It's a good thing I learned to look for tiny caterpillars, which necessarily make tiny little black poops. I followed a liberal sprinkling of black dots to a leaf up above and found this 5/8" long baby tomato hornworm. Used my hand for scale. So...if you're looking for these very destructive creatures on your tomatoes, check for black droppings first - those from a large hornworm look like extruded black rippled particles. Then look above them. They're easier to find than their producer, who blends in with the foliage.