Denver garden pests question?

I live in Denver and I have a loosing battle with something that is eating my garden plants. I don't know what they are but they look like flees to me. Real tiny so that i can't really make out what they really look like. I would take a picture of them and post it but they are the size of black pepper flakes. You wouldn't see much. They have eaten practically every leaf from my beans, squash, pumpkin, watermelon, cucumber, radishes, basil, and mint. All that remain are stems. The only things they don't seem interested in are corn, tomatoes, peppers, onions and rosemary. I have tried spraying water infused with hot pepper and water infused with tobacco. Is there pesticide that anyone would recommend? I try to go all natural but my usual methods aren't working. I have never had this problem before but this is my first time gardening in this region. I also see earwigs occasionally, but there are no grasshoppers around. No rabbits either, my dog makes sure of that. They would go nuts if there was a rabbit around. Any thoughts? Possible solutions?