Divisi
Angoumois grain moth
Sitotroga cerealella · Storage
Photo: Clemson University - USDA Cooperative Extension Slide Series, Bugwood.org · CC BY 3.0 us
The Angoumois grain moth (Sitotroga cerealella) is a small, straw-coloured storage moth of cereals — maize, sorghum, rice and wheat. Its grub bores into a single grain and feeds, pupates and grows up hidden inside that one kernel, then cuts a neat round exit hole capped by a thin, see-through 'window' as the adult moth flies out. The trouble usually starts quietly in the field as the crop ripens, then builds through several overlapping generations in the warm store, hollowing the grain from the inside.
Clemson University - USDA Cooperative Extension Slide Series, Bugwood.org · CC BY 3.0 us 
Syrio · CC BY-SA 4.0
Why it matters
This little moth attacks your grain after you have harvested it — in the granary, the sacks, the drum — and can quietly eat up to 40% (nearly half) of the maize, sorghum, rice or wheat you kept to feed your family and to sell. It is so hard to beat because each grub feeds hidden inside a single kernel, where you cannot see it or reach it; it slips in from the field as the crop ripens, then breeds generation after generation in the warm store until the grain is hollow, webbed and musty. Grain it has hollowed out weighs less at market and will not sprout if you save it for seed. Once a store is full of moths it is very hard to clear — so the whole fight is about keeping them out and catching the very first one.
When to act
Any live moths flying in the store, or bored kernels with round exit holes found on inspection.
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 angoumois grain moth field guide
- Identify it
- Scout for it
- Control it
13 field-guide sections in the app
The full guide to angoumois grain moth — 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 angoumois grain moth?
The first thing you see is the damage: kernels with a neat round hole about the size of a pin-head, often capped by a thin, see-through flap or 'window' of grain skin where the moth pushed its way out. Hold a handful up to the light — the bored grains look empty and papery and feel light. Tip the handful into water and the hollow, moth-eaten grains float while the good, solid grain sinks.
When should I take action against angoumois grain moth?
Any live moths flying in the store, or bored kernels with round exit holes found on inspection.
How do I control angoumois grain moth?
Prevent it — dry the grain hard first. This moth needs damp grain (about 12% moisture or more) to breed, so dry your grain right down before you store it — until a kernel is so hard it cracks instead of denting when you bite it, or shatters under a stone. Well-dried grain alone starves most of them out, and this drying-and-clean-store routine is the strongest defence you have that needs no chemical, so do it properly.
Which crops does angoumois grain moth affect?
Among the crops covered here: Maize, Rice, Sorghum, Wheat.
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.
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