Brief Summary of Minutes of Annual Meeting

Accomplishments: March 7, 2012: 22 NCCC46 scientists submitted a letter to US Environmental Protection Agency providing recommendations to sustain the use of transgenic Bt corn in the United States. The letter provides clear information on the occurrence of CRW resistance to the Cry3Bb1 Bt corn hybrid event, and provides IPM recommendations to prevent or slow the spread of further resistance over the long term. Contents of the letter were widely distributed in local, state and national news media in 2012. EPA-HQ-OPP-2011-0922-0013. Porter, P., E. Cullen, T. Sappington, A. Schaafsma, S. Pueppke, D. Andow, J. Bradshaw, L. Buschman, Y. Cardoza, C. DiFonzo, et al. 2012. Comment submitted by Patrick Porter, North Central Coordinating Committee NCCC46. http://www.regulations.gov/#!documentDetail;D=EPA-HQ-OPP-2011-0922-0013 The NCRA Agricultural Experiment Station Directors approved a proposal co-authored by Eileen Cullen (University of Wisconsin  Madison) and David Andow (University of Minnesota) to provide financial resources necessary for North Central Region corn insect entomologists to develop a regional research and extension approach to further data on resistance, communication of results and resolution of the problem with IPM recommendations. " Total funded for NCCC46 and NC205 corn insect entomologist NCRA committees to hold three project meetings: (June 2012, Ames, IA; October 2013, Mpls, MN; March 2013, Mpls, MN): $90,000 " Total funded for corn rootworm bioassays: $46,900 " Total funded for corn grower focus groups in affected areas: $39,031 The North Central Regional Association of State Agricultural and Experiment Station Directors issued a written resolution of support for the work of NCCC-46 corn insect entomologists in identifying Bt resistance in corn rootworm, and efforts to communicate these findings to the EPA and other stakeholders. Specifically, the NCRA recognized NCCC-46 proactive approach to clarifying the extent of the problem and its implications for corn production in the North Central Region. During the 2012 growing season, NCCC-46 scientists monitored transgenic Bt-rootworm cornfields throughout the North Central region. Corn roots were sampled from each field and assigned a node-injury score from 0 to 3. Cornfields with a node-injury score of 1.0 or higher were classified as an unexpected damage location. Field history information was collected for each location going back 3 or more years (e.g., crop rotation, Bt trait use, insecticide use and refuge placement if available). Approximately 45 WCR populations were collected across six states from Bt rootworm protected cornfields with higher than expected root damage (MN, IL, IA, NE, MI, SD). Field-collected WCR populations have been sent to participating NCCC-46 public university laboratories and corn plant-based greenhouse assays are underway to determine resistance status of individual field populations from 2012 field collections. NCCC-46 members (Art Schaafsma  University of Guelph, Christian Krupke  Purdue University, and John Tooker  Pennsylvania State University) organized a P-IE Section Symposium at the 2012 Entomological Society of America Annual Meeting titled Remember IPM? Risks and Benefits of Global Expansion of Transgenes and Insecticide Seed Treatments in Field Crops http://esa.confex.com/esa/2012/webprogram/Session17990.html The symposium was well attended, generated a lot of good discussion, and a peer-reviewed paper may be written summarizing the main points and recommendations. October 2012, Dr. Eileen Cullen (2012 NCCC46 chair) delivered an invited talk to the Land Grant University ECOP/ESCOP National IPM Meeting in Washington, D.C. titled Overview of the Corn Rootworm Resistance Issue to Cry3Bb1, Multi-State Committee Special Projects, and Support by the Agriculture Experiment Station Directors to Address the Problem. (Audience: land-grant university administrators, IPM specialists, USDA NIFA national program leaders, IPM Center directors, Extension administrators/personnel). Progress update regarding the western rootworm genome: (Tom Sappington, ARS) The genome has been sequenced but assembly has been challenging due to large introns, lots of transposable elements, and lots of repetitive sequence. Hugh Robertson (Univ. of Illinois) is leading this project with involvement of several on this Committee. The transcriptome is being sequenced in France, with assembly of the reference genome underway. The next part of the project is to use the reference transcriptome in RNA-seq experiments to determine which genes are differentially expressed or regulated during different stages or under different stresses. The project is led by Thomas Guillemaud of INRA in France, with several Committee members as CoPIs and collaborators. Two corn rootworm-related projects are underway or just concluded in Dr. Joe Spencers lab at University of Illinois: " USDA-AFRI: How do western corn rootworm beetles use refuge and transgenic corn? J. Spencer 2009-2012. This project concluded on September 1, 2012. Data suggest that a seed blend is superior to block refuges for moving and mixing mateseeking WCR. Final analyses of the individual WCR collected in 2011 and 2012 continue. Its important to pay attention to what insects are actually doing because their behavior, not our assumptions about their behavior, determine how well refuge designs function. Observation of actual behavior, not our assumptions should guide refuge design. " USDA-AFRI: Do gut proteinases and microbial biodiversity facilitate soybean herbivory in rotation-resistant western corn rootworm beetles? M. Seufferheld, J. Spencer, and J. Zavala. 2009-2013. This project was granted a no-cost extension in 2012. This research provides the link between patterns of enhanced protease activity, gene expression and the periodicity of movement and residence that typifies RR-WCR, and the economic implications of these findings. This is the first time that a study has demonstrated the relationships between specific RR-WCR traits and a mechanism that can explain the RR-WCRs ability to consume soybean foliage. These are a significant findings because now we have physiological and biochemical parameters to anticipate the transition of WCR from WT to RR and respond to the urgency to develop tools to counteract this billon dollar corn pest. Dr. Michael Gray, University of Illinois continues to monitor and report on severe cases of rootworm damage to Bt hybrids expressing the Cry3Bb1 protein in some producers fields in northwestern and north-central Illinois. In collaboration with Dr. Aaron Gassmann, Iowa State University, Gray has analyzed beetle populations from these problem fields (2011) using Gassmanns on-plant bioassay and found these problem Illinois fields fit a pattern similar to one described by Gassmann for Iowa fields in which resistance to the Cry3Bb1 protein was confirmed in 2011. University of Illinois root evaluation experiments were conducted in 2012. Each year the research team (Dr. Mike Gray, Ron Estes, and Nick Tinsley) evaluates root protection products (soil insecticides and Bt hybrids) targeted at corn rootworms. Reports can be viewed in their On Target report online at http://ipm.illinois.edu/ontarget/ Western corn rootworm mate choice studies at Purdue University (Dr. Christian Krupke) comparing beetle emergence from Bt corn hybrids vs. non-Bt varieties have found female-biased sex ratios, and delayed emergence in Bt plantings. This information has implications for models of Bt/refuge cornfields, which assume all mating in this system is random. This work is still in its early stages. [Outputs/potential impacts]: When completed, it will allow us to determine mating rates between refuge and Bt beetles, and match beetle weights/head capsules with natal hosts. We are starting to get data from staple isotope testing now, and anticipate one more field season of data collection (2013). The potential utility of this work is to fine-tune IRM strategies with enhanced knowledge of WCR mating preferences in Bt/refuge plantings, although these trials should be performed in open fields as well to determine whether behavioral differences between cage and open environments exist. Volunteer corn in hybrid corn and soybeans following stacked trait corn: Agronomic considerations and implications for corn rootworm IRM plans. (Purdue University, Dr. Christian Krupke). Outputs: " Surveys demonstrate that volunteer, glyphosate-tolerant Bt corn is an increasingly common weed in both soybeans and corn. In soybeans it is easily managed using a grass herbicide. In corn, there are no yield penalties at typical field rates of volunteer plants (at or below 4 plants/m2). " Rootworm adults commonly emerge from patches of volunteer corn in both soybean and corn fields. The expression rate of Bt toxins (Cry3Bb1) in volunteer corn is more highly variable than the rate in hybrid corn. In both cases, nitrogen deficiency (as typically found in soybean fields), correlate with reduced levels of toxin expression. Michigan State University (Dr. Chris DiFonzo) : Suspected western corn rootworm resistance location, Michigan 2012. In communication with the grower and seed company representative, beetles were collected and shipped to University of Illinois to the lab of Dr. Joe Spencer for on-plant bioassay (using Gassmann method) to collect eggs. Larvae will be resistance bioassayed in 2013. University of Wisconsin (Dr. Eileen Cullen). Seedcorn maggot management fact sheet published for organic or conventional cropping systems with spring cover crop incorporation and/or weed cultivation and non-treated corn seed planting. Outputs: The UW-Extension Ag Weather online seedcorn maggot degree day calculator tool overcomes perceived grower time constraints survey respondents had about accessing pest degree days http://www.soils.wisc.edu/uwex_agwx/thermal_models/scm The UW-Extension publication A3972-1 Insect IPM in Organic Field Crops  Seedcorn Maggot presents IPM appropriate to an organic (and some conventional) systems. Together these tools help farmers assess peak seedcorn maggot flight and avoid planting corn during peak. http://learningstore.uwex.edu/Insect-IPM-in-Organic-Field-Crops-Seedcorn-Maggot-P1584.aspx University of Wisconsin root evaluation experiments were conducted in 2012. Each year the research team (Dr. Scott Chapman and Bryan Jensen) evaluates corn root protection products (soil insecticides and Bt hybrids) targeted at corn rootworms. Report was distributed at NCCC46 annual meeting in New Orleans and will be available online at http://labs.russell.wisc.edu/cullenlab/.

Representative Publications: Chen, H., H. Wang, and B.D. Siegfried. 2012. Genetic differentiation of western corn rootworm populations (Coleoptera: Chrysomelidae) with resistance to insecticides. Ann. Entomol. Soc. Am. 105: 232-240. Clark, T, L., D. L. Frank, B.W. French, L. J. Meinke, D. Moellenbeck, T. T. Vaughn, and B. E. Hibbard. 2012. Mortality impact of MON863 transgenic maize roots on western corn rootworm larvae in the field. J. Appl. Entomol. 136: 721-729. Coates, B.S., A. Alves, H. Wang, K. Walden, B. W. French, N.J. Miller, C.A. Abel, H.M. Robertson, T.W. Sappington, and B.D. Siegfried. 2012. Distributions of genes and repetitive elements in Diabrotica virgifera virgifera: prelude to assembling a large, repetitive genome. J. Biomed. Biotechnol. doi:10.1155/2012/604076. Cullen, E.M. and K.M. Holm. 2013. Aligning insect IPM programs with a cropping systems perspective: Cover crops and cultural pest control in Wisconsin organic corn and soybean. Agroecology and Sustainable Food Systems 37: 550-577. Curzi, M. J., J.A. Zavala, J.L. Spencer M.J. Seufferheld. 2012. Abnormally high digestive enzyme activity and gene expression explain the contemporary evolution of a Diabrotica biotype able to feed on soybeans. Ecology and Evolution, 2(8) 2005-2017. Devos, Y., L.N. Meihls, J. Kiss, and B.E. Hibbard. 2013. Resistance evolution to the first generation of genetically modified Diabrotica-active Bt-maize events by western corn rootworm: management and monitoring considerations. Transgenic Research 22: 269-299. DeVries, T. & R. Wright. 2012. Rootworm traited and refuge corn hybrids in combination with soil insecticides for larval corn rootworm control, 2011. Arthropod Management Tests 37: F13. Dunbar, M. W. and Gassmann, A. J. In Press. Abundance and distribution of western and northern corn rootworm (Diabrotica spp.) and prevalence of rotation resistance in eastern Iowa. Journal of Economic Entomology. Dunbar, M. W. and Gassmann, A. J. 2012. Effect of soybean varieties on western corn rootworm survival and fecundity. Journal of Economic Entomology 105:625-631. Gassmann, A. J. and Hutchison, W. D. 2012. Bt crops and insect pests: past successes, future challenges and opportunities. GM Crops and Food 3:139. Gassmann, A. J., Petzold-Maxwell, J. L., Keweshan, R. S., Dunbar, M. W. 2012. Western corn rootworm and Bt maize: challenges of pest resistance in the field. GM Crops and Food 3:235-244. Gassmann, A. J. 2012. Field-evolved resistance to Bt maize by western corn rootworm: predictions from the laboratory and effects in the field. Journal of Invertebrate Pathology 110:287-293. Gassmann, A. J., Hannon, E. R., Sisterson, M. S. Stock, S. P., Carrière, Y., and Tabashnik, B. E. 2012. Effects of entomopathogenic nematodes on the evolution of pink bollworm resistance to Bt toxin Cry1Ac. Journal of Economic Entomology 105:994-1005. Gray M.E. 2012. Continuing evolution confirmed of field resistance to Cry3Bb1 in some Illinois fields by western corn rootworm. In: The Bulletin: Pest Management and Crop Development Information for Illinois, Issue No. 20. University of Illinois Extension, Urbana, IL, p. 120. http://bulletin.ipm.illinois.edu/article.php?id=1704. Holm, K. and E. Cullen. 2012. Insect IPM in Organic Field Crops: Seedcorn Maggot. Publication A3972-01. University of Wisconsin-Extension Cooperative Extension Publishing, Madison, WI. 6pp. http://learningstore.uwex.edu/Insect-IPM-in-Organic-Field-Crops-Seedcorn-Maggot-P1584.aspx Marquardt, P., C. Krupke, and W. Johnson. (2012). Competition of transgenic volunteer corn with soybean and the effect on western corn rootworm emergence. Weed Sci. 60(2): 193-198. Marquardt, P.T., R.M. Terry, C.H. Krupke, and W.G. Johnson. (2012). Competitive effects of volunteer corn on hybrid corn growth and yield. Weed Sci. in press. Meihls, L.N., M.L. Higdon, M.R. Ellersieck, and B.E. Hibbard. 2012. Greenhouse-selected resistance to Cry3Bb1-producing corn in three western corn rootworm populations. PloS ONE 7:e51055. Murphy, A.F. and C.H. Krupke. (2011). Mating success and spermatophore composition in the western corn rootworm. Environ. Entomol. 40: 1585-1594. Petzold-Maxwell, J. L., Cibils-Stewart, X., French, B. W., and Gassmann, A. J. 2012. Adaptation by western corn rootworm (Coleoptera: Chrysomelidae) to Bt maize: inheritance, fitness costs and feeding preference. Journal of Economic Entomology 105:1407-1418. Petzold-Maxwell, J.L., Jaronski, S.T., Gassmann, A. J. 2012. Tritrophic interactions among Bt maize, an insect pest, and entomopathogens: effects on development and survival of western corn rootworm. Annals of Applied Biology 160:43-55. Petzold-Maxwell, J. L., Jaronski, S. T., Clifton, E. H., Dunbar, M. W., Jackson, M. A. and Gassmann, A. J. In Press. Interactions among Bt maize, entomopathogens and rootworm species (Coleoptera: Chrysomelidae) in the field: effects on survival, yield and root injury. Journal of Economic Entomology. Raghu, S., J.L. Spencer, A.S. Davis, and R.N. Wiedenmann. 2011. Ecological considerations for the sustainable development of terrestrial biofuel crops. Current Opinion in Environmental Sustainability, 3:15-23. Rangasamy, M. and B.D. Siegfried. 2012. Validation of RNA interference in western corn rootworm, Diabrotica virgifera virgifera (Coleoptera: Chrysomelidae) adults. Pest Manag. Sci. 68: 587-591. Rudeen, M. L. and Gassmann, A. J. In Press. Effects of Cry34/35Ab1 corn on survival and development of western corn rootworm, Diabrotica virgifera virgifera. Pest Management Science. Spencer, J., D. Onstad, C. Krupke, S. Hughson, Z. Pan, B. Stanley, and L. Flexner. 2013. Isolated females and limited males: evolution of insect resistance in structured landscapes. Entomologia Experimentalis et Applicata, 146:38-49. Tinsley NA, Estes RE, Gray ME, 2012. Validation of a nested error component model to estimate damage caused by corn rootworm larvae. J. Applied Entomology. DOI: 10.1111/j.1439-0418.2012.01736.x. Valencia, A., A.P. Alves, and B.D. Siegfried. 2013 Molecular cloning and functional characterization of an endogenous endoglucananse belonging to GHF45 from the western corn rootworm, Diabrotica virgifera virgifera. Gene 513: 260-267. Wang, H., B.S. Coates, H. Chen, T. Sappington, T. Guillemaud, and B.D. Siegfried. (Submitted). Role of a gamma-aminobutryic acid (GABA) receptor mutation in the evolution and spread of Diabrotica virgifera virgifera resistance to cyclodiene insecticides. Insect Molec. Biol. Wright, R. J., and L. J. Meinke. 2011. Corn rootworm management update. CropWatch Newletter. 22 September 2011. http://cropwatch.unl.edu/web/cropwatch/archive?articleID=4651826. Wright, R. J., and L. J. Meinke. 2012. Results from consultant survey on Bt corn rootworm damage. CropWatch Newsletter 3 February 2012. http://cropwatch.unl.edu/web/cropwatch/archive?articleID=4734708.