By Robert Kibet
As Africa grapples with an escalating plastic waste crisis, scientists at the International Centre of Insect Physiology and Ecology (ICIPE) have made an intriguing discovery. They found a natural and unexpected ally in tackling plastic pollution: the lesser mealworm.
The lesser mealworm, or Alphitobius diaperinus, is a species of darkling beetle whose larvae appear capable of consuming and degrading plastics, according to a study published in Scientific Reports. This promising finding highlights the insect’s potential role in plastic biodegradation, a breakthrough with significant implications for Africa and beyond.
“While they may look like ordinary worms, these mealworms are the larvae of darkling beetles,” explains Dr. Fathiya Khamis, ICIPE Senior Scientist and lead researcher. “Worldwide, the yellow mealworm, Tenebrio molitor, has been studied for its plastic-degrading abilities. But this is the first time we’ve documented that lesser mealworms, native to Africa, possess this capacity.”
Globally, more than 400 million tonnes of plastic are produced annually, yet less than 10% is recycled. A staggering 19 to 23 million tonnes of plastic pollute waterways each year, including rivers, lakes, and oceans.
This relentless flow contaminates ecosystems, degrades soil quality, and eventually enters the food chain, posing risks to wildlife and human health. Despite producing only 5% of global plastic, Africa is now the world’s second-most polluted continent due to the rapid spread of single-use plastics.
In the ICIPE study, researchers tested the ability of lesser mealworms to consume polystyrene, a key component in products like Styrofoam food containers and insulation materials.
“Our findings showed that the mealworms could ingest nearly 50% of the Styrofoam we fed them,” says Evalyne Ndotono, a PhD scholar at ICIPE. “Now, we aim to dive deeper into understanding how they process polystyrene and whether they derive any nutritional value from it.”
One fascinating aspect of the study is the role of bacteria in the mealworm’s gut. Researchers discovered that specific gut bacteria seem to assist the insect in breaking down plastics, potentially making it feasible to harness either the mealworm itself or these microbes for large-scale biodegradation.
“We are particularly interested in understanding whether these bacteria are naturally present in the mealworm, or if they are a defense mechanism that develops after feeding on plastic,” Ndotono adds. "Knowing this could be key to scaling up this bioremediation process."
While methods such as chemical, thermal, and mechanical recycling exist for polystyrene, they tend to be costly and produce toxic byproducts. The potential to use lesser mealworms as a sustainable solution is both cost-effective and environmentally friendly, making it a compelling option in efforts toward a circular economy.
Africa’s plastic pollution problem requires innovative solutions, and ICIPE work could pave the way for broader applications of mealworm-based bioremediation. Dr. Abdou Tenkouano, Director General of ICIPE, sees this research as an opportunity to address plastic waste sustainably while advancing the center’s work on edible insects.
“Mealworms have been recognized for their nutritional value, and with this new knowledge, we have a dual opportunity to address waste and promote food security,” says Dr. Tenkouano. “Our research aligns with icipe’s vision for a circular economy, turning waste into value.”
The potential benefits of using mealworms in waste management go beyond environmental cleanup. AsICIPE researchers explore the mealworm’s ability to degrade various types of plastics, they hope to convert the byproducts into safe, useful products, creating added economic value.
Bioremediation, the use of living organisms to clean contaminated environments, is gaining traction globally. ICIPE study expands knowledge in this field and sets the stage for collaborations with other scientists, policymakers, and industry leaders to maximize the mealworm's potential.
“The next step will be a collaborative effort,” says Dr. Khamis. “We aim to work with partners across Africa to further this research and make it practical at a large scale. There’s a real opportunity here to not only reduce waste but also create new industries around plastic degradation.”
This discovery underscores a promising approach to mitigating Africa's plastic problem. Instead of relying solely on conventional recycling methods, the continent could adopt a nature-based solution rooted in its biodiversity. With further research and collaboration, the humble mealworm might just hold the key to a cleaner, greener future.
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