Use Them for What They Are Good at: Mealworms in Circular Food Systems

SIMPLE SUMMARY: Different challenges exist, such as climate change and a growing number of people living on the planet, that put pressure on current and future food systems. In the future, more food must be produced on less land. At the same time, food-related greenhouse gas emissions must be reduced to be in line with the 2 °C climate goal, to limit potential risks of climate change. In this context, mealworms have been discussed as a sustainable and resource-efficient protein production option in circular food systems. They are an efficient biomass converter of low-quality by-products, such as wheat bran and brewer’s spent grain. In this article, we provide an overview of by-products that have been used in mealworm feeding trials. We quantify commonly available by-product types in Austria, and discuss potentials and limitations associated with mealworm farming. We found that further research is needed to better understand the strengths of mealworms in circular food systems, and several hurdles need to be addressed so that mealworm farming becomes more attractive in Western countries. ABSTRACT: Future food systems must provide more food produced on less land with fewer greenhouse gas emissions if the goal is to keep planetary boundaries within safe zones. The valorisation of agricultural and industrial by-products by insects is an increasingly investigated strategy, because it can help to address resource scarcities and related environmental issues. Thus, insects for food and feed have gained increasing attention as a sustainable protein production strategy in circular food systems lately. In this article, we provide an overview on by-products, which have already been fed to T. molitor (mealworms), a common edible insect species. In addition, we investigate other by-products in Austria, which can be suitable substrates for T. molitor farming. We also provide an overview and discuss different perspectives on T. molitor and link it with the circular economy concept. We identify several future research fields, such as more comprehensive feeding trials with other by-products, feeding trials with mealworms over several generations, and the development of a standardized framework for insect rearing trials. In addition, we argue that due to their ability to convert organic by-products from agricultural and industrial processes into biomass in an efficient way, T. molitor can contribute towards resource-efficient and circular food and feed production. However, several hurdles, such as legal frameworks, need to be adapted, and further research is needed to fully reap the benefits of mealworm farming.