Last week the UN’s Food and Agriculture Organization (FAO) released a two hundred page report (available here) encouraging everyone to take seriously the potential of edible insects to fit into food security programs as a sustainable and economical source of human food and animal feed. The extensive report reviewed cultural practices of entomophagy, discussed current trends in the early stages of industrial development of insect breeding, rearing and processing, and outlined many areas that require further research and development on the path to modern, sustainable and industrial scale use of edible insects.
Following the report, Business Insider published an article featuring Professor Tom Turpin of Purdue University (http://www.businessinsider.com/insect-eating-wont-solve-world-hunger-2013-5). Professor Turpin is both an experienced researcher and bug-eater, and in his discussion with Business Insider, he took a stance that was possibly surprising to all those of us who espouse the virtues of entomophagy. Neatly summed up in the article’s title “PROFESSOR: Here’s Why Insects Won’t Solve World Hunger”, Professor Turpin claims that edible insects are not a viable avenue for sustainable scalable agriculture. The article highlights several arguments against the viability of edible insects, each of which I would like to discuss and rebut.
Quoted from the Business Insider Article:
“I think the issue is not whether or not we would be willing to eat them, but whether we could produce enough to make a dent in world hunger,” Turpin said. “We have spent thousands of years trying to master crop production, master animal husbandry, to produce the volume that we need to rely on something as a food source.”
Professor Turpin argues that given the thousands of years it has taken to develop modern agricultural practices and livestock breeds, it is unrealistic to expect our researchers to acquire the mastery of insect breeding and rearing in the mere 20-50 years predicted to be available to meet growing food demands. As evidence Professor Turpin takes the absence of existing scaled production facilities. I will address the argument and evidence in turn.
Regarding the timeframe for the development of modern agriculture, Professor Turpin’s statements are somewhat misleading. Although humans have been practicing agriculture for thousands of years, the vast majority of advances in agricultural practice and science have occurred within the last 50-100 years, with the rate of advancement accelerating in tandem with advances in biochemistry, genetics, ecology, and information technology among other relevant fields. With the current rate of advancement, we should expect insect farming to advance from the most rudimentary practices to modern standards in much less time than the century it took traditional agriculture to develop into the food producing wonder it currently is. Development of insect farming can not only bootstrap itself into modernity utilizing relevant knowledge that has been acquired in related fields of agriculture, but also take advantage of the unique and unprecedented landscape in which modern research and development takes place. A recent commencement speech given by Ben Bernanke, chairman of the Federal Reserve, supported by many sound observations, culminates in the bold statement that “humanity’s capacity to innovate and the incentives to innovate are greater today than at any other time in history.”
(entire text of the address available here)
This is because the current state of technology, and specifically information technology allows for a significantly faster rate of experimentation and information dissemination than ever previously possible. Advanced computer models allow us to design better experiments and iterate predictions of our models at incredible speed. Simultaneously the free and instantaneous information sharing enabled by the internet allows disparate researchers to communicate, share data, iterate and collaborate and progress in ways previously unimaginable. To briefly sum up this point, Professor Turpin believes it will take too long to develop insect based agriculture based on the history of existing agriculture. However modern agriculture developed in significantly less time than Turpin gives credit, and given the trends we should expect new agriculture to develop in less time still.
The evidence presented, that Professor Turpin has not seen any existing industrial scale insect farming operations does not directly relate to his point about our ability to rear bugs at scale, but is actually an economic argument that there is no incentive to develop industrial scale insect rearing. This market demand based statement ties with Turpin’s statements to the effect that in the West there is not enough cultural acceptance for entomophagy to take hold and in developing cultures it is a practice on the decline because individuals who are gaining wealth and entering the middle class give up their traditional practices of eating insects preferring to adopt a meat-centric western diet. This trend can be observed in many nations such as China, India, and Mexico. However there are convincing counter-arguments to both the points made regarding Western culture and trends in developing nations.
First I will briefly address the argument about Western cultural acceptance because it is less relevant. Western culture does not currently accept widespread consumption of edible insects. The practice is isolated to thrill-shows such as Fear Factor, specific isolated cultural instances such as with Casu marzu the Sardinian maggot cheese, and high-end cuisine such as esteemed Noma in Denmark. The oft-cited parallel in western culture of sushi – reviled by most Americans 20 years ago, but now found in grocery store delicatessens even in middle America – exemplifies the flexibility of the western palate.
However the second argument, regarding wealth and diet choices has more subtlety and requires more thorough discussion. The core of the issue here is the assumption that “resorting to” eating insects is an economically based decision. Specifically, people don’t eat insects if they don’t have to. Although there may be counterexamples such as seen in Thailand where insect consumption may actually be increasing as wealth increases (discussion of Thailand’s insect sector found in this FAO report), the largest developing countries experiencing significant economic growth follow the trend of decreased entomophagy with increased wealth. However this very trend is in fact a major driver of the economic forces that will push insects into the fore as a necessary source of dietary protein. This will result in a potential 73% increase in demand for animal protein by 2050 according to the FAO (reported in Global Meat News). However it is widely known that existing resources for traditional animal livestock production are nearly maxed out. On the one hand there is simply no more space to farm grazing animals. Desertification is pressuring pasture and farmland in many regions, leaving nowhere to expand short of destroying what remains of the world’s rainforests. On the other hand increased feedlot factory farming will generate ever more competition with human consumption for stable cereal and legume crops (wheat, corn, soy, etc.) forcing up prices of those food sources.
Let’s quickly review some land-use economics. Depending on the source, a cow is estimated to require 1-6 acres to raise. A cow/calf pair requires 2 acres in Pennsylvania, according to http://www.beefexcellence.com/faq/. I will use this figure because it is a low-end estimate, figuring based on 1 acre per cow. An acre is 43,560 square feet, and an average steer produces 430lbs of retail cut beef (according to the Oklahoma Department of Agriculture here). That is about .001lb per square foot, or 1000 square feet per pound. The bin pictured here is just about 2 square feet and contains about 5000 mealworms, weighing in between 1 and 2 lbs total.
To be conservative let’s estimate 1lb, so we have .5lb of mealworms per square foot. To again conservatively account for the land use for feed of these insects, let’s assume an additional 6 square feet of wheat plus a couple of carrots are required to support this batch of mealworms (although it should be noted that mealworms can consume non-competing bran and chaff, so the actual wheat berries are left available for human consumption). This puts us at 8 square feet of land for 1 lb of mealworm, or .125lb per square foot. Those basic numbers mean you can grow 125 times the weight of mealworms on the same land footprint as cattle. Even still this calculation is massively oversimplified because the mealworms can be stacked – theoretically one could stack thousands of bins vertically – reducing their footprint much further still. With demand for meat quickly outpacing our capacity to produce, the price will skyrocket. As that happens, there will necessarily follow a significant market demand for more affordable protein and even from a quick look at land use it is obvious that insects offer an extremely viable economic alternative to traditional livestock. It is this growing demand for meat (and corresponding rise in prices) that will provide the major incentive for the innovation and development (discussed above) for alternative protein sectors such as insect agriculture.
The final point made in the Business Insider article, though not directly attributed to Professor Turpin, also deserves address.
Environmental threats to insect populations around the world may yet be the biggest obstacle to worldwide insect-eating. Collapsing wild bee populations and evidence of declines in other insect numbers may turn what is now a plentiful resource into a rare delicacy.
Scale insect farming will most likely be developed as a controlled environment agriculture. Like hydroponic and hot-house farming of crops with specialized environmental needs such as tomatoes, lettuce, cucumbers, etc.. insect farming will have to carefully control temperature, humidity and air quality to maximize year-round production. Instead of being an economic barrier, this approach to insect rearing will provide the robustness necessary to thrive through unpredictable weather and seasons, minimize water use, and maximize use of available space, adding further weight to the economics in favor of the practice as traditional agriculture will suffer unpredictable yields and potentially significant price fluctuation in the face of droughts, floods and other weather phenomena as global climate changes continues to take affect
Having addressed the arguments made by Professor Turpin against the viability of insect farming, I hope this post encourages further thoughtful discussion of the issues at hand. Given economic and agricultural statistics and trends, the pursuit of an insect based agriculture presents itself as an irresistible alternative source of high-quality animal protein, and extremely worthy of continued exploration and development.
Co-Founder, Tiny Farms
Caterpillars are the larval forms of moths or butterflies. They emerge from their eggs with the sole mission of finding food and eating it (while staying well enough hidden to avoid predators) until they are large enough and have enough stored energy to pupate – temporarily becoming a sack of free floating proteins and genetic material that reorganizes itself into the adult moth. As such, the caterpillar is behaviorally a perfect livestock candidate. It is not concerned with physical exercise – there is neither physical nor moral imperative for “free-range” caterpillars. There is also no issue of force-feeding – given the opportunity in nature, a caterpillar will eat, more or less constantly, through this entire phase of its life.
In addition to their favorable behavioral tendencies, caterpillars are also physically well suited for human consumption. Unlike the larvae of many other insects (e.g. mealworms), caterpillars do not have an indigestible exoskeleton which means better texture and you get more nutritional bang for your buck, and they are extremely high in protein (Hornworms measuring in ~60% protein by dry weight based on nutritional testing done for http://www.greatlakeshornworm.com/). These attributes make them great for ground-meat applications such as burgers. They also tend to grow VERY fast. In one experiment, our hornworms grew from 1 inch length to 4 inches length in just two weeks, and silkworms can take just 28 days from hatching to pupating. Plus, as you can see in the last sentence, they get BIG. Big is good for a lot of reasons – you can raise fewer of them, and they are easier to contain as they quickly grow too big to squeeze through standard screening.
So this all sounds great! It should be a piece of cake to start rearing thousands of caterpillars in our closets and cupboards and quickly wean off our dependency on traditional animal livestock. But, as always, there’s no free lunch and the better product comes at a higher price. That higher price for caterpillars comes in the form of labor and energy required for careful habitat management required to successfully raise large populations of caterpillars, which is much greater than required for other popular species like crickets or mealworms.
Firstly there is the issue of waste. Caterpillars eat a lot, and eat fast. This also means they produce a much higher volume of waste and at a much higher rate than their smaller counterparts. The waste is moist and high in ammonia so it must be cleaned out frequently to avoid mold growth and prevent the evaporating ammonia and other gases from poisoning the caterpillars. As a result these critters should not simply be grown in a flat tray on a substrate of food (which is space efficient and works well for “dry” species like mealworms), because it can be very labor intensive to separate out the caterpillars to clean their habitat. Their soft bodies must be handled very carefully to avoid bruising, so mechanical separation methods like the one we developed for mealworms are not usable. Instead the caterpillars should be raised vertically, such as on a mesh, below their food source so they orient to eat from the bottom of their food, and let their droppings fall onto an easily removable and cleanable surface or container. This setup is common in small scale “worm cups” sold to grow and keep hornworms for pet food, but may be trickier to design for a larger scale. (Note this problem is most prevalent when feeding caterpillars an artificial diet. Silkworms are traditionally grown in flat trays filled with mulberry leaves and will migrate up through a net to a clean layer of leaves. However as discussed previously, the dependence on fresh mulberry leaves renders silkworm rearing uneconomical in North America, and it may not be desirable or possible to raise other caterpillars on fresh leaves).
The other main concern with raising caterpillars is their environmental requirements. They generally need high and consistent temperature and humidity levels in order to stay healthy and grow quickly. This requires more active climate control both to maintain these levels, and to ensure good ventilation and fresh airflow to inhibit the growth of molds and fungi that also thrive in warm humid environments. While it is reasonably simple to maintain temperature and humidity with a simple thermostat, fan, and moisture source, it still requires extra attention and electricity. The habitats will require more careful design and maintenance – possibly even utilizing custom components, versus inexpensively assembled off-the-shelf setups that work so well for species like mealworms
In spite of the extra work and planning involved, the up-sides of raising caterpillars for food are significant, and we are continuing to investigate species and rearing methods, and we wholeheartedly encourage others to do the same. Keep an eye on this space as we will be sharing designs and advice for growing and harvesting many species of insects.
Co-Founder, Tiny Farms