Hunting Cicadas With Airguns (off-hand cicada challenge)

Can I ask what harm they do except for noise?

I know they do some damage to citrus trees, primarily some branch dieback from their egg laying activities where they cut many slits in smaller branches to deposit their eggs. I have only seen very insignificant small branch dieback as a result on our mature citrus, although I understand they can be more damaging to younger trees. Their populations have really declined over the years in my area, only see a few every summer these days.