Scale insects are represented by a large group of species that infest a wide variety of host plants. The Scale insects are a very particular group of pests that go through different stages of development. In juvenile stages the insect is mobile with six legs and extremely small. At maturity Scale insects become immobile scales with strong protective shells. Damage caused by scale is the result of feeding on plant sap. This turns the plant tissue yellow and reduces the plant’s vigour. The accumulation of the insects and their excrement also impairs plant physiology and photosynthesis, and ultimately, crop productivity.
Scale insects at maturity are immobile (sesile). They are round, or oval to elongate, and flattened or humped in appearance.
When scouting, inspect plants to determine whether female scales, nymphs, honeydew, or sooty mold are present. When assessing whether scales or their damage are abundant enough to require chemical control, first distinguish live scales from dead or parasitized ones by flipping over the female scale body or cover using a sharp tool (since the live insects are difficult to remove).