Peach bark aphid

Taxonomic position
The peach bark aphid (Pterochloroides persicae) belongs to the order Hemiptera and the family Aphididae. Unlike common leaf aphids, this species has evolved to colonize the bark of woody perennial parts of host plants, making it a distinct and challenging pest in stone fruit production.

Host crops
This aphid primarily targets peach trees, but it also infests almonds, apricots, plums, and cherries. The pest colonizes the main trunk, primary scaffold branches, and occasionally twigs, where it finds sufficient protection and vascular flow for feeding.

Biology and life cycle
The species exhibits a colonial lifestyle with multiple generations occurring throughout the growing season. Overwintering typically occurs as eggs laid in the crevices of the bark. Once temperatures rise in spring, nymphs emerge to form large, dense colonies that suck sap from the inner bark layers.

Damage and economic significance
Feeding activity drains vital nutrients from the tree, leading to stunted growth, reduced vigor, and leaf chlorosis. Furthermore, the secretion of honeydew promotes the growth of sooty mold fungi, which coat the bark in a black layer, potentially hindering the bark's physiological functions and reducing the tree's resilience.

Control measures
Integrated pest management is crucial. Mechanical control involves cleaning the trunk and applying white-wash paint to disrupt overwintering sites. Chemical control involves dormant season applications of oil-based sprays, followed by systemic insecticide treatments during the growing season if populations exceed threshold levels.

• Monitor bark in early spring.
• Apply dormant oil sprays.
• Use selective systemic insecticides.
• Prune heavily infested limbs.
• Encourage natural predators like ladybirds.