Garden Pests and Diseases: Unhappy tomato plants, leaves w/brown spots and others dying, 0 by crabbygardener

crabbygardener wrote:
My tomato plants have gone weird lately. Some leaves have small brown spots, while some entire branches seem to be withering and dying.

Is there a viral, fungal, or bacterial pathogen at work?

An insect pest? (We've had leaf-footed bugs, Leptoglossus phyllopus, on these plants recently, if that helps. No tomato hornworm sightings, though.)

A nutrient imbalance or deficiency? (My garden soil is probably ridiculously fertile with a pH of around 7 (a little high for most veggies) according to a professional soil test.)

Or could it be environmental? (We've had a VERY wet summer here, and not as hot as most years.)

Thanks for your help!