Ask-a-Dave's-Gardener: Bugs on tomato plants AND leaf damagepossibly related?, 5 by crabbygardener

crabbygardener wrote:
My tomato plants have had some problems lately--some leaves have brown or yellow spots, some have holes in them (like something's eating them), and other leaves look brown and dead/dying/wilty. This is mostly on the bottom branches; I trimmed off everything ~1.5 feet from the ground a few weeks ago. I just trimmed off some of the damaged leaves and noticed a bunch of bugs--possibly aphids. I've attached pix of the bugs and the plant damage. Are these in fact aphids? What can I do to mitigate their damage? Insecticidal soap? I'd prefer not to use a synthetic pesticide. Should I be worried about the bugs being vectors of plant diseases? I thought I saw some brown fuzz (maybe) on some of the lower stems, and maybe a white fuzzy blob as well, but I could be wrong.

Thanks!