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United States Department of Agriculture

Agricultural Research Service

Research Project: CONTROL OF ARTHROPOD PESTS OF PECAN AND PEACH
2006 Annual Report


1.What major problem or issue is being resolved and how are you resolving it (summarize project aims and objectives)? How serious is the problem? Why does it matter?
This project addresses several components of National Program 304 (Crop Protection and Quarantine) Action Plan. These include investigations of efficient utilization of beneficial organisms used in biological control, development of selective chemicals and other biologically-based strategies (Component V), as well as elucidation of pest and natural enemy biology and ecology, (Component II).

Pecan is an important horticultural crop that can suffer severe losses in yield due to insect and mite damage. Annual pecan production value in the US averages approximately 260 million dollars; up to 90% of the crop can be lost due to insect damage. Therefore, profitable husbandry of pecan is not feasible for most pecan growers without the ability to control insect and mite pests. The overall goal of this project is to provide economically and environmentally sound pest management strategies for control of arthropod pests of pecan.

Specific objectives are:

1) Determine the potential of biological control agents to suppress pecan insect pests. Several pecan insect pests are major problems limiting profitability and yields. The potential loss of synthetic chemical pesticides would devastate the pecan industry. Development of improved safe and effective alternatives to synthetic chemical pesticides is important for the long-term survival of the pecan industry and for the environment.

2) Develop improved non-biological methods for pecan pest suppression that are consistent with cultural practices to minimize alternate bearing. Several pecan insect pests are major problems limiting profitability and yields. Non-biological control strategies are critical short-term substitutes to efficacious pest control until efficacious biological control strategies are developed. The industry would cease to exist in the U.S. without efficacious pest control.

3) Examine population ecology and behavior of pecan pests as affected by biotic and abiotic factors. Several pecan insect pests are major problems limiting profitability and yields. An understanding of the subtleties of arthropod ecology and biological cycles are key to identifying weak links that can be capitalized upon for control of pest. This is especially necessary for the development of efficacious biological control strategies.

The first objective will focus on the potential of entomopathogenic nematodes and fungi to suppress the pecan weevil. In addition, the ecology of lady beetles inhabiting pecan will be studied with regard to inter- and intraspecific interactions and their impact upon aphid populations. The second objective will focus on examining efficacy of chemical insecticides applied to target-specific areas, and a kaolin-based pesticide alternative for management of certain pecan pests. The third objective will examine stink bug movement across agricultural landscapes because they repeatedly colonize pecan throughout the season. Additionally, emergence/post-emergence behavior of adult and larval pecan weevils will be studied to better time application of control measures.

Obtaining the objectives will reduce the potential for environmental contamination but still provide for profitable production of pecans from commercial operations. Potential new products to be developed include new approaches for biological control of major pecan pests, improved monitoring of pest populations, and low-impact chemical control methodology. Large and small farmers throughout the pecan-growing region will benefit from improved pest management strategies and reduced exposure to class I pesticides. New pest control technology may also benefit farmers in other commodities. Scientists (entomologists and pest management specialists) will benefit from basic and applied information on biological control and from ecology and behavior studies of pecan pest species. Consumers will benefit from production of high-quality, affordable pecans. Environmental benefits will apply to the general public through reduced chemical inputs.


2.List by year the currently approved milestones (indicators of research progress)
Year 1 (FY 2006) 1. Microbial control strain improvement laboratory studies, assess soil amendments in lab for effects on microbial persistence, conduct nematode trait deterioration studies and small plot field studies to evaluate microbial control agents.

2. Evaluate target specific application of pesticides and alternative broad spectrum chemicals.

3. Assess seasonal movement of Hemiptera and farmscape ecology.

4. Determine diel periodicity of pecan weevil, conduct research on weevil movement and toward developing a pecan weevil degree day model.

Year 2 (FY 2007) 1. Continue microbial control strain improvement laboratory studies, complete assessment of soil amendments in lab, and conduct nematode trait deterioration studies and small plot field studies to evaluate microbial control agents.

2. Continue evaluation of target specific application of pesticides and alternative broad spectrum chemicals.

3. Further assess seasonal movement of Hemiptera and farmscape ecology.

4. Continue determination of diel periodicity of pecan weevil, conduct research on weevil movement and toward developing a pecan weevil degree day model.

Year 3 (FY 2008) 1. Complete microbial control strain improvement laboratory studies and nematode trait deterioration studies, and continue small plot field studies to evaluate microbial control agents.

2. Complete evaluation of target specific application of pesticides and continue research on alternative broad spectrum chemicals.

3. Further assess seasonal movement of Hemiptera and complete farmscape ecology studies.

4. Continue determination of diel periodicity of pecan weevil, conduct research on weevil movement and toward developing a pecan weevil degree day model.

Year 4 (FY 2009) 1. Complete small plot field studies to evaluate microbial control agents, and begin large plot studies; also begin evaluation of pruning strategy effects on microbial control agents.

2. Continue research on alternative broad spectrum chemicals.

3. Initiate trap crop studies.

4. Continue determination of diel periodicity of pecan weevil, conduct research on weevil movement, and begin validation of a pecan weevil degree day model.

Year 5 (FY 2010) 1. Continue large plot studies on microbial control and evaluation of pruning strategy effects on microbial control agents.

2. Continue research on alternative broad spectrum chemicals.

3. Continue trap crop studies.

4. Continue research on weevil movement and validation of a pecan weevil degree day model.


4a.List the single most significant research accomplishment during FY 2006.
Discovery of novel and highly virulent insect-killing nematode strains for enhancing biological control. This accomplishment addresses National Program 304 Component V (Pest Control Technologies), and addresses the problem of identifying and testing potential biological control agents for established and emerging insect and mite pests. Orchard crops such as pecan, citrus, peaches, and apples are in need of viable biological control solutions to suppress harmful insect pests. ARS scientists from the Southeastern Fruit and Tree Nut Research Lab, Byron, Georgia, in cooperation with colleagues at the University of Florida, have isolated and identified new strains of an insect-killing nematode called Steinernema riobrave. These strains have been shown to be more virulent than conventional strains. The strains have been licensed to a commercial biocontrol producer and may be used for improved biocontrol of various insect pests such as pecan weevil, plum curculio and citrus weevils.


4b.List other significant research accomplishment(s), if any.
An insect-killing fungus possesses high levels of virulence toward key pecan pests. This accomplishment addresses National Program 304 Component V (Pest Control Technologies), and addresses the problem of identifying and testing potential biological control agents for established and emerging insect and mite pests. Several aphid species cause severe damage to pecan crops. Effective and environmentally sound solutions are needed to suppress these pecan aphids. In laboratory studies, ARS scientists from the Southeastern Fruit and Tree Nut Research Lab, Byron, Georgia, in cooperation with ARS in Peoria Illinois, have discovered that an insect-killing fungus (nicknamed pfr) possesses extremely high levels of virulence toward the three main aphid species that attack pecan. Use of this fungus could lead to a novel biological control approach for suppressing pecan aphids.


4c.List significant activities that support special target populations.
Information was derived and disseminated that helps small farmers and homeowners to better control pecan weevils and to do so with less pesticide usage.


4d.Progress report.
Progress made toward control of pecan arthropod pests. Research is progressing on how to effectively use nematodes and fungi to control pecan weevil in the soil before getting into the tree, and in characterizing the ecology of important pecan pests including pecan weevil, stink bugs, and aphids.


5.Describe the major accomplishments to date and their predicted or actual impact.
Major accomplishments over the life of the project (and its predecessor): a) discovery that pecan aphids are a major threat to the economic profitability of pecan, rather than being minor pests, and that the subsequent development of control strategies has greatly reduced aphid associated losses linked to alternate bearing; b) development of a superior trapping system for monitoring pecan weevils, stinkbugs, and hickory shuckworms; c) development of biological control strategies and technology for aphids; d) development of cover crop recommendations to control spring aphid populations without pesticides; e) development of information necessary to effectively register and use chemical pesticides; f) discovery that pecan weevil adults are highly susceptible to entomopathogenic nematode infection; g) an introduced species of lady beetle that helps control pecan aphids is not as susceptible to a natural fungal pathogen as a native lady beetle species; h) genetic deterioration in biocontrol agents can be deterred through creation of inbred lines; and i) development of novel methods to produce and apply entomopathogenic nematodes in their infected host cadavers. Through these accomplishments pecan insect pest management has been vastly improved. Trapping & monitoring systems have been adopted in pecan and other crops, and biological insect control strategies have been discovered, improved, and made in pecans and other crops. These accomplishments address several components of National Program 304 (Crop Protection and Quarantine) Action Plan including investigations of efficient utilization of beneficial organisms used in biological control, development of selective chemicals and other biologically-based strategies (Component V), as well as elucidation of pest and natural enemy biology and ecology, (Component II).


6.What science and/or technologies have been transferred and to whom? When is the science and/or technology likely to become available to the end-user (industry, farmer, other scientists)? What are the constraints, if known, to the adoption and durability of the technology products?
Orchard managers were appraised via industry publications and grower educational meetings (e.g., Southeastern and Georgia pecan grower meetings, and a Fall field day) on emerging technology in pecan pest management.

Technology on novel methods of producing and applying insect-killing nematodes in their infected hosts is being transferred to a biological control producer through a new CRADA and cooperation on a USDA-SBIR grant. This technology expands access to environmentally friendly pest control strategies.

Biocontrol company licensed novel nematode strains from ARS. New highly virulent insect-killing nematode strains were discovered and characterized by ARS scientists (Byron, GA) and University of Florida cooperators. A biological control company has licensed these strains and has initiated production and sales for biological pest suppression in orchard and ornamental crops, as well as home gardens.


7.List your most important publications in the popular press and presentations to organizations and articles written about your work. (NOTE: List your peer reviewed publications below).
Shapiro-Ilan, D.I., Cottrell, T.E., Gardner, W.A., Behle, R.W., Nyczepir, A.P., Wood, B.W. 2006. Alternative pest control tactics in pecan. Proceedings of Southeastern Pecan Growers Meeting. 99:86-94.

Shapiro-Ilan, D.I., Cottrell, T.E. 2006. Are beneficial nematodes likely to affect lady beetles in pecan orchards? Pecan Grower. 17:(4):30-33.


Review Publications
Shapiro Ilan, D.I., Cottrell, T.E. 2005. Susceptibility of lady beetles (Coleoptera: Coccinellidae) to entomopathogenic nematodes. Journal of Invertebrate Pathology. 89:150-156.

Bai, C., Shapiro Ilan, D.I., Wang, Y., Gaugler, R., Crowles, E.A., Yi, S. 2005. Protein changes in the symbiotic bacterium Photorhabdus luminescens during in vitro serial culture. International Journal of Nematology. 15:126-135.

Shapiro Ilan, D.I. 2006. Formulations and methods for enhancing post-application survival [abstract]. In: Program and Abstracts. 38th Annual Meeting of the Society for Invertebrate Pathology, July 7-11, 2006, Anchorage, Alaska. p. 96.

Last Modified: 12/18/2014
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