:
- pyrethoids, which were one of a very few effective options and the go-to product for many years,
- Acelepryn (chlorantraniliprole),
- Provaunt (indoxacarb), and
- Ference (cyantraniliprole).
WeevilTrak users sign in to access information for their specific regions and monitor progress through the seven-stage tracking system, providing detailed guidance to encourage proper scouting and determination of when to apply the prescribed stage recommended solution.
A Little Help from Your Friends
McGregor says that as valuable as the wealth of detailed information is, word-of-mouth is just as important to successful ABW management. “One of the biggest advantages to using WeevilTrak is the support you get – from Syngenta, of course, but even more importantly, from the other people in your community who are following the program, just like you are,” says McGregor, who’s been using the program since 2014.
WeevilTrak is backed by massive amounts of constantly updated data, including live reports from independent researchers in the field and email updates on ABW development in the individual user’s region.
However, the one thing it can’t do is predict what the environmental conditions will be at a given time in a specific microclimate. The weather in spring determines when adult ABWs become active, so the threat on one course could advance at a much faster pace than on another property just a short drive away. Sometimes, the ABW life cycle can vary by as much as 10 days in different parts of the same course.
That’s why Robertson says people shouldn’t take the guidelines as gospel. “WeevilTrack is useful because of the way it guides you through the season with the best recommended times for applications,” he says, “but it can be a drawback if you become too reliant on it. You still need to scout and do soap flushes, salt flushes or vacuuming. Sometimes my sprays don’t coincide with the guidelines. In 2015, for example, my sprays were very different from the ones suggested by WeevilTrack.”
Once they become active, there’s no time to waste because ABWs move quickly through their reproductive stages. The treatment products are tailored to the insect’s development stage, so application timing is crucial.
“WeevilTrak provides the greatest value when superintendents put in the time and effort to customize it for their own course’s needs,” McGregor says. “For example, it can tell you the exact larval development stage to apply a treatment, but you need to know when that stage is occurring on your specific property. If you watch your course conditions carefully and keep in touch with other users in your local community, that’s when you’ll get the best results.”