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United States Department of Agriculture

Agricultural Research Service

Related Topics

Research Project: CONTROL OF ARTHROPOD PESTS OF PECAN AND PEACH

Location: Fruit and Nut Research

2008 Annual Report


1a.Objectives (from AD-416)
The goal of this project is to develop improved strategies for control of arthropod pests attacking pecan and peach. Strategies will be employed to suppress key insect and mite pests using economically and ecologically sound methods that result in sustainable management systems and increased profitability.


1b.Approach (from AD-416)
Research to control arthropod pests involves development of IPM programs. Biological control efforts focus on developing entomopathogens (e.g., nematodes and fungi) to suppress pecan weevil and peachtree borer. A multifaceted improvement program is being employed to enhance entomopathogenic nematode and fungus efficacy and persistence; the program includes survey and genetic enhancement of strains, improved formulations, refinement of application, mass production, and conservation methods, and pertinent basic studies e.g., on beneficial trait stability. Other research on improved pest management focuses on efficacy of chemical insecticides applied to target-specific areas, soft chemistry and plant derived pesticide alternatives, and physical barriers to protect the crop. IPM and monitoring efforts focus on stink bug movement across agricultural landscapes. Additionally, emergence/post-emergence behavior of adult and larval pecan weevils will be studied to better time application of control measures. Research efforts on pecan focus on control of pecan weevil, aphids, and stink bugs, but may also include efforts to control hickory shuckworm, pecan nut casebearer, and other pest complexes. Research efforts on peach focus on development of control of strategies for sesiid borers using mating disruption and entomopathogenic nematodes; IPM for plum curculio management; and impact of root-feeding weevils.


3.Progress Report
This progress falls under National Program (NP) 304, Crop Protection and Quarantine, Component V Pest Control Technologies, Problem Areas Traditional Biological Control (A) and Other Biologically Based Control (D). Also addresses Component II Biology of Pests and Natural Enemies (Microbes), Problem Areas Basic Biology (A) and Rearing (B). Specifically, novel strategies for controlling a key pecan pest, pecan weevil, with microbial control agents (fungi and nematodes) were investigated. These biocontrol approaches appear to be promising for use against pecan weevil and other pests.

This report serves as the final report for research conducted under Agreement # 58-6606-7-120, “Microbials for Suppression of Pecan Pests,” a trust fund between the GACCP and USDA-ARS (Byron). This project relates to Objective 1 of this in-house project: Determine the efficacy of biological control agents in suppressing pecan insect pests, thereby reducing reliance upon chemical insecticides. In this research, fungi were found to be virulent to pecan aphids and weevils, and bacterial metabolites suppress pecan diseases.

This report serves to document research conducted under CRADA 58-3K95-6-1124, “Mechanization of in vivo production of entomopathogenic nematodes in Tenebrio molitor” between ARS (Byron, GA and Stoneville, MS) and Southeastern Insectaries, Inc. This project relates to Objective 1 of this in-house project: Determine the efficacy of biological control agents in suppressing pecan and peach insect pests, thereby reducing reliance upon chemical insecticides. Novel methods to enhance production methods for insect-killing nematodes are required to expand the usage of these promising biocontrol agents. This project’s goal is mechanizing and optimizing host insect and nematode production systems. Advancements have been made in production of mealworms and nematodes for application in aqueous suspension or infected host cadavers.

This report serves as the final report for research conducted under Agreement 6606-22000-021-19R, "Risk Reduction for Southeastern Peaches: Implementing Mating Disruption for Management of Borers," between the University of Georgia and ARS. This project relates to Objective 2 of this in-house project: Develop new or improved chemical or physical methods for control of pecan and peach pests that are compatible with cultural practices. The lesser peachtree borer was tested using mating disruption as an alternative management method to organophosphate insecticides. We showed that high rates of the pheromone over a period of multiple years are needed to have a significant impact upon this pest.


4.Accomplishments
1. Beneficial Nematodes for Control of Plum Curculio: The plum curculio is a major pest of stone and pome fruits such a peach, plum, cherry, apple, and pear. Safe and effective methods of controlling this pest are of interest. Beneficial insect-killing nematodes are safe environmentally friendly natural insecticides. ARS scientists from the Southeastern Fruit and Tree Nut Research Lab, Byron, Georgia, in cooperation with colleagues at the University of Georgia and University of Florida, have discovered that a certain species of beneficial nematode is capable of causing high levels of mortality in plum curculio larvae in peach fields as well as in wild plum (which is a significant external source of the pest). In field trials the nematodes produced 90% to 100% mortality in plum curculio larvae. The technology has potential to be incorporated into orchard pest management programs. This accomplishment addresses National Program 304, Crop Protection and Quarantine, Component V Pest Control Technologies, Problem Area Traditional Biological Control (A).

2. Natural Nematode Bacteria May Thwart Pecan and Peach Diseases: Various plant diseases result in over $3.5 million in losses for peach growers and $13 million in the pecan industry. Effective environmentally sound management approaches are needed. ARS scientists from the Southeastern Fruit and Tree Nut Research lab, Byron, Georgia discovered that natural bacterial extracts may offer some assistance for peach and pecan growers in treating these diseases such in peach and pecan. Bacteria that produce these extracts come from nematodes that are known as natural biocontrol agents of insects; the nematodes are being researched as potential control agents of the pecan weevil. In laboratory studies the bacterial compounds caused substantial suppression of pecan scab, pecan shuck and kernel rot, and brown rot of peach. These environmentally friendly compounds will be studied further for their potential to control important pecan and peach diseases under field conditions. This accomplishment addresses National Program 304 Crop Protection and Quarantine, Component V Pest Control Technologies, Problem Area Biologically Based Control (D).

3. Plant Hormones Keep Aphids in Check: The black pecan aphid feeds on pecan leaves causing the leaves to turn yellow and eventually fall prematurely from trees. This energy drain on the pecan tree is costly to nut production for growers. ARS scientists (Byron and Tifton, GA) have shown that black pecan aphids prime leaves for feeding by inducing leaf yellowing –‘chlorosis’, and that this damage can be prevented by applying certain plant growth regulators. Aphids were discovered to prefer previously damaged leaves and grew significantly faster than when fed non-damaged leaves. A better understanding of this pest’s biology improves the ability to implement alternative control strategies such as plant growth regulator application which were discovered to prevent the black pecan aphid from damaging pecan leaves. These aphids cannot assimilate nutrients necessary for normal growth and development resulting in aphid death or delayed maturity with weakened adult aphids. This accomplishment addresses National Program 304, Crop Protection and Quarantine, Component II Biology of Pests and Natural Enemies (Microbes), Problem Area Basic Biology (A).

4. Borers Sniff Out Injured Peach Trees: The lesser peachtree borer has caused significant injury to SE peach orchards since the cancellation of broad spectrum insecticides that previously kept it under control. Scientists with ARS (Byron, GA) and the University of Georgia have discovered that egg-laying behavior of this pest and its preference for peach over native host trees may be reasons for its recent population surge. The borer was found to prefer to lay eggs on tree wounds that afford the hatching larvae immediate access to bark cambium for feeding and shelter. Tree wounds resulting from physical damage (e.g., pruning wounds), disease injury and even existing, infested wounds were highly attractive to females for egg laying. In addition, peach was found to be a highly attractive host plant compared with the native host plants black cherry and wild plum. This accomplishment addresses National Program 304 Crop Protection and Quarantine, Component V Pest Control Technologies, Problem Area Biologically Based Control (D).


5.Significant Activities that Support Special Target Populations
More than 33% of commercial pecan acreage is managed on small farms (<$250,000). Pest management research activities, such as biological control studies, that are conducted by ARS scientists at the Southeastern Fruit and Tree Nut Research Lab, Byron, Georgia, may be of substantial benefit to growers on small farms with limited resources.


6.Technology Transfer

Number of Active CRADAs1
Number of the New MTAs (providing only)1
Number of Invention Disclosures Submitted1
Number of Non-Peer Reviewed Presentations and Proceedings2
Number of Newspaper Articles and Other Presentations for Non-Science Audiences1
Number of Other Technology Transfer1

Review Publications
Lacey, L.A., Shapiro Ilan, D.I. 2007. Microbial Control of Insect Pests in Temperate Orchard Systems: Potential for Incorporation into IPM. Annual Review Of Entomology 53:121-144.

Scocco, E.A., Gardner, W.A., Shapiro Ilan, D.I. 2007. Microscopic evaluation of the fate of Conidia of two entomogenous fungi in soil. Journal of Entomological Science. 42:413-414.

Shapiro Ilan, D.I., Mizell, R.F., Cottrell, T.E., Horton, D.L. 2007. Control of plum curculio, Conotrachelus nenuphar with entomopathogenic nematodes: effects of application timing, alternate host plant, and nematode strain. Biological Control. 44:207-215.

Shapiro Ilan, D.I., Gardner, W.A., Cottrell, T.E., Behle, R.W., Wood, B.W. 2008. A comparison of application methods for suppressing the pecan weevil (Coleoptera: Curculionidae) with Beauveria bassiana under field conditions. Environmental Entomology. 37:162-171.

Nguyen, K.B., Shapiro Ilan, D.I., Mbata, G.N. 2008. Heterorhabditis georgiana n. sp. (Rhabditia: Heterorhabditidae) from Georgia, USA. Nematology. 10:433-448.

Cottrell, T.E., Shapiro Ilan, D.I. 2008. Susceptibility of endemic and exotic North American lady birds (Coleoptera: Coccinellidae) to endemic fungal entomopathogens. European Journal of Entomology. 105(3): 455-460.

Roy, H.E., Cottrell, T.E. 2008. Forgotten natural enemies: interactions between Coccinellids and insect-pathogenic fungi. European Journal of Entomology. 105(3):391-398.

Last Modified: 7/25/2014
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