Pink Bollworm Control

Symptoms

Look for small entry holes on green bolls that are often plugged with frass, and rosetted (twisted) flowers that fail to open properly. On cutting open affected bolls you find pinkish larvae inside, with damaged seeds and interlocking lint. Affected bolls open prematurely and burst poorly.

Damage

Pink bollworm is the most damaging cotton pest in India and has developed resistance to Bt cotton in many regions. Larvae feed inside bolls on developing seeds and lint, lowering both yield and lint quality. Heavy infestation can cause 30 to 60 percent yield loss along with reduced ginning percentage and oil content.

Organic & cultural control

Install pheromone traps with gossyplure lures at 8 to 10 traps per hectare for monitoring and 40 or more for mass trapping. Use pheromone based mating disruption (PBKnot or SPLAT) where available. Release Trichogramma bactrae egg parasitoids. Spray neem oil or neem seed kernel extract 5 percent. Remove and destroy rosetted flowers and damaged bolls. Follow timely sowing and avoid extending the crop beyond December.

Chemical control

When monitoring traps cross the threshold of 8 moths per trap per night for three consecutive nights, sprays of recommended actives such as chlorpyriphos, profenophos, thiodicarb, emamectin benzoate or quinalphos can be used in rotation. To slow resistance, plant the non-Bt refuge as advised on the seed packet. Always read and follow the product label, observe the pre-harvest interval, and consult your KVK or a qualified agronomist before spraying.

Always follow the product label, the recommended pre-harvest interval, and your local KVK or agronomist. Pesticide approvals change, so verify before use.

Prevention

Sow short to medium duration Bt hybrids early and synchronously across the area. Always plant the recommended non-Bt refuge to delay resistance. Destroy crop residue and unopened bolls after harvest and avoid ratooning. Do not store seed cotton with bolls in the field, and use community wide pheromone monitoring from the squaring stage.