One thing many have all been doing is spraying with either neem, horticultural oil (HO) or fish emulsion (I use a combination of neem and HO) before bringing them in to red our trees of pests before they come indoors and those pests become more of an issue. Where do you live? Many of us also do not fertilize in the winter to keep the tree from growing weak growths that are more susceptible to those pests. Keep in mind that during winter, you will not need to water as often. What do you have your trees potted in?

How much sun? How much watering do you do? What kind of mix are you using? How do you water?

Laura brought a very good point up about preventing winter pest issues...