Mechanisms and dispersal of practical resistance to Bt corn in the fall armyworm (Spodoptera frugiperda)

The fall armyworm (Spodoptera frugiperda, FAW) is an important polyphagous pest in the American continents and a devastating invasive pest in Africa, India, Southeast Asia and Oceania. In its native range, FAW is controlled by transgenic maize and cotton producing insecticidal proteins from the bacterium Bacillus thuringiensis (Bt) as plant incorporated protectants (PIPs). However, FAW populations in Puerto Rico, southeastern USA, Brazil and Argentina have developed field-evolved resistance to transgenic maize producing the Cry1Fa protein. Our research describes mechanisms and alleles linked to the resistance detected in Puerto Rico and Florida and capitalizes on this information to develop DNA-based tools to screen for resistance in field-collected FAW samples. In this presentation we will share our work on validating the use of targeted sequencing to monitor for resistance to Bt proteins and pesticides in FAW.