Coconut black-headed caterpillar
It lives in silk galleries under the fronds and scrapes them hollow — older leaves look scorched and brown, and bad attacks make a palm look fire-swept.
- Pest type
- Leaf-scraping caterpillar
- Attacks
- Underside of older fronds
- Worst in
- Dry season; older fronds
- Main risk
- Scorched, fire-swept fronds
Overview
The coconut black-headed caterpillar is a major leaf-eating pest of coconut. The caterpillar constructs galleries of silk and frass along the underside of the older fronds and lives inside them, scraping away the green tissue of the leaflets from below while sheltered within its gallery.
The scraped leaflets dry to a papery brown, so affected fronds — usually the older, lower ones first — take on a scorched, dried, burnt appearance, and a severe, spreading attack can make an entire palm look as if it has been swept by fire. Because the caterpillar is protected inside its silken gallery, cover sprays are largely ineffective and also kill natural enemies; the outstandingly successful control for this pest is the release of specific parasitoid wasps, which is the recommended mainstay.
How to identify it
- Galleries of silk webbing mixed with brown frass along the underside of the older fronds.
- Leaflets scraped from below and dried to a papery brown, giving fronds a scorched, burnt look — worst on the older, lower leaves.
- Greenish caterpillars with a dark (black) head inside the galleries when you open them.
- In a severe, spreading attack, whole palms appearing as if fire-swept.
The damage it does
- Scraped, dried, scorched fronds with greatly reduced photosynthesis, starting on the older leaves.
- Weakened palms with reduced nut yield in a sustained or severe attack.
- A fire-swept appearance across affected palms and, in outbreaks, whole plantations.
- Damage that persists because the caterpillar is sheltered in its gallery from sprays and weather.
When to act
- Watch the older, lower fronds for the first galleries and scorching, especially in the dry season when the pest builds up.
- The recommended response is to release parasitoids as soon as an infestation is detected, rather than reaching for a spray.
- Cut and destroy severely affected fronds early to reduce the population before releasing parasitoids.
Organic & cultural control
- Release the specific larval/pupal parasitoids (e.g. Goniozus, Bracon, Brachymeria) recommended for this pest — biological control is the standout, proven management for the black-headed caterpillar.
- Cut and burn severely infested older fronds to remove galleries and reduce the population before/with parasitoid release.
- Avoid broad-spectrum insecticide sprays on the crown, which kill the parasitoids and make the problem worse.
- Keep palms healthy and well-nourished so they recover foliage faster after an attack.
Chemical control
- Chemical sprays are generally discouraged for this pest — the caterpillar is protected inside its gallery and sprays destroy the parasitoids that provide the real control.
- If any treatment is used in a severe outbreak, follow the official recommendation precisely and protect the parasitoids as far as possible; it should support, not replace, biological control.
- Because it is a tall food-bearing palm, prioritise parasitoid release and frond removal over crown spraying.
- Confirm the current recommendation for your area with your local KVK or the coconut development board.
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 coconut fronds look scorched and brown from below. What is it?
That scorched, dried, brown look on the older fronds — with silk-and-frass galleries on the underside — is the coconut black-headed caterpillar. It lives in the galleries and scrapes the leaflets hollow from below, so the fronds dry and look fire-swept. Open a gallery and you will find greenish caterpillars with a black head. The main control is releasing parasitoids.
Why is spraying not the answer for this pest?
Because the caterpillar shelters inside its silken gallery, where cover sprays largely cannot reach it, and those sprays also kill the parasitoid wasps that are the outstandingly effective control for this pest. That is why the recommended approach is releasing parasitoids (plus cutting badly-affected fronds), not crown spraying.
What is the recommended control for the black-headed caterpillar?
Releasing the specific parasitoid wasps recommended for it — biological control is the proven, standout management for this pest — combined with cutting and burning severely infested older fronds to reduce the population. Avoid broad-spectrum crown sprays, which set back the parasitoids. Confirm the current parasitoid-release recommendation with your KVK or the coconut board.
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.