Indoor citrus trees are susceptible to pests and diseases, so it's important to implement proper pest and disease control measures. Regularly inspect the trees for signs of pests such as aphids, scale insects, or mites. If infestations occur, treat them with organic insecticidal soap or neem oil. Additionally, monitor the trees for any signs of diseases like citrus canker or citrus greening. Promptly address any issues to prevent further spread and damage.