Introduction

Insects are an often-overlooked food and feed source. In many areas of the world, they have been eaten for centuries. In 1885, Vincent M. Holt wrote a document called “Why Not Eat Insects?” in which he described historical instances of people who ate insects and considered them a great delicacy. Worldwide, more than 1900 insect species have been used as food (van Huis et al. 2013). Of these, beetles (mostly larvae) make up 31%; caterpillars of butterflies and moths make up 18%; larvae and pupae of bees, wasps, and ants make up 14%; and grasshoppers, locusts and crickets make up 13% (van Huis et al. 2013).

Where insects are not typically viewed as a food source, people often have an internal aversion to eating them. Even so, we all do eat insects, though often unknowingly. Insects are found in small amounts in dry goods like beans and grains, and in food products such as peanut butter. In the USA, the FDA allows a certain number of insect parts in various commodities--for example, peanut butter is allowed an “average of 30 or more insect fragments per 100 grams.” In this case, legislation exists to limit the number of insect parts. 

What about eating insects on purpose? Insects make sense as a food and feed source for many reasons. First, there is huge precedence already. Insects have been eaten for thousands of years (examples are given by Holt 1885), and more than two billion people currently incorporate insects into their diets (van Huis et al. 2013; Figure 1). 

Second, insects are very nutritious—high in protein, fat, fiber, vitamins and minerals. Nutrient content of insects varies between species and within a species depending on metamorphic stage; it also depends on what insects are fed. But Rumpold and Schlüter (2013) compiled nutritional information for many species of edible insects and concluded, “Although the data were subject to a large variation, it could be concluded that many edible insects provide satisfactorily with energy and protein, meet amino acid requirements for humans, are high in MUFA [monounsaturated fatty acids] and/or PUFA [polyunsaturated fatty acids], and rich in several micronutrients such as copper, iron, magnesium, manganese, phosphorous, selenium, and zinc as well as riboflavin, pantothenic acid, biotin, and in some cases folic acid.” According to Yhoung-Aree et al. (1997), the protein content of insects ranges from 7 to 21 grams per 100 grams edible portion. This compares well to that of eggs (14 g/100 g; approximately two large eggs) or meat (18-20 g/100 g). Insects are nutritious enough that a team of researchers in Kenya is using grasshoppers and locusts, ground together with malted finger millet, to produce nutritious baby food that will combat malnutrition (Oniang'o 2017).

Third, eating insects makes sense from an environmental point of view. Insects have a high feed conversion efficiency, meaning that a high proportion of the feed and water they are fed is converted into edible matter. According to Marcel Dicke (2010), 10 kg of feed translates to 9 kg of harvestable locusts. By contrast, feed conversion efficiencies for animals range from 5 kg edible matter per 10 kg feed (chickens) to 1 kg edible matter per 10 kg feed (cows). An FAO web page shares slightly different but still encouraging statistics: “Insects have a high food conversion rate, e.g. crickets need six times less feed than cattle, four times less than sheep, and twice less than pigs and broiler chickens to produce the same amount of protein. Besides, they emit fewer greenhouse gases and less ammonia than conventional livestock. Insects can be grown on organic waste. Therefore, insects are a potential source for conventional production (mini-livestock) of protein, either for direct human consumption or indirectly in recomposed foods (with extracted protein from insects); and as a protein source into feedstock mixtures.” 

It is best not to assume that such high efficiency is possible in every case. In an article titled “Crickets are not a free lunch,” authors Lundy and Parrella (2015) point out that crickets’ growth and even viability depends on the quality of their diet, especially at an industrial scale. Still, a company called Agriprotein, raising black soldier fly larvae as a protein source for animal food, harvests six and a half tons of MagMeal (ground and dried larvae) from 100 tons of organic waste (Thomas 2017a). Considering that the six and a half tons are dry weight and that the company sources the organic food waste for free, it is a pretty good ratio.

Fourth, insects need very little space, so they can be raised even by those with little access to land. Many insects thrive in close quarters. And finally, raising insects has potential to be an income-generating endeavor (Figure 2).

This article will give a brief overview of insects for food and for feed. It will describe ways to obtain and prepare insects, and will outline some of the challenges that exist when it comes to eating insects.

Insects for Food

Insects are an excellent food source for humans, as previously mentioned. However, most people in Western countries are unused to eating insects. Because of their internal aversion to it, eating insects is sometimes communicated or viewed as a disgusting practice or “last resort.”

Even the terminology we use affects the impression we give about the desirability of eating insects. "Entomophagy" is the term most commonly used for the practice of eating insects. Evans et al. (2015) explain why this is problematic. They point out, for example, that other terms ending in “phagy” refer to animal-like, “inappropriate or even pathological behaviors” (e.g. hyalophagy—eating glass).

Also, the term "insects" is used to mean different things. It has a taxonomical definition (see the text box), but people sometimes also use it—or the term "bugs"—to refer to other small, edible creatures, including spiders, scorpions, centipedes, and earthworms. Some people only use the term "insects" to refer to pest species; for this reason, it can be helpful to distinguish between "insects" and "edible insects."

Evans et al. (2015) point out that “food taboos are complicated.” People groups have their own preferences and aversions to different kinds of insects. "Insect" is a general category, but in order for insects to be embraced as food, people need familiarity with specific types of insects. Instead of speaking of the broad category of "insects," it can be helpful to speak of individual species and preparations. For example, try to use names from the local culture where possible (e.g. grasshoppers called chapulines in Mexico). Alternatively, rename insects to make them sound more appealing; for example, Marcel Dicke has referred to grasshoppers as “land shrimp” (Dicke 2010).

An overview of some traditionally eaten insects around the world can be found on pages 15 to 20 of the FAO document “Edible Insects: Future prospects for food and feed security" (Van Huis et al. 2013).

Insects for Feed

Insects can be an excellent protein source for animal feed. They need no processing to be fed to chickens or to fish; free-range chickens peck and eat insects naturally. Meal made from insects can be used in feed rations for pigs and cows, replacing expensive protein-rich ingredients such as fishmeal or soybean. In a podcast episode, Elsje Pieterse from the University of Stellenbosch explained why soy and fishmeal are problematic. Production of soy is linked with deforestation and loss of plant diversity, while fishmeal is made from small fish that are important in oceanic food chains and are in danger of being overharvested (Thomas 2017b). 

Larvae of the black solder fly (Hermetia illucens) are a popular protein source for animal feed. Ian Banks, working in research and development with Agriprotein, shared several characteristics that make black soldier fly larvae good candidates for mass-rearing (Thomas 2017a). The larvae are omnivorous, able to eat both meat and vegetable waste. They also grow quickly, reaching 2 cm in less than two weeks, and have less of a “disgust factor” than do the maggots of houseflies. Adult flies do not spread disease like houseflies do.

As mentioned in the introduction to this article, BSF larvae are being farmed on an industrial scale, by Agriprotein and other companies. Two episodes of the BBC Food Chain podcast (hosted by E. Thomas) describe Agriprotein’s basic farming process. The BSF larvae are fed food waste such as vegetable and fruit peelings. Once the larvae consume the food waste, the residue can be used as compost. For their part, the larvae in the form of MagMeal are an excellent source of protein for animal feed. Nutrition Hub, a consultant company running tests at the University of Stellenbosch, has compared the health and growth performance of fish that are fed fishmeal and fish that are fed a mixture of fishmeal and MagMeal. When up to 50% of fishmeal in their feed was replaced with MagMeal, farmed trout experienced no negative effects on growth (though growth was reduced with 100% replacement of fishmeal) (Thomas 2017b).

Though larvae at Agriprotein are fed on fruit and vegetable waste, BSF larvae have also been found to grow well on pig liver and pig manure (Nguyen et al. 2015). Still, food waste is the most logical thing to feed to black soldier fly larvae. Jason Drew, cofounder of Agriprotein, commented that where there are people, there is food waste. His company is expanding to a number of other countries. In a podcast interview, he stated, “We have many more customers than we could ever supply.” (Thomas 2017b).

Information on smaller-scale methods for rearing black soldier fly larvae can be found online, for example at the Black Soldier Fly Farming website and at Black Soldier Fly Blog. 

Black soldier fly and several other insects have their own section on the Feedipedia website (an “animal feed resources information system”).

Research on the use of insects for feed is also being led by ICIPE (The International Centre of Insect Physiology and Ecology. Programs by ICIPE include INSFEED (“Insect feed for poultry and fish production in sub Saharan Africa”); GREEiNSECT (“Mass-rearing insects for greener protein supply”) and ILIPA (“Improving livelihood by increasing livestock production in Africa”; this one is focussed mainly on the black soldier fly). Some of the work being done in Kenya through this program is described in an article in Spore Issue 184: “…the INSFEED project has trained more than 75 farmers and young agripreneurs in insect mass rearing using sustainable, accessible and cost-effective techniques, such as harvesting the locally abundant blue Calliphora fly.”

Ways to Obtain Insects

Insects are typically obtained in three main ways. 

First, they can be wild-caught. Sometimes traps are set up overnight, to be checked in the morning. Alternatively, insects can be collected in the early morning, when temperatures tend to be cool and insects are sluggish and slow. At certain times of year, insects are plentiful and easy to catch. This is true, for example, where the winged reproductives of termites emerge en masse once a year in parts of Africa, or when flying ants called “chicatanas” swarm through the air in Mexico. But be careful--if insects have been in or near farmers’ fields, they may have been sprayed with insecticides!! Even if you do not use chemicals on your farm or project site, do not assume that the insects found there are safe; insects, especially those that fly, may have encountered pesticides elsewhere.

Second, insects can be farmed on a large, industrial scale. This is risky and requires significant investment, but is being done successfully by companies like Agriprotein.

Third, insects can be "farmed" on a small, backyard scale. This can be done with local technology as a low-capital investment. Insects can be grown in a very small space with few resources; however, raising them requires a relatively high level of knowledge about the species’ life cycle, diet and habitat needs. A literature review by Gahukar (2011) includes references to papers that describe rearing techniques for palm weevils (see Figure 3), silkworms (in India and Thailand; see Figure 4), giant hornets (Japan), crickets (Thailand), and more.

Species that people commonly raise themselves include:

Mealworms

A series of videos at www.mealflour.org/diy explains how to make a small three-tiered mealworm farm. Instead of a plastic organizer (as is used in the videos), wooden boxes could be used. The top box houses adult beetles. Mesh in the bottom of the top box (tightly sealed where the mesh joins the box) allows eggs to fall through to the next level. Small worms are transferred to the bottom box. They are harvested when they reach a certain size (Figure 5), or else allowed to pupate and placed in the top box to continue the cycle. Instructions for raising mealworms are also found in the Food Insects Newsletter, Volume 9 Issue 1. Mealworms would need to be found or bought initially. Check if they can be ordered online, or check at a local pet supply store.

Crickets

An article from Popular Science describes a basic way to raise crickets. Another helpful document is at this site from the FAO. To obtain crickets initially, ask around if people are already raising them and might sell you some, or buy some at a pet store.

Black Soldier Flies

Sources of information for raising black soldier flies were shared in the section on insects for feed. BSF in the larval stage are sometimes referred to as “latrine larvae,” since they are often found around manure piles (van Huis et al. 2013)—so they could potentially be sourced that way if not available commercially.

Preparing Insects

Though some are eaten raw, most insects used for food are cooked and/or dried. Insects can be sautéed with garlic and salt, baked or roasted in an oiled pan until golden and crispy, or battered and fried. Roasted crickets or mealworms are sometimes ground, then added to sauces or baked goods. Table 1 lists a few relatively common edible insects, with some information about collecting and preparing them. But the table only names a few of the many insects that are edible; Mr. Yde Jongema has compiled an extensive list of edible insects of the world, available online. As a general rule of thumb, Holt recommended collecting insects that eat non-poisonous plants, and avoiding insects that are carnivorous and/or eat poisonous plants. 

Yhoung-Aree et al. (1997) described when and how various insects are collected and eaten in Thailand, including details about specific preparation methods. They comment that in rural communities in Thailand, insects are often cooked as main dishes, eaten with rice; in urban areas, where insect-eating is less common, insects are eaten more as snack foods. 

Challenges

In a TEDx talk, Arnold van Huis shared his excitement over the potential of insects for food but also pointed out some challenges. For example, little legislation exists around insects. Though most insects are safe to eat, pesticides can be a concern with wild-caught insects. Also, for insects raised specifically for food, one hopes for at least a base level of sanitation and standards, but no official rules or guidelines currently exist. 

In an NPR interview, Robert Allen described the advocacy role of his organization (educational non-profit Little Herds) as, “pushing both businesses and regulatory agencies to adhere to the highest standards when creating the rules and laws of this new sector.” He added, “We believe insects can and should be raised and harvested hygienically, organically, antibiotic and hormone free, humanely and at least in part locally. If we set the bar high now, we don’t risk following in the footsteps of the factory farming that we now realize has serious negative side effects.”

Food safety is not the only concern. When it comes to harvesting insects in the wild, forest management and insect conservation are linked. Measures to preserve edible insects must include efforts to maintain forest cover and manage host plants of edible insects. This may require community efforts and also government incentives for conservation (Gahukar 2011). 

Potential economic development is also a consideration, and one that can be at odds with regulations. Government involvement in setting regulations is important in multiple sectors, including food safety and conservation. However, Halloran et al. (2015) point out that, “Formalization through regulation can threaten local, informal economy. On the other hand, informal economy provides employment and income, especially in areas of high unemployment.” 

Some existing regulations limit the use of insects for food and feed. In the European Union, regulations on animal feed ingredients (because of concerns related to bovine spongiform encephalopathy (BSE), also known as “mad cow disease”) have prohibited the use of animal protein, including insect protein (Stout, 2016). However, in the summer of 2017, the European Commission relaxed its rules on insect protein, approving it for use in aquaculture (Thomas 2017b). 
Cost can be a challenge for those looking to purchase insects. In most places, farm-raised insects are not very common, especially insects raised for food, and their price may reflect that. Where I live in Canada, two small 227 g bags of insects, one of crickets and one of mealworms, would have cost me $60 with shipping. By contrast, 454 g of ground beef at a local grocery store would cost around $5. Cost is less of an issue if you raise your own insects in a small-scale, locally appropriate backyard situation. 

Another concern is that individuals who  are allergic to or react to shellfish might also be allergic to insects, because of shared allergenic substances including a protein called tropomyosin (Palmer 2016). Rumpold and Schlüter (2013) commented, “Liabilities of entomophagy include the possible content of allergenic and toxic substances as well as antinutrients and the presence of pathogens.” Allergies can also develop with exposure; Phillips and Burkholder (1995) commented that "[contact with] insects and related arthropods pose a very real occupational health threat to workers repeatedly exposed to them." Health concerns are summarized in an issue of The Food Insects Newsletter. 

Conclusion

Insects have tremendous potential as a food and feed source. Small-scale farmers can collect insects in the wild, or raise them inexpensively on-site with local technology. Insects are incredibly diverse and can be a delicious way to improve nutrition. Are insects currently eaten and enjoyed in your community? If you have experience using insects for food and/or feed, we would love to hear from you!

References

Dicke, M. 2010. Why not eat insects? TED Talk.

Evans, J., M.H. Alemu, R. Flore, M.B. Frøst, A. Halloran, A.B. Jensen, G. Maciel-Vergara, V.B. Meyer-Rochow, C. Münke-Svendsen, S.B. Olsen, C. Payne, N. Roos, P. Rozin, H.S.G. Tan, A. van Huis, P. Vantomme and J. Eilenberg. 2015. ‘Entomophagy’: an evolving terminology in need of review. Journal of Insects as Food and Feed 1(4): 293-305. Wageningen Academic Publishers.

Van Huis, A., J. Van Itterbeeck, H. Klunder, E. Mertens, A. Halloran, G. Muir and P. Vantomme. 2013. Edible insects: Future prospects for food and feed security. FAO Forestry Paper 171.

Gahukar, R.T. 2011. Entomophagy and human food security. International Journal of Tropical Insect Science 31(3):129-144.

Halloran, A., Vantomme, P., Hanboonsong, Y., and Ekesi, S., 2015. Regulating edible insects: the challenge of addressing food security, nature conservation, and the erosion of traditional food culture. Food Security 7: 739-746.

Holt, V.M. 1885. Why Not Eat Insects?

Lundy M.E. and M.P. Parrella. 2015. Crickets Are Not a Free Lunch: Protein Capture from Scalable Organic Side-Streams via High-Density Populations of Acheta domesticus. PLoS ONE 10(4): e0118785. doi:10.1371/journal.pone.0118785

Nguyen, T.T.X., J.K. Tomberlin, and S. Vanlaerhoven. 2015. Ability of Black Soldier Fly (Diptera: Stratiomyidae) Larvae to Recycle Food Waste. Environmental Entomology 44(2): 406-410.

Oniang'o, M. 2017. Grasshoppers and locusts for protein-rich baby food? Africa.com; also republished on Agrilinks.org.

Palmer, L. 2016. Edible insects as a source of food allergens. M.Sc. thesis, University of Nebraska.

Phillips, J. and W. Burkholder. 1995. Allergies Related to Food Insect Production and Consumption. The Food Insects Newsletter. Volume 8, Issue 2. USDA-ARS Stored Product Insects Research Laboratory. Department of Entomology. University of Wisconsin-Madison.

Reeve, S. 2017. Nutrient rich fish and poultry feed. Spore 184.

Rumpold, B.A. and O.K. Schlüter. 2013. Nutritional composition and safety aspects of edible insects. Molecular Nutrition & Food Research 57(5):802–823.

Stout, J. 2016. Insects as food is one thing—but how about insects as feed? Blog post on www.bugsfeed.com.

Thomas, E. 2017a. Maggot Masters. The Food Chain Podcast. BBC World Service. September 20, 2017.

Thomas, E. 2017b. A Fly Future? The Food Chain Podcast. BBC World Service. September 27, 2017

Yhoung-Aree, J., P. Puwastien and G.A. Attig. 1997. Edible insects in Thailand: an unconventional protein source? Ecology of Food and Nutrition 36:133-149.

Other Resources

Bugs Documentary

This looks like a fabulous documentary! Unfortunately, it was not available for viewing in North America when I was working on this article. In a review of the documentary, Barbara King wrote:

“Chef Ben Reade and food researcher Josh Evans of the Nordic Food Lab in Copenhagen travel the world, from Uganda to Italy and Japan to Australia, sampling local insects. They become excited (ecstatic, even) over the array of delicious protein choices out there, ranging from roasted termite queens to the honey of stingless bees.

“But they also push back hard against any simple notion that "insects can save the world." They become especially jaded by schemes to turn insect products into food brands that will mostly serve to line the pockets of big corporations. For Reade and Evans, the key to environmentally healthy eating isn't mass-produced insects; it's diversity in growing and eating good, locally sustainable foods.”

More on BSF for animal feed

This links to a short video about another company raising black soldier fly larvae, with footage of the flies, larvae, and resulting meal.