False California scale

Hemiberlesia mendax is a significant insect pest belonging to the Diaspididae family within the Hemiptera order. Known as the False California scale, this insect is a recognized threat in agricultural and horticultural settings, causing notable economic damage to various woody plant species.

This species primarily targets fruit-bearing trees, including pome and stone fruits, as well as a variety of ornamental shrubs. The scale insect colonizes the bark of branches and trunks. In cases of heavy infestation, it can also spread to fruits, causing aesthetic damage and negatively affecting the market value of the harvest.

The biology of Hemiberlesia mendax is centered around its protective waxy scale, which shields the female and her eggs from environmental stressors and contact pesticides. The life cycle involves a dispersal stage known as "crawlers." These mobile larvae are responsible for the spread of the population within an orchard, traveling via wind or on the bodies of other insects.

The damage caused by this pest is primarily due to the extraction of plant sap. Feeding activity disrupts the vascular system of the bark and cambium, leading to the weakening of the host tree, stunted growth, and, in severe cases, branch dieback. Continuous sap depletion makes the trees significantly more susceptible to secondary infections and abiotic stress.

• Implementation of strict phytosanitary measures for nursery stock.
• Application of horticultural oils during the dormant season to suffocate overwintering stages.
• Targeting crawler emergence phases with systemic or contact insecticides.
• Pruning and destroying heavily infested branches to reduce the overall population density.
• Promoting natural biological control agents such as predatory beetles and parasitoid wasps.