Five things to know about African farmers’ latest foe - the Fall Armyworm

A look at Africa’s winged invader up-close

Fall Armyworm up-close on a maize leave in Ghana. ©FAO/Keith Cressman


Plant pests – the kind that can put our crops and vegetation at risk – come in many shapes and forms. Some are earthworms, others marine, some still jumping worms.

Then, there is the Fall Armyworm (FAW) - Africa’s winged invader and farmers’ latest foe.  

Its scientific name comes from Latin - Spodoptera frugiperda (from “frugiperda” or “lost fruit” because of the worm’s ability to destroy crops); its origin is the Americas.

FAW first landed in West Africa, by ship or plane, in early 2016. Then, it spread its wings and reign across most of the continent, from one country to more than 40.  

This fast-spreading, crop-munching worm is now here to stay, and cannot be eliminated. So what should we know about it?

A small-scale farmer in Swaziland working in her maize field (right). ©FAO/Giulio Napolitano. An Ethiopian small-scale farmer in his FAW-damaged maize field (left). ©FAO/Tamiru Legesse. Smallholders are the worst affected by FAW.

1. Fall Armyworm can feed on over 80 crops, including rice, sorghum, millet, sugarcane, vegetable crops and cotton, but it prefers maize.

FAW has already infected millions of hectares of maize in Africa, a staple crop across the continent.

In most areas of North America, FAW arrives seasonally and then dies out in cold winter months. In much of Africa, in the absence of freezing conditions, FAW is continuous throughout the year, keeping farmers constantly on their toes.

Who are these farmers? Mainly smallholders who grow maize on less than two hectares of land.

In short, FAW affects some of Africa’s most vulnerable people – small-scale farmers who are already struggling to make ends meet and have enough food for their families.

2. Fall Armyworm is already having a devastating impact and continues to push more people into hunger.

If left unchecked, FAW could threaten the food security of more than 300 million people in Africa, and cause significant economic losses, up to $4.8 billion from maize production alone.

A strong flyer, the adult moth can fly 100 km per night, and is capable of migrating long distances. FAW is also very prolific; the female moth can lay up to 1,000 eggs in her lifetime.

All this to say - FAW is set to continue spreading.

Fall Armyworm Lifecycle graph. An excerpt from FAO’s FAW guide.

3. Fall Armyworm can be managed so that it doesn’t wreak havoc on people’s livelihoods. 

Farmers need to: know how to identify FAW and the damage it causes; understand its bahaviour; know how to monitor FAW; and learn to identify the best way to manage it to reduce its impact.

To help them do that, FAO has developed a guide packed with hands-on advice from how to prevent, identify and monitor FAW to destroy it. 

Here are some examples: grow maize with another crop like cassava or sweet potatoes; avoid planting late; handpick and destroy eggs and young caterpillars on the maize leaves; spray infected maize with botanical pesticides (based on neem or other plants); pour ash, sand, or soil into the whorl of the plant (where FAW feeds); protect and encourage natural biological control agents (“farmers’ friends”).

With this guide, FAO has begun a continent-wide programme for the sustainable management of FAW, aiming to reach 10 million farmers through 40,000 Farmer Field Schools over five years.

Apart from the guide, work is also underway to launch a FAW Monitoring and Early Warning System (FAMEWS) app across the continent. The FAO app will enable farmers, agricultural staff and others to send vital info about FAW infestation levels, helping to generate detailed and reliable information to manage FAW.

4. Farmers can manage Fall Armyworm in a way that doesn’t pose threats to their environment and health.

Faced with a threatening new foe, many countries in Africa resorted to using synthetic pesticides to ward off FAW. Their response was fueled by a sense of emergency, not based on a careful analysis of costs and benefits.

Older pesticide molecules, banned in industrialized countries, are often still readily available and widely used in African countries. These products put farmers' health and their environments at risk.

The good news is that bio-pesticides, including those based on bacteria, virus, and fungus have been already tested, developed and used successfully in the Americas. FAW’s natural enemies have also proved to be fierce combatants of FAW.

African farmers are already seeing their benefits.

Crop diversity, ants, botanical solutions of neem and other plants, or fungal and viral organisms, and continuous monitoring and learning are at the forefront of African farmers’ fight against FAW.

5. Fall Armyworm management starts with prevention.

With FAW set to continue spreading, countries not yet affected but likely to be affected soon, need to get prepared.

What should these countries do? They should: raise awareness about FAW amongst farmers and front line agricultural workers; use early warning systems at community level; and use available resources such as FAO’s FAW guide.

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