Enhancing Biological Control of Corn Earworm in Hemp

Project Overview

GW23-252
Project Type: Graduate Student
Funds awarded in 2023: $29,613.00
Projected End Date: 05/31/2025
Grant Recipient: Oregon State University
Region: Western
State: Oregon
Graduate Student:
Principal Investigator:
Govinda Shrestha
Oregon State University

Commodities

  • Agronomic: hemp

Practices

  • Education and Training: extension, mentoring, workshop
  • Pest Management: biological control, integrated pest management

    Proposal abstract:

    Presently, the U.S. is third leading country in the world for industrial hemp production. In 2021, the total hemp value from three western states (Oregon, Washington, and California) was $298 million. Floral and cannabinoid hemp are the current production focus in the western U.S. This proposal addresses corn earworm, a flower bud-damaging pest, causing losses to the main marketable materials (flower and cannabinoid) in all major U.S. production regions. Corn earworm larvae feed on flower buds which can lead to bud rot, thereby reducing the crop’s economic value. Currently, corn earworm control in hemp largely depends on insecticide use, but the insecticide strategy alone does not provide full protection. In this project, we plan to investigate the biological control agent, Microplitis croceipes, a larval parasitoid that we recently found was able to parasitize corn earworm larvae feeding on flower buds. However, before we recommend releasing this biological control agent as part of a pest management program, it is critical to understand the parasitoids’ fitness and behavior in corn earworm larvae on hemp. The research objectives are to 1) assess M. croceipes parasitism rate and fitness in relation to different stages of corn earworm larvae feeding separately on flower buds and 2) determine parasitoid preference between different stages of corn earworm larvae feeding simultaneously on flower buds. The educational component will engage hemp producers in the project, and the results will be communicated to stakeholders at Extension education events, through Extension publications, and to the scientific community via peer-reviewed journal publications.

    Project objectives from proposal:

    The research objectives are to 1) assess M. croceipes parasitism rate and fitness in relation to different stages of corn earworm larvae feeding separately on flower buds and 2) determine parasitoid preference between different stages of corn earworm larvae feeding simultaneously on flower buds. The educational component will engage hemp producers in the project, and the results will be communicated to stakeholders at Extension education events, through Extension publications, and to the scientific community via peer-reviewed journal publications.

    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.