CABI’s laboratory in Zambia has successfully harvested its first spores of a local strain of Metarhizium rileyi for the management of fall armyworm, marking a significant milestone after three years of dedicated research and development. Metarhizium rileyi is a highly specific fungus that kills fall armyworm.
In 2018, scientists from the Zambia Agricultural Research Institute (ZARI), University of Zambia (UNZA) and CABI discovered the fungus occurring naturally where fall armyworm was devastating maize. This led to activities geared towards Village-based biocontrol of fall armyworm in Zambia project, funded by ACIAR, alongside the CABI PlantwisePlus programme, to test the fungus in the field. Trials run across the three agroecological zones of Zambia, where liquid and dry formulations are tested for efficacy and optimal start and frequency of application.
For four years, the spores used in this work were produced in the CABI labs in Egham, UK and shipped to Zambia. That has now changed: for the first time, they have been grown on rice entirely in-country, from a strain found killing fall armyworm in local fields.
ZARI has also taken up the challenge by testing the production of the spores on various varieties of rice, sorghum, wheat and barley. This initiative will allow researchers to identify the right cereal and formulation for optimal mass production of the entomopathogenic fungus.
Young scientists helping shape sustainable agriculture
Ms Sihle Blessings Nakombe, CABI’s Lab Technician who led this work, said the achievement reflects years of patient effort finally paying off. Sihle’s focus since she joined CABI in January 2023 has been on the biological control of pests affecting small-scale farmers in Zambia, using fungus and natural enemies.
“Harvesting the first spores of M. rileyi is a great milestone for our research and skill development among young scientists. It is the result of three years of dedicated work to develop a biological control option for more sustainable fall armyworm management in Zambia, and we’re excited about where it can take us next,” said Ms Sihle.
For Sampa Kazembe, an intern at CABI’s centre in Zambia, who also worked on the mass production process, the milestone has been as much personal as scientific. “Working on the mass production of M. rileyi has been an inspiring chapter in my professional journey,” she said.
“Being part of the team that achieved this breakthrough has been incredibly rewarding, strengthening my confidence, practical laboratory expertise, and hands-on skills in biocontrol production.”
As an Agronomy graduate, this experience has deepened my appreciation and passion for the role of biocontrol in building sustainable agricultural systems, while reinforcing my commitment to developing innovative, science-based solutions that protect both farmers and the environment.”
A locally adapted solution to one of Zambia’s biggest crop threats
Fall armyworm has become Zambia’s most damaging invasive species, affecting at least 98% of smallholder farmers every cropping season and causing estimated annual losses of US$159 million.
Across Africa, the pest continues to threaten maize production, resulting in significant crop losses and undermining the livelihoods and food security of millions of smallholder farmers. As the pest continues to spread and challenges associated with conventional control methods persist, the need for sustainable and environmentally friendly management options has become increasingly urgent.
M. rileyi is an entomopathogenic fungus, a naturally occurring organism that infects and kills insect pests and is particularly effective against fall armyworm (Spodoptera frugiperda), making it a promising biological control option for sustainable pest management.
Because the strain was found naturally infecting fall armyworm under Zambian conditions, scientists know it is well adapted to the local environment, giving it strong potential for use in augmentative biological control.
A milestone for Zambia and the region
Dr Natasha Mwila, CABI’s Regional Director for Southern Africa, said the successful production of spores from a locally sourced strain represents an important milestone in developing sustainable, science-based solutions for Zambia’s farmers.
“This achievement demonstrates the value of investing in local scientific capacity to develop biological control solutions that are tailored to Zambia’s agricultural systems. By harnessing naturally occurring organisms, we are advancing more sustainable approaches to managing fall armyworm while reducing reliance on conventional pesticides.”
She added that the breakthrough also strengthens Zambia’s contribution to regional efforts to improve plant health and food security. “This work not only benefits farmers in Zambia but also creates opportunities for knowledge sharing and collaboration across Africa as countries seek more resilient and environmentally sustainable ways to manage fall armyworm.”
Additional information
Main image: Ms Sihle Blessings Nakombe, a laboratory technician, displays a sample of locally produced Metarhizium rileyi, marking a key milestone in Zambia’s efforts to develop sustainable biological control of fall armyworm.
Further reading
- Successful on-farm trials using Metarhizium rileyi in Zambia
- How can Metarhizium be used to address pests and diseases?
- Village-based biological control of fall armyworm in Zambia
- Study examines potential for collective action to fight fall armyworm with biological controls in rural Zambia
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