Biological control of cassava mealybug

Enhancing Cassava Resilience: Targeted Biocontrol with a Beneficial Wasp

Biological control using Anagyrus lopezi is a method of managing pests naturally without relying on chemical pesticides. In this case, a small wasp from South America, A. lopezi, is used to control the cassava mealybug—a pest that damages cassava crops. The process begins by raising large numbers of these wasps in a controlled environment. Then, they are released into the field where they actively seek out the mealybugs. When a wasp finds a mealybug, it attaches itself and lays an egg on or inside the pest. Once the egg hatches, the wasp larva feeds on the mealybug from the inside, eventually killing it. This approach has been implemented in over 20 countries, reducing mealybug populations by about 90% and protecting cassava crops while saving farmers significant amounts of money.

This technology is pre-validated.

9•7

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

Adults 18 and over: Positive medium

Adult farmers experience increased yields and financial returns, enhancing overall community well-being.

The poor: Positive high

Cassava is a staple food for many low-income populations; effective CM control ensures food security and stabilises incomes for these communities.

Under 18: Positive low

Children benefit from improved household food security and nutrition, contributing to better health and educational outcomes.

Women: Positive high

Women, who often play key roles in cassava cultivation and processing, benefit from reduced labor and increased productivity due to effective CM management.

Climate adaptability: Moderately adaptable

By releasing A. lopezi the problem was solved. No negative impacts on alternate hosts or the environment were ever found. Interestingly the impact of A. lopezi was 90% in all ecological zones (except in dry areas) and permanent, i.e. throughout the year.

Farmer climate change readiness: Moderate improvement

Adopting biocontrol methods reduces reliance on chemical pesticides, leading to more sustainable farming practices that are better suited to adapt to climate change impacts.

Biodiversity: Positive impact on biodiversity

Biocontrol methods preserve and enhance biodiversity by reducing the use of chemical pesticides that can harm non-target species, thereby maintaining ecological balance.

Carbon footprint: A bit less carbon released

In Africa, our travel to release and monitor CM and A. lopezi wass made by airplane and car. The initial impact and initial costs were therefore high, but of short duration only, whereas the continuous impact will have no costs.

Environmental health: Greatly improves environmental health

By minimizing chemical pesticide usage, biocontrol contributes to improved environmental health, reducing soil and water contamination and protecting beneficial organisms.

Soil quality: Does not affect soil health and fertility

Reducing chemical inputs through biocontrol helps maintain soil health by preserving beneficial microorganisms essential for nutrient cycling and soil structure.

Water use: Same amount of water used

While healthier cassava plants resulting from effective pest management may have improved water use efficiency, direct impacts of biocontrol on water use are less documented.

Problem

Severe Crop Loss: The cassava mealybug invaded Africa in the 1970s, decimating cassava crops and drastically reducing yields.
Famine and Food Insecurity: The massive loss of cassava, a staple food, led to widespread famine and severe food shortages.
Economic Hardship: The pest outbreak destabilized the livelihoods of millions of farmers, causing significant economic losses in rural communities.
Ineffective Traditional Pest Control: Conventional chemical and cultural pest management methods were insufficient to control the rapidly spreading mealybug, exacerbating the crisis.

Solution

Natural Enemies: Introducing A. lopezi—a parasitoid wasp from South America—provided a natural enemy to the invasive mealybug.
Targeted Control: The wasp lays its eggs on or in the mealybug; the hatching larvae then consume and kill the pest, directly reducing its population.
Mass Production and Release: After rigorous testing and quarantine, A. lopezi was mass-reared and released across more than 20 African countries.
Effective and Long-Term Impact: Once established, the wasp continuously suppressed mealybug numbers by about 90%, restoring cassava yields and stabilizing food supplies and farmer incomes.
Eco-Friendly Alternative: This biological approach eliminated the need for harmful chemical pesticides, ensuring a safe, lasting, and environmentally sustainable control method.

Key points to design your program

The SIS Framework is a structured roadmap that enables governments and development institutions to design, strengthen, and sustain national Soil Information Systems by integrating financial sustainability, institutional development, technical capacity, and FAIR data management into a single implementation process. By supporting demand-driven and interoperable soil information systems, the framework strengthens evidence-based land management, agricultural planning, climate adaptation, and sustainable natural resource management. It is well suited for sustainable soil management, digital agriculture, and agricultural planning programmes, contributing to SDGs 2 (Zero Hunger), 13 (Climate Action), 15 (Life on Land), and 17 (Partnerships for the Goals). The framework creates opportunities for women and youth through specialized roles in data stewardship, digital information management, geospatial analysis, and technical advisory services. To successfully integrate this framework, consider the following key actions:

Identify national priorities, target users, existing soil information assets, and institutional needs to define the scope and objectives of the Soil Information System.
Establish partnerships among government agencies, CABI, ISRIC, research institutions, universities, development partners, and private-sector stakeholders to strengthen institutional ownership and coordinated implementation.
Assess financial sustainability, institutional capacity, technical infrastructure, and data governance requirements to determine the investments needed for the long-term operational and financial viability of the Soil Information System.
Strengthen institutional and technical capacity by defining key roles, developing training programmes, and building expertise in Soil Information System design, maintenance, data stewardship, geospatial information management, and digital services.
Promote FAIR data management by establishing governance policies, metadata standards, data-sharing agreements, and management procedures that ensure soil information is Findable, Accessible, Interoperable, and Reusable.
Support continuous stakeholder engagement and cross-sector collaboration to ensure the Soil Information System responds to evolving user needs and effectively informs agricultural planning, climate adaptation, sustainable land management, and national investment decisions.
Monitor programme performance through indicators such as institutional adoption, FAIR compliance, data accessibility, stakeholder engagement, data reuse, and the integration of soil information into policy, planning, and investment decisions.

9.4 billion USD

Estimation of benefits over 40 years (1974–2013) across 27 African countries

IP

Open source / open access

Scaling Readiness describes how complete a technology\’s development is and its ability to be scaled. It produces a score that measures a technology\’s readiness along two axes: the level of maturity of the idea itself, and the level to which the technology has been used so far.

Each axis goes from 0 to 9 where 9 is the “ready-to-scale” status. For each technology profile in the e-catalogs we have documented the scaling readiness status from evidence given by the technology providers. The e-catalogs only showcase technologies for which the scaling readiness score is at least 8 for maturity of the idea and 7 for the level of use.

The graph below represents visually the scaling readiness status for this technology, you can see the label of each level by hovering your mouse cursor on the number.

Scaling readiness score of this technology

Maturity of the idea 9 out of 9

Uncontrolled environment: validated

Level of use 9 out of 9

Common use by projects NOT connected to technology provider

Maturity of the idea										Level of use
9
8
7
6
5
4
3
2
1
	1	2	3	4	5	6	7	8	9

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

Countries where the technology is being tested or has been tested and adopted
Country	Testing ongoing	Tested	Adopted
Benin	–No ongoing testing	–Not tested	Adopted
Burkina Faso	–No ongoing testing	–Not tested	Adopted
Burundi	–No ongoing testing	–Not tested	Adopted
Cameroon	–No ongoing testing	–Not tested	Adopted
Central African Republic	–No ongoing testing	–Not tested	Adopted
Chad	–No ongoing testing	–Not tested	Adopted
Côte d’Ivoire	–No ongoing testing	–Not tested	Adopted
Democratic Republic of the Congo	–No ongoing testing	–Not tested	Adopted
Equatorial Guinea	–No ongoing testing	–Not tested	Adopted
Gabon	–No ongoing testing	–Not tested	Adopted
Gambia	–No ongoing testing	–Not tested	Adopted
Ghana	–No ongoing testing	–Not tested	Adopted
Guinea	–No ongoing testing	–Not tested	Adopted
Guinea-Bissau	–No ongoing testing	–Not tested	Adopted
Liberia	–No ongoing testing	–Not tested	Adopted
Malawi	–No ongoing testing	–Not tested	Adopted
Mali	–No ongoing testing	–Not tested	Adopted
Mozambique	–No ongoing testing	–Not tested	Adopted
Niger	–No ongoing testing	–Not tested	Adopted
Nigeria	–No ongoing testing	Tested	Adopted
Republic of the Congo	–No ongoing testing	–Not tested	Adopted
Senegal	–No ongoing testing	–Not tested	Adopted
Sierra Leone	–No ongoing testing	–Not tested	Adopted
South Africa	–No ongoing testing	–Not tested	Adopted
Tanzania	–No ongoing testing	–Not tested	Adopted
Togo	–No ongoing testing	–Not tested	Adopted
Uganda	–No ongoing testing	–Not tested	Adopted
Zambia	–No ongoing testing	–Not tested	Adopted
Zimbabwe	–No ongoing testing	–Not 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 1: no poverty

The establishment of A. lopezi solved a crisis by halting the cassava mealybug's destruction of cassava fields thereby safeguarding the livelihoods of millions of farmers and contributing to the reduction of poverty

Goal 2: zero hunger

The establishment of A. lopezi solved a crisis caused by the cassava mealybug's destruction of cassava fields, which are the main staple food in these countries.