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

2024 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 report documents progress for project 2040-22430-027-000D, titled, “Development of New and Improved Surveillance, Detection, Control, and Management Technologies for Fruit Flies and Invasive Pests of Tropical and Subtropical Crops”, which started in October 2020. In support of Objective 1, ARS scientists in Hilo, Hawaii, have continued behavior, host association, and genomics work on braconid wasps. Wild infestation of different host fruits across Hawaii Island were assessed with a focus on Diachasmimorpha longicaudata biotypes. Hosts plants (tropical almond and coffee) were sampled for parasitized immature fruit flies, and the presence of virus-associated (e.g., long venom gland) and virus-free (e.g., short venom gland) individuals was assessed. There was clear distribution of both biotypes found across the island, with some localities harboring predominately a single biotype and others having a mix of short and long venom gland biotypes across temporal spans. Separately, behavioral bioassay experiments were completed on five different braconid wasp species from the European Biological Control Laboratory (EBCL) in France and Hawaii. Video data on color preference for oviposition was recorded and is being analyzed via computer vision methods. All genome sequencing has been completed for the proposed braconid wasp species and they are being curated to the National Center for Biotechnology Information (NCBI). RNAseq experiments to assess viral production in Fopius and Diachasmimorpha have been completed of both the insect and virus, and clear host variation has been detected between different fruit fly species for viral reproduction and replication, which additionally followed the wasp’s suitability as a biocontrol agent on each pest species. For Sub-objective 2A, ARS scientists identified genes and gene functions associated with Spinosad resistance in melon fly from previously sequenced individuals. Building upon this are contributions to Sub-objective 2C where ARS scientists identified genetic variants associated with Spinosad resistance in melon fly. Further work investigating the allele frequencies of these variants in wild populations beyond what was originally planned is expected in FY25. Under Sub-objective 2B, three studies and one review were published in peer-reviewed journals (see 1-4 below). Three manuscripts under this sub-objective are in preparation: 1) Achievements and challenges in the development and adoption of mobile app technology for monitoring and detection of pests and diseases in coffee, 2) Efficacy of Beauveria bassiana against coffee berry borer on Hawaii Island, and 3) Susceptibility of different forage grasses to feeding damage by Prosapia bicincta (Hemiptera: Cercopidae) adults in Hawai'i. Supporting Sub-objective 2C, surveys for Coffee Leaf Rust (CLR) are in the third and final year of data collection. CLR life stage and germination data have been collected over two seasons and are currently being analyzed. Fungicide trials were completed (two seasons) and a manuscript is being prepped for submission. Fertilizer experiments are in the second season and ongoing. The predictive model is being assessed for accuracy and model inputs are being investigated for adaptation to Hawaii’s conditions (e.g., rainfall vs. dew as a source of free water driving infection, impact of preventative vs. systemic fungicides on infection). A manuscript is in press describing the biogeography, phylogeny, and host range of spore-feeding Mycodiplosis, a genus of midge flies that are being investigated as a potential biocontrol for CLR in Hawaii. Finally, an AI-driven mobile app called “CoffeeMD” is being developed to detect coffee pests, diseases, and nutrient deficiencies. This app will use deep-learning and computer vision to analyze photographs within a digital library curated by experts. The app will provide decision support to growers by identifying new and common issues in coffee and providing recommendations for mitigation.

Accomplishments

Review Publications
Posadas, B.C., Stafne, E.T., Blare, T., Downey, L., Anderson, J., Crane, J., Gazis, R., Faber, B., Stockton, D.G., Carrillo, D., Morales-Payan, J.P., Dutt, M., Chambers, A., Chavez, D. 2023. Grower and operational characteristics of US passionfruit farms. Technology in Horticulture. 3. Article 25. https://doi.org/10.48130/TIH-2023-0025.
Kean, J.M., Manoukis, N., Dominiak, B.C. 2023. Review of surveillance systems for tephritid fruit fly threats in Australia, New Zealand, and the United States. Journal of Economic Entomology. 117(1):8-23. https://doi.org/10.1093/jee/toad228.
Stockton, D.G., Aldebron, C., Gutierrez-Coarite, R., Manoukis, N. 2023. Previously introduced braconid parasitoids target recent olive fruit fly (Bactrocera oleae) invaders in Hawai’i . Scientific Reports. 13. Article 22559. https://doi.org/10.1038/s41598-023-49999-x.
Fezza, T., Shelly, T., Fox, A., Beucke, K., Rohrig, E., Aldebron, C., Manoukis, N. 2024. Less is more: Fewer attract-and-kill sites improve the male annihilation technique against Bactrocera dorsalis (Diptera: Tephritidae). PLOS ONE. 19(3). Article e0300866. https://doi.org/10.1371/journal.pone.0300866.
Eitam, A., Stockton, D.G., Vargas, R.I. 2024. Understanding the movement and dispersal patterns of released Fopius arisanus (Hymenoptera: Braconidae) parasitoids in a papaya orchard. Environmental Entomology. 53(3):364-373. https://doi.org/10.1093/ee/nvae029.
Aristizabal, L., Johnson, M.A., Marino, Y., Bayman, P., Wright, M. 2023. Establishing an integrated pest management for coffee berry borer (Hypothenemus hampei) in Hawaii and Puerto Rico coffee agroecosystems: Achievements and challenges. Insects. 14(7). Article 603. https://doi.org/10.3390/insects14070603.
Johnson, M.A., Manoukis, N. 2024. Coffee berry borer (Coleoptera: Scolytidae) population dynamics across Hawaii Island’s diverse coffee-growing landscape: Optimizing location-specific pesticide applications. Journal of Economic Entomology. 117(3):963-972. https://doi.org/10.1093/jee/toae061.
Coffman, K.A., Kauwe, A.N., Gillette, N.E., Burke, G.R., Geib, S.M. 2024. Host range of a parasitoid wasp is linked to host susceptibility to its mutualistic viral symbiont. Molecular Ecology. Article e17485. https://doi.org/10.1111/mec.17485.
Bosch, M.J., Liang, P., Sun, X.N., Hall, S., Love, K., Cox, D., Matsumoto Brower, T.K., Follett, P.A., Stockton, D.G. 2024. Avocado cultivar and tree-to-tree leaf compositional differences affect infestation severity of Pseudocysta perseae (Hemiptera: Tingidae). Environmental Entomology. Article nvae066. https://doi.org/10.1093/ee/nvae066.
Collignon, M.R., Siderhurst, M.S., Cha, D.H. 2023. Evidence of queen-rearing suppression by mature queens in the little fire ant, Wasmannia auropunctata. Insectes Sociaux. 70:259-263. https://doi.org/10.1007/s00040-023-00917-4.
Roh, G., Kendra, P.E., Zhu, J.J., Roda, A., Loeb, G.M., Tay, J., Cha, D.H. 2023. Coconut oil derived five-component synthetic oviposition deterrent for oriental fruit fly, Bactrocera dorsalis. Pest Management Science. 79(10):3852-3859. https://doi.org/10.1002/ps.7584.
Cha, D.H., Skabeikis, D.D., Kim, B., Lee, J.C., Choi, M.Y. 2023. Insecticidal properties of erythritol on four tropical tephritid fruit flies, Zeugodacus cucurbitae, Ceratitis capitata, Bactrocera dorsalis, and B. latifrons (Diptera: Tephritidae). Insects. 14(5). Article 472. https://doi.org/10.3390/insects14050472.
Kempraj, V., Auth, J.E., Cha, D.H., Mason, C.J. 2024. Impact of larval food source on the stability of the Bactrocera dorsalis microbiome. Microbial Ecology. 87. Article 46. https://doi.org/10.1007/s00248-024-02352-9.
Kwon, T., Kim, D., Kim, B., Bloese, J., Lee, B., Cha, D.H. 2024. Ethyl formate fumigation against pineapple mealybug, Dsymicoccus brevipes, a quarantine insect pest of pineapples. Insects. 15(1). Article 25. https://doi.org/10.3390/insects15010025.