To keep your Plumeria free of aphids, it’s important to inspect it regularly for signs of infestation. Look for clusters of small, soft-bodied insects on new growth and undersides of leaves. If you find any, you can use a strong stream of water or insecticidal soap to remove them from the plant. It’s also helpful to encourage natural predators, such as ladybugs and lacewings, to control the aphid population. If any parts of the plant are heavily infested, prune and dispose of them. By taking these steps, you can keep your Plumeria healthy and prevent extensive damage from aphids.