Coordinated Diabrotica Genetics Research: Accelerating Progress on an Urgent Insect Pest Problem

American Entomologist • Summer 2006 Diabrotica spp. (western, northern, and Mexican corn rootworms) represent the main pest complex of continuous field corn, Zea mays (L.), in North America (Levine and Oloumi-Sadeghi 1991, Levine et al. 2002, Rice 2004). The western corn rootworm, Diabrotica virgifera virgifera LeConte, also has become the main pest of continuous corn in Central and Southeastern Europe since its introduction near Belgrade 15–20 years ago, and it represents a major risk to Western Europe (Sivcev et al. 1994, Barčić et al. 2003, Baufeld and Enzian 2005). It has already caused economic losses in Eastern Europe, and Western countries such as France have committed large expenditures for containment and/or eradication (Anonymous 2003). Rootworm larvae feed on corn roots, and damaged plants are more susceptible to drought and disease, have decreased yield, and are prone to lodging (Reidell 1990, Spike and Tollefson 1991, Urías-López and Meinke 2001). A recent economic analysis estimates that costs of control and yield loss are about $1.17 billion a year in the United States (P. Mitchell, University of Wisconsin, personal communication). Crop rotation and chemical control have been the primary management strategies (Levine and Oloumi-Sadeghi 1991), but the western corn rootworm is becoming increasingly difficult to control because of its sequential ability to evolve resistance to almost all management strategies that have been used (Meinke et al. 1998, Wright et al. 2000, Levine et al. 2002). The recent deployment of transgenic Bt corn in the United States for controlling Diabrotica pests has raised concerns that rootworms will develop resistance to this technology as well, unless appropriate resistance management strategies are developed and practiced (Onstad et al. 2001, Storer 2003, Crowder et al. 2005, Siegfried et al. 2005b). The evolution and spread of resistance to insecticides and crop rotation, the introduction and spread of the western corn rootworm in Europe, and the recent large-scale commercial deployment of rootworm-active Bt corn in North America have converged to generate a sense of urgency among scientists who are involved in rootworm research. Of particular importance to all these issues is an increased understanding of rootworm genetics. Over the past 3 years, a group of more than 35 scientists from 21 institutions in North America and Europe have organized to form the Diabrotica Genetics Consortium. Members of the consortium organized and convened the first International Conference on Diabrotica Genetics Research in Kansas City, MO, 13–15December 2004. The conference brought together 45 participants from nine countries, including members of the consortium, their students/postdocs, and other interested scientists to facilitate information exchange, formalize collaborations, and identify research needs and directions for future corn rootworm genetics research. Contacts and negotiations facilitated by this conference have accelerated progress through collaborative research in several critical areas. For example, hyper-variable genetic markers shared among laboratories were used to identify western corn rootworms’ routes of invasion into Europe Coordinated Diabrotica Genetics Research: Accelerating Progress on an Urgent Insect Pest Problem