I need a little more information before I can guess. When were the plants set out? What kind? How big the container? How often are they watered?

Can you post a pic? And if you can't, do the leaves yellow first? Do they have black spots, or brown target like spots? Do they have squiggly lines like tunnels?

The insects may or may not be a problem.......need a description of those, too, to make a guess.

I will try and post a picture here. They are in quite large containers and are cherry's. They are watered a few times a week depending on the temperature outside. Yes, the leaves do yellow first and then have black spots. I think a picture would help. The leaves turn brown and die. This is all at the bottom of the plants and effects the stems. There are tomato's growing on it.

If they have spots, then turn yellow and fall off, my guess is that you have a fungal leaf disease. It can happen in containers (it's much more common in the ground). The two most common such dieases are Early Blight and Septoria Leaf Spot.

Pick off the worst leaves; I'd suggest that you not overhead water, but I'm not sure whether the soaking rain has stopped out there yet. :) Then you should consider picking up some Ortho Garden Disease Control, aka Daconil, and spray according to the label. Make sure you get both the tops and undersides of the leaves.

Daconil is pretty effective at preventing the fungus from spreading, though any spots that are already there will stay. It isn't absorbed by the plant, and you can spray right up to the day of harvest -- just wash the residue off the skin of the tomatoes, and they're fine to eat.

--Alison