Flat-headed cherry borer

The flat-headed cherry borer (Dicerca divaricata) is a beetle species belonging to the family Buprestidae, commonly known as jewel beetles. This pest is a significant threat to orchards, particularly targeting various fruit-bearing tree species that are often already weakened by environmental stressors.

This insect primarily attacks stone fruit trees such as cherry, plum, peach, and apricot. Occasionally, it can also infest pome fruits like apples or pears. The presence of the beetle is often a sign of poor tree health, as they prefer to lay eggs on stressed or dying woody tissues rather than vigorous, healthy specimens.

Regarding its biology and life cycle, the adult beetles emerge in late spring or summer. After mating, females deposit eggs into crevices of the bark. Upon hatching, the larvae, which are characteristically flattened at the head, bore into the inner bark and cambium layer, where they feed and create complex galleries.

The damage caused by these larvae is severe and can lead to the decline of individual branches or the entire tree. As they tunnel through the wood, they disrupt the vascular system, preventing the transport of nutrients and water. Typical signs of infestation include yellowing foliage, twig dieback, and the presence of frass near exit holes on the bark.

Effective control requires a multi-faceted approach. Preventive measures include proper sanitation: removing dead or dying branches and maintaining tree vigor through correct fertilization and watering. Chemical control involves the application of appropriate insecticides during the emergence period of adults to prevent them from laying eggs on the bark.