Oh dear - I thought I had responded to this. My apologies.
These grubs are actually throughout the garden. We have a blue and green metallic "june-bug"-like infestation (not the green june bug that is normally seen) annually and I think this is their grub stage. They showed up for the first time 5-7 years ago in the fruit trees. At the time, I spoke to the nursery down the street and they said that the area had been hit by Japanese Beetles but they don't resemble the photos I have seen on the net. Also, these bugs and grubs are a lot larger than that of the Japanese Beetle. I have noticed that as the grub population has grown, so has the annual "june-bug" infestation.
