Echeverias (Echeveria spp.) are attractive, rosette-shaped succulents native to warm, arid regions. They grow outside in U.S. Department of Agriculture plant hardiness zones 9b through 11 or as houseplants. Like many plants, echeverias can fall prey to an infestation of aphids. If not controlled, the insects will leach the sap from surface of the plant, leaving it weak and vulnerable to infection. You have several options for controlling aphids.
Aphids can be removed from the surface of echeveria rosettes using a damp paper towel. You'll see the small green, black, yellow, brown or pink insects clinging to the surface of the plant. Wipe the undersides of the leaves to get any aphids hiding there.
You can sometimes dislodge aphids with a hose. A medium-strength spray should be strong enough to blast the insects off of the echeveria without damaging it. If the aphids return after a few days of being removed using a hose or paper towel, then it will be necessary to use insecticidal soap or lady bugs to eradicate the infestation
Apply a ready-to-use insecticidal soap in the early morning or in the early evening. Spray all surfaces of the echeveria, including inside the rosettes and under the stems. The soap will degrade quickly, and will only kill the aphids it touches. Although insecticidal soap is organic and safer to use than stronger chemical pesticides, it can still burn the surface of the plant if applied in strong sunlight. Monitor the plant for the next few days and reapply the insecticidal soap if the aphids reappear.
Ladybugs can also be used to control aphids as an alternative to insecticidal soap. Place insect netting -- such as a mosquito net -- over the area where the echeveria grows and release the ladybugs inside the netting. The ladybugs will devour the aphids over the course of a day or two. Once the aphids have been wiped out, remove the netting to free the ladybugs.