NCR46: Development, Optimization and Delivery of Management Strategies for Corn Rootworms
(Multistate Research Coordinating Committee and Information Exchange Group)
Status: Inactive/Terminating
NCR46: Development, Optimization and Delivery of Management Strategies for Corn Rootworms
Duration: 10/01/2001 to 09/30/2006
Administrative Advisor(s):
NIFA Reps:
Non-Technical Summary
Statement of Issues and Justification
The western corn rootworm, Diabrotica virgifera virgifera LeConte, and the northern corn
rootworm, D. barberi Smith and Lawrence, are the most serious insect pests attacking corn in
North America. With the movement of the Mexican corn rootworm, D. virgifera zeae Krysan
and Smith, into Texas, corn from the Rocky Mountains to the Atlantic Ocean and from Texas
into southern Canada is attacked by this complex. Because the pest is distributed throughout
most of North America's corn producing areas, it transcends production systems and crop-use
patterns. The insect infests irrigated corn in the west and dry-land production systems further
east; it infests corn that will be used for on-farm feed as grain or silage as well as grain that will
be sold for off-farm use as food, feed, and industrial manufacturing. The diverse geographies,
environments, and production systems this insect is established in make it appropriate to
coordinate research throughout its range.
The original corn rootworm Multistate Research Coordinating Committee was approved in 1964
as a NCR project and the committee has operated continuously since then. The intent of the
project was to "study, on a regional basis, the biology of the corn rootworm complex in relation
to current and projected cultural practices and to identify vulnerabilities of the pests that could be
used as control measures benefiting farmers in the North Central Region." At that time the
northern corn rootworm was an economic pest in the central Corn Belt and the western corn
rootworm had just began its spread out of Kansas and Nebraska. In 1964 the western had moved
into South Dakota, southern Minnesota, and was established in the western half of Iowa. The
"official" membership of the earlier research coordinating committees came from the 12 north
central state agricultural experiment stations and the USDA-ARS Northern Plains Insect
Research Laboratory. As the western corn rootworm spread, scientists from the newly infested
corn-growing states and countries, i.e., Canada, began attending the committee's meetings as
"associate" members. This proposed renewal of the corn rootworm Multistate Research
Coordinating Committee contains internal and external linkages to resources from nearly all
areas and corn production systems in North America currently infested by the pest complex.
As stated previously, the original intent of the previous committees was to study the biology of
the corn rootworm complex to identify vulnerabilities of the pests that could be used as control
measures. Understanding the host/pest interaction led to the promotion of crop rotation as a
reliable and safe control option and the release ofrootworm-tolerant corn inbreds. Pooling data
across states generated management decision guidelines and chemical tools. Examples of
tangible results that were achieved and delivered to growers because of regional coordination
include: the understanding of how the repeated use ofcarbamate insecticides on some soils can
result in an enhanced rate of degradation that eliminates their effectiveness in those fields; by
combining data across states, a large enough database under differing environments and
production systems was generated to demonstrate that the rate at which many insecticides are used could be reduced and effective control still achieved at a lower cost to the grower; and the concept of controlling adult corn rootworms with reduced rates of insecticides before they lay
eggs was refined and demonstrated across Midwest corn production systems.
Advances to date have not eliminated the need for regional coordination of corn rootworm
research because of changes in corn rootworm biology, pest management technologies, and
regulatory issues. Crop rotation will no longer guarantee corn rootworm control. A variety of
the northern corn rootworm has been selected for in parts of SD, NE, MN, IL, and IA that has a
two-year lifecycle and is adapted to annual rotation of corn with another crop. In eastern Illinois
and western Indiana a strain of the western corn rootworm has evolved that oviposits in
soybeans, making it a pest of rotated corn. This strain has been spreading into Michigan, Ohio,
and has been found in eastern Iowa. New classes of insecticides are being introduced by industry
that may be able to prevent larval injury by merely coating the corn seed with them. Before they
can be recommended to state extension specialists and agricultural product vendors, a large
public database across production systems and environments must be generated to demonstrate
their effectiveness. The western corn rootworm is again developing resistance to insecticides
used in Nebraska. A coordinated monitoring program is needed to determine if the genes for
resistance are spreading throughout the rootworm population and how this might effect
integrated management strategies. The seed industry is on the verge of releasing genetically
modified corn varieties that are resistant to rootworms. To ensure that these products of
biotechnology are environmentally benign and that resistance to the proteins deployed will not
develop, the combined expertise of the technical committee will be needed to evaluate
environmental impacts and to design and test resistance management strategies that are
compatible with production practices throughout the corn producing region.
Objectives
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Systematically design and implement research on rootworm mating, dispersal, survival, and host range across environments and production systems to understand gene flow in the landscape for the design of insecticide and transgenic resistance management plans and the spread of pest strains that differ behaviorally. These research needs may be identified by and used in resistance-management computer simulation models.
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Coordinate regional research on the impact of new corn rootworm management technologies, such as transgenic varieties and new classes of insecticide chemistry, on non-target organisms and environmental quality.
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Produce a Corn Rootworm Management Guide that collates current management knowledge for this pest complex across regional production systems and make it publicly available through both a brochure and a web publication.
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Publish a statement that draws on published research and the expertise of the committee that lists considerations that must be addressed in an Insect Resistance Management program before transgenic varieties are released.
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Coordinate the monitoring of insecticide resistance and develop a regional strategy that can be used to stop or delay the spread of resistance.
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Continue to evaluate the efficacy of conventional insecticides in various crop production systems, assist in the development of new chemical tools and modes of delivery, and calculate the impact on corn production of the failure to reregister existing insecticides.
Procedures and Activities
Expected Outcomes and Impacts
- Through committee discussions and with the help of simulation models, identify data needs and design and coordinate regional research to provide this missing information for the design and deployment of management strategies.
- Publish and maintain (revise) a Corn Rootworm Management Guide that provides practitioners with a thorough, but relevant and understandable description of corn rootworms and their management.
- Publish public statements concerning the appropriateness, methods of deployment, and environmental safety of new corn rootworm management strategies such as transgenic varieties and treatment of corn seeds with insecticides.
- Propose, plan, and officiate symposia and research presentations at national and regional professional meetings.
Projected Participation
View Appendix E: ParticipationEducational Plan
- In conjunction with the committee's annual meeting, sponsor a joint open meeting with customers, e.g., representatives of growers associations, seed industries, agricultural chemical manufacturers, etc., to summarize the committees research activities and discuss appropriate deployment of new insect management strategies.
- Plan, sponsor, and officiate public discussions concerning the use of new corn rootworm management technologies such as genetically engineered varieties.
- Support an Internet site that offers up-to-date summaries of corn rootworm biology, ecology, and management.
- Serve as a resource for legislative agencies that regulate and industries that develop new pest management tools concerning the appropriate deployment and safety of technologies under development.
Organization/Governance
The proposed Multistate Research Coordinating Committee will be administered as the previous
committee (NCR-46) was. The administrative team will consist of an Executive Committee of a
Chair, Vice Chair, Past Chair, and Secretary. The Committee members' terms in each office will
be one year, with each member moving through the four offices. At the first business meeting of
the annual meeting, the current Chair will appoint a Nominating Committee consisting of two
members of the Research Coordinating Committee. The Nominating Committee will identify
one or more eligible committee members that are willing to serve on the Executive Committee.
The candidate(s) will be presented to the whole committee during the final business meeting and
an officer approved by majority vote. At the close of that meeting, the newly elected officer will
become the Secretary of the Research Coordinating Committee, the previous Secretary will
become Vice Chair, the Vice Chair will move into the Chair's position, and the Chair will
become the Past Chair. The incumbent Past Chair will leave the Executive Committee.
Literature Cited
APPENDIX 2: Notable committee accomplishments, October 1996 - Present
NCR-46 Committee members continue to conducted research on the efficacy of registered and
experimental soil and foliar applied insecticides for corn rootworm control in various crop
production systems. More recently, research on the efficacy of reduced rates of soil insecticides
for corn rootworm control as well as evaluations oftransgenic "rootworm protected" corn
was also done by committee members. NCR-46 members are a non-biased source of
information for extension personnel, consultants, and growers on all aspects of rootworm
biology and management.
Journal articles
Fuller, B.W., M.A. Boetel, D.D. Walgenbach, J.A. Grundler, G.L. Hein, K.J. Jarvi, A.J. Keaster,
D.A. Landis, L.J. Meinke, J.D. Oleson, K.R. Ostlie, J.J. Tollefson, J.L. Wedberg, G.E. Wilde, &
P.D. Evenson. 1997. Optimization of soil.insecticide rates for managing corn rootworm
(Coleoptera: Chrysomelidae) larvae in the North Central United States. J. Econ. Entomol.
90:1332-1340."
Extension bulletins
Edwards, C.R., L.W. Bledsoe, and J.L. Obermeyer. 1999. Managing corn rootworm-2000.
Purdue University.
Wedberg, J. 1999. Corn Rootworms. University of Wisconsin CES.
Wright, R., L. Meinke, and K. Jarvi. 1999. Corn rootworm management. University of
Nebraska.
Research by NCR-46 Committee members identified resistance to foliar insecticides by corn
rootworm beetles as being the cause of poor performance of these materials in some parts of the
corn belt. Research continues on detecting resistance and identifying resistance mechanisms
for these, as well as other, materials.
Journal articles
Meinke, L.J., B.D. Siegfried, R.J. Wright, and L.D. Chandler. 1998. Adult susceptibility of
Nebraska western corn rootworm (Coleoptera: Chrysomelidae) populations to selected
insecticides. J. Econ. Entomol. 91:594-600.
Miota, F., M.E. Scharf, M. Ono, L.J. Meinke, R.J. Wright, L.D. Chandler, and B.D. Siegfried.
1998. Mechanisms of methyl and ethyl parathion resistance in western corn rootworm
(Coleoptera: Chrysomelidae). Pesticide Biochem. Physiol. 61: 39-52.
Scharf, M. E., B.D. Siegfried, L.J. Meinke, R.J. Wright, and L.D. Chandler. 2000. Cytochrome
P450 mediated N-demethylation activity and induction in insecticide-resistant and susceptible
western corn rootworm populations (Coleoptera: Chrysomelidae). Pestic. Biochem. Physiol. 67:137-143.
Scharf, M. E., B.D. Siegfried, L.J. Meinke, and L.D. Chandler. 2000. Fipronil metabolism,
oxidative sulfone formation and toxicity among organophosphate and carbamate-resistant and -
susceptible western corn rootworm populations. Pesticide Manag Sci.56:757-766.
Scharf, M.E. and B.D. Siegfried. 1999. Toxicity and neurophysiological effects offipronil and
fipronil sulfone on the western corn rootworm (Coleoptera: Chrysomelidae). Arch. Insect
Biochem. Physiol. 40: 150-156.
Scharf, M.E., L.J. Meinke, B.D. Siegfried, R.J. Wright, and L.D. Chandler. 1999. Carbaryl
susceptibility, discriminating concentration determination, and synergism for U.S. populations of
western corn rootworm (Coleoptera: Chrysomelidae). J. Econ. Entomol. 92: 33-39.
Scharf, M.E., L.J. Meinke, R.J. Wright, L.D. Chandler, and B.D. Siegfried. 1999. Metabolism of
carbaryl by insecticide resistant and susceptible western corn rootworm populations (Coleoptera:
Chrysomelidae). Pesticide Biochem. Physiol. 63: 85-96.
Siegfried, B.D., L.J. Meinke, and M.E. Scharf.. 1998. Resistance management concerns for
areawide management programs. J. Agric. Entomol. 15: 359-369.
Wright, R.J., M.E. Scharf, L.J. Meinke, X. Zhou, B.D. Siegfried, and L.D. Chandler. 2000.
Larval susceptibility of an insecticide-resistant western corn rootworm (Coleoptera:
Chrysomelidae) population to soil insecticides: laboratory bioassays, assays of detoxification
enzymes, and field performance. J. Econ. Entomol. 93(1): in press.
Extension bulletins
Wright, R.J., L.J. Meinke, and B.D. Siegfried. 1999. Larval western corn rootworm insecticide
resistance in Nebraska. Nebfact NF99-366, Univ. Nebr. Coop. Ext, 3 p.
Wright, R.J., L.J. Meinke, and B.D. Siegfried. 1999. Adult western corn rootworm insecticide
resistance in Nebraska. Nebfact NF99-3 67. Univ. Nebr. Coop. Ext., 2 p.
Wright, R.J., L.J. Meinke, and K. Jarvi. 1999. Corn rootworm management. Univ. Nebr. Coop.
Ext.,EC99-1563-C.
An adult corn rootworm management ("areawide") strategy has been under development by
members of the NCR-46 Committee. This approach uses semiochemical attractants and
feeding stimulants along with reduced rates of insecticide and novel delivery systems.
Because the insecticide is targeted, less than 5 of the amount of insecticide applied to control
adults by foliar applications is needed.
Journal articles
Siegfried, B.D., L.J. Meinke, and M.E. Scharf. 1998. Resistacne management concerns for
areawide management programs.. J. Agric. Entomol. 15: 359-369.
Tollefson, J.J. 1998. Rootworm areawide management program in Iowa. J Agric Entomol
15(4): 351-357
Wilde, G.E., R.J. Whitworth, R.A. Shufran, K.Y. Zhu, P.E. Sloderbeck, R.A. Higgins, and L.L.
Buschman. 1998. Rootworm areawide management project in Kansas. J. Agric. Entomol
15(4): 335-349
Extension bulletins
Sloderbeck, P.E., R.A. Higgins, G.E. Wilde, R.A. Shufran, R.J. Whitworth, K.Y. Zhu, and L.L.
Buschman. 1998. Kansas corn rootworm areawide management program using semiochemicals.
Kansas State University.
Members of the NCR-46 Committee discovered populations of the northern corn rootworm with
a prolonged egg diapause and populations of the western corn rootworm that lay eggs in
soybean fields. These two traits compromise crop rotation as a pest management practice for
these pests where the traits occur. Cooperative efforts resulted in the assignment of geographic
areas subject to severe injury by these pests. By delineating areas subject to potential losses of
$20-$60 per acre, economic impact to producers has been dramatically reduced. In addition,
areas of low risk have not been subjected to unnecessary insecticide applications.
Journal articles
O'Neal, M.E, M.E. Gray, and C.A. Smyth. 1999. Population characteristics of a western corn
rootworm (Coleoptera: Chrysomelidae) strain in east-central Illinois corn and soybean fields. J.
Econ. Entomol. 92(6): 1301-1310.
Onstad, D.W., M.G. Joselyn, S.A. Isard, E. Levine, J.L. Spencer, L.W. Bledsoe, C.R. Edwards,
C.D. DiFonzo, and H. Willson. 1999. Modeling the spread of western corn rootworm
(Coleoptera: Chrysomelidae) populations adapting to soybean-corn rotation. Environ. Entomol.
28(2): 188-194.
Sammons, A.E., C.R. Edwards, L.W. Bledsoe, P.J. Boeve, and J.J. Stuart. 1997. Behavioral and
feeding assay reveal a western corn rootworm (Coleoptera: Chrysomelidae) variant that is
attracted to soybeans. Envom. Entomol. 26: 1336-1342.
Spencer, J.L., S.A. Isard, and E. Levine. 1999. Free flight of western corn rootworm (Coleoptera:
Chrysomelidae) to corn and soybean plants in a walk-in wind tunnel. J. Econ. Entomol. 92- 146-
155.
Extension bulletins
DiFonzo, C.D. 1998. Special corn rootworm issue. Michigan State University IPM program's
Field Crops CAT Alert newsletter.
O'Neal, M., C. DiFonzo, and D. Landis. 1999. A new strategy for an old pest: Western corn
rootworms in first-year corn. Michigan State University.
Spencer, J. and E. Levine. 1998. Western corn rootworm: New behavior threatens crop rotation.
University of Illinois.
Research by NCR-46 Committee members using yellow sticky traps to sample corn rootworm
beetle population densities has provided a means for predicting the potential for rootworm
larval injury to occur in corn grown after soybeans (in areas where western corn rootworms lay
eggs in soybeans). Use of such traps with thresholds developed by members of the NCR-46
Committee has enabled consultants and growers to predict the need for a soil insecticide at
planting time.
Journal articles
O'Neal and Gray paper on thresholds - just went in for review.
Extension bulletins
O'Neal, M., C. DiFonzo, and D. Landis. 2000.Westem corn rootworms in soybeans:
recommendations for rotated corn. Michigan State University.