2006 Annual Report 4d.Progress report. This report serves to document research conducted under a Specific Cooperative Agreement between Mississippi State University and ARS. Additional details for this subordinate project may be found in the inhouse project 6402-22000-047-00D entitled, "Resistance Management and Injury Potential of Lepidopterous Pests to Transgenic Cottons." Objective 1- To study development of non-selected populations of bollworm and tobacco budworm in crop hosts (soybean, corn, and cotton), insect sampling in cotton, soybean (two maturity groups and two planting dates), and corn were conducted. Cotton produced budworms and bollworms. Corn produced bollworm only. In addition, soybean produced large numbers of bollworm larvae and very low numbers of tobacco budworm larvae. Objective 2- To determine the potential of remote sensing techniques for detection and quantification of both wild and crop hosts of BW and TBW: Field crops and non-crop areas of vegetation on the Delta Branch Experiment Station, Stoneville, and at ten off-station locations (main sites with variable number of sub-sites) were classified from early spring fall of 2004 by ratings of habitat type and quality for both bollworm and tobacco budworm. Discrete aerially acquired multispectral (red, green, NIR) images (Duncan 2100 digital video-camera) of each site off-station (forest and non-forest vegetation) and at on-station sites containing crops (corn, cotton, soybean, and rice) were acquired at intervals (weekly intervals as weather permitted) from early spring into the fall of 2004. In addition, multispectral (red, green, NIR) imagery was aerially acquired twice during the summer of 2004 over a large area (23-kilometer width) reaching from near Arcola, MS, to near Perthshier, MS, (104-kilometer width) with an ADS 40 video camera. Wild host populations at 12 sites have been assessed (spring through fall) for host suitability. A model is being developed to automatically grade the suitability for a site based on wild host constituents suitability for reproduction of BW and TBW for a given temporal position in the growing season. Imagery is being analyzed using spectral, structural features, and temporal setting to delineate wild host habitat. Objective 3- To study the economic impact of regulated transgenic Bt resistance management plans in cotton: An economic analysis of the impact of transgenic Bt cotton used three data resources, (1) USDA, NASS data for years 1996-2003, (2) state and county level on-farm data for years 1997-2000, and (3) economic threshold studies of Heliothinine species larval infestation on cotton in Mississippi. Results of analyzing four years of these data show that Bt cotton was slightly more profitable each year than conventional cotton with insecticide application. Insect control with insecticide applications to non-Bt cotton considerably reduced profit. Analyses of the net return for transgenic Bt cotton crops with 0,1,5,10,20 and 26 percent non-Bt cotton (refuges) showed consistently higher returns with each lower proportion of the crop planted in a non-Bt cotton variety. The differences in returns were less when the non-Bt portion of the crop was sprayed with insecticides. Studies are continuing to determine the optimum proportion of a transgenic Bt crop that can be planted to conventional non-Bt unsprayed cotton for resistance management.