Tea Shot-Hole Borer

📖 Description

Tea Shot-Hole Borer is an increasingly important pest of tea across the Indian subcontinent, particularly severe in Sri Lanka, South India (Nilgiris, Munnar, Wayanad) and Assam where climate change has expanded its range. Unlike most pests that feed on plant tissue, this ambrosia beetle cultivates a symbiotic fungus (Fusarium ambrosium) inside its galleries — both adults and larvae feed on the fungus, not the plant tissue directly. The plant damage comes from gallery construction (which disrupts vascular tissue) and the introduced fungus (which colonises the wood around galleries). Outbreaks are favoured by drought stress, excessive sun exposure and poor shade management — climate change is increasing stress conditions across traditional tea belts, making the pest a growing concern. IPM with pruning and burning of infested branches, biological control with Beauveria bassiana, and proper shade and nutrition management provides effective control. The pest is polyphagous, attacking coffee, avocado, cacao and many forest trees, so area-wide management is essential. Quarantine of planting material is critical to prevent introduction into new areas.