The reason for my excitement when i first heard about this potential study system was the insect that eats the leaves of the shea tree. It’s an edible caterpillar, collected in large numbers (as you can see from the above photo) and sold in huge quantities at markets.
 
African edible caterpillars are delicious, fascinating creatures. Many of them are highly seasonal, but very abundant when in season. However, the vast majority are only found in forest environments. This was the first time i’d ever heard of an agricultural system that had edible caterpillars. Looking into it, i found papers that referred to the caterpillar as a ‘pest’ of shea. i had endless unanswered questions, and decided a pilot trip would be necessary to try and understand which of my questions would be most relevant to those living in the region.

Methods

Farmer interviews & consultations
In 2016 I spent a couple of weeks visiting villages and interviewing men and women whose primary income source was smallholder farming. I consulted them about their priorities, and it was clear that one of the most important questions to people here was: what are effects of defoliation by caterpillars on yields of shea and maize? 
 
I decided to ask this as the driving research question for one of the chapters of my thesis.
 
Following pilot interviews, I randomly selected a sample of 45 households, stratified by household size, all of whom owned at least 1ha of maize. I selected three shea trees in each field - also stratified by size. I did approx 14 months of fieldwork in 2016-17.

Field data collection
In 2016 I collected observational data on shea tree defoliation and the growth of maize plants under and outside of tree canopies. In 2017 I repeated this data collection and also collected data on the abundance of shea nuts and the weight of maize cobs relative to plant height.
​
Field experiment
In 2017, in collaboration with two farmers, I conducted a field experiment: we planted two rows of maize (30 plants each row) and applied caterpillar faeces as fertiliser to one of the rows. We then measured the growth of each plant and weighed the eventual harvested cobs.
 

The event was a collaboration between
Insects & Wine
Anthroenology
Cambridge Food Security Forum
Trinity College Wine Society
Tsukahara-chimni 

*admittedly the air miles involved are not so sustainable...but until we have certified producers sustainably harvesting delicious wild-caught insects closer to home, this is the option I'm leaning towards. Happy to discuss other options, though!
​

Cricket Man launched Ento Nation, an ento-taining podcast that features interviews with different representatives of the insect-eating world, and always includes a recipe.


November

This isn't a highlight, but is very important for anyone concerned with insects - a study based on long-term data at protected sites in Germany showed that flying insect populations have dropped by 75% during the course of the past 27 yrs, for no apparent reason. Something about the modern world is doing more damage to the ecosystems around us than we had previously realised...

December ​​

This fortnight is the Cambridge Festival of Ideas - a series of events celebrating the arts, humanities and sciences.

One of these events was a panel discussion around the question "What's stopping your diet being more sustainable?", and I was one of the four panelists.

It's a challenging question. And my instinctive & defensive "Well, I do really like seafood.." wasn't going to do the trick. The 'you' in question isn't just me, it's (presumably) consumers in the global North. So I decided to approach it through the lens of edible insects: If we all 'know' insects area more sustainable protein source, what's stopping us from embracing them and eating less meat as a result? 

I'll summarize my talk at the end of this post, but firstly, here are the messages from my fellow panelists, each of whom approached it from their area of expertise..

Emma Garnett spoke about meat consumption and how we live in a  world where we expect, and can afford to, eat meat on a  daily basis. The livestock industry continues to contribute to growing environmental degradation and carbon emissions at an alarming rate, but the all-pervasive meat industry makes it easy to ignore these facts. She concluded that to eat a more sustainable diet, we should eat more plant-based food.

Chris Kaplonski spoke about sustainable wine and how some of the most 'sustainable' wines - in the sense that they do not use pesticides, have low energy consumption, and the growers consider their farming practices to be as 'natural' as possible - are very unconventional in taste. Many such wines 'do not taste like wine' as we know it. So, we need to be prepared to adjust our palates and our expectations in order to have a more sustainable diet.

Jean Adams spoke from a health perspective. Healthy diets tend to be more sustainable, but the environment in which we live and shop for food makes it very difficult for most people to achieve such diets. The biggest barriers are: Affordability, accessibility and advertising. Often, the most affordable and easy-to-access foods are not the most sustainable - yet they do (as the photo above shows) get a lot of advertising space. And no matter how we might like to think we're immune to advertising, we're not - and importantly, neither are our children, who are exposed to approximately 23 adverts for unhealthy food items per day.

I was introduced as 'the person who's going to persuade us all to eat insects' - so I hope my choice of slide (above) made it clear that's not my agenda at all!

I spoke about how sustainability is co-opted by a lot of advertising despite no one being entirely sure what it really means. Sustainable for how long? Somewhere between tomorrow and the end of the world, presumably, but where that line is drawn is a  matter of debate, or more commonly, convenience.

The above quote from Ben Reade is great because it highlights this as well as the now-ubiquitous claim that insects are 'more sustainable' than their animal-protein counterparts. There really isn't enough evidence to suggest this. And as the pictures above show - on the left, locally sourced bee larvae ceviche in homemade vinegarette, on the right, a muffin made with farmed mealworm flour - not all insect foods are alike in terms of their energy use and carbon footprint.

And surely a key part of sustainability is socio-economic sustainability for the producers of food?

This is a tricky one and can't be put into numbers as easily as greenhouse gas emissions, but I don't think that makes it any less important. Truly sustainable foods should also support fair livelihoods, social mobility and (I'm probably going too communist for some here, but I'm ok with that actually, especially after spending 12 months in West Africa) redistribution of wealth.

I also spoke about how cultural inertia and the constraints of a fairly restrictive buying environment make it hard for even the most motivated people to make dietary changes. When doing so, we may be further misled by the information available to us, since a food described by marketing campaigns as 'sustainable' may have any number of hidden unsustainable consequences.

We were lucky to have a brilliant audience with lots of great questions and thoughts for discussion, and we all agreed that next time we'd like a bit longer to discuss the issues being raised. What can we do as individuals to make our diets more sustainable? Eat more plants, be open to new tastes and textures in our food and drink, and think carefully about the implications of how we're spending our money. What can policy-makers do? Create a buying environment in which sustainable foods are more accessible and more affordable, whilst giving less (or no) advertising space to unhealthy, unsustainable options.