Diploschema

Diploschema is a genus of beetles belonging to the longhorn beetle family (Cerambycidae), known as significant technical pests of wood. The most notable species, Diploschema rotundicolle, poses a serious threat to a variety of woody plants across its native range, causing substantial economic losses in forestry and agriculture.

This pest affects a wide range of host plants, including citrus, coffee, cocoa, eucalyptus, as well as various fruit and ornamental trees. The larvae lead a concealed life, tunneling deep into the trunks and branches, which makes the early detection of infestation particularly difficult for growers.

The biology of the pest involves a prolonged life cycle, often spanning more than one year. Females deposit eggs into bark crevices; upon hatching, the larvae penetrate the cambium layer and gradually bore deeper into the heartwood. Adult beetles may also cause damage by feeding on the bark of young shoots, further weakening the host tree.

The primary damage is caused by the disruption of nutrient transport and the mechanical destruction of the trunk's internal structure. Larval galleries, often packed with frass (wood dust), compromise the tree's vitality, leading to branch dieback or total tree mortality. Heavily infested trees are also more susceptible to secondary pathogens and further pest attacks.

Protection strategies require an integrated approach combining cultural and chemical methods:

• Regular monitoring of plantations to identify early entry holes made by larvae.
• Sanitary pruning and removal of heavily infested branches or dead trees.
• Application of contact or systemic insecticides during the active flight periods of adult beetles.
• Treating bark wounds and damaged areas with grafting wax or sealants containing repellent agents.