Insect Biomass to Enhance Food Production
Special Report - 01/09/15
Juan A. Morales-Ramos, M. Guadalupe Rojas, and Michael J. Grodowitz
USDA-Agricultural Research Service, National Biological Control Laboratory, Stoneville, MS, USA.
In the coming decades, there will be increasing problems producing enough food for the blossoming world population. This is exasperated by a loss in agricultural lands due to increased urbanization and environmental degradation resulting from erosion and other factors. To sustain food production at its current levels is challenging enough, but production must be increased yearly to meet the needs of an increasing human population. If productive agricultural areas cannot be added, then a possible solution is to increase the productive efficiency of existing land. This can be accomplished by converting agricultural waste products into food. Insects can consume such low value products converting them into valuable biomass to serve as a source of animal protein. During the past decades growing interest in using insects as a source of food and feed has resulted in the development of insect farming as an important and growing industry.
The value of insects as a protein source for animal feed is well recognized. Horse flies, soldier flies, mealworms, silkworms, and crickets have been used successfully to feed a variety of poultry species. Insects have also been considered for cultured fish like tilapia, catfish, and trout. Current sources of protein for animal feed originates mostly from fishing refuse, and is considered unsustainable due to current commercial fishing practices. Insect protein could provide a more sustainable alternative, however, current insect production levels are insufficient to provide protein for the poultry and aquaculture industries.
Substantial advances in insect production technology are required to supply the required volumes of insect biomass. Mass-rearing insect technology has been developed for other purposes in the past. For example, sterile insect release technology has been used to control important pests including the screw worm, the Mediterranean, Oriental, and Mexican fruit flies, and the pink boll worm, among others. The application of sterile male release technology requires the development of advanced insect production technologies at affordable costs. Insect production technology has also been developed to mass produce insect natural enemies for biological control of insect pests. These mass-rearing strategies can easily be adapted to produce large numbers of insects for food and feed.
In the U.S. Department of Agriculture, Agricultural research service, National Biological Control Laboratory (NBCL) a team of scientists are working, in cooperation with industry, to apply insect mass rearing technologies to increase the production capabilities of mealworms and crickets. On-going research is focusing on increasing the knowledge of the biology and behavior of farmed insects. Growing insects in high densities saves space, but crowding can have a detrimental impact on the productivity and food conversion efficiency of insects. One of the research objectives focuses on determining optimal densities to maximize insect productivity and minimize space requirements. Other important lines of research include determining the impact of environmental factors and age on grow rate and productivity. Converting agricultural by-products into an effective insect diet is one of the most important research avenues being pursued. Knowledge on the nutritional content of agricultural by-products is limited especially in terms of its suitability as insect food. Scientists and engineers at the NBCL have also developed new and novel methods to mechanize the critical tasks of insect mass production. Methods of separation of mealworm larvae by size have been patented and new methods of cricket separation and packaging are in development. To be able to increase insect production from a few hundred kilograms to millions of tones, production procedures must be changed radically through the development of new insect rearing technology.
Insects not only are a good source for animal feed, but can also be a highly nutritious source of food for human consumption. Insects have been used as food for millennia and today in many cultures are an acceptable source of food. In countries like China, Japan, Thailand, India, Mexico, Brazil, Colombia and many African Countries, insects can be found on restaurant menus and purchased in market places. It is estimated that more than 900 insect species are used as food around the world including several species of grasshoppers, crickets, caterpillars, beetle grubs, termites, ants, bees, wasps, and true bugs. Persisting cultural issues have limited the use of insects as food in Western countries, but in recent years, attitudes have been changing.
Many studies have been accomplished to determine the nutritional value of insect species. These studies have established that insects are an excellent source of protein in comparison to conventional animal food (between 15 and 67% dry weight content). Insects also contain essential amino acids and fatty acids. Insect fat has a higher content of polyunsaturated (essential) fatty acids and a lower content of saturated fat than beef and pork. Omega-3 fatty acid content in some grasshopper species is comparable to that present in salmon and tuna. The content of iron and calcium in insects is higher than what is found in beef, pork, and poultry. In countries where animal protein is scarce, nutritional deficiencies of essential amino acids like lysine, leucine, tryptophan, and threonine and B vitamins could be alleviated by consuming insect-based food products. Insect farming requires less resources than cattle production or any other livestock farming. Insects can be mass-produced in less space and require decreased water than conventional farm animals. Also, insects grow fast and their life cycle is shorter.
Despite all the advantages, most insects consumed around the world are not mass produced, but instead they are harvested from the wild. Naturally grown Insects, as any other natural resource, are limited by the productivity of the environment and their availability is seasonal. In order to take advantage of insects as a consistent year-round source of food, technologies must be developed to mass-produce new insect species suitable for human consumption. Insects as food and feed have tremendous potential to generate new industries and revenue while helping to solve problems of food production and malnutrition around the world. Focusing on the technology and strategies to produce and utilize insects may lead to better ways to sustain the growing world population.