|(Photo: Sheryl Pollock, 2011)|
The object of their attention is the grub stage of the green June beetle which spends most of this time of year near the soil surface. Activity will should stop in a few weeks (peak activity should be in about 10-14 days depending on where you are). As with the other ground-nesting solitary bees and wasps, pesticide broadcast sprays are rarely needed or very effective.
For more information on this wasp, see the web page: