Symptoms
Brown discoloration and decay of rhizomes from larval tunneling. Plants show yellowing, reduced vigor, and wilting from root damage. Bore holes visible in rhizomes when lifted.
Prevention
Inspect planting material for weevil damage before planting. Soak rhizomes in insecticide solution before planting. Practice crop rotation with non-host plants.
Treatment
Organic
Apply entomopathogenic nematodes to soil. Use Beauveria bassiana mycoinsecticide. Remove and destroy heavily infested rhizomes to reduce population.
Chemical (last resort)
Treat planting material with chlorpyrifos or carbofuran before planting. Apply systemic insecticide soil drench at first sign of infestation.
Affects 1 crop
Sources
MARDI Spice Crop Pest Guide; DOA Extension Bulletin