BIOLOGY, IMPACT, AND MANAGEMENT OF SOYBEAN INSECT PESTS IN SOYBEAN PRODUCTION SYSTEMS.(S-1010)

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 0221611
• Multistate No.: S-1039
• Project Start Date: Apr 1, 2010
• Project End Date: Sep 30, 2012
• Program Code: [(N/A)]- (N/A)

Recipient Organization
UNIVERSITY OF NEBRASKA
(N/A)
LINCOLN,NE 68583

Performing Department
Northeast Res & Extension Center

Non Technical Summary
In 2006, more acres of soybean were harvested in the U.S. (74.6 million) than acres of any other crop, including corn (70.6 million). Given this large acreage and wide distribution, it is not surprising that soybean continues to suffer from insect pests that impact plant growth, grain quality, and yield. Changes in cropping practices, or global climate change, the distribution and impact of native and established pests is increasing in soybean. Producers are encountering insect problems that they have never seen or managed. Changes in pest distribution and status require greater understanding of pest biology and movement, as well as the development or modification of scouting and control methods. Although pesticides are often the easy first tools used to deal with new or growing insect problems, long-term sustainable solutions must include host plant resistance and biological control. In the northern U.S. and eastern Canada, the discovery of the soybean aphid (SBA) in 2000 fundamentally changed soybean insect management. SBA feeding impacts all components of yield; under heavy aphid pressure, yield differences between treated and untreated research plots may reach 50%. Although scouting methods and an economic threshold (ET) for aphid control were developed under the previous multi-state project, these management practices are only applicable to soybeans in the R1 to R5 growth stages planted in 30-inch rows. The thresholds must be modified to account for plant maturity group and age, differences in planting systems (for example, varying row widths), and populations of biological control agents. Specialty soybean production is a growing, profitable market for producers, including production of seed, non-GMO, identity preserved (IP) and USDA-certified organic soybeans. IP soybeans are sought for traits such as high protein, high isoflavone, or improved flavor or texture in the case of tofu (bean curd) and edamame (vegetable soybean). By volume, soybeans make up the largest segment of organic legumes in the U.S. Production practices and quality requirements of specialty beans differ from those of conventionally-produced roundup-ready beans, thus insect management practices are also likely to differ. The introduction of soybean aphid resulted in an increase in pesticide use on soybeans in the Midwest. Industry recommendations to customers now routinely include tank mixes of insecticides and fungicides for plant health benefits, even in the absence of pest pressure. The recent registration of seed-applied insecticides also encourages growers to use products as insurance treatments rather than basing applications on scouting. The efficacy and economic viability of insurance treatments need to be addressed in a concerted way. To move beyond chemical use, particularly to control bean leaf beetle, soybean aphid, stink bug, and other chronic pests, alternatives are critically needed. These alternatives include both biological control and host plant resistance, preventative tactics which form the foundation of IPM, and which must be integrated with therapeutic tactics such as insecticide use.

Animal Health Component

(N/A)

Research Effort Categories

Basic

(N/A)

Applied

(N/A)

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
211	1820	1130	50%
216	1820	1130	50%

Knowledge Area
211 - Insects, Mites, and Other Arthropods Affecting Plants; 216 - Integrated Pest Management Systems;

Subject Of Investigation
1820 - Soybean;

Field Of Science
1130 - Entomology and acarology;

Keywords

soybean pests

soybean aphid

bean leaf beetle

stink bug

dectes stem borer

host plant resisistance

economic thresholds

Goals / Objectives
1. Characterize insect-soybean interactions and their impact on plant growth, grain quality, and yield. 2. Develop and validate tactics for management of key soybean insects. Outputs: 1. New or refined thresholds for soybean pests. 2. Assessment of the impact of cultural management practices on pest numbers, natural enemies, and plant nutrient profiles. 3. Identification of insecticides and spray technologies with improved activity and economic viability. Detection of insecticide resistance in soybean aphid. 4. Increased understanding of the impacts of native natural enemies on soybean aphid, and how these impacts can be conserved and enhanced. 5. Incorporation of aphid resistance into commercially available soybean varieties. Increased understanding of the mechanisms of resistance to SBA and Dectes stem borer. Increased understanding of the interaction between aphid resistance and biocontrol.

Project Methods
1. Characterize insect-soybean interactions and their impact on plant growth, grain quality, and yield. Sub-objective 1a. Establish or modify thresholds of important regional pests to account for maturity group, planting systems, plant age, and natural enemy populations. Bean Leaf Beetle: Recent changes in agronomic practices and the increase in organic soybean production limit the usefulness of current management strategies. Season-long BLB and soybean plant phenology surveys will be conducted in regions where current phenology-based management is proving inadequate. Relationships will be identified for each region and management programs will be developed that exploit these relationships. Soybean Aphid: A computer-simulation model of soybean aphid population dynamics has been developed abd depending on the results of validation, modifications for direct or indirect use in developing new management tools is expected. The current soybean aphid (SBA) economic threshold (ET) was developed for soybeans in the R2-early R5 soybeans. In areas like Nebraska, aphid populations often occur during R5-R6, so there is a significant need to develop or modify current recommendations for aphids infesting R5-R6 stage soybeans. Stink bug: Stink bugs populations have recently been increasing in the north central region, but management recommendations are lacking for these regions. Current thresholds for stink bugs are rudimentary and vary considerably by state. We will initiate a project to assess the risk for stink bug damage to Nebraska soybean and begin to develop an IPM program for stink bug in Nebraska. 2. Develop and validate tactics for management of key soybean insects. Sub-objective 2a. Efficacy of seed treatments and foliar insecticides for key soybean insects. Soybean Aphid: New and currently registered products will continue to be tested in the laboratory, replicated small-plots and on-farm trials to determine efficacy against SBA, and impacts on natural enemies. Sub-objective 2c. Screen, characterize, and incorporate host plant resistance to soybean aphid and other key insects. Soybean aphid: We will continue to screen for resistance, evaluate resistance levels in lines under development, and look for new sources of resistance. We will also examine how host plant resistance impacts soybean aphid thresholds, and how it interacts with natural enemies, since there are many examples of these two tactics synergizing each other. Another component of this objective is to apply functional genomics in an explanatory role, to help support and expand our existing physiological understanding of plant tolerance mechanisms and identify gene changes unique to soybean aphid-tolerant soybean.

Progress 04/01/10 to 09/30/12

Outputs
OUTPUTS: A NCSRP Project was continued that included laboratory and field studies examining mechanisms of soybean aphid resistant soybean (with Dr. Tiffany Heng-Moss, UNL Entomology), a study examining soybean aphid economic thresholds on resistant soybeans (antibiotic Rag1 line), and a study examining soybean aphid economic thresholds on R6 stage soybean. One graduate student assigned to the project graduated (Travis Prochaska) and another finished her research and will be graduating this December (Lia Marchi). A project examining soybean aphid resistant soybean was continued (tolerant KS4202 and others) with a visiting Brazilian scientist, Edson Baldwin. A Nebraska Soybean Board project was funded in collaboration with Drs. Tiffany Heng-Moss and Bob Wright that examines a reduced area application of chlorpyrifos for soybean aphid management and the effects on natural enemies. A stink bug monitoring and natural enemy assessment study was continued. A soybean aphid foliar insecticide trial were conducted. A Nebraska NCSRP project was continued in collaboration of Dr. Blair Siegfried examining the subletal effects on seed treatments on bean leaf beetle was completed and the assigned student graduated (Chelsea Piitz, M.S. grad student). A graduate student (Matheus Ribiero)was assigned to the NCSRP project to determine baseline susceptabilities of soybean aphid populations to neonicotinoids across accross the NC region - 11 populations have been assayed (Dr. Blair Seigfried collaborator). Results of this research were presented in ten national research presentations at regional and annual meetings and at the USDA Multistate Research Committee S-1039, and at several extension venues. A peer-reviewed journal article and a book chapter were published. Two Crop Production Clinic Extension Proceedings articles on stink bugs and other soybean pests were published. PARTICIPANTS: Tiffany Heng-Moss, Co-PI, Dr. Blair Seigfried, Dr. Robert Wright, and Univ. of Nebraska Entomology Department and Edson Baldwin, University of Sao Paulo, Botocatu, Brazil. TARGET AUDIENCES: Soybean farmers, Agricultural professionals, Researchers and Extension personnel. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Tolerance was identified and mechanisms were further elucidated soybean germplasm (KS42092). Soybean aphid resistant soybeans will significantly reduce pesticide use directed at the soybean aphid. This will in turn reduce environmental impact of insecticide use and will increase grower profits by reducing the costs associated with insecticide application (up to $15/acre) and the yield loss caused by the aphid, an insect that can easilly reduce yields by 30-40% if left uncontrolled. In addition, improved economic thresholds that result from this research will significantly add to producer profitability by providing more precise decision-making tools and reducing unnecessary treatment. Reducing unnecessary treatment will, in turn, reduce the introduction of pesticides into the environment. Several stink bug egg parasitoids were identified in Nebraska. Effective management of the stink bugs could result in a savings of $31.85/acre. Neonicotinoid levels were examined in seedling soybean leaves, and a thiamethoxam bioassy method was developed to assist resistance monitoring for bean leaf beetles in soybean. Bean leaf beetles are common in Nebraska's 4.3 million acres of soybean, and treatment costs (foliar or seed treatments) can reach $15/acre. Producers often either treat when unnecessary, particularly with seed treatments, or treat too late when treatment is necessary. The recommendations that resulted from this research significantly added to producer profitability by providing more precise decision-making tools and reducing unnecessary treatment. Reducing unnecessary treatment has, in turn, reduced the introduction of pesticides into the environment.

Publications

• Piitz, Chelsea L. 2012. Effects of thiamethoxam seed treatments on bean leaf beetles. M.S. Thesis. Univ. of Nebraska-Lincoln, Lincoln, Nebraska.
• Tiroesele1, Bamphitlhi, Thomas E. Hunt, Robert Wright, Erin E. Blankenship and John E. Foster. 2012. The soybean aphid, Aphis glycines (Hemiptera: Aphididae): Population dynamics on edamame soybeans in Nebraska, USA. African Journal of Agricultural Research Vol. 7(44), pp. 5912-5918.
• Hunt, Thomas E., Edson L. L. Baldin. 2012. Soybean Insects: Ecology and Control. In Encyclopedia of Pest Management. Taylor and Francis: New York, Published online: 08 Aug 2012; 1-4.
• Hunt, T. E., R. J. Wright, W. Z. Mamut. 2012. Stinkbugs in Nebraska Soybean and Corn. pp. 16-17, Proceedings of the 2012 Crop Production Clinics, UNL Extension.
• Wright, R. J. and T. Hunt. 2012. Review of 2011 Entomology Pest Issues. pp. 19-20, Proceedings of the 2012 Crop Production Clinics, UNL Extension.
• Prochaska, Travis J. 2012. Characterization of the tolerance response in the soybean KS4202 to Aphis Glycines Matsumura. M.S. Thesis. Univ. of Nebraska-Lincoln, Lincoln, Nebraska.

Progress 10/01/10 to 09/30/11

Outputs
OUTPUTS: A NCSRP Project was continued that included laboratory and field studies examining soybean aphid resistant soybeans (with Dr. Tiffany Heng-Moss, UNL Entomology), a study examining soybean aphid economic thresholds on resistant soybeans (antibiotic Rag1 line), and a study examining soybean aphid economic thresholds on R6 stage soybean. Two graduate students, Travis Prochaska and Lia Marchi, are assigned to this project. A project examining soybean aphid resistant soybean was continued (tolerant KS4202). Three peer-reviewed papers were published. A Nebraska Soybean Board funded study was completed in collaboration with Dr. Bob Wright (with Zaki Wan Mamut, Fulbright PhD. student) that monitored stink bugs in overwintering sites and throughout the growing season using sweepnets and light traps in or near soybean and corn fields at the Haskell Ag Lab, South Central Ag Research Farm at Clay Center, and the ARDC at Mead NE. Six soybean seed treatment and foliar insecticide trials were conducted. A Nebraska NRI project was continued in collaboration of Dr. Blair Siegfried (Chelsea Piitz, M.S. grad student) examining the subletal effects on seed treatments on bean leaf beetle. Results of this research were presented in six national research presentations, at the annual meeting of the USDA Multistate Research Committee S-1039, and at several extension venues. two peer-reviewed journal articles were published. Two Extension NebGuides on soybean stem borer and soybean aphid, a downloadable soybean aphid Extension Circular, and a soybean aphid iPod application were published. PARTICIPANTS: Tiffany Heng-Moss, Co-PI, Univ. of Nebraska Entomology Department. TARGET AUDIENCES: Soybean farmers, Agricultural professionals, Researchers and Extension personnel. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
Tolerance was verified in soybean germplasm (KS42092), and Nebraska adapted soybean varieties with the antibiotic Rag 1 gene were found to be very effective. Soybean aphid resistant soybeans will significantly reduce pesticide use directed at the soybean aphid. This will in turn reduce environmental impact of insecticide use and will increase grower profits by reducing the costs associated with insecticide application (up to $15/acre) and the yield loss caused by the aphid, an insect that can easilly reduce yields by 30-40% if left uncontrolled. In addition, improved economic thresholds that result from this research will significantly add to producer profitability by providing more precise decision-making tools and reducing unnecessary treatment. Reducing unnecessary treatment will, in turn, reduce the introduction of pesticides into the environment. Five economically injurious species species of stink bug were were found in Nebraska. Effective management of the stink bugs could result in a savings of $31.85/acre. A significant finding is that seed treatments are not economic for bean leaf beetle on bean leaf beetle. Bean leaf beetles are common in Nebraska's 4.3 million acres of soybean, and treatment costs (foliar or seed treatments) can reach $15/acre. Producers often either treat when unnecessary, particularly with seed treatments, or treat too late when treatment is necessary. The recommendations that resulted from this research significantly added to producer profitability by providing more precise decision-making tools and reducing unnecessary treatment. Reducing unnecessary treatment has, in turn, reduced the introduction of pesticides into the environment.

Publications

• Pierson, L. M., T. M. Heng-Moss, T. E. Hunt, and J. Reese. 2011. Physiological Responses of Resistant and Susceptible R1 Stage Soybean Genotypes to Soybean Aphid (Aphis glycines Matsumura) Feeding. Arthropod-Plant Interactions 5:49-58.
• Brosius, T. R. L. G. Higley, and T. E. Hunt. 2010. Biotic and Abiotic Influences on Within-Plant Distribution of Soybean Aphid (Aphis glycines). J. Kansas Entomol. Soc. 83:273-282.
• Wright, R. J. and T. E. Hunt. 2011. Soybean stem borers in Nebraska. University of Nebraska Extension NebGuide G2082.
• Hunt, T. E., K. J. Jarvi, W. J. Ohnesorg, L. M. Pierson. 2011. Soybean Aphid Management in Nebraska. University of Nebraska Extension NebGuide G2063.
• Ohnesorg, W. J., T. E. Hunt, and R. J. Wright. 2011. Soybean Aphid Speed Scouting Spreadsheet. University of Nebraska Extension Circular EC1582.
• Ohnesorg, Wayne J., and Thomas E. Hunt. 2011. Managing soybean defoliators. pp. 40-42, Proceedings of the 2011 Crop Production Clinics, UNL Extension.

Progress 10/01/09 to 09/30/10

Outputs
OUTPUTS: A NCSRP Project was continued that included laboratory and field studies examining soybean aphid resistant soybeans (with Dr. Tiffany Heng-Moss, UNL Entomology), a study examining soybean aphid economic thresholds on resistant soybeans, and a study examining soybean aphid economic thresholds on late stage soybean. Two graduate students, Travis Prochaska and Lia Marchi, are assigned to this project. A project examining soybean aphid resistant soybean was continued. Results of this work were presented in three national research presentations, at the annual meeting of the USDA Multistate Research Committee S-1039, and at several extension venues. One peer-reviewed paper was published and two more are in press. A Nebraska Soybean Board funded study was continued in collaboration with Dr. Bob Wright (Zaki Wan Mamut, Fulbright PhD. student) that monitored stink bugs in overwintering sites and throughout the growing season using sweepnets and light traps in or near soybean and corn fields at the Haskell Ag Lab, South Central Ag Research Farm at Clay Center, and the ARDC at Mead NE. Results were presented in a national reserch presentation, at the annual meeting of the USDA Multistate Research Committee S-1039, and at several extension venues. A long-term bean leaf beetle survey was continued, two soybean seed treatment and foliar insecticide trials were conducted. Results were presented at several extension venues and at the annual meeting of the USDA Multistate Research Committee S-1039. A Nebraska NRI project was initiated with collaboration of Dr. Blair Siegfried (Chelsea Piitz, M.S. grad student) examining the subletal effects on seed treatments on bean leaf beetle. Results were presented in two national research presentations. A manuscript is in preparation for publication in a peer-reviewed journal. PARTICIPANTS: Tiffany Heng-Moss, Co-PI, Univ. of Nebraska Entomology Department. TARGET AUDIENCES: Soybean farmers, Agricultural professionals, Researchers and Extension personnel. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
Tolerance was identified in soybean germplasm, and Nebraska adapted soybean varieties with the antibiotic Rag 1 gene were found to be very effective. Soybean aphid resistant soybeans will significantly reduce pesticide use directed at the soybean aphid. This will in turn reduce environmental impact of insecticide use and will increase grower profits by reducing the costs associated with insecticide application (up to $15/acre) and the yield loss caused by the aphid, an insect that can easilly reduce yields by 30-40% if left uncontrolled. In addition, improved economic thresholds that result from this research will significantly add to producer profitability by providing more precise decision-making tools and reducing unnecessary treatment. Reducing unnecessary treatment will, in turn, reduce the introduction of pesticides into the environment. Five economically injurious species species of stink bug were were found in Nebraska. Effective management of the stink bugs could result in a savings of $31.85/acre. A significant finding is that seed treatments are not economic for bean leaf beetle on bean leaf beetle. Bean leaf beetles are common in Nebraska's 4.3 million acres of soybean, and treatment costs (foliar or seed treatments) can reach $15/acre. Producers often either treat when unnecessary, particularly with seed treatments, or treat too late when treatment is necessary. The recommendations that resulted from this research significantly added to producer profitability by providing more precise decision-making tools and reducing unnecessary treatment. Reducing unnecessary treatment has, in turn, reduced the introduction of pesticides into the environment.

Publications

• Pierson, L.M., T.M. Heng-Moss, T.E. Hunt, and J.C. Reese. 2010. Categorizing the Resistance of Soybean Genotypes to the Soybean Aphid (Hemiptera: Aphididae). J. Econ. Entomol. 103(4): 1405-1411.
• Ferguson, R., Giesler, L., Hunt, T., Jarvi, K., Jasa, P., Kruger, G., Lemmons, T., Specht, J., Schneider, J., Sandell, L., Wortmann, C., Glewen, K., 2010, Soybean Management Field Day - Growers Study Guide, University of Nebraska Extension, Lincoln, Nebraska.
• Hunt, T. E., R. J. Wright, K. J. Jarvi, W. J. Ohnesorg. 2010. Soybean insect update: Aphids, stem borers, and stink bugs, pp. 118-121, Proceedings Crop Production Clinics, University of Nebraska Extension, Lincoln, Nebraska.