2007 Annual Report 1a.Objectives (from AD-416) The purpose of this agreement is to contribute to a scientific information framework for managing insect resistance to transgenic plants by evaluating and integrating insect resistance management models. This information can provide enhanced support to the concerned public in its deliberations about the use of transgenic plants. 1b.Approach (from AD-416) Currently there are a number of different models of insecticide resistance to Bt crops. These models run the range from simple deterministic analytic models to complex stochastic simulation models. Some models incorporate space, others do not. All of the models capture important dynamics, but sorting through the complex intricacies of these models is vitally important for the management of Bt resistance. This effort will bring together modelers working in the area of insect resistance to assist stakeholders in sorting out the implications of insect resistance management (IRM) models. Furthermore, it will identify important data needs for protection of transgenic crops and will assist in the development of modeling efforts that will benefit the science of resistance management in general and Bt resistance in particular. 3.Progress Report This report serves to document research conducted under a Specific Cooperative Agreement between ARS and the University of Illinois to conduct research related to an Interagency Agreement (60-3625-4-0574) with the Environmental Protection Agency (National Risk Management Research Lab, Cincinnati, OH) and USDA-ARS. Additional details of research can be found in the report for the parent CRIS #3625-22000-016-00D, Ecologically-Based Management of Insect Pests of Corn. The purpose of this agreement is to contribute to a scientific information framework for managing insect resistance to transgenic crops. Four published insect models were tested according to rules designed by the modeling coordinator and agreed to by collaborators on the USDA project. Results of the many simulations were submitted in an Excel file for evaluation. All models returned the same theoretical results. With no selection pressure for resistance to Bt toxin, all models should return the starting allele frequency after a 15-year run. All models satisfied this requirement under all initial conditions tested. The collaborator and others analyzed published field data concerning western corn rootworm (Diabrotica virgifera virgifera LeConte) and northern corn rootworm (Diabrotica barberi Smith and Lawrence) survival from egg to adult to create general relationships between density and survival. These empirical results will be incorporated into improved models of these species for IRM analysis. A series of equations were generated that best fit the data, and these equations may be used to help understand density-dependent survival in future studies. In general, the datasets showed a decline in the proportion surviving to adulthood as egg density increased. The survival of northern corn rootworm was lower than that of western corn rootworm. Data for both natural and mechanical infestations of soil with eggs demonstrate decreasing proportion surviving as density increases. Several non-linear equations fit the data for both species very well. Density-dependent survival can account for differences in observations of insecticide survival at different initial western corn rootworm densities. Onstad, D. W., B. E. Hibbard, T. L. Clark, D. W. Crowder, and K. G. Carter. 2006. Analysis of density-dependent survival of Diabrotica (Coleoptera: Chrysomelidae) in cornfields. Environ. Entomol. 35:1272-1278. Onstad, D. W. 2006. Modeling larval survival and movement to evaluate seed mixtures of transgenic corn for control of western corn rootworm (Coleoptera: Chrysomelidae). J. Econ. Entomol. 99:1407-1414. Project Monitoring This modeling project is monitored with frequent conference calls and numerous emails with modeling project coordinators and the EPA collaborator. Conference call dates: 8/18/06 11/01/06 4/10/07 5/09/07 7/11/07 7/19/07 Also, the participants met at meetings listed below: 12/13/06 (with ESA National meeting, Indianapolis, IN) 1/31/07 (with NC205 regional meeting, Dallas, TX).