Symptoms
Larvae bore into flower buds, flowers, and pods causing shedding. Entry holes on buds and pods with frass. Young larvae initially feed on leaves and shoots before attacking reproductive parts.
Prevention
Use pheromone traps for adult monitoring. Intercrop with trap crops such as marigold or African mustard. Remove crop debris after harvest. Encourage natural enemies.
Treatment
Organic
Apply Bacillus thuringiensis (Bt var. kurstaki) targeting early instars. Spray spinosad. Release Trichogramma egg parasitoids. Hand-pick larvae from buds and pods.
Chemical (last resort)
Apply emamectin benzoate or chlorantraniliprole. Rotate chemical groups — Helicoverpa develops resistance rapidly. Time sprays at egg hatch for maximum effectiveness.
Affects 1 crop
Sources
MARDI Pest Guide; FAO Helicoverpa Management