Jackson’s scale

Jackson’s scale (Pulvinarisca jacksoni) is a member of the soft scale family (Coccidae) within the order Hemiptera. This pest is a specialized sap-sucker known for causing significant stress to various ornamental and exotic plant species, particularly in greenhouses and tropical environments where it can thrive year-round.

The host range of this insect includes various broad-leaved shrubs and trees. The pest primarily colonizes stems, the underside of leaves, and petioles. Due to their ability to produce dense wax covers and protective egg sacs, they can easily go unnoticed until a severe infestation has already caused visible damage to the plant tissue.

The biology of Pulvinarisca jacksoni follows a typical soft scale cycle. Females produce characteristic white, cottony ovisacs containing numerous eggs. Once the eggs hatch, the mobile crawlers move to new feeding sites, settle, and begin producing a waxy layer. Their sedentary nature as adults makes them highly dependent on the plant’s sap flow for survival and reproduction.

Damage caused by this scale insect includes yellowing, curling, and premature leaf drop. Furthermore, their feeding activity results in the secretion of honeydew, which attracts sooty mold fungus. This mold covers the leaf surface, further inhibiting photosynthesis and reducing the aesthetic appeal of ornamental plants or the vigor of fruit-bearing species.

Effective management requires an integrated pest management (IPM) approach. Chemical control using systemic insecticides is most effective during the crawler emergence phase, as the adults are protected by their waxy armor. Biological control involving parasitic wasps has shown promise in specialized settings. Regular sanitation and monitoring are essential to prevent the pest from establishing large, difficult-to-treat colonies.