My research team studies the evolution and management of insect resistance to crops genetically engineered for pest control. Current work focuses on resistance to insect-killing proteins from the bacterium Bacillus thuringiensis (Bt). These Bt proteins are highly effective against some key pests, but are not toxic to most other organisms including arthropod natural enemies, wildlife and people. Transgenic Bt corn and cotton have been planted by millions of farmers on a cumulative total of more than 2 billion acres worldwide during the past 25 years. Our work ranges from analyses of the genomics of resistance to global patterns of field-evolved resistance to Bt crops. Progress is facilitated by synergistic collaborations that benefit from expertise in molecular and population genetics, ecology, modeling, and pest management.