It's a good idea to spray your houseplants with an ultrafine oil, pyrethrum, or insecticidal soap spray to remove any pests before bringing them in the house. Read the label to determine if your plants are sensitive to the spray. Ferns, succulents, and certain plants can be injured by some sprays. Sprays are relatively safe to use as they leave no residues and don't pose a significant health hazard to anything but insects. Two applications 7- 10 days apart may be necessary to kill existing pests and those which will hatch from eggs later on. There are systemic insecticide granules which can be watered into the soil to provide pest control for up to 6 weeks. Consult your local lawn and garden expert for the best product for your needs.