Japanese Beetles and Grubs
We are seeing high numbers of Japanese Beetle adults emerging now. They are flying around, feeding on trees, shrubs and certain perennials; mating then laying eggs in the lawn. Those eggs can turn into grubs if there is adequate soil moisture. In the summer of 2013, soil moisture is certainly abundant. So we expect a large grub population later this summer and into early fall.
The adult beetles can do a lot of damage in a short period of time. See this link fromfor control strategies. We do NOT recommend those yellow beetle traps because they tend to bring more beetles to your property. Insecticide sprays can help but generally rain will wash it off so in a year like 2013, multiple sprays would be necessary.
If you are on a lawn care program and you are not on the grub prevention option, you might want to consider it for 2013. The worst case scenario is that we have continue to have a wet July (so the grubs hatch and survive) then the turf dries out in August. At that time the turf has drought stress in combination with a reduced root system from the feeding of the grubs. That combination can cause damage that looks like this.Grubs in the soil.
To reiterate, if you have beetles you can expect to start seeing the grubs starting in late July and damage occurring from early August through early October. To prevent this type of damage to your property, we strongly recommend that you consider a grub preventive application as soon as possible.
Mark Schlossberg is the President of ProLawnPlus in Baltimore, MD. He graduated from the University of Maryland in 1977 with a B.S. in agronomy. He is the President of the Maryland Association of Green Industries, and past president of the Maryland Turfgrass Council.