If indoors get rid of them. Fast. Check leaf bottoms. WPM can go through a room like shit through a goose. Some strains are more resistant than others. The plant I showed had more WPM on the bottoms of the leaves so they curl down. Carefully check your other plants. A faint dusting of white powder is all you need to see.

Go into Plant Problems and look for White Powder Mold. You are not the first to deal with this.