Bug infestation

Spinosad work well with a large range of pest including thrips, spider mites etc, and can be used up to two weeks before harvest.

Unless I'm very much mistaken, that is a thrip.... You have a couple of options... cut that leaf off and immerse it in some soapy water (to kill that particular thrip)... you'll have to inspect your entire plant for the little b*st*rds and remove any leaf you find that has a thrip on it... Or you can spray with some neem oil but you're awfully close to harvest and I personally wouldn't want to do that... I also wouldn't want to use Diatomaceous Earth at this point either (although that would kill the thrips, too)... the problem with that is it would stick to all your lovely trichomes and, yeah, ruin your harvest (although it's organic and some people even eat it, I dount anyone would want to smoke it)... Those are all the "remedies" I can come up with - but do some research on how to get rid of them... maybe there's something else that would work.. I'm so sorry I couldn't help more!

Mmm looks like thrips and thrip damage. I’ve never dealt more than a few and my regular IPM took care of it. Depends how widespread the issue is. Google thrips on cannabis and find an option that works for you (“all natural” or whatever you fancy as far as that’s concerned)