I am currently fighting spider mites on this plant so I know that is part of the problem...but the spots on the plant worry me. Does this look like there is something else wrong, like a virus or something? The wierd thing is only leaf stem seems to be seriously affected. Every other part looks healthy. But this is spreading quickly. Two days ago those leaves on the plant didn't look nearly this bad. I'm concerned about it spreading to my other tomato plants.