Look like aphids from here.
Your plants are still small. Try touching the buggers with a q-tip dabbed in a pyrethrin based insecticide. (Just about any will do.) The swab doesn't need to be dripping with the stuff, just damp. (Drops of insecticide on the leaf may damage the plant.) 'Tag' as many as you can find, then repeat the next day to get any survivors and noobs. Once the population is knocked back, you can probably get by with twice-weekly inspection and repeat treatments.
Alternately, find a 'bug bomb' fogger. Modify the mechanism (usually by trimming a plastic tab) so that the trigger doesn't lock when activated.
Position the fogger 2~3 feet below the plants and briefly, lightly, mist the plants from below. Again, you don't want to wet the leaves - just a hint of the stuff will kill most of the critters. Repeat as needed.
IMO, of course!