We saw the decline of Bremuda used as a test on the par 3 tees, sod that was frozen for most of the winter and the opening of the new tee at 2, complete with new concrete cart path. Of course by now you have heard of the master plan being developed by Tom Doak and Renassiance Golf Design.
For us on the turf side, our winter was spent almost exclusively learning about a new, small turf pest called the annual blue grass weevil or ABW for short. This little pest has been plaguing the northeast for a while. We always dismissed it as a northern problem, much like many of our issues are never experienced by them. Well unfortunately this pest has come roaring into our area, and since we have a large population of annual bluegrass, it is something we are very concerned about.
First this little weevil is small, about 8-10 can fit on the head of a penny. Secondly, it has about 4-5 adult generations per year, which each generation produces a larvae (grub) that feeds on roots. Lastly there is no perfect timetable to monitor its advance and no great products to kill the larvae stage.
With so many generations in the mix, it is very hard to predict which stage we are witnessing. Much less trying to find this little pest to start with. Although eradicating adults can be done, research has shown that even a few sprays applied to control them may make the species resistant to future applications, so we have to be very carful in our planning and monitoring to be effective.
We start by using a vacummn to collect samples from areas we believe to be susceptible and look for adults. We then continue to collect for several days in these areas to assess if the population is moving and building. Next we apply products that target the adults, but not all will be contianed.
Next we begin to take turf samples and flush them with a salt bath solution for over an hour and look for the very small larvae. Think a very small grain of rice for a size reference.
After this salt bath, we attempt to determine which of the 5 stages of the grub are in the plant/soil. The first two stages are not affected by any pesticides. They are still in the plant, but only for a few days. Once they move from there to the soil, they will feed on roots for 10 days before they pupate and begin the transformation into the next generation of adults.
The above picture shows a few small larvae on the blade of the knife. They are the small white sand size grubs. This is the only time they are vunerable to pesticide applications. It needs to be stated that in order for us to effectively kill the grub, the products we use must get to where the pest lives, down in the soil. This requires us to pre water to soak the soil, then spray and immediateluy water heavy again to make sure the products reach the pest. This is why you may see us spray and water in the rain. These products are expensive and short lived, so they need to be put down at a moments notice and irrigaion run immediately or the whole process is wasted.
When missed, they cause damage to the root system of the plant that can be seen here on the 12th green. This damage showed signs after 2 days; even with a month of monitoring, using vaccumns and salt flushes. Notice the damage is confined to the poa collar. They feast on poa first, maybe bent later, but in any case it is one we are becoming experts on.
Below is a picture of a collar damaged from the pests. The right side is all unaffected bent grass. The left side is a mixed stand where all the poa has been damaged.
The future of this pest is on the rise, so if we start waving our hands and shaking our heads when the term ABW is mentioned, please forgive us.
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