Japanese beetle damage generally isn't holes, but skeletonizing the leaves. A single beetle can't do much damage, the problem is when they feed in large numbers. You would know if this was happening.

There is some evidence that a plant that gets preyed upon by pests releases compounds into the air that predator bugs recognize and they will move in to find a meal. Not all pests are going to be controlled this way, but I wouldn't use anything on your plants to control a single Japanese beetle.

If the damage is holes rather than skeletonized leaves you have more investigation to do in order to correctly ID the culprit. Ideally while you conduct this investigation the problem goes away on it's own. If it doesn't you will find the culprit and can then come up with a smart way to control them as best as you can.

I have been searching for eggs on all of my cucurbits, none there so far, thanks goodness! There are a few holes on my potato leaves also, but not as many and as fast as these beans.

Thanks for the reply Jag, I'll keep an eye on them.