Those tiny brown, honeycomb-like clusters on tree bark are likely wheel bug eggs, laid in neat rows of miniature barrel-shaped cases.
If the tops are sealed, the eggs may still be developing; if they’re open or cracked, the young bugs have likely already hatched.
Wheel bugs are beneficial garden predators that feed on caterpillars, beetles, and other plant-damaging insects.
It’s best to leave the egg clusters undisturbed, but avoid handling adult wheel bugs, as their defensive bite can be painful.