Susceptibility of Louisiana and Florida populations of spodoptera frugiperda (Lepidoptera: Noctuidae) to Pyramided Bt corn containing genuity®vt double pro^™ and Smartstax^™ traits

The fall armyworm, Spodoptera frugiperda (J. E. Smith), is a target species of transgenic corn containing pyramided Bt genes in the United States. During 2011, a total of 149 F2 two-parental family lines were established using single-pairing of S. frugiperda collected from 3 locations in Louisiana and Florida. This study examined the susceptibility of these F2 two-parental family lines to 2 commonly used pyramided Bt corn traits, Genuity^®VT Double Pro^™ and Genuity^®SmartStax ^™. Nine out of the 149 family lines showed less susceptibility to the leaf tissue of Genuity^®VT Double Pro^™ or Genuity^®SmartStax plants. Larvae of these 9 family lines exhibited significant survivorship and growth on leaf tissue of the Bt corn plants. Two laboratory colonies were established from the F2 survivors of 2 of the 9 family lines. However, larvae from both colonies could not survive on whole plants of their corresponding Bt corn products in the greenhouse, suggesting these families were not resistant to the pyramided Bt corn traits. The results suggest that the pyramided Bt corn products containing Genuity ^®VT Double Pro^™ or Genuity ^®SmartStax^™ corn traits are effective in protecting against S. frugiperda.