Location: Beneficial Insects Introduction Research Unit
2017 Annual Report
Objectives
1: Discover, characterize, identify, evaluate the efficacy, and determine the ecological safety of exotic predators and parasitoids as classical biological control agents of invasive insect pests, including tarnished plant bug, brown marmorated stink bug, and spotted wing drosophila, and may include other new invasive species, such as kudzu bug.
Sub-objective 1A: Discovery
Sub-objective 1B: Characterization and identification
Sub-objective 1C: Evaluation and risk assessment
2: Develop an improved understanding of factors and processes that influence the successful establishment of introduced biological control agents, such as climate adaptation, release methodologies, genetic variation in source and founder populations, using natural enemies of current target pests as model systems.
Sub-objective 2A: Conduct retrospective analyses of current/past biological control programs (where appropriate).
Sub-objective 2B: Conduct laboratory and field studies of selected biological traits and ecological requirements relevant to the establishment and efficacy of the target biological control agents.
3: Prepare (with collaborators, when appropriate and necessary) petitions to regulatory agencies for field release of candidate agents, conduct field releases for establishment of new agents, and monitor and evaluate the impact of these natural enemies on target pest populations and on non-target species in the field.
Sub-objective 3A: Develop and submit a petition for release that describes the importance of the target pest and the efficacy and safety of the candidate biocontrol agent; and participate in the regulatory decision process as needed.
Sub-objective 3B: Conduct releases and post-release monitoring (with cooperators when necessary) of permitted natural enemies.
Approach
Classical (importation) biological control is a pest management technology that is environmentally safe and sustainable. This project focuses on discovery, evaluation, and establishment of classical biological control agents of selected agricultural pests in the U.S. Previous research continued into this project addresses as targets tarnished plant bugs, brown marmorated stink bug; and spotted wing drosophila. New targets may be added at any time according to national need.
To address objective (1) we will conduct foreign exploration in Asia and other regions as needed to discover, identify and evaluate the biology, ecology, and efficacy of exotic predators and parasitoids as classical biological control agents of the targeted pests. Agents discovered in exploration will be returned to our laboratory and identified using the best available morphological characters in conjunction with molecular sequence data, and evaluated in our quarantine facility for efficacy by measuring attack rates, reproductive output and development rates, and for host specificity by testing both close relatives to target hosts and progressively more distantly related species under choice and no-choice conditions.
Objective (2) will address the role of environmental factors such as climate and photoperiod or inherent genetic variability in determining establishment success. Using a parasitoid of tarnished plant bug that established in some regions of the US but not others as the model subject, we will characterize the genetic variability of populations established in the US and their relation to genetic source populations in Europe. Using parasitoids of any or all target pests, we will test the influence of differing environmental factors such as temperature, soil moisture and photoperiod regimes on parasitoid survival in environmental growth chambers and comparative field exposures.
To address objective (3) we will prepare petitions for field release of qualified candidate agents of all target pests determined to be both effective and safe, based on satisfactory results of evaluation studies. These will be submitted to technical advisory panels and APHIS, in collaboration with relevant project partners as necessary. Supplemental research will be conducted to provide additional information if requested by APHIS. Once permits are received we will participate with cooperators as needed in conducting releases and post-release monitoring of the natural enemies. Where possible the releases will be designed to compare different geographic populations or genetic accessions of the agent for differences in climate adaptation, efficacy or other behavioral characteristics.
Progress Report
Populations of the brown marmorated stink bug (H. halys) have been significant pests in soybeans, vegetables, nut and various tree fruits in the eastern and western U.S. and are increasing in other regions where their impact is also increasing. We have continued to provide technical support to cooperators across the U.S. for expanded sentinel surveys to monitor parasitism of H. halys by resident native stinkbug parasitoids in different crop systems, including survey protocols and identification of specimens. We provided technical and quarantine laboratory support for new surveys in Pennsylvania by cooperators for indigenous natural enemies of spotted lantern fly, Lycorma delicatula, a new Asian invasive species found in Pennsylvania and a potential pest of grapes and tree fruit. Foreign exploration was again conducted during the summer of 2017 in China for natural enemies of the lantern fly, focusing on natural enemies of lanternfly nymphs. Collections of natural enemies made during the previous year in southern China for candidate agents of spotted wing drosophila, Drosophila suzukii, were identified by cooperating ARS-Systematic Entomology Laboratory and Italian National Research Council (CNR) taxonomists. Research was conducted to determine the potential impact of Asian Trissolcus japonicus on non-target species in the U.S. The studies indicate that behavioral and ecological responses will likely moderate and reduce their potential impact. Field collections in Asia were made of parasitoids of other stink bug species to document the actual host stink bug range of Trissolcus in the native range. The data are needed to support a release petition in preparation. Surveys were continued to monitor the overwinter survival, establishment and spread of the Asian parasitoid of H. halys, Trissolcus japonicus. Discovered in the U.S. in 2014, it was newly found in Oregon, New Jersey, New York and West Virginia in 2016, bringing the total known distribution to eight states and D.C. This research addresses objective 1. Non-Assistance Cooperative Agreements (NACAs) with Seoul National University (#58-1926-3-012F) and with the Yunnan Academy of Agricultural Science (#58-0212-3-006F with ARS/European Biological Control Laboratory (EBCL)) provided local assistance in Asia for foreign exploration for natural enemies of H. halys and Drosophila suzukii and fund continuing studies on natural enemies of these invasive pests in their native range. Through subordinate projects 8010-22000-030-01R (Management of Brown Marmorated Stink Bug BMSB) and 8010-22000-026-29I (Classical Biological Control of the Brown Marmorated Stink Bug) extramural support was received for ongoing biological studies and host range evaluations for exotic and native natural enemies of the stink bug. 8010-22000-030-10R (Sustainable Spotted Wing Drosophila Management for United States Fruit Crops - Coordinated Agricultural Project) provides support for foreign exploration and host range testing of candidate natural enemies of spotted wing drosophila. This research addresses objectives 1 and 3. Field surveys were made in Delaware and neighboring northeastern states to provide specimens of the previously established P. digoneutis in support of an ongoing retrospective population genetics study of its establishment (in conjunction with ARS/EBCL). Collections of Asian H. halys were made and provided to cooperators for new research to detect parasitic microsporidians and determine their impact on stink bug populations. This research addresses objective 2. ARS researchers compiled and updated a master key for the identification of stink bug parasitoids in Europe and Asia that contributed to ongoing taxonomic research on Asian Trissolcus. This research-related activity addresses objective 3. The overall impact of the research is that producers will have new biological control agents available that will help them manage key insect pests by reducing chemical pest management inputs, thereby maximizing profits and sustaining yield.
Accomplishments
1. Stink bug identification tool for the research community. Invasive exotic stink bugs, such as brown marmorated stink bug, bagrada bug and kudzu bug, are important agricultural pests in the U.S. ARS scientists at Newark, Delaware developed tool-kits to help researchers identify the bugs accurately and develop biological control and integrated management approaches. The tool-kits identified Asian species of wasps (Trissolcus parasitoid) that are important natural enemies of stink bugs. The tool-kits are being used by a large community of researchers involved in the biological control of brown marmorated stink bug and bagrada bug, for which Trissolcus wasps are also important natural enemies.
Review Publications
Nystrom, E., Venette, R., Dieckhoff, C., Hoelmer, K.A., Koch, R.L. 2017. Cold tolerance of Trissolcus japonicus and T. cultratus, potential biological control agents of Halyomorpha halys, the brown marmorated stink bug. Biological Control. 107:11-20. doi:10.1016/j.biocontrol.2017.01.004.
Milnes, J.M., Wiman, N., Talamas, E.J., Brunner, J.F., Hoelmer, K.A., Buffington, M.L., Beers, E.H. 2016. Discovery of an exotic egg parasitoid of the brown marmorated stink bug, Halyomorpha halys (Stål) in the Pacific Northwest. Proceedings of the Entomological Society of Washington. 118:466-470.
Cornelius, M.L., Dieckhoff, C., Vinyard, B.T., Hoelmer, K.A. 2016. Parasitism and predation on sentinel egg masses of the brown marmorated stink bug (Hemiptera: Pentatomidae) in three vegetable crops: Importance of dissections for evaluating the impact of native parasitoids on an exotic pest. Environmental Entomology. 45(6):1536-1542.
Lesieur, V., Martin, J., Weaver, D.K., Hoelmer, K.A., Shanower, T.G., Smith, D.R., Morill, W.L., Kadiri, N., Cockrell, D., Randolf, T.L., Waters, D.K., Bon, M. 2016. Origin and phylogeography of the wheat stem sawfly, Cephus cinctus Norton (Hymenoptera : Cephidae): implications for pest management. PLoS One. 11(12):e0168370. doi:10.1371/journal.pone.0168370.
Mason, P., Cock, M., Barratt, B., Klapwijk, J., Van Lenteren, J.C., Brodeur, J., Hoelmer, K.A., Heimpel, G.E. 2017. Best practices for the use and exchange of invertebrate biological control genetic resources relevant for food and agriculture. Biocontrol. doi:10.1007/s10526-017-9810-3.
Dieckhoff, C., Tatman, K.M., Hoelmer, K.A. 2017. Natural biological control of Halyomorpha halys (Hemiptera: Pentatomidae) by native egg parasitoids – a multi-year survey in northern Delaware. Journal of Pest Science. 90(4):1143-1158. 10.1007/s10340-017-0868-6
Abram, P.K., Hoelmer, K.A., Acebes-Doria, A., Andrews, H., Beers, E., Bergh, C.J., Bessin, R., Biddinger, D., Botch, P., Buffington, M.L., Cornelius, M.L., Costi, E., Delfosse, E., Dieckhoff, C., Dobson, R., Donais, Z., Grieshop, M., Hamilton, G., Haye, T., Hedstrom, C., Herlihy, M.V., Hoddle, M., Hooks, C., Jentsch, P., Neelandra, J., Kuhar, T., Lara, J., Legrand, A., Lee, J.C., Leskey, T.C., Lowenstein, D., Milnes, J., Maistrello, L., Morrison III, W.R., Nielsen, A.L., Ogburn, E., Pickett, C., Poley, K., Pote, J., James, R., Shrewsbury, P., Talamas, E.J., Tavella, L., Walgenbach, J., Waterworth, R., Weber, D.C., Welty, C., Wiman, N.G. 2017. Integrative review of indigenous arthropod natural enemies of the invasive brown marmorated stink bug in North America and Europe. Journal of Pest Science. 90(4):1009-1020.
