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!