ISSUE FOCUS Alternative Proteins Magazine April 2025 27 POTENTIAL APPLICATIONS IN FERTILIZERS Beyond feed, the byproducts of plastic-fed larvae are also being evaluated for use in agriculture. Frass produced by these larvae could be used as a biofertilizer. In a recent study, T. molitor larvae fed exclusively with EPS produced less frass than those fed organic or mixed diets (Bastidas Proaño, 2024). Moreover, the presence of microplastic fragments in the frass could not be ruled out, since chewing alone can generate small particles that may bypass digestion. This highlights the need to assess whether frass contains plastic residues before it can be safely applied to soil. That said, other studies have found cases in which EPS was fully degraded, and the resulting frass showed no detectable plastic traces when analyzed using detailed chemical methods (Siddiqui et al., 2024). Further investigation is needed to ensure that frass derived from plastic-fed insects can be safely used as a fertilizer —without compromising soil health or crop safety. A NEW STUDY QUESTIONS THE EFFECTIVENESS OF PLASTIC DEGRADATION BY INSECTS Although many studies have documented the ability of T. molitor to degrade EPS, a recent study (Mohammadizadeh Tahroudi et al., 2025) challenges this view. It found that larvae could not survive or complete their life cycle on EPS alone, with mortality matching or exceeding that of starved controls. The authors argue that T. molitor may lack the enzymes or microbiota needed to degrade EPS under lab conditions. While not dismissing earlier findings, the study calls for a critical reassessment of insect-based plastic degradation strategies. WHAT'S NEXT FOR PLASTIC-EATING LARVAE? Insect larvae capable of degrading plastic represent a disruptive solution, which could simultaneously address two global challenges: Plastic waste and sustainable protein production for feed. Over the past decade, significant progress has been made, yet several aspects require further evaluation —from feed performance and long-term health effects, to frass quality and microplastic residues. Beyond aquaculture, the potential use of these larvae in feeding other animals such as poultry, pigs, and pets also needs to be carefully assessed to understand nutritional performance, digestibility, and safety risks. The advancement of this insect-based solution must also address external barriers such as regulatory frameworks and consumer acceptance. References available upon your request. About Rodrigo Llauradó Casares Rodrigo Llauradó Casares is a communicator and content creator with over 10 years of experience researching the use of insects for food, feed, and non-feed applications. With a background in Social Sciences and Marketing, he has founded startups, written scientific articles, created courses, and participated as a seminar speaker. He currently supports companies across the insect protein value chain through content and strategies that communicate science-based innovation and industry impact.
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