Massive swarms of locusts are sweeping across South Asia, the Middle East and the Horn of Africa. The current outbreak is the worst in recent decades. One million hectares of land is under threat in eight countries in the Horn of Africa. This is a crisis and a serious threat to crops, economies and livelihoods. New bands and swarms are currently forming so the crisis will continue for several more weeks.

Locusts are a group of short-horned grasshoppers. They are mostly solitary, but under certain conditions they rapidly multiply in numbers and form swarms.

In some of the countries affected by the locust swarms, where millions of people already struggle with access to food, citizens are asking why the locusts can’t be turned into food or animal feed.

This is an old strategy used to get food after locusts devastated crops, but things have changed. Currently, outbreaks are managed using chemical insecticides or an insect fungus. This would make the locusts toxic.

I would therefore strongly advise against eating swarming locusts. It is highly unlikely that the nutritional benefits can outweigh the negative effects of chemical residues.

Made sense

There are various reasons why eating swarming locusts used to make sense. When they’re swarming, they can be collected in large numbers, and relatively quickly and easily. This can even be done using hands, bags and buckets.

From a nutritional point of view, grasshoppers and locusts are excellent sources of protein and other essential nutrients.

But one major factor that must be considered today is the use of chemicals. The current locust outbreak is so severe that authorities have turned to using insecticides.

For instance, organophosphate, carbamate and pyrethroid are types of insecticide commonly used against locusts and are used in emergency situations. Even if not much is used, they are extremely toxic.

For example, organophosphates are neurotoxic. This means they can cause a variety of health problems including headaches, nausea, sleeplessness, diarrhoea, breathing problems and mental confusion. Even a low-level exposure to organophosphate insecticides, has been known to cause metabolic dysregulations, such as hyperglycemia. In addition, some studies suggest that exposure may cause diabetes.

This can be extremely dangerous. At the end of the 1980s, Kuwait was hit by a locust plague. Locals gathered the locusts to eat them, even though the swarms had been sprayed with pesticides. Research showed that these locusts contained chemical residues, including phosphorous. This is highly toxic to humans. It can cause kidney, liver and heart damage, and osteoporosis.

The Food and Agriculture Organisation has weighed into this issue stating that:

“Locusts that have been killed by pesticides should under no circumstances be consumed, because they may still contain traces of pesticides. In the context of the ongoing locust upsurge and the control campaign in East Africa, no one should eat any locusts, living or dead. Pesticide does not always kill the locusts immediately.”

Eating locusts

Eating swarming locusts wasn’t always dangerous, and it was a widespread practice wherever plagues occurred – such as in Africa, the Middle East and South Asia, and North America. Plagues were an ancient challenge that many communities addressed by turning them into food.

For centuries, Native Americans had locusts, and other insects, in their diets. These included locust swarms. For instance, when the swarms encountered the Great Salt Lake, millions would get caught in the water and die. These eventually ended up on the lake shores, already salted by the water, ready for collection.

In the Middle East, such as Israel, eating swarming locusts was also a strategy. Grasshoppers and locusts are, in fact, the only halal insect in local diets.

In parts of Africa, locusts and grasshoppers have also been eaten for centuries. And, in some places, still are today.

For instance in Madagascar, during locust swarm outbreaks with crops gone, locusts were used as both food and animal feed. During my research in Madagascar I found that this is still the case today.

But given that governments are now turning to chemicals to manage the outbreaks, the correct advice is that people should not eat the locusts or use them for animal feed. Chemical residues pose a major health risk.

Joost Van Itterbeeck, Postdoctoral Researcher, Andong National University.

This article first appeared on The Conversation.