Divisi
Nettle caterpillars
· Insect
Photo: Masaki Ikeda · CC BY-SA 3.0
Nettle caterpillars are the larvae of slug moths (family Limacodidae) — flat, sluglike, brightly coloured caterpillars armed with rows of stinging spines, which is why brushing against one burns like a nettle. They feed in tight clusters on the undersides of oil-palm and coconut fronds and on banana leaves, first scraping the surface into pale windows and then stripping whole fronds down to the bare ribs. When they are full-fed they seal themselves inside hard, seed-like cocoons stuck to the fronds, leaf bases or trunk, and later hatch out as small brown moths.
Susenoqurnia · CC BY-SA 3.0 
Amonrat Sanedee · CC BY-SA 4.0
Why it matters
Nettle caterpillars can strip your oil palm, coconut or banana fronds right down to the bare ribs, and a tree with no green leaves cannot fill its bunches or nuts. A heavy attack can cost you up to 40% — about four in every ten of your harvest. They breed fast in warm, damp weather, feed in stinging clusters that hurt to touch, and glue hard cocoons onto the tree that seed the next wave — so once an outbreak spreads across a block it is slow and painful to beat back. Catching them early, while the colonies are small and on just a few trees, is everything.
When to act
Rising numbers of larvae feeding on the fronds and visible defoliation building in a block; act before whole fronds are skeletonised.
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 nettle caterpillars field guide
- Identify it
- Scout for it
- Control it
16 field-guide sections in the app
The full guide to nettle caterpillars — 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 nettle caterpillars?
The damage shows first: on the fronds (the big palm leaves) and on banana leaves, look for pale, thin, see-through patches — like little windows — where the caterpillars have scraped one side of the leaf away. As they grow the windows join into ragged holes, and then whole leaflets are stripped down to the bare ribs and midrib, like a leaf skeleton, leaving the tree looking dry, scorched and brown. It usually starts on the older, lower fronds and spreads across a patch of neighbouring trees.
When should I take action against nettle caterpillars?
Rising numbers of larvae feeding on the fronds and visible defoliation building in a block; act before whole fronds are skeletonised.
How do I control nettle caterpillars?
Prevent it by protecting the helpers: tiny parasitic wasps and flies — whose young feed on the caterpillars — normally keep nettle caterpillars in check on their own. Blanket-spraying the whole plantation kills these helpers and is the main reason outbreaks flare up, so do not spray the whole block. Keep scouting instead, and deal with colonies while they are still small and on only a few trees.
Which crops does nettle caterpillars affect?
Among the crops covered here: Coconut, 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.
Check what grows on your farm