I've had flea beetles in my mesclun mix...I think they are focused on the mustard and maybe arugula that is mixed in. I have radishes in my bed also. The flea beetles are eating up those little mustard leaves, the arugula and radishes...but leaving everything else alone including all of my lettuces, spinach and peas. I have radishes scattered around my tomato and pepper bed also, though little damage has been done to them. I also put them around my beans and, like you, the beetles have ravaged the radishes but have largely left the beans alone. This weekend I'm going to put them amoung my cukes and squash plants and throughout my bean beds.

I'm coming to the same conclusion as you! Seems the beetles love the radishes and maybe their attention is drawn away from key plants!
I will add however, your damage is more severe than mine. I'm going to stop complaining about MY flea beetle problem!

Very interesting finding, anney and thanks for sharing.
I think there are different kinds of flea beetles. I have som radishes but no damage to them nor to my beans. But I have holes in my eggplants instead.
I am familiar with this kind of beetles. They love eggplants and horse nettles. I am not weeding the nettles, hoping they will
host the flea beetles.This particular FBs do not chew up but only make tiny hole.
I am experimenting with some home made spray to deter them but so far no conclusion.

Flea beetles are much rougher on greens in spring than in fall. Good thing that when you cook em, the holes disappear. My eggplant either must stay beneath secure row cover or be grown in containers on the deck. The flea beetles don't find the plants when they are up off the ground away from the garden.

I have found Nasturtiums to be a good Flea Beetle trap crop.

The only trouble I seem to have with flea beetles is on my eggplants. I have not noticed them on anything else except, oh yeah, arugula. So, just two things. So, noinwi, you think nasturtium is a good trap crop if I were to plant them around the eggplants?

noinwi

I planted nasturtiums, the short ones, one row over at the base of some cucumbers but there's nary a hole in those leaves. I suspect the flea beetles have done their thing for the time being though.

A couple of years ago I planted Nasties between my bush beans and peppers(just for some color), and also away from my garden along side other annual flowers. It was early summer when the FBs found them, so maybe it's a timing thing. There were tons of them on the Nasties but no other plants. They were doing so much damage I quickly wrapped each plant with a trash bag and pulled them up to get rid of them and the beetles.