Divisi
Fall armyworm
Spodoptera frugiperda · Insect
Photo: Wee Hong · CC BY-SA 4.0
A migratory caterpillar pest of cereals. Moths lay egg masses on leaves; young larvae scrape leaf tissue then move into the whorl, where they feed protected from sprays. Later they can attack tassels and cobs. The pest breeds continuously wherever young cereal foliage is available and spreads long distances by flight.
Wee Hong · CC BY-SA 4.0 
Frank Peairs, Colorado State University, Bugwood.org · CC BY 3.0 us
Why it matters
Fall armyworm is the worst pest of young maize. A bad attack can take a third of your crop, and because the caterpillars hide deep in the whorl where sprays can't reach, they are hard to kill once they grow big. Catching them early — while they're small and near the surface — is everything.
When to act
at least 2 in 10 plants (20%) show fresh whorl damage at seedling to early whorl stage
This guidance is general, compiled from published agronomic references including FAO and CABI. Thresholds and timing shift with your crop, your variety and the season.
In much of the region a spray is simply called mushonga — medicine. But a chemical group you cannot name is one you cannot rotate, and a product you did not write down has no pre-harvest interval you can observe. Mushonga, and other farming words →
The full fall armyworm field guide
- Identify it
- Scout for it
- Control it
12 field-guide sections in the app
The full guide to fall armyworm — every symptom to check, how and when to walk your field looking for it, and the controls that actually work, ranked. Built into your crop plan, so you are told to look before it costs you a harvest.
Crops it affects
Frequently asked questions
How do I identify fall armyworm?
The damage: the first sign is pale, papery "windows" on young leaves where tiny caterpillars have scraped one side. As they grow you'll see ragged holes and torn whorls filled with moist, sawdust-like droppings (frass).
When should I take action against fall armyworm?
at least 2 in 10 plants (20%) show fresh whorl damage at seedling to early whorl stage
How do I control fall armyworm?
Prevent it: plant early and all at once with your neighbours, so the crop passes the tender stage before moth numbers build up. A push-pull layout — a repellent legume such as desmodium between the rows with a trap grass around the edge — cuts egg-laying.
Which crops does fall armyworm affect?
Among the crops covered here: Maize, Pearl millet, Rice, Sorghum, Sugarcane.
Catch it before it costs you a harvest
Divisi builds scouting into your crop plan — it tells you when to walk your field, what to look for at that stage, and what to do when you find it. Free for farmers, works offline.
Check what grows on your farm