Pestipedia

Xiphydria Wood Wasps

**Xiphydria Wood Wasps** (*Xiphydria* spp.) are a genus of slender, black or brown wood-boring wasps. The conflict is **structural and ornamental tree damage**: the female lays eggs in the wood of stressed or recently dead deciduous trees (especially **birch and willow**), and the larvae tunnel through the wood for 1 to 2 years. While they typically attack weakened wood, their large exit holes and the extensive larval tunnels can cause significant damage, especially in ornamental birches.

Taxonomy and Classification

Xiphydria Wood Wasps belong to the Order Hymenoptera (Sawflies, Wasps, Bees) and the Family Xiphydriidae (Wood Wasps). They undergo complete metamorphosis. Unlike hornets, the adults possess a non-venomous **ovipositor** (for egg-laying), not a stinger.

Physical Description

Adults are 10 mm to 25 mm long.

  • **Adult (Key ID):** Slender, elongated, dark-colored body; they have a long, conspicuous **ovipositor** (looks like a stinger) at the rear end of the female; often mistaken for large, menacing wasps, but they are harmless.
  • **Larva (Key ID):** Creamy-white, legless grub found tunneling deep inside the wood.
  • **Damage ID (Key):** Large, circular **exit holes** (about 5 mm to 8 mm) in the trunk or branches; piles of boring dust (frass).
  • **Conflict:** Ornamental, Forestry.

Distribution and Habitat

Found across temperate regions, often associated with forests and parklands. Habitat is the trunks and branches of weakened or recently dead deciduous trees.

Behavior and Conflict

The conflict is the large size of the insect and the resulting tunnel damage.

  • **Odor Detection:** The female uses its antennae to detect stressed or dying wood, which is easier for her larvae to penetrate.
  • **Harmless to Humans:** The “stinger” is purely an egg-laying device and cannot be used for defense.

Management and Prevention

Management is **Prevention and Sanitation**.

  • **Prevention (Key):**
    • **Tree Health:** Maintaining the health and vigor of susceptible trees (especially birch) through proper watering and fertilization.
  • **Sanitation:**
    • Promptly removing and destroying heavily infested or dead wood to eliminate breeding sites.

    • Conservation and Research

    Research focuses on the specialist parasitic wasps that prey on wood wasp larvae, which act as important natural control agents.