Divisi
Oil palm leaf miner
Coelaenomenodera lameensis · Insect
Photo: USDA · Public domain
The oil palm leaf miner (Coelaenomenodera lameensis) is a small leaf-eating beetle — not a caterpillar — and one of the worst pests of oil palm across West and Central Africa. The adult scrapes thin pale slits along the leaflets, while its flat, pale grubs tunnel and feed inside the leaf, hollowing out brown, blister-like pockets called 'mines'. Breeding in several overlapping generations, its numbers can suddenly explode into an outbreak that browns and dries whole blocks of palm, robbing them of the green leaf they need to fill their bunches. Tiny parasitic wasps normally keep it in check for free — the real trouble begins when careless spraying wipes those helpers out.
Why it matters
When this beetle gets out of hand it strips the green from your palms and can cut bunch yield by up to half — and because the palms stay weakened, that loss keeps dragging on for one to two years even after the beetles are gone. The grubs do their damage hidden inside the leaf, where an ordinary surface spray simply cannot reach them, so once an outbreak has built up across a block it is slow and costly to turn around. Your cheapest and strongest guard is the tiny wasps that quietly kill the miner for nothing — lose them to careless spraying and the beetle multiplies unchecked.
When to act
Rising larval mines on the fronds and visible browning of the canopy across a block; act on early build-up before an outbreak takes hold.
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 oil palm leaf miner field guide
- Identify it
- Scout for it
- Control it
13 field-guide sections in the app
The full guide to oil palm leaf miner — 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 oil palm leaf miner?
The damage (look for this first): thin, pale scrape-slits run along the leaflets where the adult beetles have rasped the surface, and right beside them sit brown, dry, blister-like patches — these are the 'mines', pockets where the grubs have eaten the leaf out from the inside. Where many palms are hit at once, the whole crown takes on a scorched, burnt-brown look, as if a grass fire had swept through it.
When should I take action against oil palm leaf miner?
Rising larval mines on the fronds and visible browning of the canopy across a block; act on early build-up before an outbreak takes hold.
How do I control oil palm leaf miner?
Prevent — don't trigger the outbreak yourself: the miner is normally held down for free by tiny wasps, and the fastest way to spark an outbreak is a broad-spectrum spray (a broad poison that kills everything, the helpful wasps included). So do not routinely spray the crown, and don't let careless spraying by neighbours drift onto your palms.
Which crops does oil palm leaf miner affect?
Among the crops covered here: Oil palm.
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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