I've no clue as to what kind of critters they are but people out this way use a light mixture of soapy water, sprayed under the leaves to keep white flies and other bugs off of plants. I don't know what's in the soap that helps repels but I guess it works.
They look like whiteflies.
Not good.
Looks like alien bugs.
Yeah, Lux, but think of the new toy you'd have to play with!!!!!
Sevin works great, except I don't like any kind of toxin if I can avoid it --- I'm not fanatic about it tho. I was really pissed when Dursban went off the market.
You might try a nicotine spray. Don't know if you can still buy Green Flag nicotine concentrate (literally dangerous stuff), but you might soak a plug of "Brown's Mule" chaw in a quart of water for a couple of days and try that as a spray.
The diatomaceous earth is the very best thing for tomato worms. Not toxic at all.