Coconut Leaf Beetle (Hispid Beetle)

📖 Description

Coconut Leaf Beetle (Brontispa longissima) is one of the most destructive pests of coconut and other palms across the Indian subcontinent, particularly severe in the Andaman & Nicobar Islands, Lakshadweep, Kerala, Tamil Nadu, Karnataka, Andhra Pradesh and coastal Maharashtra. The pest is unusual among palm pests in that both adults and larvae attack the youngest unopened leaflets in the coconut crown — by the time damaged fronds open and become visible, larvae have typically moved to new unopened fronds. This cryptic behaviour makes the pest particularly difficult to detect and control — by the time symptoms are visible, significant damage has already occurred. Outbreaks can defoliate young palms (1-3 years) completely, killing them within months. Classical biological control with the larval parasitoid Tetrastichus brontispae (originally introduced from Java in the 1930s) and Asecodes hispinarum provides excellent suppression when broad-spectrum insecticides are avoided — these parasitoids can parasitize 60-90% of larvae in well-managed plantations. The pest is most severe in monoculture coconut gardens and in areas where quarantine measures are inadequate. Quarantine of planting material is critical — most new infestations originate from infested suckers moved between regions. IPM with parasitoid releases, pruning and burning of infested fronds, and need-based biopesticide application provides effective and sustainable control.