White peach scale

Systematic position: The white peach scale (Pseudaulacaspis pentagona) belongs to the order Hemiptera and the family Diaspididae. It is a significant quarantine pest worldwide, known for its ability to infest a diverse range of woody hosts and thrive in various climatic conditions.

Affected crops: This insect has a very broad host range. It primarily attacks mulberry, peach, plum, apricot, cherry, and apple trees. Additionally, it can infest a variety of ornamental plants, including lilac, catalpa, and sophora, making it a persistent challenge for both commercial orchards and residential landscapes.

Biology and life cycle: The insect overwinters as an adult fertilized female protected by a tough, waxy scale on the tree bark. In the spring, females lay eggs under their scales. Once hatched, the mobile nymphs, known as crawlers, move to new parts of the host plant to feed. They eventually settle, secrete a new scale, and lose their mobility for the rest of their development.

Damage and harm: By inserting their piercing-sucking mouthparts into the bark, these pests extract plant sap. Heavy infestations result in a characteristic white, powdery appearance on branches and trunks. This feeding weakens the tree, leads to branch dieback, reduces fruit yield, and can eventually cause the death of the entire tree if left untreated.

Control measures: Managing white peach scale requires a combination of cultural and chemical strategies. Key practices include:

• Pruning and destroying heavily infested branches.
• Monitoring for crawler emergence to time insecticide applications accurately.
• Applying dormant oil sprays to suffocate overwintering females.
• Encouraging natural predators such as lady beetles and parasitic wasps.
• Maintaining tree vigor through proper fertilization and watering.