Q: What could cause all these holes in my eggplant leaves?
A: It’s flea beetle damage. They attack radish and mustard leaves too, but eggplant seems to be their favorite food in my garden.

You can use organic controls like diatomaceous earth (click for sources) or Pyola (a pyrethrin/canola oil combination) or a synthetic insecticide like carbaryl (click for sources) or Bayer Systemic Vegetable Insecticide.

Flea Beetle Control

Flea Beetles

flea beetle damage top of leaf

flea beetle damage bottom of leaf

flea beetle