Divisi
Leaf-eating caterpillar
· Insect
Photo: Lua Eva Blue · CC BY 3.0
The leaf-eating caterpillar is the young stage (the larva) of several night-flying moths and butterflies that chew the leaves of vegetables and field crops — cabbage, tomato, soybean and cotton. The moth lays its eggs in a cluster on one leaf; the tiny caterpillars that hatch feed side by side in a crowd at first, then spread across the plant as they grow, and in a bad year they can strip a plant down to bare stalks and veins. They thrive in warm weather (about 20–32°C) with soft, lush growth, and hide on the underside of leaves or in the litter at the plant base during the heat of the day.
Andy Potter · CC BY-SA 2.0 
Whitney Cranshaw, Colorado State University, Bugwood.org · CC BY 4.0
Why it matters
When these caterpillars build up they can eat up to half your crop (50%) — and a young plant robbed of its leaves has nothing left to fill its heads, pods or fruit. They are hard to stop once they get going: one moth lays hundreds of eggs in a single patch, the caterpillars hide under the leaves and down at the plant base where you and your spray miss them, and the big ones eat the most while being the hardest to kill. The whole game is to catch them small, and while they are still bunched in their first crowd, before they spread across the field.
When to act
small caterpillars or fresh feeding on 2 in 10 plants, or defoliation approaching 15-20 percent before flowering
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 leaf-eating caterpillar field guide
- Identify it
- Scout for it
- Control it
16 field-guide sections in the app
The full guide to leaf-eating caterpillar — 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 leaf-eating caterpillar?
The first sign — 'window' leaves. Where the tiny new caterpillars feed together they scrape the leaf down to a thin, pale, papery skin — hold it up to the light and it looks lacy, like a little window — because only the soft green flesh is eaten and the tough veins are left behind. It shows up on one or two leaves first, right where the egg cluster hatched.
When should I take action against leaf-eating caterpillar?
small caterpillars or fresh feeding on 2 in 10 plants, or defoliation approaching 15-20 percent before flowering
How do I control leaf-eating caterpillar?
Prevent it — starve the moths. After harvest, clear away crop residues and leafy weeds, which shelter the moths and their eggs. Plant early and all at once with your neighbours so the crop is sturdy before moth numbers peak, and on vegetable seedbeds lay a light net or cover (a 'floating row cover') over the young plants so the moths cannot land and lay.
Which crops does leaf-eating caterpillar affect?
Among the crops covered here: Cabbage, Cotton, Moringa (drumstick tree), Soybean, Tomato.
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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