There are 250 species, therefore aphids tend to be plant-specific and won't spread to different types of plants.
Aphids reproduce faster than any other insect.
Feeding generally takes place on new growth and underside of the leaf. Aphids can stunt growth, deform and discolor, or cause leaves to drop prematurely. Some aphids transmit plant diseases. Monitor often for early detection and to determine if control is needed. For minor infestations, spray host plants with water at high pressure to dislodge aphids.