Fall Grubs

During the hot summer months it is common to see areas of turf under stress in our fairways and rough, but as the weather cools down heading into fall we expect these areas to improve.  Over the last couple weeks there still have been some areas that persist to look as if they under stress.

13 fairway with stress areas

15 fairway

These areas have been infested with white grubs, black turfgrass ataenius to be precise.

The white dots are the ataenius grubs

The larvae feed on the roots of the plant and allow you to pull the turf right up when you grab it.  You can see in the above photo how I rolled it back. By eating the roots and cutting them off they prevent the turf from being able to take up water and thus the areas look like the are drought stressed the same as summer.
We spot treated all of the areas and then fertilized to get proper re-growth and healthy turf before we go into winter.

Bluegrass Billbug

The beginning of June always marks the start of our season and damage from bluegrass billbug.  They are small insects that feed on the roots of Kentucky Bluegrass, causing the plant to not have a root system to take up water and that is the dry spots that you are seeing on the golf course right now.

Wilt stress in the front middle of this tee from billbug

The adult insects lay their eggs in the fall and over winter in that dormant stage as an egg.  Once the soil temperature increases and it starts to get warmer out, the larvae emerge out of the eggs and feed very rapidly on the root system of Kentucky bluegrass.  It always coincides with warmer temperatures and you think we are getting dry spots on the course and need to water more, but in all reality, the plant cannot take up the water that is available.  You can go to these areas and lift the turf right up off the ground.

Dry area caused by billbug root pruning

We have mapped these areas over the years and they show up in the same spot almost every year, so today we applied an insecticide to kill the larvae and these spots will recover in the couple weeks.

Spraying bluegrass billbug, see the dry turf area under the sprayer

We also do a lot of scouting to see if we can find them in the thatch layer right below the crown of the plant, also the birds will start to peck at them in the mornings and either seeing the birds or seeing the tufts of grass pulled up gives an indication that the larvae are present.

Tufts of grass pulled up from the birds pecking at the billbugs