Scale Insects
Scale insects are sap-feeding insects, many of which become relatively immobile and develop a protective covering. Mango trees can host different kinds, and some honeydew-producing scales encourage sooty mold and ant activity. Other scales do not produce honeydew, so black coating is not a universal symptom. Examine living insects and their distribution before selecting management. Protect natural enemies where possible, and do not mistake every fixed bump on a branch for an active pest.