Eat Ze Bugs: Insects as Food

Insect Farming as an Alternative Source of Proteins

Asian Honey Bee brood is fried and sold as street food in the Philippines. Further west, wild Apis mellifera brood comb is consumed alongside honey by indigenous African tribes for protein. Wasps, ants, crickets, beetle larvae… the list goes on. Many insects are edible and have been eaten for thousands of years. The resurgence of this topic is a matter of commercialisation attempts to globally adopt alternative protein via insects.

Currently, insects are available for sale as human food, pet food and livestock feed. This article is an introduction to the topic of insect farming and its current progress. Further articles will expand on the use cases for each species, and their future directions.

What are the Most Commonly Farmed Insects?

As of writing, there are six common commercially-reared edible insect species:

• European honey bee Apis mellifera,
• House cricket Acheta domesticus,
• Domesticated silkworm Bombyx mori,
• Mopane caterpillar Imbrasia belina,
• African palm weevil Rhynchoporus phoenicis and,
• Yellow mealworm Tenebrio molitor.

Farming methods for these species differ from industrial containers (crickets, mealworms) to colonies with deep brood boxes (honey bees). In some species, only the larvae are consumed (Mopane caterpillar, Palm weevil & mealworms) as a source of fats and protein (reviewed in Tang et al., 2019). Adult crickets are consumed, whereas the silkworm pupae is eaten¹. Honey bee brood is eaten in all three stages, along with the pollen, nectar and comb. After all, humans are also honey bee predators, fully harvesting wild colonies for consumption.

Benefits of Insect Farming

You’ll hear plenty of benefits about the benefits of farming insects as food. In my opinion, the process produces additional protein sources alongside our traditional meat and fish. Further, it is “organic” farming: the current production of farmed insects does not require antibiotics, steroids, hormones, pesticides², or other chemicals used in traditional livestock operations.

I consider the above to be the major benefits of insect farming. Others aspects include environmental sustainability, food security, reducing wastes, and blah blah blah. It is to these blah blah blah-isms that we turn to next.

Environmental Sustainability

Heralding insects as “sustainable for the future stems” from a lower land, water and feed requirement. Further, insect farming produces less greenhouse gases when compared to traditional livestock on a per-kilogram basis. Insect droppings, “frass”, are also collected and used as a strong organic fertiliser.

Organic waste is reduced by reuse as insect feedstock. Black soldier flies, grasshoppers and yellow mealworms can consume food scraps, agricultural by-products (shells, seeds etc…), and animal manure (Parodi et al., 2020, Derler et al., 2021 & Acur et al., 2024). These insects convert the otherwise-landfill waste into protein and fat, for use in human or animal consumption.

Vertical Farming

As the name implies, vertical farming is rearing “upwards” in stacked layers, unlike the traditional horizontal farming. This reduces land use requirements, makes it scalable, and introduces optimisation: insect farming can occur in a controlled environment where factors like temperature, humidity, and ventilation can be manipulated for maximum yield. The other upside (pun intended) is a reduced risk of pests and disease, after all – it’s all controlled.

Reducing Food Waste

Insects can be fed organic waste materials, such as food scraps and agricultural by-products. The principle is similar to adding food waste to your compost bin, but instead of turning into garden fertilizer, it raises the next generation of insect protein. Leftover or unwanted food that your spouse brought home can be funneled into the insect farming container, rather than going to landfill.

Nutritional Benefits

In general, insects are high in protein, vitamins, minerals and essential fatty acids (reviewed in van Huis & Oonincx, 2017). A more precise nutritional value and composition is difficult as it varies with insect diet, developmental stage, sex, species, growth environment, and of course, the measurement method of those nutritional profiles.

On Anti-Nutrients

Anti-nutrients are compounds that interfere with the absorption of food and impact the digestive system. They are beneficial in small quantities, such as tannins in teas, or phytic acid in plants. Anti-nutrients deserve their own article, as the insect rearing method determines the levels of anti-nutrients. The rule of thumb is that when insects that are fed a variety plant materials (common for black soldier flies), then they’ll accumulate a variety of anti-nutrients from those plants.

All insects contain the anti-nutrient chitin, the polymer that makes up their exoskeleton. Humans lack chitinase and are unable to digest it, so it passes through the gut as is, potentially causing complications in large amounts over the long term.

Avoiding problems associated with anti-nutrients could be as simple as consuming a varied diet, and perhaps seasonally rotating food sources. Ironic coming from me, as I consume the same items year-round, which could be the same for you too my dear reader. If food rotation is not possible, multiple processing methods can be used to reduce the impacts of anti-nutrients, from cooking (boiling vs frying), fermenting, or enzymatic breakdown of the target compound (e.g. chitinase-secreting bacteria to remove chitin; Liceaga et al., 2021).

Food Security & Job Opportunities

As with any new venture, there is the “XYZ will create new jobs, XYZ will address the current XYZ issue”, and insect farming is no different. Like beekeeping, farming insects has a low-cost entry barrier and is beneficial in developing countries where the resources are not always available.

As insects reproduce quickly and in larger numbers, they can provide relief from food insecurity. Remember the “supply chain issues” of the COVID years? Me neither. Insects were devised as a solution that can be farmed in in urban environments… Would urban beekeepers have to compete with urban insect farmers for rooftop space?

Insects as a Sustainable Protein Source

Insects have a smaller feed conversion ratio than cattle (i.e. require less food per gram of protein produced) and need less space to farm (hence the interest in “vertical farming”). In this regard, house crickets are around four times more efficient than pigs and twelve times better than cattle (reviewed in Skriverik, 2020).

Comparing chickens to mealworms shows that the latter requires a third or half as much land, and half the water usage of chickens to generate one gram of edible protein (Oonincx and De Boer 2012). It will not surprise you to know that beef requires 8-14 times as much land and five times more water than mealworms to generate a single gram of protein.

Another factor is that we generally eat livestock for the meat, while the bones and select organs (eyes, brain) are discarded. In the case of insects, most, if not all, the insect is consumed whether as powder or as a whole, meaning less food waste.

“Circular Economy”

A circular economy is one where resources are used in a closed loop – A makes B, B makes C, C makes A, and the cycle repeats with no external input required. This model contrasts our current “linear economy”, which goes A makes B, B makes C, and only by adding more “A” can you continue the process.

For insects, it is all in efficiency – making valuable products, minimising waste, or even reusing the waste (frass, pupal casing) to produce more valuable product – frass feeds the soil, the soil feeds plants, the plants feed insects, and so forth.

“Waste Valorisation”

Waste valorisation is the process of turning refuse into something useful. A hot topic in mining and manufacturing given the wastes generated, but for our purposes, the wastes generated from insect farming are reused as follows:

• Depending on the food processing method, the extracted fatty acids or proteins are repurposed into feed substrates for aquaculture and livestock industries. The fats extracted from insects can be used in biodiesel production, which can be an alternative to the current usage of edible (and inedible) vegetable oils (Manzano-Agugliaro et al., 2012).

• In addition to the frass mentioned above, the exoskeletons shed from moulting larvae can be used as organic fertilizers. They are alternatives to chemical fertilizers, and are more effectively utilised by soil microorganisms, relative to manures (Amorim et al., 2024).

Insect Farming Disadvantages

Food safety the greatest concern to mass adoption, beyond the anti-nutrients mentioned above. The industry is still young, and many aspects are ill-defined, for example:

• What is the ideal insect rearing diet?

• What percentage of animal feed can be replaced by insects without detrimental effects?

• Which cooking method is most optimal?

• Will any health issues arise if insects are reared on food waste?

The factors listed above need to be defined (and alas, regulated) before insect farms can establish themselves in the market. Limits and requirements will vary between country, with food safety standards having different levels of acceptable pathogen or containment levels – much like pesticides in honey.

Another drawback are the High startup costs with the initial investments for automated, large-scale facilities and energy (heating) expenses. The chances of initial profits are slim, considering that competition is the traditional protein sources of meat, fish and soy.

Public Perception of Eating insects

Good luck convincing the average Joe to ditch cattle for crickets. In Western cultures there is a significant “yuck” factor associated with eating insects or using them as animal feed. Social pressure will also play in, as someone would be shunned if they were found to “eat bugs”. Prolonged educational and marketing efforts are required to make them acceptable, which comes downstream of having proper regulation in place.

Agricultural Impact: Insect Pests as Food

If non-native species are used, there is a risk of these insects escaping and becoming invasive, potentially disrupting local ecosystems. In Africa, insect pests are also considered source of protein, despite causing loss of produce. Aidoo & colleagues suggested that the crop loss could be worth it, considering the superior profile of insect proteins to their plant counterparts (Aidoo et al., 2023). Determining which pests are consumable and at what stage could lead to the emergence of an eco-friendly biological control strategy.

Operational Issues: Ensuring Consistency in Producing High Quality Protein

As with any form of farming, insects are susceptible to pests and disease which can impair entire containers (“colonies”). Mealworms are prone to densovirus infections (Armien et al., 2023), whereas other diseases may arise under mass-rearing conditions in black solider fly larvae (Jensen & Lecocq, 2023).

Once diseases are accounted for, then comes the issue of optimisation to meet regulatory standards. We know how to farm crickets and mealworms, but can we control the process to consistently produce high quality produce, generation after generation? After all, you have to deliver what you promise on the nutritional label, and sustained high volume production demands precise control over temperature, humidity, and feed quality, amongst other conditions.

High Energy Consumption to Maintain Ideal Temperatures

The energy use of insect production systems is high compared to traditional farming. Insects are poikilothermic (“cold blooded). – their internal body temperature is highly dependent on external ambient temperatures. The upside is that feed provided to insects is dedicated to growth, rather than for maintaining a constant body temperature as that is taken care of.

One may wonder if the tropics will become the future of insect farming, since these areas are warm and humid 365 days a year.

How Insects are Processed for Eating

Traditional methods of eating insects involve the usual boiling, roasting, frying or sun drying. Heat treatment is ideal for removing pathogenic bacteria in mealworms and crickets (Kroncke et al., 2018), which is no different to heating chicken to kill the Salmonella bacteria within it.

Other methods like deep frying, freezing and powdering were evaluated by Grabowski and Klein, who showed that dried and seasoned crickets had higher microbial counts than those that were cooked or deep fried (Grabowski & Klein, 2017). Heat treatment increases the bioavailability of proteins and subsequent protein per gram of insect, while also decreasing or eliminating pathogens.

Insects processed into powders can be added to wheat flour to increase its protein content. In the case of bread formulation, a 10% roasted speckled cockroach (Nauphoeta cinerea) powder mix was found to be most similar to the whole wheat control bread, and a better nutritional composition: higher protein (22.6% vs 9.7%) and fiber (2.3% vs 2.0%). It had an “acceptability index” of 75%, in which, on average, three-quarters of the participants deemed it acceptable for consumption. Yum (de Oliveira et al., 2017).

Market Acceptance and Challenges of Insect Foods

The simple solution? Have them turned into powders or flours, blended into other foods like pasta and protein bars.

Edible Insects as Disease Vectors

So far, there do not appear to be reports of diseases directly arising from commerically-reared insect consumption. This will not always be the case, as the sector grows and more people are introduced to insects as a food. We know that house flies (Musca domestica) can carry diseases of humans and livestock. Perhaps if they are incorrectly prepared and later consumed, diseases arise, such as orf virus infections that cause ecthyma in sheep and goats (Raele et al., 2021).

In mealworms and crickets, Vandeweyer & colleagues found moderate levels of Bacillus cereus spores, a bacterial strain known to cause food poisoning (Vandeweyer et al., 2020). Remember the lack of regulations in the farmed insects sector? The absence of regulations means that what is a “relevant threshold” in the laboratory, may not be a “relevant threshold” in edible insects – perhaps these spores are perfectly fine, or harmful – we will not know until more tests are conducted.

Insect Lifecycles and Species-Specific Consumption

While one species of cricket may be safe to consume, another is not. This will take time, due to the diversity of insect species and depth of research required to determine their suitability. Insects contain various pathogens that could be harmful to humans (Anthes, 2014), and produce toxins at specific stages of their development (egg, larvae, pupae, adult) that could further impact human health.

Insects Reared on “Food Waste”

If insects were advertised as being “environmentally friendly” and as part of the circular economy, there could be backlash from the public as they might not accept “insects reared on food waste”. Unfortunate, considering that the farmed insects are decomposer species who thrive on rotten or inedible human food. Further to that, the availability of food waste from suppliers (restaurants, supermarkets…) might be low, irregular, or non-existent. Research is required to determine the most optimal insect rearing diet – perhaps food waste will not make the list?

Allergies & Dietary Factors Hindering Insect Consumption

Allergic reactions have been noted following insect consumption or exposure, namely in silkworms, grasshoppers and crickets, amongst others (reviewed in Liceaga, 2022). Tropomyosin is a protein present in the muscles of in all animals, and triggers prawn (shrimp) and shellfish allergies. Given that crustaceans and insects are both invertebrates, it is likely that the insect tropomyosin protein profile is similar to the shellfishes’, so individuals with a shellfish allergy should avoid eating insects (Pali-Schöll et al., 2019).

Chitinases found in silkworms can trigger an allergic response in susceptible individuals (reviewed in Leoni et al., 2019). Chitinases are normally found in plants, and are split in four classes based on protein length and structure; the discovery a silkworm chitinase was the first one in insects. Perhaps the worms developed this material as an adaptation to their mulberry leaf-rich diet? Or perhaps it was a random mutation that got conserved over time? I am welcome to clarifications.

Is Insect Farming a Solution to the World Problems?

The recent literature and news releases show how “eating bugs” will solve world hunger, manage our depleted resources, and sustain overpopulation. In reality, this is does not single-handedly create a sustainable food system, but rather contributes to creating a more sustainable one. The biggest challenge with making this work in Western countries are the biases against eating insects. Maybe further education and advertising will normalise eating bugs as with other “foreign” foods like sushi or plant-based meats.

Further, the literature rarely mentions accessibility issues associated with buying insects for human consumption. There are a few supermarkets to choose from, and having to buy online creates an extra barrier for new customers. Worse, resorting to purchasing insects from pet or bait shops is problematic, as that stock is not bred under conditions suitable for human consumption.

So for insect-based foods to become successful in the Western market, their price, associations (“yuck!”), tastiness (“yuck!” but in italics), and availability have to be improved. The potential insect livestock to harbor and transmit diseases also needs identification and management, as they can directly and indirectly impact human, animal, and plant health.

You vill eat ze bugs, you vill provide feedback on thiz article, und you vill be happy. Alternatively, (politely) write to me at admin@tgbee.com.au

Footnotes

1. The empty cocoons are the source of silk. When a silkworm pupates, the resulting cocoon can be placed in hot water to extract the pupa, with the subsequent heating softening the silk fibers so that the cocoon can be unwound and the threads reeled together. ↩︎
2. Amusing, considering that some of the species are pests themselves (palm weevil, mopane butterflies) ↩︎