Regularly inspect your Plumeria for signs of pests, especially on the undersides of leaves and near flower buds. If you notice pest infestations, isolate the affected plant to prevent further spread. Use insecticidal soap or neem oil to treat minor infestations. For severe infestations, consider using chemical insecticides, but follow the instructions carefully to avoid harming beneficial insects. Encouraging natural predators, like ladybugs, can also help control pests.