Anisandrus

Anisandrus is a genus of bark beetles belonging to the Curculionidae family, subfamily Scolytinae. These insects are known as ambrosia beetles because they do not consume the wood directly but instead cultivate specific fungi within the galleries they carve into the host plant.

This pest affects a wide range of deciduous trees, with a particular impact on commercial fruit orchards including apple, pear, and stone fruits. They are also known to colonize various forest species, often targeting trees that are stressed, injured, or suffering from environmental factors such as drought.

The life cycle involves the adult female boring deep into the xylem of the tree. She introduces symbiotic fungi into the tunnels, which serve as the sole food source for the larvae. The larvae develop within these specialized galleries, and once they mature, the new generation emerges through the original entrance holes to seek new hosts.

The damage caused by Anisandrus manifests as tiny pin-sized holes on the bark, often accompanied by frass (boring dust). The internal gallery system disrupts the tree's vascular transport, which can lead to wilting, branch dieback, and in severe cases, the death of the entire tree. The presence of the fungi can also lead to secondary infections and wood discoloration.

Effective management and control strategies include:

• Sanitary pruning and removal of infested wood to reduce local populations.
• Improving tree vigor through proper irrigation and fertilization to prevent attacks.
• Using pheromone traps for monitoring flight activity and timing chemical applications.
• Applying targeted insecticides during the period of adult dispersal and colonization.
• Maintaining field hygiene by clearing debris where beetles might overwinter.