Enhancement of Samurai Wasp [Trissolcus japonicus (Ashmead)] for Biocontrol of Invasive Brown Marmorated Stink Bug [Halyomorpha halys (Stål)] in Utah

Project Overview

Project Type: Graduate Student
Funds awarded in 2021: $30,000.00
Projected End Date: 12/01/2022
Host Institution Award ID: G219-22-W8615
Grant Recipient: Utah State University
Region: Western
State: Utah
Graduate Student:
Principal Investigator:
Dr. Diane Alston
Utah State University
Principal Investigator:
Curtis Rowley
Cherry Hill Farms
Dr. Lori Spears
Utah State University

Information Products


  • Agronomic: buckwheat, clovers, grass (turfgrass, sod), medics/alfalfa
  • Fruits: apples, apricots, cherries, peaches
  • Additional Plants: native plants, ornamentals, trees


  • Crop Production: cover crops, intercropping, no-till
  • Education and Training: extension, mentoring, on-farm/ranch research, workshop
  • Natural Resources/Environment: biodiversity, habitat enhancement, strip cropping
  • Pest Management: biological control, chemical control, competition, cultural control, field monitoring/scouting, integrated pest management, traps, weather monitoring
  • Sustainable Communities: local and regional food systems, sustainability measures

    Proposal abstract:

    The brown marmorated stink bug (BMSB, Halyomorpha halys Stål) is an invasive insect that feeds on specialty fruit and vegetable crops in North America. Current management of BMSB relies heavily on broad-spectrum insecticides which are only moderately effective and disrupt sustainable integrated pest management (IPM) programs by killing natural enemies and contributing to insecticide resistance and secondary pest outbreaks. The samurai wasp [Trissolcus japonicus (Ashmead)], a highly effective biocontrol agent native to the home range of BMSB, has shown strong promise in providing long-term and effective management of BMSB. While adventive populations of samurai wasp have been discovered in Utah, geographic distribution models suggest this region is only marginally suitable. Utah’s high-elevation climate provides unique challenges to wasp establishment; therefore, conservation efforts are critical next steps to enhance samurai wasp populations. The objectives of this research are to answer: 1) What is the distribution of samurai wasp in northern Utah specialty crops and nearby urban areas, and how does the diversity of understory vegetation influence their abundance? 2) Which cover crops can increase wasp lifespan and fecundity? 3) How effective are stink bug host chemical cues (kairomones) in attracting the samurai wasp and increasing stink bug egg parasitism rates? Results will be disseminated to specialty crop producers and other stakeholders through multiple presentations (grower meetings and field days), two extension fact sheets, one newsletter article, and two research journal publications. This research will produce applicable information that supports improved sustainability of BMSB management and reduced economic losses to specialty crops.

    Project objectives from proposal:

    My research will focus on the status, conservation, and enhancement of an effective egg parasitoid, the samurai wasp, [Trissolcus japonicus (Ashmead)] of the invasive insect pest, brown marmorated stink bug (BMSB) (Halyomorpha halys Stål) in northern Utah by pursuing the following objectives:

    • Objective 1- Determine the establishment and spread of the samurai wasp (e.g., overwinter survival) since its first detection in northern Utah in June, 2019, including assessment of the impacts of understory vegetation diversity on its occurrence and abundance.
    • Objective 2- Determine cover crop floral resource candidates to attract and sustain the samurai wasp, including impacts on wasp lifespan and reproduction.
    • Objective 3- Determine the viability of stink bug host chemical cues (kairomones) in attracting samurai wasps and increasing egg parasitism rates in a field setting.

    My educational objectives will focus on increasing the knowledge of specialty crop producers, research and extension colleagues, the general public, youth, and other interested stakeholders on conservation and enhancement of the samurai wasp for biological control of the invasive brown marmorated stink bug (BMSB).

    • Objective 1- Promote the samurai wasp for the sustainable management of BMSB to approximately 10,000 specialty crop producers and other relevant stakeholders.
    • Objective 2- Add to the national BMSB research knowledge base and share project results with professional colleagues through two journal publications and three scientific conference presentations.
    • Objective 3- Disseminate information on invasive species and sustainable pest management to the general public via varied outreach venues and formats.
    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.