I have gotten rid of flea beetles with dustings of diatomaceous earth and blasts of water. If you happen to have some DE on hand or the plants are in large enough containers to give them a good blast, it may be worth a try.

I know we all hate to spray, but I used a Sevin solution twice on my eggplants (leaves only, before they had fruit) and that took care of the flea beetles. You have to use the Sevin while the beetles are there and spray them. That is the most effective way to kill them with the least amount of chemical used.

(I was doing a search for yellowing leaves on a potted eggplant I bought at wallyworld and came across this thread.)

I use a small tomato cage in the pot over the eggplant and cover it with fine tulle from the fabric store. (Watch for it to go half price and buy for next year.) Buy your favorite color! You can use clips or clothespins or just drape and tie a pretty knot around the bottom.

It does work tho.

Believe it or not, I just catch them and squish or smesh them. They are slow so it is easy to catch. Also, they are not that many in number, on my eggplants anyway. I never have true problems with them. I do have some beatle damages, but they are negligible, for my eggplants have always been very productive.

I find that once my eggplants reach a certain size (and if yours are setting fruit then they have reached it), that they resist the flea beetles just fine. I cover the seedlings with row cover.

Mine can always outgrow the flea beetle damage.