Research Project: Development of New and Improved Surveillance, Detection, Control, and Management Technologies for Fruit Flies and Invasive Pests of Tropical and Subtropical Crops

Location: Tropical Crop and Commodity Protection Research

2022 Annual Report

Objectives
Objective 1: Enhance or develop new technologies for the biological control of tephritids and other tropical pests by developing new methods for testing for host specificity, improved mass rearing techniques, enhanced understanding of the fundamental biology of parasitism and insect pathology, and the integration of biological control agent ecology into management techniques. Sub-objective 1A: Investigate cues driving host specificity in braconid parasitoids of fruit flies in order to improve the safety and acceptability of biological control programs using these wasps. Sub-objective 1B: Explore the genomic basis for host preference and the role of associated viruses in host suitability of tephritid parasitoids. Objective 2: Develop new methods for invasive pest control including reduced-risk insecticides, new practices for insecticide resistance management, and new components and programs for IPM for tephritids and other tropical plant pests of quarantine significance for Hawaii and the U.S. mainland to promote the unimpeded movement of fruit and vegetable exports. Sub-objective 2A: Investigate the molecular, physiological, or behavioral basis of evolving resistance to chemical and biological control of tephritids and other tropical pests. Sub-objective 2B: Validate the effectiveness of coffee berry borer pest control techniques in the context of a comprehensive IPM system to enable economically viable control. Sub-objective 2C: Develop baseline biological assessments, survey, monitoring, and control tools based on behavioral interventions and other methods for established and emerging insect pests of tropical agriculture (e.g. the Queensland longhorn beetle, Acalolepta aesthetica and the little fire ant, Wasmannia auropunctata).

Approach
Hypothesis 1A: Visual cues, particularly color and shape, are drivers of host specificity in parasitoids used in classical and augmentative biological control programs against tephritid pests (Psyttalia, Fopius, and Dichasmomorpha). Hypothesis 1B: Across braconid parasitoid species which parasitize tephritids, novel mechanisms for overcoming hosts defenses have developed, which play a role in a species host specificity and host range. Research Goal 2A: Determine the extent to which wild melon fly have become resistant to insecticides and devise strategies for insecticide rotation and resistance monitoring. Prescribe a standardized test for resistance for use by collaborators at other research centers in geographic locations where flies are established. Research Goal 2B: To determine the optimal combination of control measures for CBB management in Hawaii, add new techniques, and deliver a "smart agriculture" app. Research Goal 2C: Develop trapping systems and genetic assays for new invasive species that attack tropical crops and commodities.

Progress Report
This research project focuses on improving detection, control, and eradication of fruit fly pests and other tropical pest species as well as general protection of tropical and sub-tropical crops. This report covers the second year of the project 2040-22430-027-000D, “Development of New and Improved Surveillance, Detection, Control, and Management Technologies for Fruit Flies and Invasive Pests of Tropical and Sub-tropical Crops”, which this year was split into two projects due to creation of a new unit in Hilo, Hawaii. Former Objectives 2 and 4 are now Objectives 1 and 2, respectively. Research on visual cues driving host specificity in support of Objective 1 on a variety of braconid wasps that are biological control agents against tephritid fruit flies has continued at USDA locations in Hilo, Hawaii, and Montpellier, France. Scientists at those locations have completed the most basic assay (contrast test) on five different species. Data from these experiments are currently being analyzed. Pandemic travel restrictions significantly impacted the pace of research, so assays on color preferences have been halted since summer 2019 and locomotor assays have not begun. In support of Sub-objective 1B, over the past year, sequencing and assembly has been completed for several braconid wasps, including Diachasmimorpha longicaudata, Psyttalia fletcherii, and Fopius arisanus (updating with the current sequencing methods). Material was obtained from the European Biocontrol Lab for P. lounsburryi and P. ponerophaga, but quality was not sufficient for sequencing and new samples are currently being collected and sent. The underlying data for these assemblies have been submitted to the National Center for Biotechnology Information (NCBI) and are awaiting release. In addition to generation of novel genomic assemblies, viral associations are being explored in these wasp species. Most interesting is the discovery of several unique strains (sub-species) of D. longicaudata in local agroecosystems, with one strain having a unique ovary and calyx phenotype that appears to be lacking the expected virus particles. Quantitative polymerase chain reaction (PCR) verified the lack of the expected entomopoxvirus that is found in other strains of this species, and deep sequencing is ongoing to verify no other virus types are present. Sequencing of the host wasp cytochrome oxidase I region shows distinct separation of this strain from other wild collected D. longicaudata as well as the laboratory reared strain, suggesting that the virus loss is linked to a genetic separation of the host wasp RNA. Sequencing experiments of three distinct host fly species that were artificially inoculated with purified D. longicaudata entomopoxvirus were performed to explore the changes in host fly response to virus presence in two permissive hosts (Ceratitis capitata and Bactrocera dorsalis) as well as a marginal host (Zeugodacus cucurbitae). Differential expression analysis along with pathway mapping show differences in response to toll-like pathway genes in the permissive versus marginal species as well as other immune related pathways. These data are being prepared for publication. Pursuant to Objective 2, ARS scientists in Hilo, Hawaii, are completing a second year of Spinosad resistance monitoring in melon fruit fly across Kauai, Oahu, Maui, and Hawaii Islands which includes checking for cross-resistance. Some monitoring is also being conducted on Medfly and oriental fruit fly. A rapid resistance screening tool is in development to assist these surveys. Additionally, a reduced-risk insecticide (spider knottin peptide) has been tested against four tephritid species by ARS scientists in Hilo, Hawaii, and a manuscript describing the results has been submitted for publication. On coffee berry borer (CBB), a second year of data collection to investigate the flight behavior (height and time of day) of CBB on the Hawaiian Islands was completed by ARS scientists in Hilo, Hawaii. Data analysis is currently underway to investigate the relationship between CBB flight and coffee plant phenology, tree height, and weather variables. Research to quantify minimum levels of post-harvest ground and tree sanitation for successful CBB management was initiated in 2021; a second year of data will be collected during the 2022/2023 post-harvest season. Additionally, a study on the economics of CBB management practices in collaboration with University of Hawaii economists, namely biopesticide (Beauveria bassiana) application and cultural controls (frequent and efficient harvesting), is reaching completion with data analysis and manuscript preparation in progress. “Best Beans”, the CBB and Coffee Leaf Rust (CLR) control decision support and coffee quality app developed by ARS scientists in Hilo, Hawaii, and a cooperative research and development agreement (CRADA) partner is now available for growers to download and test on both Apple and Android mobile devices. The current version of the app includes a “no-count” trap estimation method, dual monitoring for both CBB and CLR, a map showing locations of pest/disease hotspots in the field, reports on current infestation/infection percentages, graphs showing pest/disease activity over time, text alerts to notify growers of optimal spray times based on local weather conditions, management recommendations based on the data submitted by the user, and links to educational information and tutorials for coffee management and best practices. University of Hawaii extension is leading testing trials for the app, with growers in the test group providing input and suggest changes to improve the app. CRADA partner is pursuing predictive model integration and analytics. Also, in support of Objective 2, surveys for CLR (first detected on Hawaii Island in November 2020) are ongoing. Published results for year 1 of surveys showed that: 1) CLR incidence peaks during the harvest season, 2) incidence is higher at mid and high-elevation farms relative to low-elevation farms, 3) CLR incidence and severity are positively correlated, and 4) defoliation is positively correlated with CLR incidence. The total costs to apply fungicides using tractor and backpack sprayers have been reported by ARS scientists in Hilo, Hawaii, along with the percent of profits needed to cover the cost to manage this disease using fungicides. A second year of data collection is underway. Regarding Sub-objective 2C, researchers from Hilo, Hawaii, sent live Queensland Longhorned Beetles (Acalolepta aesthetica) to the USDA-Animal and Plant Health Inspection Services (APHIS)-Center for Plant Health, Science and Technology (CPHST), Otis Lab in Buzzards Bay, Massachusetts, where an ultraviolet (UV)-excited volatile was identified from adult male beetles. The compound was similar to one found in Anoplophora chinensis, the Citrus Longhorned Beetle and warranted further testing. Therefore, the lure was synthesized and sent to Hilo, Hawaii, where it was tested in the field May and June of 2021. However, the lure was not effective in attracting adult beetles in field trapping experiments. Also, in support of Sub-objective 2C, researchers from Hilo, Hawaii, maintained a Queensland Longhorned Beetle citizen science and outreach project where residents of East Hawaii could report beetle findings via the user-friendly aeronautical reconnaissance coverage geographical information system (ArcGIS) web application. Data from these community-reported beetle sightings provides evidence for slow expansion of the invaded ranges. This web app was deployed in April of 2020 and now carries more than two years of beetle distribution data in East Hawaii. Finally, researchers in Hilo, Hawaii, are working with a company which manufactures and distributes a product with the entomopathogenic fungus B. bassiana as its active ingredient to amend the label for these two products to include that pest: Cacao, Breadfruit, and kukui. As of September 2021, the label had been amended at the federal level and awaits approval by the state.

Accomplishments
1. Queensland Longhorned Beetle distribution maps. The aeronautical reconnaissance coverage geographical information system (ArcGIS) web application designed, deployed, and maintained by the USDA, ARS since April 2020, is being used by the Big Island Invasive Species Committee (BIISC) and the United States Geological Survey (USGS) to monitor Queensland Longhorned Beetle (QLB) spread throughout east Hawaii. Up-to-date beetle distribution maps are populated by community reporting. These reports are validated for taxonomic accuracy by USDA-ARS and population densities and movement are measured by USDA, ARS using ArcGIS analysis functions. The maps are important for determining where to focus management efforts and where to actively monitor in emerging invasion zones. The USGS uses this data to monitor beetle distribution in forested land adjacent to Volcanoes National Park. By having data that can be used to determine where to manage and where to monitor, beetle spread, and population densities can be more efficiently addressed.

2. Beauveria bassiana products label amendment by the Environmental Protection Agency (EPA). Through collaboration with the private company, Certis USA LLC, the label for their Beuveria bassiana products was amended and submitted to the EPA for approval. As justification for this label amendment, USDA-ARS provided evidence that A. aesthetica is susceptible to B. bassiana infection based on wild-collected QLB that were discovered dead by fungal infection. The fungus was amplified and sequenced by USDA, ARS to show that the B. bassiana was the fungal species on the dead beetles. The label amendment was approved at the federal level and once approved at the state level, will be available for commercial growers of cacao and breadfruit to treat for Queensland Longhorned Beetle. Prior to this amendment, there were no labeled products available for cacao or breadfruit, and this development gives the small family-owned farms of east Hawaii and ability to treat their crops without the necessity of losing their commodity for the season.

Review Publications
Caton, B.P., Fang, H., Manoukis, N., Pallipparambil, G.R. 2021. Simulation-based investigation of the performance of delimiting trapping surveys for insect pests. Journal of Economic Entomology. 114(6):2581–2590. https://doi.org/10.1093/jee/toab184.
Sim, S.B., Curbelo, K.M., Manoukis, N., Cha, D.H. 2022. Evaluating Bactrocera dorsalis (Hendel) (Diptera: Tephritidae) response to methyl eugenol: Comparison of three common bioassay methods. Journal of Economic Entomology. 115(2):556–564. https://doi.org/10.1093/jee/toac018.
Caton, B.P., Fang, H., Manoukis, N., Pallipparambil, G.R. 2021. Quantifying insect dispersal distances from trapping detections data to predict delimiting survey radii. Journal of Applied Entomology. 146(1-2):203-216. https://doi.org/10.1111/jen.12940.
Stockton, D.G., Loeb, G.M. 2022. Diet hierarchies guide temporal-spatial variation in Drosophila suzukii resource use. Frontiers in Ecology and Evolution. 9. Article 816557. https://doi.org/10.3389/fevo.2021.816557.
Mason, C.J., Peiffer, M., St Clair, A., Hoover, K., Felton, G.W. 2021. Concerted impacts of antiherbivore defenses and opportunistic Serratia pathogens on the fall armyworm (Spodoptera frugiperda). Oecologia. 198:167-178. https://doi.org/10.1007/s00442-021-05072-w.
Shelly, T.E., Manoukis, N. 2022. Mating competitiveness of Bactrocera dorsalis (Diptera: Tephritidae) males from a genetic sexing strain: Effects of overflooding ratio and released females. Journal of Economic Entomology. 115(3):799-807. https://doi.org/10.1093/jee/toac027.
Wan, X., Saito, J.A., Hou, S., Geib, S.M., Yuryev, A., Higa, L.M., Womersley, C.Z., Alam, M. 2021. The Aphelenchus avenae genome highlights evolutionary adaptation to desiccation. Communications Biology. 4. Article 1232. https://doi.org/10.1038/s42003-021-02778-8.
Mason, C.J., Ray, S., Davidson-Lowe, E., Ali, J., Luthe, D., Felton, G. 2022. Plant nutrition influences resistant maize defense responses to the fall armyworm (Spodoptera frugiperda). Frontiers in Ecology and Evolution. 10. Article 844274. https://doi.org/10.3389/fevo.2022.844274.
Fang, H., Caton, B.P., Manoukis, N., Pallipparambil, G.R. 2022. Simulation-based evaluation of two insect trapping grids for delimitation surveys. Scientific Reports. 12. Article 11089. https://doi.org/10.1038/s41598-022-14958-5.
Aristizábal, L., Johnson, M.A. 2022. Monitoring coffee leaf rust (Hemileia vastatrix) on commercial coffee farms in Hawaii: Early insights from the first year of disease incursion. Agronomy Journal. 12(5). Article 1134. https://doi.org/10.3390/agronomy12051134.
Hsu, J., Chou, M.Y., Mau, R., Maeda, C.T., Shikano, I., Manoukis, N., Vargas, R.I. 2021. Spinosad resistance in field populations of melon fly, Zeugodacus cucurbitae (Coquillett), in Hawaii. Pest Management Science. 77(12):5439-5444. https://doi.org/10.1002/ps.6583.
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.
Sim, S.B., Corpuz, R.L., Simmonds, T.J., Geib, S.M. 2022. HiFiAdapterFilt, a memory efficient read processing pipeline, prevents occurrence of adapter sequence in PacBio HiFi reads and their negative impacts on genome assembly. Biomed Central (BMC) Genomics. 23. Article 157. https://doi.org/10.1186/s12864-022-08375-1.
Chen, B., Mason, C.J., Peiffer, M., Zhang, D., Shao, Y., Felton, G.W. 2022. Enterococcal symbionts of caterpillars facilitate the utilization of a suboptimal diet. Journal of Insect Physiology. 138. Article 104369. https://doi.org/10.1016/j.jinsphys.2022.104369.
Johnson, M.A., Manoukis, N. 2021. Influence of seasonal and climatic variables on coffee berry borer (Hypothenemus hampei Ferrari) flight activity in Hawaii. PLoS ONE. 16(12). Article e0257861. https://doi.org/10.1371/journal.pone.0257861.
Desurmont, G.A., Tannieres, M., Roche, M., Blanchet, A., Manoukis, N. 2022. Identifying an optimal screen mesh to enable augmentorium-based enhanced biological control of the olive fruit fly Bactrocera oleae (Diptera: Tephritidae) and the Mediterranean fruit fly Ceratitis capitata (Diptera: Tephritida. Journal of Insect Science. 22(3):1-7. Article 11. https://doi.org/10.1093/jisesa/ieac027.