Fig longicorn

Acalolepta vastator

Overview:

The Mango Longhorn Beetle, scientifically known as Acalolepta vastator, is a formidable wood-boring insect originating from Southeast Asia. With a widespread presence, particularly in mango orchards, this beetle poses a significant threat to fruit trees on a global scale. Known for its distinctive appearance and lifecycle, understanding its characteristics is crucial for effective pest management.

Detailed Appearance:

  • Adult beetles are large, measuring approximately 2.5 cm (1 inch) in length.
  • They have elongated bodies with distinctive long antennae, usually brownish-black in color.
  • The larvae (grubs) are creamy white with a cylindrical shape, often found tunneling into the wood.

Life Cycle:

  • The life cycle of Acalolepta vastator consists of four stages: egg, larva, pupa, and adult.
  • Eggs are laid on the bark of trees, and upon hatching, the larvae burrow into the wood to feed and grow.
  • Larval development can take several months, depending on environmental conditions.
  • Once mature, larvae pupate within the wood before emerging as adult beetles.

Identification of Crop Infection:

  • Presence of small, round exit holes (6-8 mm or 0.24-0.31 inches in diameter) on the trunk and branches of mango trees.
  • Sawdust-like frass around the base of the tree or on lower branches.
  • Weakened or dead branches, indicating damage to the tree's vascular system.

Management Strategies:

  • Preventive Measures:

    • Regularly inspect orchards for signs of infestation.
    • Plant resistant mango varieties when possible.
    • Maintain overall tree health through proper watering and fertilization.

  • Cultural Controls:

    • Remove and destroy infested branches to reduce beetle populations.
    • Prune trees during the dry season to minimize attractants.

  • Chemical Controls:

    • Insecticides containing imidacloprid or cypermethrin can be applied to the trunk and branches during the beetle's active season.
    • Follow recommended application rates and safety guidelines.

  • Biological Controls:

    • Introduce natural predators such as parasitic wasps or nematodes to help control beetle populations.
    • Encourage biodiversity in the orchard to support beneficial insects.

By incorporating these management strategies, farmers can reduce the impact of the Mango Longhorn Beetle and protect their valuable mango crops. Regular monitoring and a combination of control methods are often the most effective approach to manage this pest.