Cotton Pink Bollworm

One of the most destructive pests of cotton worldwide, the pink bollworm (PBW) attacks cotton bolls, feeding on lint and seeds. Larvae bore into green bolls and developing seeds, causing direct damage to the harvested fiber. PBW is the primary target pest for Bt cotton in India. In 2015-2017, PBW developed resistance to Bt cotton (Cry1Ac) in India's Gujarat and Maharashtra states, causing major crop losses and controversy.

Adults are small, grayish-brown moths (15-20 mm wingspan) that are difficult to see. Larvae are initially white, becoming distinctly pink as they mature (hence the name), reaching 12 mm. They are found inside cotton bolls, between lint and seed, or boring in seeds. Pupation occurs in soil or inside bolls.

• 1

  Open green bolls and look for pink-colored larvae between lint and seed — diagnostic

• 2

  Rosetted flowers (petals stuck together by larval silk) are an early sign of PBW attack

• 3

  Double seeds (two seeds stuck together by silk) indicate PBW damage

• 4

  Deploy gossyplure pheromone traps from first flower for early detection

• 5

  Compare larvae with bollworm (Helicoverpa) — PBW larvae are smaller (12 mm), distinctly pink, and always inside bolls, never on foliage

• Rosetted flowers (petals stuck together) — larvae tie petals before boring into developing boll

• Entry holes in green bolls, often at the base near the calyx

• Pink larvae found between lint and seed when bolls are opened

• Stained, damaged lint reducing fiber quality

• Seeds with tunnels — reduced seed viability and oil content

• Double seeds (two seeds stuck together by larval silk)

Cotton Pink Bollworm can attack 1 crop species.