Insect and Spider Identification: CLOSED: Young bugs on oak trees, eggs in honeycomb cluster, 0 by dividedsky

dividedsky wrote:
My brother has a lot of these on his oak trees (white oak, perhaps?) and they have bright red abdomens. Bright red on the tips of the antennae as well.

The egg clusters are all in honeycomb shapes - mostly black, but they have specks of gold on the top.

It looks like most of them are hatched and scattered by now, but I did find this one today. What are they and are they good or bad for landscape and vegetable garden?