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United States Department of Agriculture

Agricultural Research Service

2008 Annual Report

1a.Objectives (from AD-416)
The therapeutic approach of killing pest organisms with toxic chemicals has been the prevailing pest control strategy for over 50 years. Safety problems and ecological disruptions continue to ensue, and there are renewed appeals for effective, safe, and economically acceptable alternatives. The overall objectives of this project are to conduct research on the basic biology and ecology of weeds and insect pests and beneficial insects in corn/soybean/wheat production systems and to develop integrated pest management systems and decision aids. Our specific objectives are to:.
1)investigate the behavior and genetics underlying the resistance of corn rootworms to pest management tactics and develop novel pest management technologies for northern and western corn rootworms; .
2)reduce emerging weed and insect problems in corn/soybean and corn/soybean/wheat rotations; and.
3)develop and evaluate cultural, biological control and host plant resistance management tactics for emerging and invasive insect pests of soybean. Attaining the objectives as outlined above will provide farmers with new and refined methods of pest and crop management for improved crop productivity and quality.

1b.Approach (from AD-416)
Our interdisciplinary research brings emerging technological advances and integrated pest management practices together to develop short- and long-term pest management strategies for sustainable agriculture. Our approaches are to characterize the ecology, behavior, and genetics of insect and weed pests in agricultural systems of the northern Great Plains as a basis to:.
1)develop and evaluate resistance management and pest control strategies;.
2)determine pest-crop interactions and pest-landscape relationships to develop sampling/monitoring technology;.
3)optimize management tactics;.
4)assess yield loss potential;.
5)establish action thresholds;.
6)define management zones;.
7)develop risk assessment models; and.
8)improve understanding of the interactions between pest and beneficial insects and impacts of agronomic practices on beneficial insects in corn/soybean/wheat cropping systems. Benefits potentially derived from this research include reduced chemical usage, improved crop production efficiency, better cultural control options for pest management, and the development of integrated pest management systems based upon a better understanding of pest biology and ecology.

3.Progress Report
Insect and weed pests cause significant economic loss to farmers and foster dependence on pesticides. New pest management tactics are needed that will provide efficacious, economically viable, safe, and environmentally sustainable alternatives to conventional pesticides and that prolong the useful life of existing and emerging management technologies. The overall philosophy of the Crop Protection and Quarantine National Research Program (NP 304) is to develop and implement ecologically-based sustainable approaches to the management of native and invasive insect, mite, and weed pests through a combination of biological, cultural, physical, and chemical methodologies that reduce pest populations to acceptable levels while minimizing impacts on human health and the environment.

The research described in this annual report addresses several high-priority research needs as outlined in this National Program: Integrated pest management systems and areawide suppression (accomplishment “corn rootworm areawide pest management in South Dakota”); Integrated weed management in cropland (accomplishment “impact of crop residue and tillage on weed seedling density”); Establishment of action thresholds (accomplishment “soybean aphid effects on crop yield and quality); Cultural control of insect pests of wheat and insect-vectored disease (accomplishment “essential crop nutrients to reduce yield loss to cereal aphids and aphid-vectored disease); Breeding for host plant resistance (accomplishments “screening maize germplasm for resistance to corn rootworm, identification of soybean lines resistant to soybean aphid, additional soybean lines with resistance to soybean aphid, identification of wheat and triticale lines resistant to bird cherry-oat aphid); Basic biology of pests and natural enemies (accomplishment “status of previously common native lady beetles in South Dakota”).

We are obtaining basic biological, behavioral, and ecological knowledge concerning key weed and insect pests as well as beneficial insects in corn/soybean/wheat agricultural systems. This information will be synthesized into ecological concepts as a basis to minimize insect resistance to genetically modified crops and to develop integrated pest management systems and decision aids based upon improved cultural pest control and risk assessment models for decision support. Benefits result from providing farmers with new and refined methods of pest management for improved crop productivity and quality. Farmers will also see increased pest management efficiency and profitability from reduced pesticide use and from preserved yields that result from new pest sampling and monitoring methodology, precise application of pesticides, strategies for prolonging the use of insect-resistant crops, and the conservation of insects that prey upon crop pests. Benefits include reduced chemical usage and better cultural control options for pest management, leading to integrated production systems based upon a better understanding of agroecological principles.

1. Corn rootworm areawide pest management in South Dakota: The overall objective was to employ integrated pest management tactics to suppress adult Diabrotica populations over a broad geographic area using aerially applied semiochemical-baited insecticides. The baited insecticides were effective in reducing adult populations one and two weeks following application, and most remained low for the duration of the corn growing season. Additionally, fewer adult beetles were captured in adult traps in the areawide site than in the control site, but egg counts, adult emergence, and root damage were similar between the areawide and control sites. Based on our findings, the areawide approach to managing Diabrotica beetles in corn is as effective as traditional management strategies. NP304 Program Component VI - Integrated Pest Management Systems and Areawide Suppression; Problem Area IIC, Development of IPM Systems.

2. Impact of crop residue and tillage on weed seedling density: Producers are considering adding other crops such as small grains to the corn-soybean rotation to help pest management and improve soil health. This practice will be especially helpful in managing weeds. The combination of leaving wheat residue on the soil surface and no-till reduces the number of weeds that emerge in corn almost 50%. Furthermore, weed seedling emergence is delayed 14 to 21 days in this no-till system, thus improving corn tolerance and competitiveness with weeds. Residue management, crop diversity, and no-till can help producers develop weed management systems that are not so reliant on herbicides for success. NP304 Program Component X – Weed Management Systems, Problem Statement B. Integrated Weed Management in Cropland

3. Soybean aphid effects on crop yield and quality: The soybean aphid is a major insect pest of soybeans in the U.S., and the development of an integrated pest management system for this pest is a high priority research need. Scientists from the USDA, ARS North Central Agricultural Research Laboratory, in cooperation with the extension entomologist at South Dakota State University, conducted greenhouse and field cage studies that examined the impact of soybean aphid populations on soybean growth, seed yield and seed composition. We observed that seed yield, yield components, and seed oil percent declined linearly as peak aphid numbers per plant and maximum cumulative aphid-days per plant increased. This research provides information to soybean producers about the relationships between aphid populations and soybean yield/quality under controlled environments and field conditions. NP304 Program Component VI - Integrated Pest Management Systems and Areawide Suppression, Problem Statement B. Establishment of Economic Thresholds

4. Efficient methods for rearing the rice root aphid: Relatively little is known about the suitability of different host plants and optimal rearing techniques for the rice root aphid, a sporadic but worldwide pest of wheat and other crops. Laboratory experiments determined that rice root aphid was more abundant on plants grown with a sandy soil surface than a surface with fine wood chips or only bare non-sandy soil. Additional observations with grassy plants showed that abundance of rice root aphid on ‘Kivu 85’ triticale, a type of wheat x rye cross, was comparable to that on Elbon rye, a favored host plant. Rice root aphid did not reproduce on potato or soybean plants, although winged adults persisted up to 24 days on caged potato plants. The differential abundance of rice root aphid on plants have implications with regard to colony rearing, future experiments and pest management. National Program 304, Component II - Biology of Pests and Natural Enemies (Microbes), Problem Area B – Basic Biology.

5. Essential crop nutrients to reduce yield loss to cereal aphids and aphid-vectored disease: Because root systems provide shoot organs with essential mineral nutrients, potential reductions in root system function in aphid-infested or barley yellow dwarf virus-infected plants may play an important role in causing grain yield reductions. Therefore we studied how cereal aphid (bird cherry oat aphid, greenbug, Russian wheat aphid) and aphid-transmitted disease affected shoot mineral concentrations in spring wheat and oats under field conditions. The goal of our research was to determine the role of specific mineral nutrients in ameliorating yield loss to cereal aphids and BYDV. The results of our experiments revealed that nitrogen, potassium, and magnesium were important crop mineral nutrients that mediated positive cereal plant responses to stress caused by aphid feeding damage or aphid-vectored disease. The data presented in this study suggest that small grain producers should undertake soil and crop management strategies that guard against crop deficiencies in these three essential crop mineral nutrients. NP304 Program Component V – Pest Control Strategies and Problem Area C. – Physical/Mechanical and Cultural Control.

6. Screening maize germplasm for resistance to corn rootworms: Corn rootworms (Coleoptera: Chrysomelidae) are devastating pests of maize (Zea mays L.), and the root damage caused by larval feeding often leads to economic loss. Plant breeders are developing novel maize germplasm and improving screening methods in the hopes of identifying lines with resistance to immature rootworms. We have determined that in its current form, the larval behavioral bioassay developed by Strnad and Dunn (1990) is not useful for screening maize germplasm for rootworm resistance, although we found differences in feeding behavior between rootworm groups (non-diapausing westerns, diapausing westerns, diapausing northerns). We assessed the resistance of 10 experimental inbred lines introgressed with genes from Tripsacum dactyloides, a wild relative of maize that is resistant to corn rootworms, in the field. Two experimental maize inbred lines had mean root damage ratings that were significantly lower than the susceptible public line B73. Two other experimental maize inbred lines appeared tolerant to rootworm damage because they exhibited yield increases after rootworm infestation in both years. NP304 Program Component V – Pest Control Strategies, Problem Area B. – Breeding for Host Plant Resistance.

7. Identification of soybean lines resistant to soybean aphid: The soybean aphid has recently become a major pest of soybean in the U.S. Several millions of acres are sprayed annually for SBA control until alternative control methods such as resistant soybean lines are developed. Growth-chamber experiments were used to identify and characterize aphid resistance among several soybean lines. Antibiosis resistance was evident in lines Cobb, Jackson and Tie-feng 8 from lowered survival of first-generation aphids, and in Cobb, Jackson, Tie-feng 8, and Braxton from diminished reproduction by first-generation SBA. Antixenosis was apparent in Cobb and Jackson during initial infestation of aphid population-growth tests, as soybean aphids were unsettled and dispersed readily from placement points on unifoliolate leaves. Results suggest that Tie-feng 8, Braxton, and especially Cobb are new and potentially useful sources of resistance. National Program 304, Component V - Pest Control Strategies, Problem Area VB – Breeding for Host Plant Resistance.

8. Additional soybean lines with resistance to soybean aphid: The soybean aphid is a pest of soybean that recently established in North America, and its recurring outbreaks have challenged pest management practitioners to seek environmentally responsible means of control. Growth-chamber experiments identified aphid resistance in soybean lines Perrin; Tracy-M, its glabrous near-isoline D88-5328, and its densely pubescent near-isoline D88-5272; D75-10169, its glabrous near-isoline D90-9216, and a densely pubescent near-isoline D90-9220. Tracy-M and D75-10169 were antixenotic to SBA in host-selection tests. The time to reproductive maturity for SBA did not differ among lines, but SBA produced fewer offspring on Perrin, Tracy-M, D75-10169 and Dowling compared to a control line. Perrin, Tracy-M, and D75-10169 have been used as sources of resistance to other insects, and discovery of resistance to SBA in these three lines may increase their utility in soybean breeding programs. National Program 304, Component V - Pest Control Strategies, Problem Area VB – Breeding for Host Plant Resistance.

9. Identification of wheat and triticale lines resistant to bird cherry-oat aphid: The bird cherry-oat aphid (BCOA) is a worldwide pest of wheat and other small grains. The research identified and characterized additional wheat and triticale lines that may serve as sources of resistance to BCOA in wheat-breeding programs. The resistant lines of wheat and triticale were characterized by lower abundance of aphids on plants compared to susceptible checks. In the future, resistant varieties may reduce economic loss from BCOA, and eliminate economic and environmental costs associated with aphicide use. National Program 304, Component V - Pest Control Strategies, Problem Area B – Breeding for Host Plant Resistance.

10. Status of previously common native lady beetles in South Dakota: In the last two decades, three previously common coccinellids (twospotted lady beetle, transverse lady beetle and ninespotted lady beetle) have declined in abundance in South Dakota, while two invasive species (sevenspotted lady beetle [C7] and multicolored Asian lady beetle [MALB]) have become established there. A survey for coccinellids in various habitats in South Dakota was conducted to characterize the current coccinellid fauna, determine the extent of exploitation by invasive coccinellids, and possibly identify refuge habitats of previously common coccinellid species. Overall, 2,827 coccinellids, comprising 23 species, were collected in field and woody habitats. Twospotted lady beetles were found in Butte County in western South Dakota, but not in eastern and central parts of the state. Transverse and ninespotted lady beetles were absent at all sites sampled. The invasiveness of C7 and MALB was evident by their presence in a wide variety of habitats surveyed, dominance of larval coccinellid assemblages, and predation upon non-target species of aphids. National Program 304, Component II - Biology of Pests and Natural Enemies (Microbes), Problem Area B – Basic Biology.

11. Bean leaf beetle larval injury to soybeans: Bean leaf beetle is a widespread pest of soybean production whose best appreciated form of damage is defoliation by adults and their action as virus vectors. Although the subterranean larval stage of bean leaf beetle can be locally abundant, the impact of this life stage on soybean is unknown. A greenhouse study was performed to determine the impact of three larval densities on soybean plant characteristics and nitrogen relationships within the plant. Our research showed that larvae fed almost exclusively on soybean nodules, and we determined that even small infestations (5 larvae per plant) resulted in measurable changes in plant nitrogen composition and the size and number of nodules per plant. This research identifies bean leaf beetle larvae as a direct threat to soybean, and provides some methodological bases for determining the economic impact of the pest under more realistic conditions. National Program 304, Component II - Biology of Pests and Natural Enemies (Microbes), Problem Area B – Basic Biology.

5.Significant Activities that Support Special Target Populations
Presentations and hands-on, field activities on biodiversity and ladybird beetles to about 25 children ages 6 to 17 of the Flandreau Sioux Tribe at the Youth Environmental Camp, July 28, 2008, Flandreau Sioux Indian Reservation, South Dakota.

6.Technology Transfer

Number of Non-Peer Reviewed Presentations and Proceedings6
Number of Newspaper Articles and Other Presentations for Non-Science Audiences3
Number of Other Technology Transfer3

Review Publications
Anderson, R.L. 2007. Crop sequence and no-till reduce seedling emergence of common sunflower in following years. Weed Technology. 21:355-358.

Anderson, R.L. 2008. Crop diversity and no-till: keys to pest management in the U.S. Great Plains. Weed Science. 56:141-145.

Anderson, R.L. 2007. A visual guide to help producers manage jointed goatgrass. Weed Technology. 21:275-278.

Beckendorf, E.A., Catangui, M.A., Riedell, W.E. 2008. Soybean Aphid Feeding Injury and Soybean Yield, Yield Components, and Seed Composition. Agron. J. 100:237-246.

French, B.W., Chandler, L.D., Riedell, W.E. 2007. Effectiveness of Corn Rootworm (Coleoptera: Chrysomelidae) Areawide Pest Management in South Dakota. J. Econ. Entomol. 100(5): 1542-1554.

Garabagi, F., French, B.W., Schaafsma, A.W., Pauls, K.P. 2008. Increased Expression of a cGMP-Dependent Protein Kinase in Rotation-Adapted Western Corn Rootworm (Diabrotica virgifera virgifera L.). Insect Biochemistry and Molecular Biology. 38:697-704.

Hesler, L.S., Kindler, D. 2007. Abundance of rice root aphid among selected plant species and on plants grown with different soil-surface media. Great Lakes Entomologist. 40(1-2), pp.83-90.

Hesler, L.S., Dashiell, K.E. 2007. Resistance to Aphis glycines (Homoptera: Aphididae) in Various Soybean Lines under Controlled Laboratory Conditions. Journal of Economic Entomology. 100:1464-1469.

Hesler, L.S., Langham, M.A.C. 2007. Book review, Disease and Insect Resistance in Plants. D.P. Singh and A. Singh (2005). Journal of Economic Entomology. 100:1496-1497.

Hesler, L.S., Dashiell, K.E. 2008. Identification and characterization of new sources of resistance to Aphis glycines Matsumura (Hemiptera: Aphididae) in soybean lines. Journal of Applied Entomology and Zoology. 43:197-206.

Hesler, L.S., Kiekchefer, R.W. 2008. Status of Exotic and Previously Common Native Coccinellids (Coleoptera) in South Dakota Landscapes. Journal of Kansas Entomological Society. 81(1), pp. 29-49.

Kim, K.S., French, B.W., Sumerford, D.V., Sappington, T.W. 2007. Genetic Diversity in Laboratory Colonies of Western Corn Rootworm (Coleoptera: Chrysomelidae) including a Nondiapause Colony. Environmental Entomology. 36(3):637-645.

Lundgren, J.G., Fergen, J.K., Riedell, W.E. 2008. The Influence of Plant Anatomy on Oviposition and Reproductive Success of the Omnivorous Bug, Orius Insidiosus. Animal Behaviour. 75:1495-1502.

Lundgren, J.G., Riedell, W.E. 2008. Soybean Nitrogen Relations and root characteristics after Cerotoma trifurcata (Coleoptera:Chrysomelidae) larval feeding injury. Journal of Entomological Science. 43(1):107-116.

Oyediran, I., French, B.W., Clark, T.L., Dashiell, K.E., Hibbard, B.E. 2008. Prairie grasses as hosts of the northern corn rootworm (Coleoptera: Chrysomelidae). Environmental Entomology. 37(1):247-254.

Riedell, W.E., Catangui, M.A. 2008. Greenhouse Studies of Soybean Aphid Effects on Plant Growth, Seed Yield, and Composition. Journal of Agricultural and Urban Entomology. 23(4):225-235.

Riedell, W.E., Osborne, S.L., Jaradat, A.A. 2007. Crop mineral nutrient and yield responses to aphids or barley yellow dwarf virus in spring wheat and oat. Crop Science. 47:1553-1560.

Wolfenbarger, L.L., Naranjo, S.E., Lundgren, J.G., Royce, B.J., Watrud, L.S. 2008. Bt Crop Effects on Functional Guilds of Non-target Arthropods: A Meta-Analysis. PLoS One 3(5): e 2118.

Lundgren, J.G., Rosentrater, K.A. 2007. The strength of seeds and their destruction by granivorous insects. Arthropod-Plant Interactions. 1(2):93-99.

Last Modified: 5/24/2015
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