2010 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.
This report serves to document progress of research conducted under in-house project 6606-22000-21-00D. Novel strategies for controlling a key pecan pest, pecan weevil, with microbial control agents were investigated including new methods of applying beneficial fungi and long-term suppression using entomopathogenic nematodes. Additionally, experiments measured the efficacy of entomopathogenic nematodes in suppressing key peach pests (e.g., lesser peachtree borer and plum curculio). These biocontrol approaches are promising for use against pecan weevil as well as key peach pests; grower adoption of the tactics has been initiated and has potential for expansion. Field collections and laboratory studies show that interspecific transfer of an ectoparasitic fungus attacking a native and an exotic lady beetle species was found to be limited. Management of brown stink bugs attacking peach was facilitated by the identification of a commercial product with high efficacy against this pest. Additionally, attraction of brown stink bugs to traps was tested using various pheromone rates and commercially available lures. This research will lead to improved stink bug control.
Research conducted under CRADA 58-3K95-6-1124 between ARS (Byron, Georgia & Stoneville, MS) and Southeastern Insectaries, Inc. “Mechanization of in vivo production of entomopathogenic nematodes in Tenebrio molitor”. This project relates to Objective 1 of this in-house project. Novel methods to enhance production methods for these nematodes are required to expand the usage of these promising biocontrol agents. This project is aimed at mechanizing and optimizing host insect and nematode production systems. Advancements have been made in in vivo production of mealworms and nematodes for application in aqueous suspension or infected host cadavers, e.g., a new formulation for nematode infected hosts was developed.
Research conducted under Agreement #60-1931-0-002 between USDA-ARS Byron, Georgia and USDA-ARS, Kearneysville, WV (the primary institution): “Manipulating Host and Mate-Finding Behavior of the Plum Curculio: Development of a Multi-Lifestage Management Strategy for a Key Tree Fruit”. This project relates to Objective 1 of this in-house project. Plum curculio is a key pest of stone and pome fruits. The project is aimed at developing an advanced pest management system for control of plum curculio. Thus, far, the ADODR at Byron station has initiated extensive screening program to determine the best nematode for plum curculio control. The project promises to reduce chemical inputs and enhance sustainable agriculture.
Ectoparasitic fungus attacks specific lady beetle species. An ectoparasitic fungus that attacks lady beetles was found to be readily transmitted to uninfected lady beetles of the same species but showed low or no transmission to other lady beetle species. Additionally, two species that are commonly found infected by this fungus are not susceptible to the fungus from each other. However, a low percentage of another lady beetle species was susceptible to the fungus from both of the commonly infected species. Two other lady beetle species were not infected by the fungus from either of the two susceptible species.
A novel packaging and formulation system facilitates biopesticide application. Beneficial insect-killing nematodes are safe environmentally friendly natural insecticides that are usually applied in aqueous suspension using various spray systems. Another application method that can be more efficacious is to apply the nematodes to the target site in nematode-infected insect cadavers; pest suppression is then achieved by the progeny nematodes that emerge from the insect cadavers. A problem with this approach is that the cadavers may rupture during shipment or application. Thus, to overcome this problem, ARS scientists (Byron, GA and Stoneville, MS) in collaboration with Southeastern Insectaries, Inc., developed method to protect the infected cadavers by rolling them in tape. Nematode-infected cadavers in the tape-packages were more resistant to rupturing than cadavers without tape; and, application of the tape-formulated approach resulted in high levels of mortality in the small hive beetle and citrus root weevils. The tape-packaging method enhances ease of handling for nematodes applied in infected hosts thereby expanding the utility of a natural biopesticide; a patent is pending based on this technology.
A novel gel formulation enhances control of wood boring insects using beneficial nematodes. The lesser peachtree borer is a major pest of stone fruits (such a peach and plum); the insect attacks aboveground portions of the tree by boring into the trunk and scaffold limbs. Safe and effective methods of controlling this pest are of interest. Beneficial insect-killing nematodes are safe environmentally friendly natural insecticides that are used to control a variety of soil-dwelling pests; however, control of lesser peachtree borer with nematodes using beneficial nematodes is hindered by the nematode’s sensitivity to desiccation and UV radiation (when applied aboveground). In response to this problem, ARS scientists (Byron Georgia) in cooperation with colleagues at the University of Georgia and University of Florida discovered a novel sprayable gel formulation that protects the nematodes from harmful environmental conditions during aboveground applications. Nematode applications made in conjunction with the sprayable gel resulted in 70 to 100% suppression of the target pest. This new formulation promises to enhance the efficacy of beneficial nematodes in controlling lesser peachtree borer as well as other wood-boring insects and other aboveground pests.
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.
Shapiro Ilan, D.I., Morales Ramos, J.A., Rojas, M.G., Tedders, W.L. 2010. Effects of a novel entomopathogenic nematode-infected host formulation on cadaver integrity, nematode yield, and suppression of Diaprepes abbreviatus and Aethina tumida under controlled conditions. Journal of Invertebrate Pathology. Journal of Invertebrate Pathology. 103:103-108.
Adhikari, B.N., Lin, C., Bai, X., Ciche, T.A., Grewal, P.S., Dillman, A.R., Chaston, J.M., Shapiro Ilan, D.I., Bilgrami, A.L., Gaugler, R. 2009. Transcriptional profiling of trait deterioration in the insect pathogenic nematode Heterorhabditis bacteriophora. Biomed Central (BMC) Genomics. 10:609.
Shapiro Ilan, D.I., Mbata, G.N., Nguyen, K.B. 2009. Characterization of biocontrol traits in the entomopathogenic nematode Heterorhabditis georgiana (Kesah strain), and phylogenetic analysis of the nematode's symbiotic bacteria. Biological Control. 51:377-387.
Shapiro Ilan, D.I., Cottrell, T.E., Mizzell III, R.F., Horton, D.L., Behle, R.W., Dunlap, C.A. 2010. Efficacy of Steinernema carpocapsae for control of the lesser peachtree borer, Synanthedon pictipes: Improved above ground suppression with a novel gel application. Biological Control. 54:23-28.
Shapiro Ilan, D.I., Cottrell, T.E., Gardner, W.A., Behle, R.W., Ree, B., Harris, M. 2009. Efficacy of entomopathogenic fungi in suppressing pecan weevil, Curculio caryae (Coleoptera: Curculionidae) in commercial pecan orchards. Southwestern Entomologist. 34:111-120.
Shapiro Ilan, D.I., Reilly, C.C., Hotchkiss, M.W. 2009. Suppressive effects of metabolites from Photorhabdus and Xenorhabdus spp. on phytopathogens of peach and pecan. Archives of Phytopathology and Plant Protection. 42:715-728.
Shapiro Ilan, D.I., Mbata, G. 2010. Compatibility of Heterorhabditis indica (Rhabditida: Heterorhabditidae) and Hebrobracon hebetor (Hymenoptera: Braconidae) in biological control of Plodia interpunctella (Lepidoptera: Pyralidae). Biological Control. 54:75-82.
Behle, R.W., Compton, D.L., Laszlo, J.A., Shapiro Ilan, D.I. 2009. Evaluation of soyscreen in an oil-based formulation for UV protection of Beauveria bassiana Conidia. Journal of Economic Entomology. 102(5):1759-1766.
Morales Ramos, J.A., Rojas, M.G., Shapiro Ilan, D.I., Tedders, W.L. 2009. Developmental plasticity in Tenebrio molitor (Coleoptera: Tenebrionidae): Analysis of Instar Variation in Number and Development Time under Different Diets. J. Entomol. Sci. 45(2):75-90.