Source: OREGON STATE UNIVERSITY submitted to
NEW PROBLEM WITH AN OLD PEST: MITIGATING RISKS OF CORN EARWORM OUTBREAKS IN HEMP
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
ACTIVE
Funding Source
OTHER GRANTS
Reporting Frequency
Annual
Accession No.
1030991
Grant No.
2023-70006-40600
Cumulative Award Amt.
$186,464.00
Proposal No.
2023-02982
Multistate No.
(N/A)
Project Start Date
Sep 1, 2023
Project End Date
Aug 31, 2025
Grant Year
2023
Program Code
[ARDP]- Applied Research and Development Program
Project Director
Shrestha, G.
Recipient Organization
OREGON STATE UNIVERSITY
(N/A)
CORVALLIS,OR 97331
Performing Department
(N/A)
Non Technical Summary
The corn earworm, Helicoverpa zea, has been newly identified as an emerging pest affecting hemp across all major U.S. production regions, including the Pacific Northwest (PNW). This insect pest inflicts feeding damage on flower buds resulting in significant economic loss to marketable hemp flowers and biomass cannabinoid yields. There is a strong need to establish a sustainable and effective integrated pest management (IPM) program to mitigate the economic and environmental impact of this pest and current management practices in hemp. There are limited insecticide modes of action that are currently labeled for H. zea in hemp, and non-chemical alternative options have not been developed. There is a dearth of overall knowledge regarding pest control in hemp due to the recent re-legalization of the crop as an agricultural commodity in the U.S. Our proposed research will develop multiple IPM tactics, including host plant resistance, biological and cultural control methods, and further understanding of local and landscape-level environmental risk factors to equip PNW hemp producers with reliable management strategies and decision-aid tools for H. zea in hemp. To develop an IPM program for H. zea in hemp, we will: 1) evaluate the hemp germplasms for host plant resistance against H. zea with an emphasis on hemp flower morphology and flower chemical content effects (e.g., cannabinoid and terpenes) on pest ovipositional preference and life history traits, 2) characterize the potential utility of a larval parasitoid (i.e., Microplitis croceipes), as a biological control agent by investigating its fitness and ability to reduce H. zea pest population growth and flower damage on hemp plants, and 3) determine cultural control methods and environmental risk factors of H. zea in hemp features including presence and plant timing of corn as a trap crop and risk associated with landscape-level variation of surrounding host crops on H. zea population abundance. Outputs from this project will directly benefit hemp growers as the research is expected to increase understanding and availability of safe and effective non-chemical management tactics for H. zea in hemp production systems.
Animal Health Component
90%
Research Effort Categories
Basic
0%
Applied
90%
Developmental
10%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
21617301130100%
Knowledge Area
216 - Integrated Pest Management Systems;

Subject Of Investigation
1730 - Hemp;

Field Of Science
1130 - Entomology and acarology;
Goals / Objectives
The primary goal of this applied research is to integrate three innovative integrated pest management tactics, namely, host plant resistance, biological and cultural control, and improved detection and risk modeling to mitigate the impact of H. zea as an emerging insect pest in hemp agroecosystems in all major U.S. production regions, including the Pacific Northwest. The objectives of this project are to evaluate the hemp germplasms for host plant resistance against H. zea with a focus on the effects of hemp flower morphology and flower chemical content (e.g., cannabinoid and terpenes) on pest ovipositional preference and life history traits (Research Objective 1). Characterize H. zea larval parasitoid (Microplitis croceipes), recently discovered as a promising biological control agent in hemp, for its fitness and ability to reduce pest population growth and hemp flower damage (Research Objective 2). Determine local and landscape-level environmental predictors of H. zea outbreaks in hemp and potential cultural control methods, including corn presence and planting date as a trap crop for H. zea management in hemp (Research Objective 3). Disseminate research findings and a comprehensive IPM program to assist hemp stakeholders with increasing profit margins and lower H. zea populations in hemp while reducing the economic and environmental impact of insecticide-centric pest management programs (Extension Objective 4).
Project Methods
In this project, we will evaluate hemp germplasm for host plant resistance against H. zea under greenhouse and lab conditions. The results will be shared with the targeted audience and scientific community via. workshop, scientific publication, conference and, extension and outreach programIn this project, we will evaluate Microplitis croceipes as a potential biological control agent of H. zea larvae in hemp. he results will be shared with the targeted audience and scientific community via. workshop, scientific publication, conference and, exension and outreach programIn this project, we will evaluate landscape features and cultural control to improve H. zea management in hemp. he results will be shared with the targeted audience and scientific community via. workshop, scientific publication, conference and, exension and outreach program

Progress 09/01/23 to 08/31/24

Outputs
Target Audience:This research project aims to address three key objectives: enhancing host plant resistance, developing biological control methods, and implementing cultural control strategies for managing corn earworm pests in hemp. As of July 2024, specifically regarding the cultural control objective, we have directly worked with over 10 hemp farms across various regions of Oregon, including the eastern, central, Willamette, and southern areas. We are monitoring corn earworm pest populations throughout the growing season. The data collected from this pest monitoring are expected to be integrated into the Oregon Pest Monitoring Network. This network serves as a crucial resource for pest data across the Pacific Northwest, enabling better-informed pest management decisions and strategies on a broader scale. Beyond hemp growers, we have also shared our preliminary data with larger audiences, including at hemp grower meetings and regional pest management conferences. Our audience includes scientists, extension professionals, commercial hemp farmers, and federal and state employees. Changes/Problems:Obj 1: The main issue with Objective 1 was producing clones from the required germplasm. Low survival rates of the cloned plants led to delays in the experiment. Obj 2: Continuous maintenance of parasitoid colony has been challenging. Obj 3: There were significant changes to this objective. The trap crop experiment was modified to a randomized complete block design. The previous design involved three large-scale plots. This study is part of a graduate student work. A graduate committee member requested a change in the design because the previous one did not use a factorial design, which could create challenges for the student. What opportunities for training and professional development has the project provided?At present, our project involves one graduate student and four undergraduate students. This project has offered valuable opportunities for these students to acquire practical skills in pest monitoring and integrated pest management specifically tailored for corn earworm control. The graduate student has also had the opportunity to present her preliminary research findings at the Pacific Northwest Pest Management Conference held in 2023, showcasing the work and progress made through this project. How have the results been disseminated to communities of interest?The preliminary research findings on host plant resistance and biological control were shared with scientists and industry representatives at the 83rd Annual Pacific Northwest Pest Management Conference in Portland, OR. Additionally, results were presented to hemp growers at a meeting in OSU-Central Point, OR. What do you plan to do during the next reporting period to accomplish the goals?In next reporting period, we will have data to share the resects of the goals.

Impacts
What was accomplished under these goals? Objective 1: Evaluating Hemp Germplasms for Corn Earworm Resistance. a) Hemp Flower Morphology and Chemical Content Effects on Moth Oviposition b) Hemp Flower Effects on Larval Survival and Adult Sex Ratio Currently, we are managing a collection of eight different types of flower germplasm (SCCW-006, RNRN-038, WICW-041, CBGB-006, SESE-001-006, ABAB-018, NCBD-031, and CTCT-038) at the OSU Corvallis Greenhouse. These germplasms are essential for both Objective 1a and Objective 1b of our project. To date, we have successfully cloned seven out of these eight germplasm types. The cloned plants are now actively being grown in potted plants at Southern Oregon Research and Extension Center outdoor conditions. The remaining germplasm type is still in the process of being cloned. Objective 2: Assessing Microplitis croceipes as a Biological Control for Corn Earworm in Hemp a) Characterize Parasitoid Fitness on Hemp Flowers. b) Assessing Parasitoid Impact on Pest Populations and Flower Damage Microplitis croceipes parasitoid cocoons were sourced from Dr. Basu Kafle at Texas A&M University. We are currently maintaining cocoons in controlled environments using artificial diet cups, which are essential for the ongoing experiment. In parallel, we are also growing potted hemp flower plants, which are another crucial component of the experimental setup. Both the parasitoid colonies and the hemp plants are being carefully managed to ensure the success of the experiment. Objective 3: Evaluation of landscape features and cultural control to improve corn earworm pest management in hemp. a) Impact of Trap Corn Planting Time on H. zea Pressure in Hem b) Assessing Landscape Variation Impact on H. zea Populations in Hemp. For Objective 3a, a trap crop experiment was established at the OSU-Southern Oregon Research and Extension Center, Central Point, OR. We are currently collecting data from the experiment plots. For Objective 3b, we have set up corn earworm pheromone traps in four regions: Willamette Valley, Eastern Oregon, Central Oregon, and Southern Oregon. The number of fields equipped with traps varies depending on regional availability, ranging from 2 to 6 fields per region. The number of traps per region varies from 4 to 9. We are conducting weekly data collection to monitor pest activity and movement. Objective 4. Disseminate research findings to hemp stakeholders that allow them to adopt best management practices. The preliminary research findings on host plant resistance and biological control were shared with scientists and industry representatives at the 83rd Annual Pacific Northwest Pest Management Conference in Portland, OR. Additionally, results were presented to hemp growers at a meeting in OSU-Central Point, OR.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Pandey, S., Baluch, S., and Shrestha, G. 2023.Integrating host plant resistance for corn earworm management in hemp. 83th Annual Pacific Northwest Pest Management Conference, Portland, OR. January 08-09, 2023, pp 23.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2024 Citation: Perez, A., and Shrestha, G. 2023.Exploring biological control methods in corn earworm management. 83th Annual Pacific Northwest Pest Management Conference, Portland, OR. January 08-09, 2023, pp 24.