Research Project: Biological Control for Management of Invasive Pest Management, Emphasizing Brown Marmorated Stink Bug, Spotted Wing Drosophila and other Invasive Insect Pests of Crops

Location: Beneficial Insects Introduction Research Unit

2022 Annual Report

Objectives
Objective 1: Discover, identify, characterize the biology, evaluate the efficacy (using native-range studies and host-range specificity testing in quarantine), and determine the physiological, behavioral, and ecological basis of the host range of exotic predators and parasitoids as classical biological control agents of invasive arthropod pests of agricultural crops, with a focus on BMSB and SWD. [NP304, C1, PS1A; C3, PS3A, 3B and 3C] Sub-objective 1A: Discovery Sub-objective 1B: Characterization and identification Sub-objective 1C: Evaluation and risk assessment Objective 2: Improve understanding of biological and environmental 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. [NP304, C1, PS1A; C3, PS3A, 3B and 3C] Sub-objective 2A: Conduct laboratory studies of basic biology and behavior to enable continuous laboratory rearing, including mass production when needed for eventual field releases. Sub-objective 2B: Conduct laboratory and field studies of selected biological traits and ecological requirements that influence the establishment and efficacy of the target biological control agents under field conditions. Objective 3: Prepare (with collaborators when appropriate) 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 the natural enemies on target 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 field releases for establishment of new biological control agents and monitor and evaluate the impact of these natural enemies on target pest populations and on non-target species in the field. [NP304, C1, PS1A; C3, PS3A 3B and 3C]

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 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 various biological, behavioral and environmental factors such as climate and photoperiod or inherent genetic variability in determining establishment success, using parasitoids of current target pests as the model subjects. Research will be conducted in environmental growth chambers and, when feasible, with in-field experiments. 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 northwestern U.S. for the past decade, and their impact continues to increase in the southeastern, north central and southwestern U.S. ARS Newark continued to provide technical support to cooperators across the U.S. for sentinel surveys to monitor parasitism of H. HALYS by resident native stinkbug parasitoids in different crop systems, including survey protocols. During previous project cycles field collections of TRISSOLCUS parasitoids of Asian stink bugs and a range of larval and pupal parasitoids of spotted wing drosophila, DROSOPHIA SUZUKII, were obtained from Asia for taxonomic and genetic studies (Obj. 1A,1B) in collaboration with university cooperators, and biological studies of these natural enemies are continuing. Research was conducted in FY22 to characterize the genetic makeup of several populations of D. SUZUKII parasitoids that may include cryptic species, and for host range and biological studies (Obj. 2A) in support of host range evaluations by numerous cooperators. Building upon a white paper prepared for ONP on the subject, exploration in China, Taiwan, South Korea, and Vietnam previously initiated with APHIS and foreign cooperators was continued by Asian cooperators for natural enemies of roseau cane scale, NIPPONACLERDA BIWAKOENSIS, an invasive insect that has established along the U.S. Gulf Coast and which is killing large areas of roseau cane (PHRAGMITES reed), dense stands of which are important for reducing coastal and shipping channel erosion. U.S. cooperator exploration could not be pursued in 2022 for the third consecutive field season due to Covid restrictions, but Farm Bill-funded NACAs were again put in place to continue native range research by cooperators. Populations of the scale from Asia and the U.S. were compared and it was found that the Louisiana population most closely resembles populations from China. The parasitoid complex in each of the four Asian countries is being documented and their impact on the scale evaluated, and several new species have been found and are being described. Three of these are present adventively in the U.S. Gulf Coast but others occur thus far only in Asia and could be potential new biocontrol agents. Laboratory research on GANASPIS BRASILIENSIS, a larval-pupal parasitoid of the spotted wing drosophila DROSOPHILA SUZUKII, was continued in 2022 (Obj. 2B) for purposes of improving the artificial diet and mass-rearing methods. These are in support of large-scale production of the parasitoid for field releases that began in summer 2022 following APHIS approval of a Petition for Field Release in the fall of 2021 (Obj. 3C). We began research at Newark on genetic sequencing of several geographic populations of G. BRASILIENSIS to compare with our mass-reared population from southern China. This information will inform our understanding of the parasitoid’s host range and specificity. As part of our involvement in an SCRI CAP project for D. SUZUKII management with biocontrol (8010-22000-033-015R) we provided live shipments of GANASPIS BRASILIENSIS to project cooperators in seventeen states along with technical support to enable them to establish their own rearing colonies. Field releases were initiated at numerous locations by the cooperators, including releases by our laboratory at sites in Delaware. These are the first widespread field releases in the U.S. of the newly permitted natural enemy of spotted wing drosophila. Research was continued in the field and the laboratory to assess the potential impact of Asian TRISSOLCUS JAPONICUS on target and non-target species in the U.S. and to monitor the regional distribution of an adventive population of T. JAPONICUS. This research addresses Objective 1. Sites of field releases throughout Delaware made during previous summers are being monitored to determine whether establishment occurred and whether any non-target species are being attacked; these are ongoing (Obj. 3B). Previous laboratory research on the behavioral response of the parasitoid TRISSOLCUS JAPONICUS to its host and to non-target kairomones (chemical footprints) has been extended to the field with a second season of ongoing open-field releases at Newark with mass-reared parasitoids released into arrays of potted trees containing H. HALYS or P. MACULIVENTRIS egg masses, or applications of isolated kairomone components. Parasitoid response was examined in field trials to determine if host kairomones would increase the chances that parasitoids will discover host stink bug eggs under actual field conditions. In this year’s field studies, further research is investigating the role of kairomone concentration. Preliminary results thus far continue to show that behavioral and ecological responses under field conditions are more moderate than under controlled laboratory conditions but are still likely to reduce the potential non-target impact of this Asian parasitoid (Obj. 1C). Other collaborative research with Asian TRISSOLCUS species included rearing methodology to support large scale field releases and a predictive model of the joint impact in the field under varied climatic conditions of T. JAPONICUS and T. MITSUKURII. Research on another target pest that was originally part of the past 5-year project, LYCORMA DELICATULA (spotted lanternfly), is now described in the annual report for project 8010-22000-031-000D. Incoming funds were received through subordinate projects 8010-22000-030-001R (NIFA/SCRI, Management of Brown Marmorated Stink Bug (BMSB) in U.S. Specialty Crops), 8010-22000-033-024R (NIFA/SCRI, for Management of DROSOPHILA SUZUKII), and annual Farm Bill awards (8010-22000-033-060A and 8010-22000-033-067I for Roseau Cane Scale) that helped with the research discussed above. 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. First widespread field releases of a newly permitted natural enemy of spotted wing drosophila. Spotted wing drosophila is an invasive Asian fly that has become a serious pest of small fruits and berries across the U.S. Foreign exploration by ARS and partners identified a key Asian natural enemy of the fly, the parasitoid wasp Ganaspis brasiliensis. After extensive host range testing, APHIS issued a permit for field release, and the Newark lab has scaled up laboratory production of the wasp for distribution to federal, state and university researchers in seventeen states for field releases during summer 2022. Widespread distribution is expected to facilitate its rapid establishment in the U.S., which will be monitored in the coming year.

Review Publications
Daane, K.M., Da Silva, P.G., Stahl, J.M., Scaccini, D., Wang, X. 2022. Comparative life history parameters of three stink bug pest species. Environmental Entomology. https://doi.org/10.1093/ee/nvac012.
Wang, X., Hogg, B.N., Biondi, A., Daane, K.M. 2021. Plasticity of body growth and development in two cosmopolitan pupal parasitoids. Biological Control. https://doi.org/10.1016/j.biocontrol.2021.104738.
Wang, X., Ramadan, M., Guerrieri, E., Messing, R.H., Johnson, M.W., Daane, K.M., Hoelmer, K.A. 2021. Early-acting competitive superiority in opiine parasitoids of fruit flies (Diptera: Tephritidae): implications for biological control of invasive tephritid pests. Biological Control. https://doi.org/10.1016/j.biocontrol.2021.104725.
Bittau, B., Dindo, M., Giovanni, B., Sabbatini-Peverieri, G., Hoelmer, K.A., Roversi, P., Masetti, A. 2021. Implementing mass rearing of Trissolcus japonicus (Hymenoptera: Scelionidae) on cold-stored host eggs. Insects. 12(9) 840. https://doi.org/10.3390/insects12090840.
Abram, P.K., Wang, X., Hueppelsheuser, T., Franklin, M.R., Daane, K.M., Lee, J.C., Lue, C., Girod, P., Carrillo, J., Wong, W.H., Kula, R.R., Gates, M.W., Hogg, B.N., Moffat, C.E., Hoelmer, K.A., Sial, A., Buffington, M.L. 2022. A coordinated sampling and identification methodology for larval parasitoids of spotted-wing drosophila. Journal of Economic Entomology. https://doi.org/10.1093/jee/toab237.
Schneider, S.A., Broadly, H.J., Anderson, J.C., Elkinton, J.S., Hwang, S., Liu, C., Noriyuki, S., Park, J., Hang, T., Lewis, M.L., Gould, J.R., Hoelmer, K.A., Diaz, R. 2022. An invasive population of Roseau Cane Scale established in the Mississippi River Delta, USA originated from northeastern China. Biological Invasions. https://doi.org/10.1007/s10530-022-02809-3 .
Tait, G., Mermer, S., Stockton, D.G., Lee, J.C., Avosani, S., Abrieux, A., Anfora, G., Beers, E., Biondi, A., Burrack, H.J., Cha, D.H., Chiu, J., Choi, M.Y., Cloonen, K., Crava, C.M., Daane, K., Dalton, D.T., Diepenbrock, L., Fanning, P., Ganjisaffar, F., Gomez, M., Gut, L., Grassi, A., Hamby, K., Hoelmer, K.A., Ioriatti, C., Isaacs, R., Klick, J., Kraft, L., Loeb, G.M., Rossi-Stacconi, M.V., Nieri, R., Pfab, F., Puppato, S., Rendon, D., Renkema, J., Rodriguez-Saona, C., Rogers, M., Sassu, F., Schoneberg, T., Scott, M., Seagraves, M., Sial, A., Van Timmeren, S., Wallingford, A., Wang, X., Yeh, D., Zalom, F., Walton, V.M. 2021. Drosophila suzukii (Diptera: Drosophilidae): A decade of research towards a sustainable integrated pest management program. Journal of Economic Entomology. 114(5):1950-1974. https://doi.org/10.1093/jee/toab158.
Lewald, K.M., Abrieux, A., Wilson, D.A., Lee, Y., Andreazza, F., Beers, E.H., Burrack, H.J., Daane, K., Diepenbrock, L., Drummond, F., Fanning, P.D., Gaffney, M., Hesler, S.P., Ioriatti, C., Isaacs, R., Little, B.A., Loeb, G.M., Miller, B., Nava, D., Rendon, D., Sial, A.A., da Silva, C., Stockton, D.G., Van Timmeren, S., Wallingford, A., Walton, V.M., Wang, X., Zhao, B., Zalom, F.G., Chiu, J. 2021. Population genomics of Drosophila suzukii reveal longitudinal population structure and signals of migrations in and out of the continental United States. G3, Genes/Genomes/Genetics. 11(12). Article jkab343. https://doi.org/10.1093/g3journal/jkab343.
Rossi-Stacconi, M., Wang, X., Stout, A.R., Fellin, L., Daane, K.M., Biondi, A., Stahl, J., Buffington, M.L., Anfora, G., Hoelmer, K.A. 2022. Methods for rearing the parasitoid Ganaspis brasiliensis, a promising biological control agent for invasive Drosophila suzukii. Journal of Visualized Experiments. https://doi.org/10.3791/63898.
Wang, X., Daane, K.M., Pickett, C.H., Hoelmer, K.A. 2022. Biological control of olive fruit fly in California. Contributions of Classical Biocontrol to the U.S. Food Security, Forestry, and Biodiversity, 1985-2022. 115-126.
Cortez, A., Chu, C., Broadley, H., Lo, Y., Chen, Y., Gates, M.W., Meyerson, L., Hoelmer, K.A., Gould, J., Hwang, S. 2022. Exploratory surveys in Taiwan of the roseau cane scale Nipponaclerda biwakoensis Kuwana (Hemiptera: Aclerdidae) and its associated parasitoids. Journal of Applied Entomology. 146(5): 596-606. https://doi.org/10.1111/jen.12982.