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

2023 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 third 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 last 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. In support of Sub-objective 1A, in-laboratory experiments on the behavioral response of braconid parasitoid wasps to colors were conducted in fall 2023 in the European Biological Control Laboratory in France and throughout 2023 in Hilo, Hawaii, by ARS researchers. Currently video data are being scored and prepared for analysis and publication. Planned work on field-cage assays was cancelled due to delays executing official travel to France for ARS scientists from Hilo, Hawaii, to conduct the work. In support of Sub-objective 1B, ARS researchers from Hilo, Hawaii, sequenced and assembled the genomes of Fopius ceratitivorus, Psyttalia fletcheri, several strains of Diachasmimorpha longicaudata, and several strains of Fopius arisanus parasitoids. Additional strains and species have been requested from USDA-IS/Moscamed in Guatemala. All species that have been sequenced have been assembled, and the results of these studies are being prepared for submission to online public databases and will be prepared for publication. Additional research on braconid parasitoids of tephritids by ARS researchers in Hilo, Hawaii, has included completion of a two-year survey for olive fly on Hawaii and Maui Islands. During the fruiting season, samples were collected monthly at five sites, two on Maui and three on Hawaii. Parasitoid emergence and species ID were recorded. ARS researchers have identified two local fruit fly parasitoids targeting olive flies in the state. This discovery provides a valuable starting place for developing an augmentative control program for this pest in Hawaii. It also opens the possible eventual release of one of the species in other olive growing regions of the world, since its ability to parasitize olive fly has not previously been reported. Surveys for avocado lace bug biocontrol agents (lacewing predators) are ongoing at two sites on Oahu Island and one on Hawaii island by ARS scientists in collaboration with University of Hawaii researchers. These assessments began during May 2022 and will continue through December 2023. Results include a growing list of natural enemies associated with avocado lace bug abundance in Hawaii including coccinellids, lacewing predators, earwigs, and spiders. ARS scientists in Hawaii also monitored avocado lace bug populations from 2021 through November 2022, determining that population dynamics closely follow that reported in subtropical climates like Florida and California. In support of Sub-objective 2A, several populations of insecticide resistant and insecticide susceptible melon fly were sequenced in November 2022. Variant detection and analysis of these populations revealed several loci under selection for insecticide resistance across three wild populations. Further work in relation to Sub-objective 2A includes completion of a 2-year effort to measure the extent and severity of spinosad resistance in tephritid fruit flies in Hawaii, resulting in data on spinosad resistance of melon fly and Oriental fruit fly from 20 sites on the islands of Hawaii, Maui, Oahu, and Kauai. Spinosad resistance in Hawaii persists in melon fly, although at lower levels than previously reported on Oahu. These data are the first record of resistance in Oriental fruit flies. In support of Sub-objective 2B, two studies investigating the economics of coffee berry borer (CBB) management practices using cultural controls (frequent and efficient harvesting) and research-based integrated pest management (IPM), were published in peer-review journals. Also, in support of coffee production, surveys for coffee leaf rust (CLR) are ongoing. Two years of data have been collected on CLR incidence peaks, defoliation, impact of elevation, occurrence in organic versus conventional coffee farms, and the effect of pruning. A third year of monitoring is underway. Additional CLR projects initiated in 2022 by ARS researchers focus on optimizing CLR control on commercial coffee farms in Hawaii. In support of Sub-objective 2C, two species of long horn beetle, Cerambycidae (Anoplophora chinensis), have been sequenced, in addition to Acalolepta aethetica, and additional species have been collected and are being prepared for sequencing. The genomes of Anoplophora chinensis and Acalolepta aethetica have been assembled, and the results of these studies are being prepared for submission to online public databases and will be prepared for publication.

Accomplishments
1. Frequent and efficient harvests to control coffee berry borer. Frequent and efficient harvests to control coffee berry borer. Coffee is the second most economically important crop in Hawaii, valued at about $175M for green and roasted coffee. Coffee berry borer (CBB) infests the coffee seed and reduces the yield and quality of coffee. In cooperative research with coffee growers, ARS scientists in Hilo, Hawaii, quantified the costs and benefits associated with sanitation picks, standard harvesting and strip picks, in addition to estimating total costs of controlling CBB using pesticides on Hawaiian coffee farms. Cultural control-focused management consisting of fewer pesticide sprays and more frequent sanitation and harvesting was found to be an effective and economically viable alternative to regular pesticide applications to control CBB. Costs of chemical controls were found to be 55% lower, coffee cherry yields increased 3000lbs/ac, and net benefit of frequent harvesting 48% higher under the proposed integrated pest management (IPM). This information has been disseminated to coffee growers in Hawaii by two grower association newsletters, via a mailing list, an Entomology Today blog post, farm visits, a consultant seminar. This information was also shared with University of Hawaii Extension.

Review Publications
Manoukis, N., Leathers, J., Beucke, K., Carvalho, L.A. 2023. Jackson trap efficiency capturing Bactrocera dorsalis and Zeugodacus cucurbitae with male lures with and without insecticides. Journal of Applied Entomology. 147(3):231-238. https://doi.org/10.1111/jen.13103.
Manoukis, N. 2023. Quantifying captures from insect pest trap networks. In: Fountain, M., Pope, T., editors. Advances in Monitoring of Native and Invasive Insect Pests of Crops. 1st Edition. Cambridge, UK: Burleigh Dodds Science Publishing Ltd. p. 91-116. https://doi.org/10.19103/AS.2022.0113.02.
Aristizabal, L.F., Johnson, M.A., Shriner, S., Wall, M.M. 2023. Frequent and efficient harvesting as an economically viable strategy to regulate coffee berry borer on commercial farms in Hawaii. Journal of Economic Entomology. 116(2):513-519. https://doi.org/10.1093/jee/toad041.
Miller, N., Yoder, T., Manoukis, N., Carvalho, L.A., Siderhurst, M. 2022. Harmonic radar tracking of individual melon flies, Zeugodacus cucurbitae, in Hawaii: Determining movement parameters in cage and field settings. PLOS ONE. 17(11). Article e0276987. https://doi.org/10.1371/journal.pone.0276987.
Lee, D., Johnson, M.A., Aristizabal, L.F., Shriner, S., Chan, C., Miyasaka, S., Wall, M.M. 2023. Economic benefits from managing coffee berry borer (Hypothenemus hampei) in Hawaii. Insects. 14(4). Article 350. https://doi.org/10.3390/insects14040350.
Hessler, S., Stockton, D.G., Loeb, G.M. 2021. The efficacy of two Sivanto products on grape mealybug infestations, 2020. Arthropod Management Tests. 46(1). Article tsab115. https://doi.org/10.1093/amt/tsab115.
Caton, B.P., Fang, H., Pallipparambil, G.R., Manoukis, N. 2023. Transect-based trapping for area-wide delimitation of insects. Journal of Economic Entomology. 116(3):1002-1016. https://doi.org/10.1093/jee/toad059.
van Klinken, R.D., Gladish, D.W., Manoukis, N., Caley, P., Hill, M.P. 2023. Simulation to investigate site-based monitoring of pest insect species for trade. Journal of Economic Entomology. 116(4):1296-1306. https://doi.org/10.1093/jee/toad112.
Stockton, D.G., Manoukis, N. 2022. Comparative efficacy of a spider knottin insecticide, GS-omega/kappa-Hxtx-Hv1a, against four species of invasive tropical tephritids. Journal of Applied Entomology. 146(10):1311-1319. https://doi.org/10.1111/jen.13072.
Chen, X., Stockton, D.G., Gossett, H., Qureshi, J.A., Ibanez, F., Pelz-Stelinski, K.S., Stelinski, L.L. 2022. Comparisons of economic thresholds for Asian citrus psyllid management suggest a revised approach to reduce management costs and improve yield. Frontiers in Sustainable Food Systems. 6. Article 948278. https://doi.org/10.3389/fsufs.2022.948278.
Schwanitz, T.W., Polashock, J.J., Stockton, D.G., Rodriguez-Saona, C., Sotomayor, D., Loeb, G.M., Hawkings, C. 2022. Molecular and behavioral studies reveal differences in olfaction between winter and summer morphs of Drosophila suzukii. PeerJ. 10. Article e13825. https://doi.org/10.7717/peerj.13825.
Follett, P.A., Asmus, G.M., Hamilton, L.J., Stockton, D.G. 2022. Susceptibility of ‘Malama’ avocados to Bactrocera dorsalis (Diptera: Tephritidae) in Hawai'i and a proposed systems approach for market access. Journal of Economic Entomology. 115(6):1894-1900. https://doi.org/10.1093/jee/toac150.
Paulo, D., Cha, A.Y., Kauwe, A.N., Curbelo, K.M., Corpuz, R.L., Simmonds, T.J., Sim, S.B., Geib, S.M. 2022. A unified protocol for CRISPR/Cas9-mediated gene knockout in tephritid fruit flies led to the recreation of white eye and white puparium phenotypes in the melon fly. Journal of Economic Entomology. 115(6):2110-2115. https://doi.org/10.1093/jee/toac166.