2011 Annual Report
1a.Objectives (from AD-416)
1: Discover, identify and evaluate the biology, ecology, and efficacy of exotic predators and parasitoids as classical biological control agents of invasive arthropod pests of agricultural crops. Determine their ecological safety for release as classical biological control agents. Current targets include soybean aphid, tarnished plant bug, brown marmorated stink bug, and spotted wing drosophila.
Sub-objective 1A: Discovery.
Sub-objective 1B: Identification.
Sub-objective 1C: Evaluation and risk assessment.
2: Develop an improved understanding of mechanisms that influence successful establishment of introduced biological control agents, using parasitoids and predators of current target pests such as tarnished plant bug 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 biological control agents.
3: With collaborators, conduct field releases, monitor for establishment and evaluate the impact of natural enemies on target pest populations (such as soybean aphid, tarnished plant bug, and brown marmorated stink bug) as well as non-target effects 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.
Sub-objective 3B: Participate in the regulatory decision process as needed.
Sub-objective 3C: Participate with cooperators in conducting releases (with permits from State and APHIS) and post-release monitoring of the natural enemy.
1b.Approach (from AD-416)
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 mirid plant bugs, soybean aphid, and brown marmorated stink bug; and a fourth target, spotted wing drosophila, has been added for evaluation of its biological control potential. 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 U.S., but not others as the model subject, we will characterize the genetic variability of populations established in the U.S. and their relation to genetic source populations in Europe. Also using lygus parasitoids, 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.
To combat a key multi-crop pest, field releases of the tarnished plant bug parasitoid PERISTENUS RELICTUS were conducted in the MidAtlantic states in a cooperative project with the NJ Dept. of Agriculture. We found survival and reproduction at several sites that indicates establishment of the biocontrol agent is occurring. This research addresses objective 3. Since its establishment in North America a decade ago the invasive soybean aphid has become a key pest of soybeans. Foreign exploration was conducted in Asia to identify aphid natural enemies and these agents were returned to ARS quarantine in Newark for host range evaluation by ARS and university cooperators. This research addresses objective 1. Field releases by cooperators in the Midwestern states of the soybean aphid parasitoid BINODOXYS COMMUNIS are ongoing. Based on quarantine evaluation results, a petition for field release of a second parasitoid species in the genus APHELINUS was submitted (see complementary project 1926-22000-025-00D). This research addresses objective 3. Through subordinate project 1926-22000-026-01S (RESEARCH ON NATURAL ENEMIES OF BROWN MARMORATED STINK BUG AND SOYBEAN APHID IN KOREA) support was provided for foreign exploration in South Korea for natural enemies of soybean aphid and brown marmorated stink bug. This research addresses objective 1. Populations of the stink bug continue to spread and have developed into a significant pest in soybeans and various tree fruits in the eastern U.S. Newark scientists provided technical support to cooperators for expanded sentinel surveys to monitor parasitism of BMSB by resident native stinkbug parasitoids in different crop systems. Additional foreign exploration was planned for late season in Asia to identify new BMSB biocontrol agents for ongoing host range evaluations. This research addresses objective 1. Exploration by cooperators proceeded in China for natural enemies of spotted wing drosophila. Under subordinate project 1926-22000-026-02N (COOPERATIVE BIOLOGICAL CONTROL INTRODUCTIONS AGAINST EXOTIC INSECT PESTS OF MUTUAL INTEREST TO CHINA AND U.S.), Newark scientists hosted a visiting Chinese cooperator for training in biocontrol of tarnished plant bug, and provided shipments of PERISTENUS RELICTUS which is currently being released in several regions of the USA against tarnished plant bugs. This research addresses objective 1 and 2. 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.
A newly introduced tarnished plant bug natural enemy has sucessfully established in the Mid Atlantic region. Tarnished plant bug (TPB) injures a large number of crops throughout the United States. A previously-introduced European natural enemy of this pest, PERISTENUS DIGONEUTIS, successfully established in the northeastern U.S. where it has helped to reduce TPB populations, but it has not moved into hotter areas of the U.S. Field releases of a second European natural enemy adapted to hot climates, PERISTENUS RELICTUS, in the Mid Atlantic region were made by ARS researchers at Newark, DE, in cooperation with the New Jersey Department of Agriculture during the past 3 years, and recovery surveys have shown that establishment is occurring. This year was the second field season for releases of a geographic population of P. RELICTUS from Morocco in southern Delaware. We anticipate that these releases will eventually cause similar reductions in TPB populations, as have occurred in the Northeast.
Hoelmer, K.A., Kirk, A., Pickett, C.H. 2011. Prospects for biological control of olive fruit fly, Bactrocera oleae (Diptera: Tephritidae) in California with introduced parasitoids. Biological Control. 21(9):1005-1025.