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Black Soldier Fly (BSF) larvae in Manombo, Madagascar. Credit – Mahefa Natt.

How flies are revolutionising farming in Madagascar

In Madagascar, rainforest communities face severe food insecurity, driven by multiple factors: destruction from cyclones and droughts, low incomes, volatile food prices, limited crop diversification, and dependence on rain-fed agriculture. According to the UN World Food Program, chronic malnutrition affects nearly 40% of Madagascar’s children. The increasing intensity of climate shocks is compounding these pressures, while rising temperatures caused by climate change are resulting in unpredictable growing seasons for smallholder farmers. Hunger seasons (the period between planting and harvesting when previous food stocks run out) are also becoming more prolonged and intense, twice a year.

For these reasons, Health In Harmony (HIH) and local HIH Collective partner Fashalamana Mirindra (FAMI) have been collaborating with local communities and the Madagascar Biodiversity Center (MBC) to develop an innovative solution: Black Soldier Fly (BSF) farming. This innovative approach to nutrition and agriculture is now tackling food insecurity head-on, as well as fallout effects such as deforestation and the hunting of endangered wildlife.

What is BSF?

BSF (Hermetia illucens) is a black fly species from the Americas. It can also be found in Madagascar, especially in warm and humid areas. In the Morafeno village, near Farafangana District, HIH and FAMI have been working with communities to create what is currently the largest community-based BSF farm in the world.

BSF has many benefits: its larvae are rich in nutrients and can be eaten as a meat substitute, providing protein, fat, and calcium. BSF can also be fed to chickens, fish, and pigs to improve livestock feed. When composted, BSF helps recycle organic waste and increases agricultural productivity, used as a high-quality organic fertiliser.

Revolutionising farming

Beginning with a robust Insect Acceptability Survey, researchers from the MBC and HIH assessed how willing people are to consume and farm BSF. One participant said, "We liked it in general because our body remains healthy after eating it, so that's why we like it."

Another study published in ‘Frontiers’ found that using composted BSF frass (larvae excrement and shed skins) as an organic fertiliser increased maize yields by 38% compared to traditional cattle manure, while using a fraction of the space and upkeep.

Notably, the unfertilised control plots produced no harvestable maize, underscoring the critical need for nutrient inputs in the region's acidic soils.

"Our results show that composting BSF frass for five weeks transforms it into a highly effective organic fertiliser," says Cédrique L. Solofondranohatra, Lead Researcher and Director of Small Farms Programs at the MBC.

Even at one-third of the recommended nitrogen input, composted BSF frass achieved 57% of the yield obtained under full fertiliser recommendations. This is crucial for smallholder farmers who cannot afford full-dose commercial fertilisers."

Community voices

What makes this research particularly notable is its community-led approach. Rather than conducting experiments in controlled laboratory settings, researchers worked alongside farmers in Morafeno village who tested BSF frass on their own fields using their own agricultural practices. “Working directly with community members in their own fields gave us insights we could never have gained in a research station," Solofondranohatra said.

“Working directly with community members in their own fields gave us insights we could never have gained in a research station."

Brunot, a maize farmer and village king in Morafeno village, who participated in the trial, says the results have changed his approach to farming: "Before this study, when we couldn't afford fertiliser, we would get no harvest at all. Now I am learning to compost BSF frass, and I can see my maize plants growing stronger. This gives me hope that I can feed my family and have maize to sell at the market."

Next steps

This research provides crucial evidence for organisations working to improve food security and environmental sustainability in Madagascar and similar contexts. Of the farmers surveyed only a couple of months after starting their BSF farms, 75% shared that "BSF farming has improved my household's livelihood," while 50% report "I feel more confident about meeting my family's nutritional needs".

“These findings are particularly significant for smallholder farmers in Madagascar who face persistent challenges with soil fertility and food production," says Sakib Burza, Chief Health & Innovation Officer at HIH. "By demonstrating that composted BSF frass can enhance crop yields even at sub-recommended fertiliser doses, this research provides a locally-accessible solution that supports both agricultural productivity and environmental sustainability.”

"This research provides a locally-accessible solution that supports both agricultural productivity and environmental sustainability.”

As climate change brings more frequent droughts and unpredictable rainfall to southeastern Madagascar, locally produced fertilisers like BSF frass can help farmers maintain soil fertility and crop yields even under increasingly uncertain conditions. By turning organic waste into a resilient farming input, BSF systems are enabling communities to build more climate-adaptive food systems while reducing pressure on surrounding forests and biodiversity.

The next steps involve scaling BSF production systems across the region. FAMI is implementing 300 BSF farms across 20 villages in the Manombo region, with 50% already operational and successfully doubling production after the first harvest and producing 1,800 kg of larvae a month. Given the success, FAMI is also currently exploring the expansion of BSF potential in partnership with Doctors Without Borders in other regions of Madagascar.

Written by Amelia Abraham and edited by Mariana Velloso Campos, Guilhem Molinie, and Stevie Youssef. For more information on this Darwin Initiative Main project 30-015, led by Health in Harmony, click here.