The bean plants in our garden have started to look like Swiss cheese. I'm guessing some bug is munching on them. From time to time I have seen a small (ladybug) sized black and green bug on them but I'm not 100% sure its the attacker. I was hoping to avoid the pesticide if possible and keep it natural. Is that now my only option? They are only eating the bean plants right now my pepper plants right next to the beans have been untouched.

Picture of the damage:

If you can, slip out after dark and check - I had similar damage this year and it was slugs.  I covered the area in DE for a few days and the beans took off like a rocket with no more damage.

can you see them looking down onto the plants or do they hide under the leaves?

With due respect, I think there's too many quick responses to use diatomaceous earth in this forum.  4 lbs for $10 is not worth it.  And this time of year, the threat is from flying things that lay eggs and hatch on the plant, then chow down.

Your picture wouldn't make me roll an eye during garden patrol.  I'd put some Sevin dust (if you can even get that anymore) and call it good.  Or spray some Malathion.  As long as the bugs aren't skeletonizing the leaves, I don't care.  I don't eat that part.

Just wait until the Japanese Beetles get there.

I think your plants look normal for June.

P.S.  Are you really a LTC?  ETA:  I just noticed your data, that would be Lt Commander, not Lt Col? (you Navy folks have such non-conventional ranks)

Thanks for the good advice on the plants.  I did put some pesticide on them but it's too soon to see any effect and it poured rain the night after I applied it it poured rain which might have washed the spray off.

As to the Navy comment I am not an officer.  The screen name is a reference to a Simmons episode where they made fun of the Navy, one of the characters was named LT Smash.  I took the name and combined it (embarrassingly) with my first semi auto rifle the cetme.

In actuality I was an ENLISTED sailor.  Second class petty officer to be exact....  Got out in '04 sadly.  It was a hell of a time.

The damage doesn't look like Japanese beetles but that is the green and black bug you described.  If slugs look up the beer trap or sprinkle some DE on the ground around the plants.  If its JB knock them into a cup with soapy water, the sooner the better because they actually attract their buddies.

Grove

We use hard wood ash.
Seems to work. An ole' timer told me about it and said that you can't use too much.
Re-apply after each rain .

Looks like classic slug damage to me. i drink my coffee every morning and kill about 20 or so a day. They calm down after it gets hot. Keep the surrounding area mowed close, and turn over rocks and wood that they hide under

Thanks for the replies guys! I'm not sure what it was but the spray seems to have gotten rid of them. They are healthy now and about twice the size as they were in the picture!