Grape Root Borer

Vitacea polistiformis

Grape Root Borer is a species-level clearwing root and crown borer associated with grapevine crowns and major roots. Root galleries, reddish frass, crown injury, poor vigor, and gradual vine decline are typical. Act before internal protection develops.

Identification

Adults mimic wasps; larvae are creamy caterpillars with legs and a brown head, feeding in roots and crowns. Pupae may protrude from soil near vines. Inspect the soil line and major roots, search for pupal skins, and use species-specific pheromone traps to time adult activity.

Symptoms / Signs

Root galleries, reddish frass, crown injury, poor vigor, and gradual vine decline are typical. Old holes may outlast activity.

Life Cycle / Process

Grape Root Borer undergoes complete metamorphosis. Egg placement follows the occupied site on grapevine crowns and major roots.

Prevention

Maintain vigor, prevent injury, and remove active reservoirs. Priority reservoir for this record: grapevine crowns and major roots.

Management / Control

Remove severely infested vines, control weed cover around crowns, disrupt or remove pupae, and use labeled tactics timed to eggs or young larvae before deep entry.

Procedure Steps

1. Inspect grape crowns and major roots for reddish frass, galleries, and pupal skins. 2. Collect larvae or pupal skins and record the exact feeding position. 3. Apply preventive control only before young larvae enter bark or roots. 4. Reinspect the original injury site for fresh frass, gum, or larval activity. 5. Close the Grape Root Borer incident only after new internal injury stops.

Safety Notes

Avoid unnecessary broad-spectrum treatment until live damaging stages and fresh injury are confirmed. Protect pollinators, natural enemies, workers, food crops, wells, aquatic areas, and Myco-Patrons. Follow the current label for crop, site, target, PPE, restricted-entry, preharvest, and disposal requirements.