How to control pink bollworm in cotton crop?

Pink bollworm is one of the most destructive insect pests in cotton. It damages the crop from the inside by boring into young bolls and feeding on the seeds. This not only reduces yield but also affects fibre quality, making the cotton less valuable. Once the larvae enter the boll, controlling them becomes difficult, so farmers must follow preventive and timely management practices to protect their crop.
The first and most important step in managing pink bollworm is timely sowing. Late-sown cotton has a higher chance of infestation because the pest population usually peaks later in the season. Sowing cotton at the recommended time helps the crop escape heavy damage.
Farmers should also adopt crop sanitation practices. After harvesting, leftover cotton stalks, damaged bolls, and crop residues must be removed from the field. If these are left in the field, pink bollworm larvae survive inside them and become a source of infestation for the next season. Stalks should be uprooted and destroyed immediately after final picking.
Using Pheromone traps (PBW traps) is a very effective method for monitoring and controlling the pest. These traps attract male moths and reduce their ability to mate. Installing 8–10 traps per acre at the start of the flowering stage helps farmers detect the presence of pink bollworm early. Regular monitoring of trap catches also helps decide when to spray.
A very important practice is following the refuge strategy, especially for Bt cotton growers. Farmers should plant non-Bt cotton plants around the field as a refuge. This prevents the pink bollworm from developing resistance to Bt cotton and helps maintain long-term effectiveness.
During the crop season, farmers should remove rosette flowers (flowers stuck together) as they are early signs of pink bollworm. Destroying them immediately helps break the pest cycle before it reaches the boll stage.
In the early stages, farmers can use egg parasitoids or biological controls like Trichogramma chilonis, which attack the eggs of pink bollworm. This reduces the number of larvae entering the bolls.
When required, farmers can apply recommended insecticides at the right stage. Sprays are most effective before larvae enter the bolls. Spraying during flowering and early boll formation helps prevent eggs and newly hatched larvae from surviving. It is important to rotate insecticides from different chemical groups to avoid resistance.
Maintaining good crop nutrition also helps the plant stay strong. Balanced fertilizers, especially potash, improve boll strength and reduce damage.
Finally, after harvesting, farmers should follow deep ploughing to expose and kill pupae present in the soil. This reduces the starting pest population for the next season.
In simple words, managing pink bollworm requires early sowing, field sanitation, pheromone traps, removal of rosette flowers, refuge planting, timely sprays, and destroying crop residues. When these practices are followed together, farmers can successfully protect their cotton crop and reduce losses caused by pink bollworm.