Over the summer spider mites got to eight of my orchids. I put those orchids in isolation and then sprayed all my orchids (infected or not) with a product containing safer's soap and pyrethrins. I repeated this on all orchids twice a week for a month. Finally, two weeks ago, since there seemed to be no sign of spider mites, I put all previously infected orchids back with the rest of the collection. Well, all except one cymbidium whose former place had been taken over in the mean time.

Yesterday I saw signs of spider mites again on that cymbidium (I'm so happy there hadn't been room for it with the rest) I checked all the other formerly infected ones, but the tissues didn't get red streaks-they still seem ok. Nevertheless, I again sprayed all the ones that had previously been affected.

My question is this. Should I again spray all orchid in my collection for the next month? Even with my husband's help, it took so long when I did it over the summer. But then again I don't want to just be lazy. Is this a case of better safe than sorry?