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Bt Cotton Resistance Monitoring Studies Submitted to EPA

Bt cotton registrants are required to submit annual resistance monitoring reports for the following lepidopteran target pests:

  • cotton bollworm (CBW);
  • tobacco budworm (TBW); and
  • pink bollworm (PBW).

These reports have generally addressed two objectives: 

  • bioassay results of pest populations sampled from random locations in cotton-growing regions; and
  • the results of investigations into unexpected pest damage to Bt cotton fields. 

The table at the link below lists the resistance monitoring reports received by EPA to date. Individual studies are generally identified by MRID numbers, though not all reports have assigned MRID numbers. 

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