Black Soldier Flies Tolerate Microplastics

On one hand, this is a good thing because they can still recycle wastes that are contaminated with microplastics. On the other hand, black soldier flies may not be very useful in removing them from the substrates. Time will tell.

Piersanti, S., Rebora, M., Turchetti, B., Salerno, G., Ruscetta, M., Zucconi, L., D’Alò, F., Buzzini, P. and Sannino, C., 2024. Microplastics in the diet of Hermetia illucens: Implications for development and midgut bacterial and fungal microbiota. Waste Management, 186, 259-270.

In a world with a population exceeding 8 billion people and continuing to grow, pollution from food and plastic waste is causing long-term issues in ecosystems. Potential solutions may be found by exploiting insect-based bioconversion. In this context, we investigated the impact of polyvinyl chloride microparticles (PVC-MPs) on the development of Hermetia illucens (black soldier fly; BSF) and its midgut bacterial and fungal microbiota.

The impact of PVC-MPs was evaluated feeding BSF larvae with a PVC-MPs-supplemented diet. The larvae exposed to different PVC-MPs concentrations (2.5%, 5%, 10% and 20% w/w) developed into adults with no significant increase in pupal mortality. Faster development and smaller pupae were observed when 20% PVC-MPs was provided. The BSF larvae ingest PVC-MPs, resulting in a reduction in MPs size. Larvae exposed to PVC-MPs did not exhibit differences in gut morphology. Regarding the impact of PVC-MPs on the structure of both bacterial and fungal communities, the overall alpha- and beta-diversity did not exhibit significant changes. However, the presence of PVC-MPs significantly affected the relative abundances of Enterobacteriaceae and Paenibacillaceae among the bacteria and of Dipodascaceae and Plectospharellaceae among the fungi (including yeast and filamentous life forms), suggesting that PVC-MP contamination has a taxa-dependent impact.

These results indicate that BSF larvae can tolerate PVC-MPs in their diet, supporting the potential use of these insects in organic waste management, even in the presence of high levels of PVC-MP contamination.