Pole beans sick or damaged by bugs?
I have some kentucky wonder pole beans and some italian purple pole beans. Seemingly overnight (or over the past few days), the lowest leaves have started getting little brown spots and it looks like they are dissolving. We have had a lot of rain over the past week on and off, and I've seen some little fungus things here and there in the soil. I haven't seen any bugs except a few whiteflies a couple weeks ago, and when I look on the underside of the leaves, all I see are bits of dirt that splashed up from the rain.
I don't know if this is some fungus/sickness or if some bugs may be eating the leaves. It hasn't happened yet with the upper leaves. The spots look different on the purple pole beans vs the wonder beans. I planted most of these about 1 month ago as seeds. Please help!
1st two photos are kendtucky wonder. 2nd two are purple pole "trionfo violetto".
Here is a link that might be useful: pole bean photos