Black mulberry longhorn beetle

The Black mulberry longhorn beetle (Dorcaschema nigrum) belongs to the order Coleoptera and the family Cerambycidae. It is a wood-boring insect recognized as a significant pest of various tree species, particularly those within the Moraceae family.

The primary hosts for this beetle are mulberry trees (Morus species). The insect is known to target the trunk and larger branches of these trees, where it carries out its destructive developmental stages. Both the larvae and adults can impact the long-term health and structural integrity of the host plant.

The biological cycle of this pest involves the deposition of eggs in bark crevices. Upon hatching, the larvae bore into the tree, creating tunnels in the sapwood and heartwood. This internal feeding continues through several developmental stages before the larvae pupate. The adult beetles then emerge to mate and continue the cycle, often feeding on foliage or tender bark.

The damage caused by Dorcaschema nigrum is primarily internal. Larval tunneling disrupts the transport of water and nutrients, leading to branch dieback, crown thinning, and severe tree weakening. In cases of heavy infestation, the structural stability of the tree is compromised, eventually resulting in the death of the host.

Effective management strategies require an integrated approach:

• Sanitation: Regularly pruning and destroying infested wood to reduce local populations.
• Monitoring: Using visual inspections to detect early signs of larval entry holes.
• Chemical control: Applying systemic insecticides during the adult emergence phase to prevent new egg-laying.
• Tree health: Maintaining vigorous tree growth through proper irrigation and fertilization to help them withstand minor infestations.