Aphids are common on house plant insects but fortunately, are easily controlled. Aphids suck sap from the plant and can cause new growth to be distorted. Aphids are found on new growth and the undersides of the leaves. Heavy infestations cover the plants with a sticky syrup called honeydew. Aphids can be controlled with most commonly available house plant insect sprays.
Mealybugs look like little white tufts of cotton so are often mistaken for a disease.
They are normally found on the undersides of leaves or on stems at the point where a leaf joins. The white, waxy coating protects the insects from sprays, making control difficult. Moving infested plants causes the adults to fly away. Controlling whitefly is difficult and repeated sprays will be needed. Avoid plants such as fuchsia that are favored by the insect.