Not a whole lot you can do this late in the game, unfortunately. Not without contaminating the buds. Pointless to do a root drench or whatever at this point if you ask me, because they are all over the plants hiding in different life cycle stages that can last quite awhile anyway. Even if you kill em, you'll be smokin em
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They don't really attack the main flowers all that much appearance wise, but they might pepper there way up into some of the sugar leaves. Its like they come out and have feeding frenzies all at once too, and do a lot of damage when your not looking. Sometimes the bigger adult flyers (probably what you seen) crawl up into buds and die. Little $%&^ers can get stuck in the trichromes trying to lay eggs, leading to little mold\bud rot spots here and there, on top of infecting the plant\roots with other diseases\pathogens that have you chasing deficiencies, etc... I really dislike thrips. Its the main nuisance pest that constantly attacks my grows year after year now, lol. They're everywhere around outside now days it seems, so a never ending battle?
They are hard to see until its a problem too. Not so much a problem with dwc plants & way more manageable with no grow mediums IME. Or when I'm vigilantly ocd the whole time with IPM, and also bomb the heck out of the place (not in my house of course) with no pest strips before starting over fresh.. Some years are worse too, and there are multiple breeds of them all over the world.. 1000's if i'm not mistaken.. Some possibly becoming resistant to some pesticides I've heard.. Yikes!