Cutworm
The night raider that cuts young seedlings off at the base and hides curled in the soil by day — you find felled plants but no obvious pest.
- Pest type
- Soil caterpillar (night)
- Attacks
- Seedling base / stem
- Worst in
- Seedlings; weedy fields
- Main risk
- Seedlings cut off at night
Overview
Cutworms are the caterpillars of night-flying moths that live in the soil and feed after dark. Their signature damage is exactly what the name says: they cut young seedlings clean through at or just below the soil line, felling the plant so it lies on the ground, often without even eating much of it.
By day the cutworm curls into a characteristic "C" shape in the soil at the base of the plant, so a farmer sees rows of felled or missing seedlings but no visible pest until they scratch the soil beside a cut plant. They attack potato, gram, onion, coriander, tomato and many young crops and vegetables, and are worst on seedlings and transplants in fields with plenty of weeds or crop debris for the moths to lay in.
How to identify it
- Young seedlings cut clean through at or just below the soil line, lying felled on the ground — the classic sign.
- Scratch the soil next to a cut plant and find a fat, greasy, greyish caterpillar curled in a "C" shape.
- Damage appears overnight and in patches; by day there is no pest visible on the plants.
- Worse in fields with weeds, green manure or crop debris, and on newly transplanted or emerging crops.
The damage it does
- Seedlings and transplants cut off at the base and felled, thinning or gapping the stand and sometimes forcing a gap-fill.
- Loss concentrated at the vulnerable seedling/transplant stage, when each plant lost is a plant gone.
- Some species also climb to feed on foliage or bore into potato tubers near the surface.
- Patchy, sudden overnight damage that can be mistaken for other causes until the grub is found.
When to act
- Watch newly emerged or transplanted crops closely — the seedling stage is when cutworm does its damage.
- Confirm by scratching the soil beside cut plants at the base to find the C-shaped grubs, ideally check at dusk when they surface.
- Act promptly on the first felled seedlings, before a patch spreads across the field.
Organic & cultural control
- Keep the field and bunds weed-free before sowing and let the soil dry/plough between crops, removing the debris where moths lay and grubs shelter.
- Collect the C-shaped grubs by hand from the soil around cut plants at dusk or after light irrigation that brings them up.
- Flood-irrigate an affected patch to force the grubs to the surface for collection or exposure to birds.
- Deep summer ploughing exposes pupae and grubs; a protective collar around valuable transplants keeps cutworms off the stem.
Chemical control
- A poison bait (bran + jaggery + a registered insecticide) broadcast at dusk near the plant rows is the classic, effective control, since cutworms feed at night on the surface.
- CIB&RC-registered soil-directed insecticides for the crop can be applied to the base/soil where cutworm pressure is high; follow the label.
- Direct control to the plant base and soil, not the foliage, and time it to the evening.
- Confirm the current recommendation and dose for your crop and zone with your local KVK.
Crops most at risk
Where this problem is called out in our crop guides — open a crop for the full package of practices.
Frequently asked questions
My seedlings are cut off at the base and lying on the ground overnight. What did it?
That clean cut at the soil line with the seedling felled is the classic sign of cutworm. The caterpillar lives in the soil, feeds at night and cuts the young stem through at the base. Scratch the soil next to a cut plant and you will find a fat greyish grub curled in a "C". A dusk poison bait and collecting the grubs are the usual controls.
I see the damage but not the caterpillar. Where is it?
By day the cutworm curls into a "C" shape and hides in the soil right at the base of the plant, which is why you see felled seedlings but no pest. Scratch the top few centimetres of soil beside a cut plant, or look at dusk when they surface to feed, and you will find it.
What is the most effective control?
A poison bait of bran, jaggery and a registered insecticide broadcast near the rows at dusk works well because cutworms feed on the surface at night. Combine it with weed-free, clean fields before sowing, collecting the C-shaped grubs, and flood-irrigating affected patches to bring them up. Confirm the current bait recommendation with your KVK.
Symptoms and control measures follow ICAR, KVK and state agricultural-university package-of-practices; any named chemical is a registered use. Always read the product label and confirm the dose for your crop and zone. editorial policy.