Bluegrass billbug damage and small Masked Chafer grubs began to show up on June 25, 2016 in Ames. This is very early for this area. The billbugs were at Veenker golf course on campus. The small chafer grubs were on a bentgrass green at the research station. The chafers are too small to do direct damage at this time, but birds are tearing the green up looking for them. We treated with Dylox shortly after we saw them.
This is the damage from billbugs in the rough at Veenker golf course in Ames.
A close up of the feeding damage. Notice the hollow stems at the base.
Billbug grub from the damaged area.
The billbugs are surprising mature for this early date. I generally wouldn't expect to see feeding damage and grubs that have emerged from sheath tissue for another 3 to 4 weeks. If you are in lawn care, you may want to scout for them early.
These are the small masked chafer grubs at the research station. Birds are causing significant damage to the greens surface and we had to treat.
For more information on billbugs see an earlier blog at https://www.extension.iastate.edu/turfgrass/blog/its-billbug-time-again-0