Garden bean pest
Thank you for your question. There are a variety of insects which eat bean leaves, you don’t indicate what variety of bean it is. Here is a list of potential pests: https://pnwhandbooks.org/insect/crop-pests?combine=Bean It is recommended that you look in the soil around the plants for slugs, eggs, larvae, caterpillars and insect skeletons. The damage is similar to that caused by seed corn maggot, and weevils. Hope you can find more evidence!