Forest Tree Diagnosis is a decision support tool for identifying the signs and symptoms of common pests and diseases of economically important tree species in the eastern United States. Designed to assist foresters, landowners and other managers with active forest management plans, host species, tree part and symptoms can be selected to provide a filtered list of possible diseases, insects and even some abiotic stresses. This app can also serve as a field guide, providing images of various insects and disease-causing pathogens.