Here are the cuprits and this is only some of the destruction they can wreak. Hornworms can strip a tomato plant in two days. You can tell they are there by the little black dropping (Poop) that they leave — that and the bare stalks and holes in your tomatoes.
Two ways to get rid of them one I read was take them of the plant and squash them. The second recommended by a nursery was a BT powder. Not knowing exactly what BY powder was I went to my local hardware store an found Sevin Powder. I thought this was banned from the market years ago, but I guess they changed the formula to be in compliance.
I was picking worms off more than I liked and my beautiful Heirloom tomatoes were suffering. I was suffering too at the sight of all my hard work vanishing to these very hungry catapillers.
Supposedly they come to us by way of a large white moth that comes out at night. The only white fliers I have seen are much smaller and are visiting my plants during the day.