For the last week or so, I have noticed several small yellow spots on the top of one of the leaves. Today, I looked under the leaf and noticed a bunch of very small, dark lumps, and a couple of small white flies. Afraid that they were eggs, I removed the branch (leaf?) entirely. I have uploaded images of what I saw. I am now beginning to see the same thing on higher leaves, after removing the one that I removed (which can be seen in the images).
Yes, it's whiteflies. You can put Encarsia or Eretmocerus to work (parasitic/predatory wasps, they won't sting you). The first if you live in a temperate zone and they are outside, the latter if you live in a warmer area or if they are in a warm greenhouse. Eretmocerus fares better with high temperatures than Encarsia. There's specialized businesses that sell predatory bugs, you can find them online and they ship the bugs to your home adress.
Research: About 5 years worth of experience growing organic produce in harmony with nature.