My strategy worked! I swept the deck this morning, and this afternoon Drew went out and looked for caterpillar poop. He found some under several plants. When you find the poop, look up at the tomato plant branches directly above the poop. You might see some half-eaten leaves. Look under the leaves, and behold the dastardly herbivores!
Total thus far: 10 dastardly tomato hornworm caterpillars.
This afternoon's caterpillar count: 5 more tomato hornworms, but they were all smaller than the ones found last night!