Invasives Blog

Rwandan Agriculture and Animal Resource Board (RAB), CABI and its partners, are marking a significant milestone – 10 years of success in mass-producing biocontrol agents at their Rubona facility located in Huye district in Rwanda.

This achievement highlights Rwanda’s commitment to sustainable agricultural practices through innovative pest management solutions, primarily the production of beneficial nematodes to fight pests such as the fall armyworm (Spodoptera frugiperda).

What are beneficial nematodes?

Beneficial nematodes, also known as entomopathogenic nematodes, are naturally occurring microscopic worms that specifically target and infect insects. They are a biological alternative to chemical pesticides and offer an environmentally friendly solution to controlling agricultural pests.

Crucially, these nematodes pose no harm to humans, livestock, crops, or the environment, making them an ideal biocontrol agent. Through mass production in artificial media, they are made available to farmers as a practical pest control solution.

A decade of growth: Technology transfer and capacity building

Rwanda’s journey with beneficial nematodes began between 2014 and 2016, when a team of international experts from China, the UK, Kenya, and Switzerland transferred the technology for mass-producing these biocontrol agents.

This project was a part of a triangular North-South-South cooperation among CABI Member Countries, supported by key partners including the Chinese Academy of Agricultural Sciences (IPP-CAAS), Guangdong Entomological Institute, and CABI centers in China, the UK, Kenya, and Switzerland.

Funded by the UK’s Foreign, Commonwealth and Development Office (the then Department for International Development) (DFID), this initiative built local capacity in Rwanda for the mass production and use of beneficial nematodes.

In Rwanda, the facility has thrived, producing over 100 billion insect -killing nematodes per batch. This is enough to treat more than 100 hectares of field crops or seed beds that can later be transplanted to over 800 hectares. This milestone has positioned Rwanda as a leader in biological pest control in Africa.

Research and development: Key to Rwanda’s success

Since the establishment of the biocontrol facility, several research initiatives have propelled Rwanda’s expertise in nematode-based biocontrol.

For example, from 2014 to 2020, Innocent Nyamwasa, a Rwandan PhD student, conducted research on soil insect pests, their management options, and DNA barcoding of beetles in East Africa. His work highlighted the importance of understanding pest behaviour and lifecycle in developing effective biocontrol solutions.

Another key researcher, Assinapol Ndereyimana, completed his PhD between 2016 and 2020, focusing on using nematodes to manage greenhouse pests in Rwanda. His research was funded by the United States Agency for International Development (USAID) under the Feed the Future initiative. The results of his research have been instrumental in applying nematodes to manage agricultural pests under controlled environments.

Innovation in biocontrol applications

One of the most notable advancements in Rwanda’s biocontrol efforts came from Patrick Fallet, a PhD student at the University of Neuchâtel, Switzerland. Between 2018 and 2023, he developed application technologies for using nematodes above ground, particularly to combat the invasive fall armyworm, a significant maize pest in Africa.

Dr Fallet’s work resulted in a gel-based formulation that allows for spot application of nematodes, making the control of fall armyworm more efficient and practical. His contribution earned him the prestigious Swiss Forum for International Agricultural Research (SFIAR) PhD-Award in 2023.

Expanding biocontrol solutions

From 2018 to 2022, CABI’s “Action on Invasives” programme further supported the research and development of biocontrol solutions against fall armyworm. More recently, between 2022 and 2024, CABI’s PlantwisePlus programme aided in the development of biocontrol measures targeting the tomato leaf miner, another major pest in Rwanda’s agricultural sector.

Collaborations have continued to evolve. As of 2024, RAB, in partnership with AgroPy Ltd, University of Rwanda, Zhongkai University of Agriculture and Engineering, China, and CABI is working on scaling up nematode production for diverse insect pests, supported by the African Centre for Technology Studies (ACTS) and Rwanda’s National Council for Science and Technology (NCST).

Looking ahead: building on a strong foundation

Over the past decade, Rwanda has successfully established a strong research and development base for nematode-based biocontrol solutions. This expertise allows the country to explore new initiatives and collaborate with international partners on further enhancing biocontrol technologies.

A new collaboration with the International Centre of Insect Physiology and Ecology (ICIPE), Dudutech Bioline Kenya, and the University of Neuchâtel is focusing on improving nematode formulations for above-ground applications, expanding the range of pests that can be targeted.

A bright future for sustainable agriculture

Dr Stefan Toepfer, Research Scientist, Arthropod Biological Control at CABI, said, “The success of Rwanda’s biocontrol facility is a testament to the power of international collaboration, scientific innovation, and a commitment to sustainable agriculture.

“With the continued support of local and international partners, Rwanda is well-positioned to further develop biocontrol solutions that will reduce farmers’ reliance on chemical pesticides, enhance food safety, improve livelihoods, and safeguard the environment.

“As the country celebrates 10 years of achievements in biological pest management, the future looks bright for Rwanda’s agriculture sector, with biocontrol leading the way to more sustainable and environmentally friendly farming practices.”

Additional information

Main image: Dr Stefan Toepfer overlooks tomato leaf let bioassay on using beneficial nematodes as biocontrol agents supported by the Rwanda National Council for Science and Technology of Rwanda.

Relevant project pages

‘Developing beneficial nematode-based biocontrol solutions to fall armyworm in Africa.’

‘Biological control of the fall armyworm with entomopathogenic nematodes for enhanced food security in Africa.’ 

‘Biocontrol solution for farmers against the fall armyworm.’

Relevant stories

‘Legacy of AgriTT programme lives on at Rwandan biocontrol facility to fight crop pests.’

‘Nematode-based solution offers possible ‘weapon’ in arsenal against devastating fall armyworm pest.’

‘Training on mass production of entomopathogenic nematodes for biological control of invasive insect pests.’

‘CABI-led review highlights potential management options for fall armyworm pest in Europe.’

‘PhD student joins the fight against devastating Fall Armyworm pest.’

‘PhD student wins international research award for fight against devastating fall armyworm pest.’

‘Team of global experts to develop beneficial nematode-based biocontrol solution to fall armyworm.’

‘Zhongkai experts are now present in the farmlands of Rwanda, the “Land of a Thousand Mountains”, and will help protect corn and tomatoes.’

‘Yan Xun from Zhongkai University of Agriculture and Engineering and Stefan Toepfer from CABI went to Rwanda to carry out training on mass cultivation and application technology of biological agents.’

New book

Shapiro-Ilan DI, Lewis E  (2024). Entomopathogenic Nematodes as Biological Control Agents. CABI Publishing, Wallingford, UK, pp 578.

https://www.cabidigitallibrary.org/doi/epdf/10.1079/9781800620322.0000

Relevant papers

Fallet P., Bazagwira D., Ruzzante L., Ingabire G., Leviver S., Bustos-Segura C., Toepfer S., Turlings TCJ. (2024). Entomopathogenic nematodes as an effective and sustainable alternative to control the fall armyworm in Africa. PNAS Nexus, 3(4). https://doi.org/10.1093/pnasnexus/pgae122

Machado RAR., Bhat AH., Fallet P., Turlings TCJ., Kajuga J., Yan X., Toepfer S. (2023). Xenorhabdus bovienii subsp. africana subsp. nov., isolated from Steinernema africanum entomopathogenic nematodes. International Journal of Systematic and Evolutionary Microbiology, 73(4). https://doi.org/10.1099/ijsem.0.005795

Fallet P., Bazagwira D., Guenat JM., Bustos-Segura C., Kajuga J., Mukundwa IP., Karangwa P., Toepfer S., Turlings TCJ. (2022). Laboratory and field trials reveal the potential of a gel formulation of entomopathogenic nematodes for the biological control of fall armyworm caterpillars (Spodoptera frugiperda). Biological Control, 176. https://doi.org/10.1016/j.biocontrol.2022.105086

Machado RAR., Bhat AH., Abolafia J., Shokoohi E., Fallet P., Turlings TCJ., Tarasco E., Půža V., Kajuga J., Yan X., Toepfer S. (2022). Steinernema africanum n. sp. (Rhabditida, Steinernematidae), a new entomopathogenic nematode species isolated in the Republic of Rwanda. Journal of Nematology, 54(1). https://doi.org/10.2478/jofnem-2022-0049

Fallet P., De Gianni L., Machado RAR., Bruno P., Bernal JS., Karangwa P., Kajuga J., Waweru B., Bazagwira D., Degen T., Toepfer S., Turlings T.C.J. (2022). Comparative screening of Mexican, Rwandan and commercial entomopathogenic nematodes to be used against invasive fall armyworm, Spodoptera frugiperda. Insects, 13, 205. https://doi.org/10.3390/insects13020205

Machado RAR., Bhat A., Abolafia J., Muller A., Bruno P., Fallet P., Arce CCM., Turlings TCJ., Bernal JS., Kajuga J., Waweru, B., Toepfer S. (2021). Multi-locus phylogenetic analyses uncover species boundaries and reveal the occurrence of two new entomopathogenic nematode species, Heterorhabditis ruandica n. sp. and Heterorhabditis zacatecana n. sp.. Journal of Nematology, 53(1) 1-42. https://doi.org/10.21307/jofnem-2021-089

Fallet P., Machado RAR., Toepfer S., Ye W., Kajuga J., Waweru B., Bazagwira D., Turlings TCJ. (2020). A Rwandan survey of entomopathogenic nematodes that can potentially be used to control the fall armyworm. IOBC-WPRS Bulletin, 150: 87-90. https://iobc-wprs.org/product/a-rwandan-survey-of-entomopathogenic-nematodes-that-can-potentially-be-used-to-control-the-fall-armyworm/