holes in green beans

I pick green (string) beans last night for dinner and discovered several with small round hole bored into them. About 1/8 to 3/16 inch in diameter, 2 to 6 per bean. Any idea what insect is causing these. Not a bug to be found anywhere in garden. I would guess some type of caterpillar but I can't locate and no leaves touched so far. If you open the bean the holes are about 1/4 inch long inside. Thanks

I have had that issues and my holes were caused by these little green looking lady bugs called cucumber beetles. Horrible to get rid of

Welcome, dryfly! Maybe the pest is out earlier in the day?

I found those holes in my beans in two different gardens, one which had cucumber beetles and one which does not.

One day I saw what looked like a tumor on one of my green (snap) beans. I thought of taking a picture of it to post here, just to show off another odd-looking vegetable. I guess I should have. Anyway, I wanted to feel whether it was hard or soft, so I touched it ... and it didn't quite feel like a green bean. I poked it a bit more and found it coming off around the lip of where it met the rest of the bean -- and that's the only thing that clued me in that it wasn't plant growth I was playing with, but a caterpillar or larva of some kind. It was the exact shade of the plant it had been feeding on.

Underneath was a hole where it had been eating a seed out of the bean pod. I'd seen a number of such holes and wondered where they came from.

At another garden, which has too few cucumber beetles for me to say whether it has an at all at any given time, I saw much the same thing -- only this time on my purple snap beans(Royal Burgundy). This time the "bump" larva/caterpillar was almost perfectly the shade of the bean, but not quite as saturated. It was right in the area where I had begun seeing holes in the pods, which were left intact, while the seeds inside had vanished.

My guess is that the creature, whatever it is, gets its color from what it's eating, and that the one I saw on the purple beans hadn't eaten enough yet to fully match the very dark purple of the beans. The one on my green snap bean in the other gardens was perfect.

I think a possible solution would be bacterial -- the use of BT(bacterium thurigensis, if I recall correctly).

Hi Dryfly.  Welcome from Atlanta, GA!  

I see you've gotten your answers already...  But glad you've joined us!