Citrus flathead borer

Systematic position. The citrus flathead borer (Agrilus auriventris) belongs to the order Coleoptera and the family Buprestidae. This beetle is a serious pest that specifically targets plants within the Rutaceae family, causing significant economic damage to citrus orchards worldwide.

Host plants. The primary host plants for this pest include various citrus species such as lemon, mandarin, orange, and grapefruit. The larvae are specialized wood-borers that thrive under the bark, making them particularly difficult to detect in the early stages of infestation.

Biology and life cycle. The life cycle consists of four stages: egg, larva, pupa, and adult. The adults emerge during the warmer months to mate and deposit eggs in crevices on the bark. Upon hatching, the larvae bore into the tree, where they feed on the cambium and phloem layers throughout their development.

Damage and severity. The primary damage is caused by the larvae as they construct winding galleries beneath the bark. This activity effectively girdles branches, disrupting the flow of water and nutrients. Consequently, infested trees exhibit symptoms like yellowing foliage, branch dieback, reduced fruit quality, and, in severe cases, the death of the entire tree.

Effective management strategies include:

• Regular orchard scouting to detect entrance holes and bark splitting.
• Pruning and destroying heavily infested branches to reduce larval populations.
• Targeted application of systemic insecticides during adult emergence peaks.
• Improving overall tree vigor through balanced fertilization and correct irrigation practices.

Because the larvae spend most of their life cycle protected under the bark, control efforts must be well-timed. Integrated pest management, focusing on early detection and maintaining tree health, remains the most sustainable approach to preventing catastrophic losses in citrus production caused by this species.