Many Scale insects look like a small circular bump that is part of the plant.
Scale insects feed by sucking sap. They feed on (suck the life out of) soft tissue new growth on leaf shoots, the underside of leaves and small stems. They are a tiny insect, ranging in size from 1/16 to 1/8 inch. They can be round, elongated, bumpy or crab-like in shape. Colors vary from white, black, tan, amber or yellow. Up close and personal, they line up in rows to such on the sap.
The sucking causes discoloration, yellowing or wilting of the leaves, stunting or unattractive appearance of the plants and eventually death of all or part of the plant when the infestation is heavy. Sooty mold, a black fungus, can also develop on plants infested with soft scale insects due to the honeydew (poop) they secrete.
Scale are generally not one of those insect pests that go away on their own. Scale spreads quickly and easily, by the wind or through cross-contamination. Scale can even infect house plants by attaching to your clothing. Control is almost always necessary.
There are several methods to control scale: Pruning, Insecticidal soap, Neem oil, Rubbing alcohol, Horticultural oils and Systemic insecticides.
Based on the infestation, T&T can recommend several options. For heavy infestation, a topical insecticide is the number one choice to “kill” as many as possible, followed by two treatments – approximately 30 days apart – using Horticultural oil to smother remaining insects and any larva. In the fall, organic fertilization is recommended to assist the plants during recovery. Otherwise, Horticultural oil is recommended.
T&T recommends that customers continue with the horticultural oil treatments for at least the following growing season, and inspections to monitor the control.
