What could be eating my green bean leaves and what organic ways can I use to combat the problem?

Here in California, growing season has already started. My green bean sprouts are a few inches tall, and already something is eating holes into the leaves. I never see any insects on the plants (do they only come out at night?), though last year there were a whole bunch of very small white flies on them. I put soap on them last year and that controlled them a bit, but they always came back. What could be eating the leaves this year?

I don't want to put any harsh chemicals on them, otherwise I'd just buy veggies at the grocery store and save myself the hassle. What organic ways are there to combat insects eating garden vegetables?

Here’s your answer –

Many common pests are nocturnal like earwigs, slugs, and ground beetles. This makes it hard to ID so use a yellow sticky trap. This can be used to identify beneficial insects and hard to find insect pests.

Protect seedlings with cheesecloth or nylon tents made by draping cloth over crossed stakes.

Straw mulch keeps adult beetles from walking between plants but provides hiding places for earwigs & slugs.

Earwig traps are plastic pots baited with fish oil (like tuna or sardines) on water, placed in a small cup sunk into the ground will be visited by earwigs. Keep the level of the oil at least an inch below the surface, forcing the earwigs to crawl deeply into the cup. Many earwigs may be attracted into oil-baited cups and drown.

Rolled corrugated cardboard can be very effective trapping earwigs, as can rolled or crumpled newspapers. Wheat bran and wheat germ are among the baits that have been effective in CSU trials. Such traps should be collected every 2-3 days, bagged and the captured earwigs discarded.

Slug trap bait; beer. However, not all beers are created equal. In 1987, a study at Colorado State University Entomology Professor Whitney found that Kingsbury Malt®, Michelob®, and Budweiser® attracted slugs far better than other brands. Can’t sacrifice the beer? Try a mixture of 1 tablespoon (T) yeast, 1 T flour, 1 T sugar, and 1 cup water. The beer will need to be replaced at least once a week or more as it looses its potency or becomes diluted by rain.

Boards laid in the straw will attract sheltering slugs. Lift every morning and drop slugs into soapy water.

Remove top & bottom from tuna or cat food cans and slip one over the seedling when planted. Push it slightly into the soil. The collar will keep out cut worms.

Pests found in beans include :-
Heliothis, Loopers, Common grass blue butterflies, Hawk moth (although only their eggs), Jassids, small numbers of Thrips and Aphids, Rutherglen bugs, and Flea beetles

Beneficial insects insects are :-
Brown smudge bugs, Striped ladybird beetles, Transverse ladybird beetles, Minute 2-spotted ladybird beetles, White collard ladybird beetles, Red and blue beetles, Brown lacewings, and a variety of Spiders.

Braconid wasps, nematodes, and soldier beetles consume the pests like the cucumber beetle.

Beneficial ladybugs and lacewings can be purchased.