looks almost like miners of some type, maybe caterpillers of some type. Either way, anything that will kill aphids or mites will do, maybe a heavy dose of
pyrethrins. Bigger problem is how they are getting in the tent. Most bugs in a tent are being brought in by accident. Clones, soil, ect. Wear clean clothes, no dogs, and no guests. The plants are young enough to wipe out the whole tent and still get the plants to come back. Whatever you use, spray well, get good coverage. Trim em back a bit and let them come back.
Good luck,
RR1