It seems increasingly likely that certain types of worms could be an amazing solution to our plastic problem — and that we may eat them and their cousins afterwards.
Last week, the European Food Safety Authority (EFSA) published a risk profile to address the potential biological, chemical and environmental hazards as well as allergenicity associated with the use of farmed insects as food and feed.
The production methods, what the insects are fed (substrate), the insects’ life stage at harvest, and the species determine the presence of biological and chemical hazards in food and feed products derived from insects. The risks of specific insects and food safety strategies will therefore need to be determined on a case-by-case basis, according to the EFSA Scientific Committee — though previous research has found that those who are allergic to shellfish are most likely also allergic to eating insects, since they are all arthropods.
There is limited data available on the transfer of chemical contaminants from different types of substrate to insects. EFSA calls for further research on specific substrates, the occurrence of microbial pathogens of vertebrates, and hazardous chemicals in reared insects.
Insects are currently a niche food market in the European Union (EU), but EFSA explains they may have important environmental, economic, and food security benefits, particularly as a source of protein. The organization reports that houseflies, mealworms, crickets, and silkworms seem to have the greatest potential for use as food and/or feed in the EU. Another study co-financed by EFSA is investigating the feasibility of using insect protein for feed.
Meanwhile, researchers in China and engineers from Stanford University have discovered that mealworms can eat a diet exclusively of polystyrene, also known as Styrofoam. The larvae form of the darkling beetle has microorganisms in its guts that biodegrade the plastic.
The findings are surprising and hopeful: Americans throw out 2.5 billion Styrofoam cups a year; polystyrene is poisonous to some animals and does not biodegrade in landfills. The ability to safely feed Styrofoam waste to worms has huge implications for the management of this waste.
“Our findings have opened a new door to solve the global plastic pollution problem,” said Wei-Min Wu, co-author of the studies and senior research engineer at Stanford.
Researchers have yet to identify any adverse effects of this plastic diet in mealworms; the insects seemed to be just as healthy as those who ate a more standard diet of bran. Now, the long-term effects on multiple generations of mealworms and small animals that consume the mealworms are being investigated.
The worms converted about half of the Styrofoam into carbon dioxide, as they would with any food source. The remaining plastic was biodegraded and excreted as small pellets. Their waste appeared to be safe to use as soil for crops.
The papers are the first to provide evidence of bacterial degradation of polystyrene in an animal’s gut. Previous research, including some of Wu’s, has shown that microorganisms in the guts of waxworms, the larvae of Indian mealmoths, can biodegrade polyethylene, the type of plastic most commonly used in bags, bottles and other types of packaging. The new findings on polystyrene are significant because Styrofoam was thought to have been non-biodegradable and therefore possibly more problematic for the environment than polyethylene.