[tomlxx]

Here is a picture




I've added the spikes border to ward off slugs in the hope that will help but I suspect it's not slugs...


edit to show picture

[snowdrops]

Flea beetle, if you touch the plants does some little beetles jump off them? You can use that to catch them, put some grease on a board & hold above the plants whilst touching the plant with your other hand,the beetles jump up & stick to the grease

[Springlands]

Flea beetle, if you touch the plants does some little beetles jump off them? You can use that to catch them, put some grease on a board & hold above the plants whilst touching the plant with your other hand,the beetles jump up & stick to the grease

And if you use something edible like lard as the grease you can leave the board out for the the birds to finish off the flea beetles. 

[allotmentann]

They only seem to like young leaves. They won't do any harm to your radishes so even if you don't get rid of them you will not lose much. I used to have it badly on my plot. I stopped growing rocket as they loved it and the texture of holey rocket leaves is not nice. Other things they stopped after the leaves matured.