Course Notes, 8/31/2016

Some of you have asked me what is making the tiny sand mounds on the greens during the day.  The answer is two fold in what I have seen.  

Moundings on 10 green

The first is the Seed Corn Beetle.  These beetles burrow about 2 inches into the soil, looking for insects and other tidbits to eat.  There are two generations of these beetles, occurring in May and in August.  

Close up of Seed Corn Beetle

The second, and more populous burrowing insect I am seeing are ants, specifically the Eastern carpenter ant and the Cornfield ant.  These ants are worker female ants looking to form new colonies with their burrowing.  They mainly feed on seeds and honeydew from aphids and mealybugs.  

Ant mounding on 17 Green

Ant crawling on 17 green

Close up of the Eastern Carpenter Ant

Normally treatment is not required, since both of these insects provide beneficial natural control of other pests to turf, such as the cutworm.  We try to set high thresholds when it comes to evaluating whether to treat or not, to limit the footprint we set on the environment.  However, we will be treating for these ants today due to the high incidences of moundings on select greens.  

If you have any questions, please contact me at ryan@elconacc.com.  Thanks, and have a safe and fun Labor Day Weekend!  

Ryan

What's Burrowing in the Greens?

Throughout the month of June and into the early part of July, you may have seen small mounds of sand on the greens as shown in the photo below.  These mounds are caused by a Seed Corn Beetle that is usually present around the course during the cooler and wetter times of the year (this year in particular). According to Entomologists at Purdue University, corn seed is not the primary food source for seed corn beetles. Rather, they feed on other things that they find in the soil, including other insects.  We also know that they are highly attracted to and fly to lights at night.  There are two generations per year, typically occurring in May/June and again in August.

Mounding on #12 green caused by the Seed Corn Beetle

Generally, treatments are not necessary because the damage is not severe and we also try to set a rather high threshold for situations like this.  The goal is to only treat when necessary to keep costs down and to reduce our impact on the environment.



Close-up view of Seed Corn Beetle removed from #12 green

In order to find out exactly what is causing the damage, a section of the turf about 2" deep must be removed where the mounding is.  By tearing the turf where the burrowing channel is, the beetle can be exposed and then identified. On the positive side, the channeling caused by Seed Corn Beetle can mimic the effect of aerification, which, in turn, can lead to better root growth and a healthier stand of turf.  Who could argue with that? Plus, the labor is free!