Pseudaulacaspis

Pseudaulacaspis is a genus of scale insects within the family Diaspididae (order Hemiptera). One of the most significant species is Pseudaulacaspis pentagona, commonly known as the white peach scale or mulberry scale. This pest is a major concern in arboriculture and horticulture due to its broad host range and potential for rapid population expansion.

These insects infest a wide variety of plants, including stone fruits such as peaches, plums, and cherries, as well as various ornamental trees and shrubs. The pests typically colonize the bark, branches, and trunks, establishing dense infestations that extract essential nutrients from the plant's vascular system, leading to severe vigor loss.

The life cycle of the scale involves egg, crawler, nymph, and adult stages. The adult female remains stationary under a protective waxy shield, while the newly hatched nymphs, known as crawlers, move across the bark to locate suitable feeding sites. Depending on the climate, the insect can undergo multiple generations per year, significantly increasing the risk of infestation outbreaks.

The damage caused by Pseudaulacaspis is characterized by the desiccation of twigs and branches due to constant sap removal. Visible symptoms include the appearance of white or yellowish crusts on the wood, bark cracking, and chlorosis of the foliage. In severe cases, the affected plant parts may die back completely, rendering the plant susceptible to secondary pathogens and climate stress.

Control strategies must be integrated, focusing on both cultural and chemical management. Pruning and destroying heavily infested branches is a critical first step. During the dormant season, horticultural oils can be applied to smother overwintering adults. When crawlers are active, systemic or contact insecticides are recommended to minimize population growth and ensure the health of the host plant.