Written by: Mika Zollner, Master of Environmental Science student
You’ve probably heard of urban farms, but what about farming insects for food in cities?
Picture it: you come home from a long day, open the fridge and to your dismay you find it empty. Your tummy rumbles as you begin to dread the inevitable trip to the supermarket, until suddenly you remember your self-contained, environmentally friendly cricket farm in the garage! With great relief you pop down, open the (pleasantly) chirping farm, select a harvest, chuck them in the freezer for a humane death1 and quickly fry them up for a delicious2 and nutritious3 dinner!
Eating insects (“entomophagy”) is a traditional practice in many parts of the world, including Aotearoa5. While it is still a pretty radical concept, the idea of household-scale, urban edible insect farming is emerging as a way to promote resilience6-8 as climate change and urbanisation place increasing pressure on our food systems9-10. Having a reliable food source close to where most people live could save carbon emissions from transport, use less land for agriculture and support urban populations in the event of an earthquake or other disaster9. Insects can be farmed at a high density with limited resources, which makes them well suited to urban food production10. Yet despite growing awareness of their potential as an alternative protein11-12, western societies have been slow to adopt these six-legged livestock13.
But if this is going to be viable, we need to know whether edible insects are really a more sustainable source of protein than other animal products. It is well established that the conventional meat and dairy industries contribute to land degradation, greenhouse gas emissions, unsustainable resource consumption and pollution14. Alternatives such as lab-grown meat can stack up large energy bills and don’t perform much better environmentally15. Although there is quite a ‘buzz’ about edible insects at the moment, there hasn’t been adequate scientific research on the environmental impacts of different farming techniques16. Thedrivers of variability in nutrition, efficiency, growth rates, emissions and survival are still poorly understood17. In fact, until 2017 most studies were over-estimating the protein content of insects by up to 20%, causing misleading claims that they were equivalent to red meat and eggs18. Although their protein is only comparable to that of grains and microalgae, these mini livestock come with a plethora of other nutritional benefits3.
Despite popular belief, edible insects are not inherently more sustainable than other protein sources if they aren’t farmed with that intention16. Sure, by requiring much less land19, emitting a lot less greenhouse gases20, more efficiently converting their food to protein18, and consuming very little water21, insects are certainly a better bet than beef, pork, chicken and most meat alternatives11,15. However, most of the negative environmental impacts of meat production relate to the land, deforestation, fertiliser and water required to produce animal feed, which would otherwise be suitable for human consumption22. Most insect farms also use animal feed because it provides the fastest growth and highest survival rates23. Although several insect species can theoretically be grown on food scraps, weeds or other waste products24-25, these food sources have unreliable nutritional value and bring their own disease risks26. In urban environments, edible insects would only really be feasible and better than other proteins if they could be reliably grown on domestic or commercial food waste.
Aside from the feed issue, the sustainability of insects is further complicated by the fact that they are cold-blooded and sensitive to changes in external temperature17. To ensure worthwhile harvests insect farms need to maintain a constant temperature and humidity, which can lead to significant electricity demands19.
If the two key caveats of electricity and diet could be solved in an affordable and accessible way, insects would certainly be an alternative protein food supply worth considering (assuming we can all just get over the disgust factor)16. Watch this space because we are nearly there!
1 Gamborg, C., Röcklinsberg, H., & Gjerris, M. (2018). Sustainable Proteins? Values Related to Insects in Food Systems. In A. Halloran, R. Flore, P. Vantomme, & N. Roos (Eds.), Edible Insects in Sustainable Food Systems (pp. 199-211). Cham: Springer International Publishing.
2 Kouřimská, L., & Adámková, A. (2016). Nutritional and sensory quality of edible insects. NFS Journal, 4, 22-26. doi:https://doi.org/10.1016/j.nfs.2016.07.001
3 Stull, V. J., Finer, E., Bergmans, R. S., Febvre, H. P., Longhurst, C., Manter, D. K., . . . Weir, T. L. (2018). Impact of Edible Cricket Consumption on Gut Microbiota in Healthy Adults, a Double-blind, Randomized Crossover Trial. Scientific reports, 8(1), 10762-10762. doi:10.1038/s41598-018-29032-2
4 Terreform 1. (n.d.). Cricket Shelter: Modular Edible Insect Farm [Online image]. Retrieved 26 September from http://www.terreform.org/projects_cricket.html
5 Tucker, C. (2013). Insects, offal, feet and faces: Acquiring new tastes in New Zealand? New Zealand Sociology, 28(4), 101-122.
6 Ayieko, M., Ogola, H., & Ayieko, I. A. (2016). Introducing rearing crickets (gryllids) at household levels: Adoption, processing and nutritional values. Journal of Insects as Food and Feed, 2, 203-211. doi:10.3920/JIFF2015.0080
7 Weigel, T., Fèvre, S., Berti, P. R., Sychareun, V., Thammavongsa, V., Dobson, E., & Kongmanila, D. (2018). The impact of small-scale cricket farming on household nutrition in Laos. Journal of Insects as Food and Feed, 4(2), 89-99. doi:10.3920/JIFF2017.0005
8 Caparros Megido, R., Alabi, T., Nieus, C., Blecker, C., Danthine, S., Bogaert, J., . . . Francis, F. (2016). Optimisation of a cheap and residential small-scale production of edible crickets with local by-products as an alternative protein-rich human food source in Ratanakiri Province, Cambodia. Journal of the Science of Food and Agriculture, 96(2), 627-632. doi:10.1002/jsfa.7133
9 Kolagar, M. (2019). Adherence to Urban Agriculture in Order to Reach Sustainable Cities; a BWM–WASPAS Approach. Smart Cities, 2(1), 31-45. doi:10.3390/smartcities2010003
10 Specht, K., Zoll, F., Schümann, H., Bela, J., Kachel, J., & Robischon, M. (2019). How Will We Eat and Produce in the Cities of the Future? From Edible Insects to Vertical Farming—A Study on the Perception and Acceptability of New Approaches. Sustainability, 11(16), 4315.
11 Halloran, A., Hansen, H. H., Jensen, L. S., & Bruun, S. (2018). Comparing Environmental Impacts from Insects for Feed and Food as an Alternative to Animal Production. In A. Halloran, R. Flore, P. Vantomme, & N. Roos (Eds.), Edible Insects in Sustainable Food Systems (pp. 163-180). Cham: Springer International Publishing.
12 Payne, C. L. R., Scarborough, P., Rayner, M., & Nonaka, K. (2015). Are edible insects more or less ‘healthy’ than commonly consumed meats? A comparison using two nutrient profiling models developed to combat over- and undernutrition. European Journal Of Clinical Nutrition, 70, 285. doi:10.1038/ejcn.2015.149
13 Wilkinson, K., Muhlhausler, B., Motley, C., Crump, A., Bray, H., & Ankeny, R. (2018). Australian Consumers’ Awareness and Acceptance of Insects as Food. Insects, 9(2), 44. doi:10.3390/insects9020044
14 Tucker, C. (2018). Using environmental imperatives to reduce meat consumption: perspectives from New Zealand. Kōtuitui: New Zealand Journal of Social Sciences Online, 13(1), 99-110. doi:10.1080/1177083X.2018.1452763
15 Smetana, S., Mathys, A., Knoch, A., & Heinz, V. (2015). Meat alternatives: life cycle assessment of most known meat substitutes. The International Journal of Life Cycle Assessment, 20(9), 1254-1267. doi:10.1007/s11367-015-0931-6
16 Berggren, Å., Jansson, A., & Low, M. (2019). Approaching Ecological Sustainability in the Emerging Insects-as-Food Industry. Trends in Ecology & Evolution, 34(2), 132-138. doi:10.1016/j.tree.2018.11.005
17 Halloran, A., Roos, N., Eilenberg, J., Cerutti, A., & Bruun, S. (2016). Life cycle assessment of edible insects for food protein: a review. Agronomy for Sustainable Development, 36(4), 57. doi:10.1007/s13593-016-0392-8
18 Janssen, R. H., Vincken, J.-P., van den Broek, L. A. M., Fogliano, V., & Lakemond, C. M. M. (2017). Nitrogen-to-Protein Conversion Factors for Three Edible Insects: Tenebrio molitor, Alphitobius diaperinus, and Hermetia illucens. Journal of Agricultural and Food Chemistry, 65(11), 2275-2278. doi:10.1021/acs.jafc.7b00471
19 Oonincx, D. G. A. B., & de Boer, I. J. M. (2012). Environmental Impact of the Production of Mealworms as a Protein Source for Humans – A Life Cycle Assessment. PLOS ONE, 7(12), e51145. doi:10.1371/journal.pone.0051145
20 Oonincx, D. G. A. B., van Itterbeeck, J., Heetkamp, M. J. W., van den Brand, H., van Loon, J. J. A., & van Huis, A. (2011). An Exploration on Greenhouse Gas and Ammonia Production by Insect Species Suitable for Animal or Human Consumption. PLOS ONE, 5(12), e14445. doi:10.1371/journal.pone.0014445
21 Rumpold, B. A., & Schlüter, O. K. (2013b). Potential and challenges of insects as an innovative source for food and feed production. Innovative Food Science & Emerging Technologies, 17, 1-11. doi:https://doi.org/10.1016/j.ifset.2012.11.005
22 Halloran, A., Roos, N., Eilenberg, J., Cerutti, A., & Bruun, S. (2016). Life cycle assessment of edible insects for food protein: a review. Agronomy for Sustainable Development, 36(4), 57. doi:10.1007/s13593-016-0392-8
23 Halloran, A., Hanboonsong, Y., Roos, N., & Bruun, S. (2017). Life cycle assessment of cricket farming in north-eastern Thailand. Journal of Cleaner Production, 156, 83-94. doi:https://doi.org/10.1016/j.jclepro.2017.04.017
24 Oonincx, D. G. A. B., van Broekhoven, S., van Huis, A., & van Loon, J. J. A. (2015). Feed Conversion, Survival and Development, and Composition of Four Insect Species on Diets Composed of Food By-Products. PLOS ONE, 10(12), e0144601. doi:10.1371/journal.pone.0144601
25 Miech, P., Berggren, Å., Lindberg, J. E., Chhay, T., Khieu, B., & Jansson, A. (2016). Growth and survival of reared Cambodian field crickets (Teleogryllus testaceus) fed weeds, agricultural and food industry by-products. Journal of Insects as Food and Feed, 2(4), 285-292. doi:10.3920/JIFF2016.0028
26 Lundy, M. E., & Parrella, M. P. (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
27 Diack, M., personal communication, 12 October 2019