Boll Weevil

Adults are small greyish to brownish weevils with the long curved snout typical of the family, used to puncture cotton squares and bolls. Larvae are pale, legless grubs that develop hidden inside the fruiting structures. Because larvae are concealed, damage is usually recognized from the reaction of the plant rather than from the insect directly.

Characteristic signs include feeding and egg-laying punctures on squares, and infested squares that flare open, yellow, and drop from the plant. Dissecting fallen or damaged squares reveals larvae or feeding cavities.

Adults emerge from overwintering shelter, move into cotton, and feed before females lay eggs singly in punctures in squares or bolls. Larvae feed and pupate within the fruiting body, and several generations can occur through a season in warm climates, so populations can build rapidly once cotton begins fruiting.

Adults overwinter in sheltered sites such as leaf litter and field margins. This overwintering, together with the concealed larval habit, makes end-of-season sanitation and the timing of the cotton crop important for reducing carry-over.

Both adult feeding and larval development destroy squares and young bolls, directly removing the plant’s fruiting potential. Infested squares commonly drop, and damaged bolls may rot or fail to produce sound lint. Because the pest strikes the fruiting forms that carry the crop, even moderate infestations can cause serious losses.

Cotton is the principal host. The weevil’s dependence on cotton fruiting bodies is central both to its damage and to the sanitation-based logic of eradication programmes.

Pheromone traps are the backbone of boll weevil detection and are used intensively in eradication and containment programmes to find and track weevils. In-field checks for punctured, flared, and dropped squares complement trapping. Coordinated, area-wide trapping and reporting guide regional decisions where programmes operate.

Boll weevil management is most effective as a coordinated, area-wide effort combining monitoring, sanitation, and treatment within integrated pest management.

• Support area-wide trapping and reporting where eradication or containment programmes operate
• Practise strict field sanitation, including timely stalk destruction to remove late-season food and shelter
• Use uniform planting and harvest timing to shorten the availability of fruiting cotton
• Reduce overwintering habitat around fields where practical
• Coordinate any treatment regionally to maintain programme effectiveness