In the past several blog pages that I posted, I discussed issues that are of broad interest rearing using insects as human food. The following paragraph presents the major issues, and so far, I have discussed 1) through 3). In this blog I will treat item 4).
Throughout this page, I am using the expression IHFE to name the Insects as Human Food Enthusiasts.
Some Basic Questions and Organizing Principles: 1) Will social or cultural constraints make it unrealistic to use insects as human food? 2) Does the food value and food safety of insects impose impossible constraints? 3) Will gathering insects from nature allow us to make a significant “dent” in the needs for human food? 4) Will systems of farming insects become feasible to make significant advances in the use of insects as human foods? 5) How far can insect mass-rearing go towards allowing us to produce enough quality insect biomass to have a significant impact on the growing needs for food?
Farming vs. rearing insects: I am making a distinction here between farming and rearing, where I consider farming a lower input process of insect production than rearing (which I consider more input intensive and more rigorously managed than insect farming). This is my own distinction, which I think will be useful in the overview that I am trying to establish. We already use what I would consider a hybrid between farming and rearing in production of silkworms fed mulberry leaves, crickets fed various mixtures of grains and supplementary materials such as vegetables and scraps from food processing systems. Conventional production of meal worms is based on supplying grains and some vegetable materials such as potatoes and carrots as supplements to the grains and sources of moisture. In each of these cases, millions of insects are handled in the production facilities.
In the case of silkworms, the major input is fresh mulberry leaves, and through the 5000 years of silkworm cultivation many improvements have been made in selection of optimal mulberry trees as well as leaf harvesting and presentation processes. The considerable expense of maintaining orchards of prime mulberry and the labor in the silkworm farms though somewhat costly are rewarded by the very high price that quality silk brings to the producers. The cultural implications of silk production is a remarkable story unto itself, but for our purposes, the silkworm model serves as an excellent example of getting a large scale biomass of insects from a fairly simple input.
For crickets, the use as food for other organisms drives the production system, and the question of cost/benefit is clearly understood when we realize that crickets are used by people who are willing to pay very high prices for crickets to feed their pets or for use in zoos and conservation programs. I have indicated in my text (Cohen 2015) that cricket protein at current market prices is more expensive the protein available from the finest cuts of beef. When we think about the cost of crickets from local pet stores being upwards of 10 cents per cricket, our incredulity is explained by realization that pet owners may pay 50 to 100 dollars for a pet lizard (some specially bred leopard geckos can be sold for upwards of $1000!) So pet owners don’t flinch at paying 10 cents per cricket to keep their lizards (or tarantulas) happy. However, if crickets are going to be used as human food at a scale that truly meets problems of human population growth and world hunger, then 10 cents per cricket would not be reasonable. Taking for example, a 0.1 to 0.2 gram cricket and an estimated protein content of 10% of the cricket’s biomass, it would take 100 crickets to provide 1 g of protein, and given the FAO/WHO standard of 50 g of protein as a basic human adult requirement, it would take between 2,500 to 5,000 crickets to meet the daily requirements of a human adult male. At 10 cents per cricket (admittedly a high price of retail crickets), it would take $250 to $500 per day to supply human protein needs from these crickets. If the crickets’ cost were brought down to 1 cent per cricket, the cost of meeting the human protein needs would be 25-50 dollars a day (way more than we would expect people from emerging nations to be able to pay. I realize that humans would not be expected to subsist on crickets alone. The diets of insect-eating people would contain vegetables, other sources of meat, etc. But the extreme example that I offer is based on the assumption that we are striving to make insects a significant contribution to the nutritional needs of our growing world population. So how much insect protein would be considered a significant insect protein contribution? If it were only 10% of the protein needs, then at the rate of 1 cent per cricket, it would require $2.50 to $5.00 per day to meet that need.
Clearly, all this means that the price of cricket production MUST come down to something more like 0.1 cent per cricket. This means that other ways of cricket farming must be developed, and this is where the promises of the insects as human food enthusiasts (IHFE) need to do some deep thinking (and I think lots more research). The standard argument that I have been hearing from the insects as human food advocates is that we can use really inexpensive foods for the crickets (or other insects to be produced for human food). The IHFE folks argue that we can use waste streams such as food wastes and crop residues can be used to produce crickets. This topic is covered elegantly in the paper in this paper: Lundy ME, Parrella MP (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 ). These authors showed that there is nothing magical about crickets in terms of ability to convert low quality organic materials into nutrient-rich human food.
This is where I offer the concept of ALCHEMY vs. SCIENCE. My wife, Jackie, suggested this metaphor when I was explaining to her what I felt that IHFE people were expecting. The practitioners of alchemy sought to convert the baser metals such as lead into gold. The idea is intriguing that a wizard could use some kind of magic to make a cheap, common substance into a precious metal. Of course we know today that this is not possible: our science teaches us why this kind of expectation is unrealistic, just as the laws of thermodynamics teach us that perpetual motion machines are fancy. Yet, today, we still hope to get something for nothing or to get a lot of output from little input.
This is what I suggest that we are doing when we pursue conversion of low quality materials into nutritious insect biomass.
Besides the cricket systems, many IHFE supporters are enthusiastic about soldier flies, advocating that we can use poultry manure to rear high quality, high nutrition food (soldier flies) from the wastes that are abundant in poultry production systems. I hope that I am clear about this: I am very supportive of recycling and systems of waste management that are efficient. It would be useful to devise farming (or rearing) systems that allow us to use insects to help clean up wastes and at the same time can be used as foods for livestock. The concept of using waste products as fertilizer is certainly in this line of thinking. The use of Candida utilis (known as torula yeast) for conversion of wood pulp products that were wastes from the paper industry to a palatable and nutritious yeast product is well-documented as are other fermentation or bio-manufacturing procedures. Use of algae to convert raw materials to nutritious food or biofuel has been accomplished with a fair degree of success.
So I am not saying that insects cannot be used in well-designed systems to improve waste remediation or other low input and sustainable strategies. But my seeming iconoclasm is in response to the many claims that I keep reading and hearing about the magic bullet that insects will be to solve world hunger problems.
My major point about this is that there are sizeable gaps in our knowledge of insect husbandry that must be filled before we have any hope of making progress towards the scale of insect production that IHFE people are missing. Filling that gap is the purpose of this website and the program that it represents.