I used DE and it didn't do diddly squat. So then tried Neem oil. Within a day or, two I had half the amount of flea beetles I started out with. Needs to be reapplied every 5 - 7 days. Hope this takes care of the problem as they started out in one of our raised beds and spread to two others.
These pests seem to hang around the garden at the beginning of the season There are several ways to deal with them This is what worked for me I put out Beer traps because I thought I had a slug problem what I found in my beer traps were flea beetles for some reason flea beetles like beer. I also made a spray of water mixed with crushed garlic,dish soap & water. I didn't spray everything just the problem areas these two in combination has seemed to wipe out the beatles.
Other methods here >> http://voices.yahoo.com/natural-methods-controlling-flea-beetles-your-6294784.html