2006 Annual Report 4d.Progress report. This report serves to document research conducted by the Diabrotica Genetics Consortium under a non-funded cooperative agreement between ARS and Colorado State University; Illinois Natural History Survey; INRA (National Institute of Agricultural Research), France; Iowa State University; Mississippi State University; Pennsylvania State University; Purdue University; University of Arkansas; University of Guelph, Canada; University of Illinois; University of Maryland; University of Missouri; University of Nebraska; University of Vermont; and University of Wisconsin. Additional details of research can be found in the report for the parent project #3625-22000-016-00D, Ecologically-Based Management of Insect Pests of Corn. Demonstration of genetic similarity of western corn rootworm (WCR) populations across the U.S. Corn Belt has led to modification of designs and objectives of ongoing population studies in Illinois, France, and at EPA. A white paper was written by ARS and Consortium members from the University of Nebraska and INRA in France entitled, "Coordinated Diabrotica Genetics Research: Accelerating Progress on an Urgent Insect Pest Problem" arguing the need for large-scale multi-institution research support. The white paper was distributed to program leaders at USDA and NSF and led to an invitation from USDA-CSREES for the authors to visit and discuss possible research initiatives. Consortium members used microsatellite markers developed by ARS and genotypes of WCR from three U.S. populations shared by ARS scientists to demonstrate that introductions of the WCR to Europe from North America are apparently ongoing and frequent. The collaboration facilitated by the Consortium framework accelerated this project by at least a year. Consortium scientists among three ARS laboratories in Ames, Brookings, and Columbia cooperated to characterize genetic variation in laboratory lines of WCR that are used extensively for experimentation in the U.S. The study showed that all of the lines have maintained genetic variation at levels comparable to wild populations, except the nondiapausing (continuous-generation) line. In addition, genetic variation was characterized in a laboratory line selected by an ARS scientist for resistance to rootworm-targeting Bt-corn, and the results indicated that some loss of variation had occurred in the selected line. In cooperative experiments among Consortium scientists at INRA, the University of Illinois, Illinois Natural History Survey, Iowa State University, and ARS, diagnostic molecular markers were sought for the rotation-resistant variety of WCR, and the scientists concluded there is no indication that the variant and wild-type populations are genetically isolated. Samples of WCR and northern corn rootworms from wild-type populations were collected in Iowa by ARS to aid Consortium scientists at the University of Illinois in conducting Expressed Sequence Tag (EST) experiments designed to reveal genes in the rootworm head that may be associated with crop rotation resistance. New molecular markers have been developed for northern and Mexican corn rootworms by cooperating scientists at EPA, and are being shared with other Consortium scientists. Cooperation and resource sharing among Consortium scientists at the University of Vermont, Kansas State University, and INRA in France made it possible to collect WCR and Mexican corn rootworms in remote areas of northwestern Mexico and to characterize the genetic structuring of these populations using molecular markers developed by ARS.