Mealybugs and scales
In order to gain an adequate intake of protein, mealybugs must ingest large quantities of sap, getting rid of the excess sugars in the form of honeydew [...] is usually the first sign of the presence of this type of pest. Among ornamental crops, ferns are particularly sensitive to soft scales, as are oleanders [...] leads to sooty mould. Infestations reduce plant vigor, fruit quality and overall yield. Effective control of mealybugs and scales is essential to maintain