Washing

• Many houseplant pests are easily dislodged or wiped off from the hosts. To treat aphids, mealybugs, scale insects and spider mites, prepare a mild detergent solution with 1 teaspoon detergent per quart of water. Moisten a towel or rag and wipe bugs off of the plant's leaves. You can remove some pests, such as aphids, with a strong stream of plain water. Hose down your plant with lukewarm water, paying attention to the undersides of the leaves.
  
  

Handpicking

• Large insects that might infest a houseplant periodically kept outdoors are best handpicked from the plant and destroyed. You can also remove some smaller insects, such as scale insects and mealybugs, by handpicking, especially if their numbers are small. Dip a cotton swab into rubbing alcohol and use this to dab off small scale insects and mealybugs. Scale insects may resist and require scraping off with a fingernail, nail file or penknife.
  
  

Pruning

• Pests like leaf miners may infest only an isolated part of the plant. Often, the best way to control the pests is to remove and destroy the infested part. Carefully monitor the plant and destroy any additional insects that you see arise.
  
  If pests have infested the roots of your plant, you can take a cutting from the plant and attempt to start a new plant in clean, sterile soil. If your cutting roots properly, you can destroy the original infected plant.
  
  

Insecticidal Soap

• Insecticidal soap will control many common houseplant pests, including mealybugs, scale insects, spider mites and aphids. In order for soaps to work, they must come into direct contact with the insect pest, so thoroughly spray the entire plant, including stems and the undersides of the leaves. Although you can make your own insecticidal soap from household soap, soaps formulated for use on insects not only work better but have a reduced risk of harming your plant.
  
  Use care when spraying houseplants with insecticidal soap, as soap will harm some houseplant favorites. Read the label carefully before applying the product and avoid applying the product if the soap hasn't been approved for use on your plant. Spray a single leaf before dousing the whole plant and wait 48 hours. If the leaf shows no signs of harm, you can spray the plant. Avoid applying insecticidal soaps to plants in direct, hot sunlight or under moisture stress.