Tomato hornworms have shown their ugly little selves on Ma's tomato plants. They're hard to spot, but she managed to find seven or eight of the little buggers.
We had them a few years ago when I had the Topsy Turvy tomato planter
on the patio. You first notice their little black grenade looking
droppings all over the place and then see where they've been munching on
The almanac site has some suggestions for getting rid of them, picking them off by hand is a simple one, but spraying with some types of 'safe' insecticide like 'BT' also works.