Detection of Protein Mark

The PIT was used to assess the movement of arthropods beyond the protein-marked vernonia trap crop rows (VTC-E) into the various cotton-sampling zones. Each arthropod collected by sweep netting was placed in a 1.5-ml microcentrifuge tube containing 1.0 ml of Tris-buffered saline and examined by ELISA for the presence of the protein mark. The ELISA data yielded from the arthropods collected in the VTC-E zone provided information on the reliability and steadfastness of the marking procedure. Specifically, the percentage of individuals with the egg albumin mark provided a temporal (e.g., 1, 3, and 6 d after marking) estimate of the efficiency of the mark-capture procedure. Distances between the center of the sweep net sampling sites and the nearest possible protein-marked vernonia plots were calculated using the measuring tool in ArcGIS Desktop since the field was planted with high precision techniques. The total number of protein-marked specimens of each arthropod group was tallied. All results for the dispersers are presented as the mean (±SD) distance traveled from the protein-marked vernonia plots.