Recent microplastics (MPs) research has focused on their ecological impact and distribution. While many studies suggest adverse effects, some have shown that certain species of Tenebrionidae beetles can use plastic as a food source in controlled laboratory settings. However, these experiments often need more ecological realism, raising questions about whether the findings can be applied to real-world environments.
In a new study, UBC zoologist Dr. Michelle Tseng and alumna Shim Gicole quantified the ability of mealworms (Coleoptera: Tenebrionidae) to consume microplastic from polypropylene and polylactic acid face masks, two of the most commonly used conventional and plant-based plastics.
Mealworms, nature’s scavengers and decomposers can survive without food or water for up to eight months and even eat their own kind when food is scarce.
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To replicate natural foraging, the researchers mixed microplastics (MPs) with wheat bran, creating an environment with multiple food sources for the mealworms. In this setup, the mealworms consumed about 50% of the available MPs, egested a small fraction, and their survival was unaffected by the consumption of microplastics. They excreted only a small portion of the ingested microplastics, about four to six particles per milligram of waste, with the rest absorbed.
UBC zoologist Dr. Michelle Tseng said, “The next step will be to learn from the insects’ digestive mechanisms how to break down microplastics and scale up these learnings to address plastic pollution. Perhaps we can start viewing bugs as friends. We’re killing millions of insects daily from general pesticides – the very same insects we could be learning from to break down these plastics and other chemicals.”
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“This study adds to our limited knowledge of the ability of insects to consume MPs. The understory or ground-dwelling insects may hold the key to sustainable plastic disposal strategies, but we caution that research in this field needs to proceed concomitantly with reductions in plastic manufacturing.”
Journal Reference:
- Shim Gicole, Alexandra Dimitriou†, Natasha Klasios, and Michelle Tseng. Partial consumption of medical face masks by a common beetle species. Biology Letters. DOI: 10.1098/rsbl.2024.0380
