Packed with protein, iron, zinc and other essential nutrients, mopane worms are a nutritional powerhouse rivalling beef and spinach. These caterpillars, a traditional African delicacy, can be roasted, stir-fried or ground into a versatile powder. Researchers highlight their potential to address food security challenges and reduce environmental strain. With their rich taste and health benefits, mopane worms are rapidly becoming the next global superfood trend.
More protein than beef, more iron and zinc than spinach – you should be eating these caterpillars.
New research published in Future Foods highlights the nutritional benefits of the mopane worm. Plump, vitamin-packed and flavourful, they can be eaten stir-fried or ground into a powder that can be incorporated undetected into other foods.
Mopane worms are a traditional favourite across many cultures, and researchers think that they are poised to improve food security across Africa – and could go mainstream as the next trendy superfood in upper-income countries.
“Insects are a food resource that was widely consumed in ancient times, but this healthy habit is gradually being forgotten,” says co-author Chrysantus Tanga, a Senior agricultural entomologist at the International Centre of Insect Physiology and Ecology in Nairobi, Kenya. “I think it is time for a reawakening.”
A traditional delicacy
Mopane worms are not really worms at all – they are the larval stage of some of the largest species of nectar-sipping moths that are native to large swaths of Southern, Eastern and Central Africa. Some are brightly coloured, with vibrant reds and greens, and others use a more muted palette as camouflage to hide from predatory birds and hungry humans.
“Especially in Cameroon, where I come from,” Chrysantus Tanga says. “My tribe actually consumes them a lot during seasonal outbreaks.”
The mopane worms get their name from their favourite food source – the mopane tree, native to southern Africa. The mopane tree has distinctively heart-shaped leaves and sturdy, termite-resistant wood often used for construction.
The caterpillars are abundant in the rainy season and harvested when they are plumpest, just before they burrow underground to metamorphose into moths. Although they can be 17 cm long, they are gigantic compared with the backyard butterfly caterpillars of Europe and North America.
Chrysantus Tanga says that preparing them to eat evokes great memories and excitement in every family,. A quick roast on a bed of smouldering charcoal facilitates removal of the spines and popping off of the last body segment during degutting – kind of like deveining a shrimp. Thereafter, the options are endless.
“As a side dish to a starchy meal or as a snack, they are eaten in a variety of ways, including grilling, stewing, roasting, drying, boiling and frying them with some tomatoes, vegetables, garnished with some ginger and chili,” Chrysantus Tanga says. “Each processing technique enhances their flavour and my favourite part is the crunchy head, “but for first-time consumers” who may be a little insect-shy, “you can also grind it into a powder and use it to fortify other food products, such as porridge for children,” he adds.
Making a nutritional label for an ancient food
Previous studies had hammered out the basic nutrient breakdown of mopane worms, but Chrysantus Tanga and his team set out to build a complete profile worthy of a grocery-store label.
They examined two species of mopane worm, both collected in Botswana. The caterpillar of the emperor moth (Gonimbrasia belina) has vibrant belts of yellow and red, and the caterpillar of the chipumi moth (Gynanisa maja) is a leafy green with a yellow and purple racing stripe along its sides.
The researchers found a staggering concentration of protein in the mopane worms – 73 grams of protein per 100 grams of dried caterpillar flour. For comparison, the same amount of beef jerky contains 59 grams of protein.
By the researchers’ calculations, just 62 grams of dry mopane worm flour would meet the WHO minimum Recommended Dietary Allowance of protein for a healthy adult.
Both species are also loaded with two essential amino acids: methionine and lysine. “These are cereal-limiting amino acids” – meaning without them, children’s growth is stunted – “and are very rare in plant-based sources,” says co-author Brian Ochieng, a researcher at the International Centre of Insect Physiology and Ecology.
The mopane worms boast 11 vitamins, including retinol, which is important for developing vision. They also provide surprisingly high doses of calcium and iron. While 100 grams of green, leafy spinach will give you 2.7 milligrams of iron, 100 grams of dried mopane worms offers between 3.6 and 21.2 milligrams.
But the mopane worm’s superfood properties keep on going, Chrysantus Tanga says. Omega-3 fatty acid levels in the worm can support heart health, while the phytosterols – a compound produced by plants and found in high concentrations in the mopane worm – can help in safely lowering cholesterol levels to avoid health risk such as heart attack and stroke. Other compounds in the worm called flavonoids have a range of health benefits including antioxidant, anti-inflammatory and anti-cancer activities.
Their findings underscore that these caterpillars stand out among insect food sources. “Consuming mopane worms provides more benefits than consuming other conventional sources of foods,” says co-author Cynthia Mudalungu, a postdoctoral fellow at the International Centre of Insect Physiology and Ecology.
How to take mopane worm products to the mainstream
With increasing food insecurity across Africa, Chrysantus Tanga thinks that insects are an insufficiently tapped resource. “In every environment, in every climate, insects are readily available,” he says. “Insects could play an important role in transforming our food systems.”
“In terms of resilience to climate change and their ability to transform agricultural by-products into high-value foods,” insects have no rival, Chrysantus Tanga adds. Insects take a fraction of feed, water and land resources to make high-quality protein than what livestock use.
Previous studies suggest that mopane worms owe some of their nutritional benefits to the unique chemical composition of mopane tree leaves. “As they say, you are what you eat, and this is no different for caterpillars,” Chrysantus Tanga says. With an eye to purposeful cultivation of mopane worms, the fact that mopane trees can thrive in environments outside their native range is very helpful. “You can grow them just like any other plant species across Africa.”
Mopane worms could soon see their big break on other continents too, according to Chrysantus Tanga. The European Union is slowly expanding the list of insects that can be sold for human consumption, greenlighting migratory locusts in 2021, house crickets and one mealworm species in 2022 and an additional mealworm species and low-fat house cricket powder in 2023. A further eight applications for new insect species or product forms are under review, according to the European Commission.
“When you look at the European market, they are being innovative by including insects in consumer-friendly products – people do not see the insect, but it increases the food’s nutritional value and attracts more consumers.”
A French company called Jimini’s – a wink to Pinocchio’s sidekick – incorporates cricket protein into energy bars, and several Italian companies are creating cricket-based pasta, pizza and snacks, the BBC reported in 2023. (Journalist Sofia Bettiza described 15%-cricket tagliatelle from a restaurant near Turin as “nutty” and surprisingly tasty.)
“Even in Africa, the younger people who have moved to the city think that they have outgrown the primitive habit of eating insects,” Chrysantus Tanga says. “We need to remind them that insects will always remain one of the healthiest products on the planet.”
