Divisi
Eldana stalk borer
Eldana saccharina · Insect
Photo: Ken Walker, Museum Victoria · CC BY 3.0 au
Eldana stalk borer (Eldana saccharina) is an African moth whose caterpillars do their damage hidden inside the stalk of sugarcane, maize and sorghum. The night-flying moths lay their eggs on dry, dead leaf material and around the base of the plant; the caterpillars that hatch bore into the stalk and tunnel through the sections between the joints, hollowing them out, letting red-rot fungus in behind them and — in sugarcane — quietly draining away the sugar. Above all it is a pest of the older, maturing, stressed crop: the longer the cane or maize stands in the field, the more the borer builds up.
சிகி பாரதி · CC BY-SA 4.0 
Paul-andre Calatayud · CC BY-SA 3.0
Why it matters
Eldana does its work out of sight — by the time you notice it, the caterpillars are already deep inside the stalk, where no spray can reach them. A heavy attack can cost you up to 40% of your harvest: hollowed-out stalks with far less sugar, weak canes that snap and fall over, and red rot creeping in behind the borer. Once it has settled inside a mature crop there is no rescue spray that will save it — your real weapons are to harvest before the numbers build up, grow tougher varieties, and clear away the old trash that carries the borer into next season.
When to act
In sugarcane, harvest before borer numbers and internode damage build; scout mature cane and older maize for entry holes and frass.
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 eldana stalk borer field guide
- Identify it
- Scout for it
- Control it
13 field-guide sections in the app
The full guide to eldana stalk borer — 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 eldana stalk borer?
You see the damage long before you see the insect — the borer lives hidden inside the stalk. Look on the outside of the stalk for small round entry and exit holes, and around the joints and behind the leaf sheaths look for little piles of reddish-brown, sawdust-like droppings (this is called frass — the borer's waste). That rusty-coloured frass is the surest sign.
When should I take action against eldana stalk borer?
In sugarcane, harvest before borer numbers and internode damage build; scout mature cane and older maize for entry holes and frass.
How do I control eldana stalk borer?
Prevent it — harvest on time (your single strongest tool): eldana feeds and multiplies in over-mature, standing cane and old maize, so never leave the crop in the field past ripeness. Cutting it as soon as it is ready starves the borer of the old stalks it needs and stops the damage and red rot spreading. Where you can get them, also plant tougher, borer-tolerant varieties with harder rinds.
Which crops does eldana stalk borer affect?
Among the crops covered here: Maize, 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.
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