2006 Annual Report 4d.Progress report. This report serves to document research conducted under a Specific Cooperative Agreement between Northeast Louisiana Expt. Station and ARS. Additional details for this subordinate project may be found in the the inhouse project 6402-22000-047-00D entitled, "Resistance Management and Injury Potential of Lepidopterous Pests to Transgenic Cottons." The objective of this agreement is to obtain bollworm and tobacco budworm samples to test their susceptibility to Bacillus thuringiensis (Bt) toxins. Plots of various plant hosts for these insects were planted in northeast Louisiana during 2006. Larvae were collected from these hosts at various times during the season. Additionally, colonies were established from other locations throughout Louisiana from both cultivated and non-cultivated hosts. Individuals from all colonies were sent to the Southern Insect Management Research Unit (Stoneville, MS) to be tested for resistance to Bt proteins. Male moths collected from baited pheromone traps were sent as well. At Stoneville, wild males are mated with females from a laboratory susceptible colony. The F1 and F2 generations of these mating pairs are subjected to dose-mortality bioassays to determine their susceptibility to Bt proteins. Based on testing to this point during the season, no changes in the susceptibility of either bollworm or tobacco budworm to Bt proteins have been detected from Louisiana.