Aphids are a pudgy, pear-shaped, winged or wingless insect that can multiply rapidly. Females lay live babies one day and the babies reproduce just a few days later. They are often green but can be yellow, red, gray, brown, or black and may be sneaky staying to the undersides of the leaves. Tender flower buds are especially attractive to the aphid.
Mature leaves may yellow and curl. New growth may appear stunted and distorted, twisting or curling as the aphids suck the sap from the plant. They secrete honeydew that you may see as a sticky trail along the leaves which contributes to the growth of a sooty mold and another problem for your plant.
Control: Isolate infected plant(s) and cover any tables or carpet, etc. that may receive any over-spray if using soap or oil sprays.
Begin with giving your plant a gentle shower either indoors or outside. Repeat every few days if necessary.
You can gently wipe leaves, both top and undersides, with a damp cloth to remove aphids rather than a shower if you have a large, heavy pot that is difficult to move.
Another method would be to spray with a homemade insecticidal soap, a homemade insecticidal oil or you can purchase these products. These sprays will kill aphids that are present so you will, most likely, need more than one application.
Always inspect your plant to be certain any treatment is necessary before using sprays.