Researchers are exploring how to turn weeds into feed for farmed insects, creating protein for food and livestock feed while producing natural fertilizer. A new review suggests a circular agriculture model could cut waste, boost farm income, and improve sustainability. The house cricket (Acheta domesticus) is a species commonly farmed to produce food and feed, and a new review finds research showing house crickets can be fed at least 12 species of weeds from nine plant families. (Photo by Joseph Berger, Bugwood.org)

By Carolyn Bernhardt

Chrysantus Tanga, Ph.D.

Dennis Beesigamukama, Ph.D.

Crop farmers worldwide face a notorious, ubiquitous adversary: weeds. A constant drain on time and resources, they reduce yields and require near-constant management. But what if weeds, in their never-ending obstinance, could actually serve a helpful purpose?

Authors of a review published in September in the Journal of Economic Entomology propose a novel, cost-effective way to reframe weeds. “Farmers [could look] at these weeds as resources for edible insect farming, growing insects like crickets, mealworms, and desert locusts,” says Dennis Beesigamukama, Ph.D., a postdoctoral fellow at the International Centre of Insect Physiology and Ecology (ICIPE) in Nairobi, Kenya, and one of the study’s lead authors.

The paper compares results from studies involving different insect and weed species, considering how factors such as diet formulation, weed species, and insect-rearing conditions affect insect production. The study’s main goal was to identify remaining research gaps in making weed-based insect farming practical on a larger scale.

The authors say a circular-economy approach that feeds farmed insects weed biomass could support sustainable agriculture and farmer income by turning unwanted weeds into a high yield of healthy farmed insects, which can be used in products that foster food security, such as human food and livestock feed. The resulting insect frass also works as fertilizer to improve soil health and promote healthier crop production.

“When it comes to animals, insects are a natural part of their diet,” says Chrysantus Tanga, Ph.D., a senior scientist and head of the Insects for Food, Feed, and Other Uses program at ICIPE and senior author on the study. “We are harnessing a part of nature and amplifying it through mass production to ensure we can feed as many animals as possible, produce enough fertilizers, control weeds, and make sure we have a transformed agricultural system, driven by insect-based solutions.”

“That is not to say we are encouraging farmers to grow weeds,” says Beesigamukama. “Just to harness existing weeds to improve [insect, animal, and crop] productivity.” He says farmers across Africa are already moving away from herbicides and toward regenerative agriculture, using environmentally friendly methods to manage weeds. Now, he says, “they are looking at how to use the weeds they have removed as a resource.”

Deeper in the Weeds

Of course, the experts say, matching the right weeds with the right insect species will be an essential step in the process. “The nutritional quality of the weed is one of the key parameters that determines its use as feedstock for insect farming,” Beesigamukama says. “So, it’s not that every weed can be used for every insect, but some can be highly suitable and tailored for mass production of specific insect species.”

“Since there are different weed species in different areas, it is key we map these species and decipher which insects to use in specific communities so we can look at the management of different weed species in different agricultural zones and systems,” says Beesigamukama.

Also, whether a weed grows annually or is perennial matters greatly, especially if that weed takes a long time to accumulate enough biomass for insect production. “Some weeds can grow several times within the year, which would be more beneficial than those that grow once a year,” says Beesigamukama. However, he says cutting and drying those weeds for long-term storage can offset this issue.

Researchers are exploring how to turn weeds into feed for farmed insects, creating protein for food and livestock feed while producing natural fertilizer. A new review suggests a circular agriculture model could cut waste, boost farm income, and improve sustainability, as illustrated here. (Figure originally published in Onyango et al. 2026, Journal of Economic Entomology)

Other study limitations linger, too. Tanga cites the limited host range of the weeds used, knowledge gaps in the insects’ feeding preferences, and inconsistent field conditions—like temperatures, rainfall, and disease—which he says “can strongly interfere with the mass production system.”

And while many farmers are already working diligently to pursue ecologically friendly solutions for weed management, pesticides and herbicides are still frequently found in the environment, including in weeds.

“We are looking at the issue related to pesticide or herbicide residues that might end up in the insects—beside heavy metals, microbial contaminants, mycotoxins, or other naturally occurring toxins,” Tanga says. When insects feed on contaminated weeds, these toxins can accumulate and transfer into insect biomass, infiltrate insect-based feed, and affect animal health. “It is important we screen [the insects] to make sure they are safe and can be used for mass or large-scale production of this insect for standard use.”

However, Beesigamukama points out that many insects can break pesticides and herbicides down into less harmful compounds, which they then pass through their frass. But the energy insects spend breaking down pollutants can hamper their growth rate and reproductive performance. “And of course, for some species,” Beesigamukama says, “there may be traces of accumulation of these compounds in their frass, thus reducing further use of the end product—frass—as fertilizer.”

The team also faces a public acceptance hurdle. “If people don’t accept [this], it can strongly affect the adoption of this approach,” Tanga says.

“We have gone past the direct consumption of insects as a whole for nutrition,” Beesigamukama points out. Other important aspects of edible insects include their high-quality oils, which are known to be rich in omega-3 and other fatty acids as well as bioactive compounds with health promoting properties or act as key supplements for human food and animal feed.

“Insects fed on plant-based materials are able to amplify nutrients by several folds,” Tanga says. “Therefore, they could be considered a good source for value addition.”

Insects are also known to be rich in chitin, which has pharmaceutical and preservative applications. “Beside these key products, antimicrobial peptides have been widely reported from insects,” says Beesigamukama, “as well as antimicrobial peptides that can be helpful in managing animal health, especially by suppressing pathogens or improving animal gut health.”

A New Kind of Harvest

Rearing insects also offers farmers an additional income stream that doesn’t cost much or take up much space to maintain. “They require low capital investment, which means they can help improve the livelihoods of marginalized communities,” says Beesigamukama. He also points out that Africa has one of the most conducive conditions for insect mass production. “This places Africa as one of the leading continents in the world advancing insect-based solutions. Here, the climate is favorable and insects take relatively short developmental cycles and could be produced year round, particularly for those with shorter cycles of less than one month to harvest.”

That means, instead of harvesting crops once a year, producers can harvest 12 times a year, generating more income. “Some insects you can harvest every two weeks, which means you can harvest them more than 25 times a year,” he says.

Insect production also puts fewer strains on the ecosystem. As the world struggles with population increases and stretching resources, Beesigamukama says, “insects are one of those enterprises [whose production] require less land and water and emit much fewer greenhouse gases.”

The experts are now prioritizing farmer outreach through various free trainings as well as capacity-building efforts to foster broader acceptance and adoption of the proposed practice. Tanga also says they are working to advance efficient feed conversion and the optimization of insect mass production, as well as ecological risk associated with these innovations. They are also studying the climate effects of mass-producing these insect species and how the insects interact with different types of weeds.

Ideally, the experts say, the proposed tactic in the new paper will help shift how farmers view weeds. As Beesigamukama puts it, “Farmers would start looking at weeds as a resource because they will know they need the weeds as a safe, high-quality resource to feed to the insects.”

Carolyn Bernhardt, M.A., is a freelance science writer and editor based in Rhinelander, Wisconsin. Email: [email protected].