If you're late into flowering, I'd recommend spraying them with water/isopropyl alcohol (50/50).
Personally, I'm nervous about using anything toxic like pyrethrum or nopest strips that late along.
The nice thing about it is that it evaporates very quickly, so you don't have to worry much about too much moisture (mold etc.).
I doubt you'll completely wipe them out with it, but it's a good way to keep them at bay while flowering IMO.