Guest post by Jo Griffin, PhD student in Evolution, Ecology and Behaviour at the Institute of Integrative Biology
Amy Eacock and I enjoyed a great day at the Family Science Fair at Ness Botanic Gardens celebrating British Science Week. The theme was ‘feed the world’, and what is more topical at the moment than entomophagy! Entomophagy is the consumption of insects and despite being regarded rather contemptuously in the developed world; it is common in certain cultures and has been practiced since prehistoric times. Due to a growing global population there has been an increased demand for farmable land, fresh water and animal protein. Around 70% of farmable land is used to produce livestock, either directly or for the production of feed. The environmental costs surrounding intensive farming require urgent attention. There are also issues surrounding feed conversion rate, which is a measure of an animal’s efficiency in converting feed mass into animal protein. Although feed conversion rates differ between livestock species, around 6kg of plant protein are required to produce 1kg of animal protein.
A simple answer could be to remove livestock from our human diet and eat an entirely arable based diet, much like our hunter gatherer ancestors did. However, meat is culturally important in some societies and to eliminate it would simply not go down well. So, what are the alternatives? We could eat less meat, to reduce our need for land to grow high-energy cereals to feed livestock. An increasingly attractive alternative is to use insects to provide protein for our projected global population of 9 billion. We could do this by raising livestock on insect diets such as mealworms and fly larvae, or by consuming insects directly. Insects have a much higher feed conversion rate, require less water and space and produce lower quantities of toxic waste and greenhouse gases. For crickets, around 1.7kg of feed is required to produce 1kg of live animal weight. The graphs below compare the edible weight of crickets with different livestock species and highlight the advantages of consuming insects.
Other benefits to eating insects include the range of high quality nutrients they provide, which are comparable or superior to other sources of animal protein. Furthermore, insects have few animal welfare issues which make them ideal to farm.
Amy and I were equipped with live mealworms, crickets and locusts (for display and handling only) and processed insects for eating. These included sago worms, queen weaver ants, crickets, locusts, mealworms, buffalo worms, which are all considered delicacies in countries across the globe. My vote on the tastiest critter had to go to the barbeque flavoured bamboo worms followed by the garlic flavoured chapulines. So how did the crunchy critters go down? Well, overall we received a lot of interest from the general public and had whole families daring each other to eat certain critters. One man decided he liked locusts so much he came back for seconds, and even thirds. Overall, the day was a roaring success. Amy and I attempted to convince the public that insects can be quite tasty after all and should be considered as a food alternative to livestock protein.