Flatheaded appletree borer

Systematic position. The flatheaded appletree borer (Chrysobothris femorata) belongs to the order Coleoptera and the family Buprestidae. This wood-boring insect is a significant pest of both orchard trees and ornamental plantings, causing serious physiological stress to its hosts.

Host plants. The pest is highly polyphagous, attacking a wide range of deciduous trees. Preferred hosts include apple, pear, cherry, and peach trees. It also frequently infests forest species such as oak, elm, maple, and sycamore. Trees that are newly planted, stressed by drought, or have mechanical damage are significantly more susceptible to infestation.

Biology and life cycle. The adult beetles are active from late spring through mid-summer. Females lay eggs in bark crevices or wounds, favoring areas exposed to direct sunlight. Upon hatching, the larvae bore into the bark, feeding on the inner bark and cambium. They grow in a flat, curved gallery and eventually bore deeper into the heartwood to pupate before emerging as adults.

Nature of damage and pest status. The larvae cause the most extensive damage by girdling the trunks or branches. This disrupts the flow of water and nutrients, leading to branch dieback, leaf yellowing, and potentially tree death. The bark over the larval galleries may appear sunken or cracked, and the emergence holes left by adult beetles are distinctively D-shaped or oval.

Control measures. Effective management integrates cultural practices and chemical interventions. Key strategies include:

• Maintaining tree vigor through proper irrigation and balanced fertilization to help trees resist attacks.
• Wrapping trunks of newly planted trees to prevent oviposition.
• Painting trunks with white latex paint to reduce sunscald, which is a key attractant for the beetles.
• Removing and destroying infested wood to reduce the local population of the pest.
• Applying systemic or contact insecticides during the adult flight period if infestations are severe.