Biological control of the pod borer Maruca vitrata with exotic parasitoids

Low-cost natural pest control

The technology of "Biological control of the pod borer Maruca vitrata with exotic parasitoids" involves the strategic use of specific parasitic wasps as natural antagonists to manage and reduce the population of the destructive Maruca vitrata pod borer. These parasitoid wasps are sourced from the World Vegetable Center labs in Taiwan and are released in collaboration with national agencies in affected regions. The approach begins with the controlled rearing of parasitic wasps in laboratory settings, using live caterpillars of the pod borer as their hosts. Once these parasitoid wasps are ready, they are released either directly onto cowpea fields during the cropping season or on wild host plants during the off-season. After these releases, the parasitoids establish themselves in the environment, typically on wild vegetation. Over time, they naturally spread to cowpea fields, where the pod borer infestations occur. The key objective is to enable these parasitic wasps to reproduce, multiply, and effectively control the pod borer population. This biological control strategy is often coupled with the use of cowpea varieties that are resistant or tolerant to the pod borer and the application of eco-friendly products like neem or other compatible biopesticides. By utilizing this approach, the need for chemical pesticides is significantly reduced or eliminated. The ultimate goal of this technology is to create a self-sustaining population of parasitoid wasps that consistently and effectively reduce the damage caused by the Maruca vitrata pod borer to cowpea crops.

This technology is TAAT1 validated.

7•7

Scaling readiness: idea maturity 7/9; level of use 7/9

Adults 18 and over: Positive high

Farmers benefit directly from increased yields and reduced crop losses. The technology offers a “bonus” in terms of surplus yields without extra costs, leading to improved economic stability.

The poor: Positive high

This technology provides a cost-free, sustainable solution after the initial biocontrol agents are established, reducing the financial burden posed by purchase and use of chemical pesticides.

Under 18: No impact

Women: Positive medium

The biocontrol approach minimizes the need for labor-intensive pesticide applications, saving time that women can use for other household or economic activities.

Climate adaptability: Highly adaptable

It enhances resilience to climate variability, reducing dependence on chemical inputs, and is effective across diverse ecosystems.

Farmer climate change readiness: Significant improvement

Farmers can better manage climate-induced pest challenges with low-input, sustainable farming practices.

Biodiversity: Positive impact on biodiversity

It preserves natural enemies and plant diversity, supporting ecosystem health.

Carbon footprint: A bit less carbon released

Reduces emissions by minimizing pesticide use and fuel consumption for applications.

Environmental health: Greatly improves environmental health

Improves ecosystems by reducing chemical pollution and supporting agroecological farming.

Soil quality: Does not affect soil health and fertility

Enhances soil health and fertility by reducing pesticide contamination.

Water use: Much less water used

This technology is water-efficient and does not place additional demands on water resources, making it suitable for use in water-scarce or drought-prone regions.

Problem

Extensive Damage to Cowpea by Pod Borer: The legume pod borer Maruca vitrata causes up to 80% yield loss in cowpea.
Over-reliance on Chemical Pesticides: Farmers frequently apply inappropriate formulations and dosage of chemical pesticides to manage cowpea pests, and this can induce the development of resistances in the pest organisms, and interfere with biological control methods.
Companion Pests: Other pests like aphids and thrips also impact cowpea production, requiring additional pest control solutions.
Sustainability of Pest Control: Lack of alternative host plants for parasitic wasps in Sahelian conditions during the dry season can limit their effectiveness.
Incompatibility with Chemical Pesticides: Chemical pesticides applied early in the season can kill biocontrol agents before they parasitize pod borers, reducing the effectiveness of the biocontrol strategy.

Solution

Biological Control with Parasitic Wasps: Recent advances involve the introduction of two specific parasitic wasps from the World Vegetable Center labs in Taiwan. These parasitic wasps are specific to the pod borer Maruca vitrata and have shown to reduce its population by over 85% in areas across Benin and Burkina Faso.
Collaboration and Release Strategy: National plant protection and quarantine agencies collaborate to release parasitic wasps onto cowpea fields during the cropping season or on wild host plants during the off-season. This collaboration ensures widespread distribution of the biocontrol agents.
Reduced Reliance on Chemical Pesticides: By incorporating parasitic wasps, farmers can reduce their reliance on chemical pesticides, thus minimizing environmental impact and promoting sustainable pest management practices.
Integrated Pest Management (IPM): The approach integrates biological control with the use of resistant/tolerant cowpea varieties and the application of biopesticides like neem products to manage companion pests effectively.
Awareness and Sensitization: Farmers need to be educated about the benefits of biological control and the importance of avoiding chemical pesticides in areas where parasitic wasps have been released. Sensitization campaigns can also highlight the significance of preserving alternative host plants for the parasitic wasps and the environment.

Key points to design your project

This approach enhances cowpea yields, reduces crop losses, and promotes food security and sustainable agriculture. It reduces reliance on chemical pesticides, thereby mitigating environmental impacts and promoting environmentally friendly pest management practices. Additionally, by targeting a key agricultural pest, it helps conserve biodiversity, maintain ecosystem balance, and promote sustainable land management practices.

To successfully incorporate the biological control of the pod borer Maruca vitrata with exotic parasitoids into your project, the following activities and requirements should be considered:

Mapping of cowpea yield losses due to pod borer
Exploring the potential for establishing mass rearing colonies of the biocontrol agents in national biocontrol laboratories.
Awareness raising in national agricultural systems
Establishment national policies for import and release of biological control agents
Costs associated with training farmers in integrated pest management practices and the use of biopesticide.

A team of trainers could provide training and support during project installation. Include the cost for training and post-training support for using the technology.

Communication support for the promotion of the technology should be developed (flyers, videos, radio broadcasts, etc.).

In tandem with this technology, accompanying solutions include:

Resistant/tolerant cowpea varieties against pests such as aphids, thrips and pod bugs.

Biopesticides such as the innovative ‘neem tea bags’ that can be produced and sold as a community-based enterprise like by women groups in Niger.

5,000 USD

To install an initial pilot colony of parasitoids

6,000 USD

Running costs

IP

Open source / open access

Countries with a green colour: Tested & adopted
Countries with a bright green colour: Adopted
Countries with a yellow colour: Tested

Countries where the technology has been tested and adopted
Country	Tested	Adopted
Benin	Tested	Adopted
Burkina Faso	Tested	Adopted
Mali	Tested	Adopted
Niger	Tested	Adopted
Nigeria	Tested	Adopted

This technology can be used in the colored agro-ecological zones. Any zones shown in white are not suitable for this technology.

Agro-ecological zones where this technology can be used
AEZ	Subtropic - warm	Subtropic - cool	Tropic - warm	Tropic - cool
Arid
Semiarid
Subhumid
Humid

Source: HarvestChoice/IFPRI 2009

The United Nations Sustainable Development Goals that are applicable to this technology.

Goal 8: decent work and economic growth

Increased productivity and sustainable job creation.

Goal 12: responsible production and consumption

Promotion of sustainable agricultural practices.

Goal 13: climate action

Enhanced climate resilience and lower carbon emissions.

Goal 2: zero hunger

Improved food security and nutrition through higher cowpea yields.

Goal 1: no poverty

Increased farmer incomes and economic stability for poor farmers.

Goal 5: gender equality

Empowerment of women farmers and reduced labor burdens.

Controlled Rearing: The parasitic wasps are reared in laboratory settings, using live caterpillars of the pod borer as their hosts.
Release Timing: Once the parasitoid wasps reach maturity, they are released either directly onto cowpea fields during the cropping season or on wild host plants during the off-season.
Collaborative Release: These parasitoid wasps are released in collaboration with national plant protection and quarantine agencies in affected regions.
Establishment and Spread: After release, the parasitoids establish themselves in the environment, primarily on wild vegetation. Over time, they naturally spread to cowpea fields, where pod borer infestations are prevalent.
Reproduction and Multiplication: The key objective is to enable these parasitic wasps to reproduce and multiply, leading to effective control of the pod borer population.
Complementary Strategies: This biological control strategy is often combined with the use of cowpea varieties that are resistant or tolerant to the pod borer and other cowpea pests, along with the application of eco-friendly products like neem or other compatible biopesticides.