Mealworm Farming: A Sustainable Solution for Protein Production in the 21st Century

Entering the 21st century, global agriculture is facing severe challenges due to population growth, resource scarcity, environmental degradation, and frequent natural disasters. How to utilize limited resources to meet the growing food demand, ensure food supply, food safety, and ecological security, and achieve sustainable agriculture are crucial issues for human survival and development. Entomologists and nutritionists predict that insects will become a primary source of food in the future. In 1978, American entomologist Atkins wrote in “The Outlook on Insects,” “Managing insects as a renewable food resource could become the next major development in entomology… The biomass of insects may surpass the biomass of all land animals. We are, in fact, surrounded by high-quality insect proteins and fats. More research is needed to find effective methods for managing and harvesting this untapped resource, but as the world’s population continues to grow and high-quality protein becomes scarcer, humans may have to turn to insects as a solution to the food crisis.” A burgeoning field of entomophagy is taking shape, and the farming and industrialization of mealworms align with this direction. Mealworm farming offers unique and multifaceted advantages not found in other livestock industries.

1.Extremely Water-Efficient Farming

In 2006, a report by the World Wide Fund for Nature highlighted the global water scarcity issue. Freshwater resources are critically scarce in China, with per capita water resources only one-third of the global average. Water scarcity is not just an issue of sustainability but also a matter of survival. As the economy rapidly develops, the demand for water resources will intensify. Frank R. LaSorte, the director of the International Water Resources Management Institute, believes that agricultural water usage already exceeds 74% of global water consumption and calls for more efficient water use in food production. Developing water-efficient livestock farming is crucial for modern agriculture, as factory farming and animal slaughter require significant amounts of water—10 m³ per 1 kg of meat production. In contrast, mealworm farming doesn’t require drinking water or washwater, making it highly water-efficient. In regions with water scarcity, mealworm farming can thrive even when other livestock industries struggle.

2.Environmentally Friendly Farming

Conventional large-scale livestock farming, often concentrated in suburban areas, generates massive amounts of animal waste that can be challenging to manage and leads to serious environmental pollution. In contrast, mealworm excrement is dry, odorless, and doesn’t require extensive waste treatment, making it a clean and environmentally friendly form of livestock farming. Developing clean production methods that control pollution at the source is essential. In the future, high-pollution livestock farming will face increasingly strict restrictions, while clean and eco-friendly livestock farming like mealworm farming will receive strong support. The Worldwatch Institute’s “State of the World” report in 2006 called for a reconsideration of global meat production. Mealworm production aligns well with the demand for healthier and more environmentally sustainable meat products.

3.A Novel Approach to Animal Protein Production

Efficiently meeting the growing demand for meat involves improving the conversion of grain into animal protein. The efficiency of this conversion varies among livestock. Cattle, for example, require approximately 7 kg of feed for every 1 kg of meat produced, whereas poultry only require 2 kg, and fish even less. Insects, while having a lower assimilation rate (the amount of food converted into body mass) compared to mammals, have a significantly higher production efficiency. They are more effective at converting primary production into secondary production. Insects typically have similar efficiency in converting food into body mass as chickens, with a feed conversion ratio of 1:3 to 1:3.5. Mealworms are among the insects with high food conversion rates and are easy to rear.

4.Low-Effort Farming

Miniature livestock, due to their small space requirements and ease of management, are being actively bred. However, transforming existing livestock into miniature breeds is challenging. True miniature livestock are insects, as proposed by American entomologist DeFoliartyi, who suggested using edible insects as small livestock. Collecting insects from the wild is not practical, so domestication is the correct path for sustainable insect resource utilization. Mealworms are small in size, originally considered warehouse pests, but utilizing them as edible insects exemplifies turning a pest into a resource. As urbanization accelerates and rural labor forces migrate, labor shortages are becoming evident. Mealworm farming requires minimal labor and can be done by women and the elderly. The equipment needed for mealworm farming is simple, including production facilities, feeding trays, and sieves, resulting in minimal energy consumption and cost. Mealworms can be raised indoors year-round, unaffected by natural disasters, and their management doesn’t require daily attention, allowing farmers to engage in other activities and increase labor productivity. Mealworms are highly adaptable and can be farmed nationwide, making use of vacant warehouses and homes without occupying farmland. Mealworm farming can be conducted in a multi-level manner, saving space and land.

5.Efficient Protein Production Technology

With urbanization and improved diets, the demand for animal protein continues to rise. Outbreaks of diseases like mad cow disease and foot-and-mouth disease, contamination of meat and bone meal, and a decline in high-quality fishmeal production and exports have led to a pressing need for new sources of animal protein. Mealworm farming undoubtedly plays a crucial role in urban entomology, resource entomology, and edible entomology. About 90% of mealworm tissues can be used as feed or food, generating minimal waste. Mealworms have high protein and fat content, up to 80% (compared to around 76% in other insect orders), making them excellent livestock. They can be used for animal protein production as well as direct animal feed, providing healthy food for humans. In terms of nutrition, mealworms have a protein content of 48%, including 17 amino acids, 7 of which are essential for humans. The ratios of essential amino acids to total amino acids and essential amino acids to non-essential amino acids meet FAO-recommended ideal protein models, making mealworms an ideal source of human dietary protein. Their fat content is 28%, superior to that of poultry, with lower cholesterol levels than most animal products. They also have a high ratio of unsaturated to saturated fatty acids (2.8:1), exceeding the general recommendation of 2:1, and are rich in vitamin E and riboflavin, making them a valuable source of edible fat. Mealworms contain abundant minerals and trace elements, with a strong enrichment effect on essential trace elements such as zinc, selenium, and iodine, which have important physiological functions. They can be used to develop zinc, selenium, and iodine-enriched functional foods. Both mealworm adults and larvae thrive in group settings, allowing for high-density farming and resulting in high yields compared to grain and oilseed production. For instance, using soybeans with a high plant protein content, 200 kg/667m² is considered a high yield. Assuming a 40% protein content in soybeans, this results in 80 kg of plant protein per 667m². Recent research at Shandong Agricultural University’s Insect Research Institute, using an indoor breeding room with an area of 125m² and a height of 3m, achieved production ranging from 7,500 to 11,250 kg in a single batch, equivalent to 60 to 90 kg/m² of fresh mealworms. This translates to 13,330 to 20,000 kg/m² of dried weight, with a protein content of 48%, resulting in 6,400 to 9,600 kg of protein per 667m². This is 80 to 120 times the protein yield of soybean cultivation. These results are based on average production levels and a single season, but with year-round, factory-scale production, the annual output can increase three to fourfold. Mealworm farming will open up new pathways for animal protein production. Europe has already recognized mealworms as edible insects. In terms of oil production, using oilseed rape with a high oil content as an example, a yield of 200 kg/667m² with a 40% oil content results in 80 kg of vegetable oil per 667m². In contrast, mealworm farming on the same area can yield 3,700 to 5,600 kg of animal fat per 667m², assuming a 28% fat content. This represents 46 to 70 times the oil yield of oilseed rape.

6.A Leading Candidate Among Resource Insects

Currently, insects such as fly larvae and mealworms are used for protein production. Mealworms, with their unique biological characteristics, stand out among resource insects. In warehouses, mealworms are among the largest pests and exhibit strong resistance to both high and low temperatures, especially drought. They can endure long periods of hunger; mealworm larvae can go without food for over six months. Their diet is incredibly versatile, and they have a high feed conversion rate (over 30%). They are scavengers that can utilize non-food resources and waste, especially various organic waste materials. Mealworm farming is a low-effort endeavor, offering benefits such as high-quality organic fertilizer with no odor, fine granules, and ease of use for gardening. Mealworm excrement is rich in nutrients and biologically active substances, making it suitable for use as a feed additive. Mealworms are averse to light and do not require illumination during farming, saving energy. They cannot fly or escape, ensuring they do not harm the natural environment.

7.The Preferred Species for Animal Factories

Currently, mealworms are primarily raised in heated buildings, but the yield is already enticing. With the potential for large-scale production according to plans and market demand, land productivity and yield per unit area can be significantly increased. Mealworms possess various characteristics that make them the ideal species for insect factory production. Developed countries have made beneficial explorations in plant factories, but research on animal factories lags behind. It can be affirmed that insect factories require far less facility investment than plant factories, and the biological yield and production efficiency of mealworms in insect factories will far exceed those of other livestock species. Currently, there are no insect factories in China, and research in this area is urgently needed.

8.Mature Mealworm Farming Technology

Mealworm farming has a history of over 100 years and has been used as feed for animals in zoos both domestically and abroad. Mealworms have a wide range of applications and have accumulated mature farming experience while continuously innovating. Mealworms undergo complete metamorphosis, with four stages: eggs, larvae, pupae, and adults. Traditional farming involved mixed rearing of these stages, but this led to significant mortality due to cannibalism, resulting in up to a 60% death rate and reduced yields. Separate rearing has become the mainstream technology in modern mealworm farming, but it still relies heavily on manual operations, posing various challenges. In the 1950s, Beijing Zoo imported mealworm farming from the former Soviet Union, gradually expanding its scale in the 1970s. Since the 1980s, Shaanxi Grain School pioneered mealworm farming research in China. In recent years, Shandong Agricultural University’s research on mealworms has taken the industry to a new level. The success of factory-scale mealworm farming technology provides a solid foundation for large-scale production. Recent research has revealed significant potential for mealworm farming, particularly in increasing egg production and raising stocking densities, which will further improve its farming efficiency. In conclusion, mealworm farming offers unique and multifaceted advantages, promising a bright future. Emerging industries represent a shift from traditional sectors, and mealworm farming will not only become a burgeoning field within the insect-rearing industry but also a rising star in large-scale agriculture. Currently, there are more than 50 insect-rearing enterprises of a certain scale nationwide, and in Taian City, Shandong Province, over 5,000 farming households are involved in insect farming. It is of great theoretical and practical significance to vigorously conduct research on mealworms and accelerate their industrialization.