I've been fighting cannabis aphids since last fall when I brought some outside branches indoors to trim. The little fuckers jumped ship and made it onto some indoor plants. By the time I realized, they had spread to the veg and flower tents. I keep the numbers down with insecticidal soap (1.5tsp soap & 1tsp veg oil per litre) but it's impossible to eradicate them from the flowering plants. I added a bunch of ladybugs last week, if that doesnt do it I'm pretty sure I'm gonna have to shut it all down, sterilize and start over from seeds.
For some reason, the aphids seem to strongly prefer the non-flowering plants, I think they know the trichomes are sticky death traps. I remove the large fan leaves in mid-to-late flower (around week 6) and that seems to remove a majority of aphids and their feeding ground. After harvest and trimming the sugar leaves, there are hardly any aphids or insect debris when examined under a microscope. Besides, I've worked in Quality Control, I'm aware of and am comfortable with the acceptable amount of insect parts in all our favourite mass-produced delicious delights - at least this is going up in smoke lol