I see that a lot in the literature when I read about flea beetles, that you just ignore them as they won't do any real damage, or if the plant is more mature they won't hurt it. Maybe in some places but when I was in Arkansas the flea beetles loved eggplant. They would turn the leaves to fine lace fairly quickly. Every leaf. Those leaves would dry out and just crumble, they'd chew them up so the roots could not get any moisture to the leaves.. The plant would soon die if I didn't treat them. They would always go to eggplant first, eggplant made a good trap plant.
@secuono I used Sevin to treat them but Sevin was my go-to insecticide then. If I had them today I'd use Spinosad because of the withdrawal period. I consider Spinosad safer for general use.