Optimising Cover Crop Strategies for Integrated Pest Management of Wireworm

Secondary Supervisor(s): Dr Matthew Back, Dr Joe Roberts, Dr Tom Pope

University of Registration: Harper Adams University

BBSRC Research Themes: Sustainable Agriculture and Food (Plant and Crop Science)

Project Outline

Wireworm (Agriotes spp.) are a significant pest in various arable crops, with potential to cause substantial yield losses. Current management strategies have limited success, and growers face challenges with the deregistration of conventional controls. Several biological controls are effective in laboratory settings but uncertain when translated to field environments and suggested cultural control is limited to cultivation to expose early instars. This project aims to investigate the use of cover crops for wireworm control within field rotations whilst advancing the understanding of fundamental wireworm biology and ecology.

Cover crops have shown potential in managing soil-borne pests and improving soil health¹. They can serve as non-host plants, disrupting pest life cycles and reducing their populations by limiting pathogen or damage spread to neighbouring plants². Certain cover crops, particularly brassicas, act as biofumigants by releasing toxic compounds such as isothiocyanates. When incorporated into the soil, these may effectively suppress soil-borne pests and pathogens. However, their effectiveness in wireworm control is uncertain, dependent on the species used and management practices. Some cover crops may even exacerbate wireworm populations by providing food sources and adult oviposition sites.

A large range of crops are susceptible to damage from wireworm, their polyphagous edacity resulting in feeding on all below-ground plant organs and those at the surface, with potato tubers particularly affected in the UK. Understanding the complex interactions between cover crops, wireworm, and the soil could be crucial for developing effective management strategies³.

Objectives

• Evaluate the effectiveness of various cover crop species for wireworm control within crop rotations.
• Investigate the impact of cover crop management practices on wireworm populations and behaviour.
• Advance understanding of wireworm biology, ecology, and life cycle in relation to cover crop systems.
• Assess the long-term effects of cover crop-based wireworm management on soil health and crop productivity.

Methods

1. Conduct field trials to evaluate different cover crop species for their ability to suppress wireworm populations or activity. Include a range of species such as mustards, buckwheat, and legumes, considering blends of species.

2. Investigate the effects of various cover crop management practices (e.g., planting density, incorporation timing, species blends and method) on wireworm control efficacy.

3. Wireworm Biology and Ecology:

a. Conduct development studies of wireworm in glasshouse / semi field cover crop pot trials

b. Use a mixture of glasshouse pot trials and field sampling to develop knowledge on wireworm development and presence under various conditions

c. Develop belowground olfactometry techniques to study wireworm behaviour and movement in soil

4. Field Trials: Establish field trials to assess the cumulative effects of cover crop-based wireworm management on soil health, beneficial soil organisms, and crop productivity

This project aims to focus on fundamental wireworm biology and ecology within the context of cover crop farming systems, to contribute to the development of more effective and sustainable wireworm management strategies.

References

1. Ngala, B.M., Haydock, P.P., Woods, S. and Back, M.A., 2015. Biofumigation with Brassica juncea, Raphanus sativus and Eruca sativa for the management of field populations of the potato cyst nematode Globodera pallida. Pest Management Science, 71(5), pp.759-769. ² Nikoukar, A. and Rashed, A., 2022. Integrated pest management of wireworms (Coleoptera: Elateridae) and the rhizosphere in agroecosystems. Insects, 13(9), p.769. ³ Innovativefarmers.org. (2023). The use of cover and biofumigant crops to reduce wireworm populations in potatoes. [online] Available at: https://www.innovativefarmers.org/field-labs/the-use-of-cover-and-biofumigant-crops-to-reduce-wireworm-populations-in-potatoes/

Enhancing the Efficacy of Entomopathogenic Control Solutions with Essential Oils for Insect Pest Management

Secondary Supervisor(s): Dr Joe Roberts, Dr Tom Pope

University of Registration: Harper Adams University

BBSRC Research Themes: Sustainable Agriculture and Food (Plant and Crop Science)

Project Outline

Entomopathogenic organisms, particularly fungi and nematodes, have shown promise as biological control agents for various insect pests. This project aims to investigate the potential of essential oils to enhance the efficacy of these entomopathogenic control solutions. The study will explore the combined effects of essential oils and entomopathogens on pest control, as well as their impact on plant health and non-target organisms².

Objectives

• Assess the co-active effects of essential oils and entomopathogenic fungi or nematodes on insect pests.
• Investigate the impact of combined essential oil and entomopathogen treatments on plant health and growth.
• Analyse the effects of these combined treatments on non-target organisms.
• Identify specific bioactive compounds from essential oils and their effects on entomopathogens.

Methods

• Laboratory Assays: Conduct in vitro experiments to screen various essential oils for their compatibility with selected entomopathogenic fungi and nematodes. Assess their combined effects on insect pest mortality and pathogen virulence.
• Greenhouse Trials: Perform controlled experiments to evaluate the efficacy of promising essential oil-entomopathogen combinations against selected insect pests on host plants. Monitor pest populations, pathogen persistence and stability, and plant health parameters.
• Plant Health Analysis: Measure various plant growth parameters, including biomass, height, and physiological indicators, to evaluate the impact of treatments on plant health and potential phytotoxicity.
• GC/MS: Quantitative analysis of essential oils to identify specific bioactive compounds.
• Non-Target Effects: Monitor and assess the impact of treatments on beneficial insects, e.g., bumblebees, and other non-target organisms to ensure ecological safety.

Expected Outcomes

This project aims to develop novel, eco-friendly pest management strategies by harnessing the synergistic potential of essential oils and entomopathogenic organisms. The study will provide insights into:

• The efficacy of essential oil-enhanced entomopathogenic solutions for insect pest control.
• Potential improvements in the persistence and virulence of entomopathogens.
• Effects of combined treatments on plant health and crop yield.
• Ecological impact and safety of the proposed pest management approach.

The findings will contribute to the development of more effective and sustainable integrated pest management strategies, potentially reducing reliance on synthetic pesticides.

References

1. Isman, M.B., 2000. Plant essential oils for pest and disease management. Crop protection, 19(8-10), pp.603-608.

2. Clunie, B., 2023. Novel strategies for the control of wireworm in potato crops.