Flatheaded borer

Systematic position. The genus Chrysobothris belongs to the order Coleoptera and the family Buprestidae, commonly known as metallic wood-boring beetles or jewel beetles. These insects are well-known pests in both forestry and horticulture due to the damaging activities of their larvae within the host tree tissue.

Host plants. These pests affect a broad variety of broad-leaved and coniferous tree species. Common hosts include fruit trees like apple, pear, and plum, as well as forest trees such as oak, beech, and birch. They typically target stressed, transplanted, or drought-stricken trees, although some species can successfully attack seemingly healthy specimens.

Biology and life cycle. The life cycle involves egg, larval, pupal, and adult stages. Adult females lay eggs in bark crevices or wounds. Upon hatching, the larvae bore into the phloem and cambium. They typically overwinter as larvae deep within the wood or under the bark. Pupation occurs in the spring, and adults emerge through characteristic D-shaped exit holes.

Damage and harmfulness. Larval feeding creates flat, winding galleries that effectively girdle the tree, interrupting the flow of water and nutrients. This results in dieback of branches, thinning of the canopy, and eventually tree mortality. Because the larvae operate beneath the bark, infestations are often unnoticed until significant structural damage has already occurred.

Control measures. Management of Chrysobothris focuses on integrated pest management practices. Key strategies are:

• maintaining tree vigor through proper watering and fertilization to improve natural defenses;
• physical removal and destruction of infested wood to reduce population density;
• application of insecticide trunk sprays during the peak adult flight period;
• protecting young or newly planted trees with specialized wraps or protective trunk paints.