Based on the photo I'd say bean mosaic virus. Hope I'm wrong but I don't think so.

https://www.gardeningknowhow.com/edible/vegetables/beans/treating-mosaic-in-beans.htm

Dave

I agree with Dave's assessment. The peppering or speckling of the foliage is a strong indication.

I often have this problem, though not as severe looking as the posted link. Is it on new growth or old? I get it on old growth from the bottom working it's way up. I just pick them off once they yellow. I still have great harvests and never worry about it. Per the link, maybe try different seed next year and grow in a different location.

It's only on old growth.

Thanks, everyone!

Yeah, I don't see any mites or evidence of them. The only insect I found was a leafhopper.

And guess which virus, among others, leafhoppers are known to be a primary transmssion source for.

https://www.annualreviews.org/doi/abs/10.1146/annurev.py.05.090167.000511?journalCode=phyto

Dave

Does that mention BCMV/BYMV? I didn't see it. Everything else I've read says aphids are the vector.

And check this out...same beans, different disease?! Maybe bacterial brown spot?

This is a brand new bed, new soil, about 8 feet away from my existing beds. I don't have any problems in those beds (so far), although I don't have this variety planted there. I also have two tomato plants in this new bed that had a little early blight. Starting to wonder/worry about this soil.

Clover or other wild legumes are probably the source of the bean aphids. I have lots of clover around my garden beds and they spread the mosaic virus to my Maxibel fillet beans. From now on I will stick with a bean variety that has high resistance to BMV. Provider is one of those varieties that I have grown several times without and BMV issues. I have grown Maxibel a few times in the fall without any issues.

Not sure if your other bed is BMV or not but I would guess that it is.