Divisi
Spiny bollworm
Earias vittella / Earias insulana · Insect
Photo: gailhampshire from Cradley, Malvern, U.K · CC BY 2.0
The spiny bollworm — also called the okra shoot-and-fruit borer or spotted bollworm — is the caterpillar of a small moth (Earias vittella and Earias insulana) that attacks okra, roselle and cotton. It hits in two waves: while the plant is growing, the young caterpillar tunnels down a soft growing shoot tip so the tip wilts and dies (a 'dead-heart'); once the plant flowers, it bores into the buds, flowers and tender pods, plugging its entry hole with moist, sawdust-like droppings (frass). A bored pod grows twisted and spoilt, unfit to eat or sell. The name comes from the row of fleshy spiny warts along the caterpillar's back. It breeds on and on wherever soft okra, roselle or cotton is growing.
gailhampshire from Cradley, Malvern, U.K · CC BY 2.0
Why it matters
Because okra and roselle are grown for their tender pods, the spiny bollworm hits you exactly where it hurts — a single caterpillar spoils a whole pod, and in a bad season it can bore more than half your pods (up to 55%), leaving them twisted and unsellable. Worse, you pick okra every 2–3 days, so the borer keeps ruining fresh pods right through the picking season, and once a caterpillar is sealed inside a shoot or pod no spray can reach it. Catching it early — clipping out the first bored shoots before the pods even set — is what saves the crop.
When to act
about 1 in 20 shoots or pods (5%) bored, or the first wilted 'dead-heart' shoot tips seen while the plant is growing
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 spiny bollworm field guide
- Identify it
- Scout for it
- Control it
15 field-guide sections in the app
The full guide to spiny bollworm — 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 spiny bollworm?
The first thing you see (while the plant is still growing): a soft shoot tip that suddenly wilts, droops and dies — this is called a 'dead-heart'. Snap the wilted tip open and you will find a small caterpillar and a tunnel packed with moist, sawdust-like droppings (frass) boring down the middle of the soft stem.
When should I take action against spiny bollworm?
about 1 in 20 shoots or pods (5%) bored, or the first wilted 'dead-heart' shoot tips seen while the plant is growing
How do I control spiny bollworm?
Prevent it first — break the pest's home (your strongest cheap tool): don't plant okra or roselle straight after okra, roselle or cotton, and at the end of the season pull, clear and burn the old stalks — that is where the caterpillars and pupae survive to attack the next crop. Rotating to an unrelated crop starves the pest before you even sow.
Which crops does spiny bollworm affect?
Among the crops covered here: Okra, Roselle.
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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