Jasmine budworm
A caterpillar that bores into and hollows out the flower buds from inside тАФ bored buds fail to open and cannot be sold.
- Pest type
- Moth caterpillar (Hendecasis duplifascialis)
- Attacks
- Flower buds (bores in and hollows them)
- Favoured by
- The flowering flush; a neglected, unmonitored crop
- Main risk
- Unsaleable bored buds at peak flowering
Overview
The jasmine budworm (Hendecasis duplifascialis) is the single most damaging pest of jasmine. The small caterpillar bores into the developing flower buds, webs them together and hollows them out from inside. A bored bud shows a tell-tale hole and frass (droppings), fails to open and is worthless тАФ so the pest destroys the marketable product directly, at the exact stage the crop earns its money.
Because the caterpillar quickly moves inside the bud, where sprays cannot reach it, control turns on monitoring and timing тАФ catching the young larvae before they bore in. A heavy infestation during the peak festival/wedding flush, when prices are highest, is a serious loss. It is managed with pheromone traps, biological and chemical sprays timed to the new flush, and prompt removal of bored buds.
How to identify it
- A small caterpillar inside the flower buds, which are webbed together and hollowed out.
- A tell-tale bore hole and frass (droppings) at the bud.
- Bored buds fail to open, discolour and drop тАФ and cannot be sold.
- Worst during the flowering flush, building up on a neglected, unmonitored crop.
What causes it and when
- The caterpillar of the moth Hendecasis duplifascialis, which lays eggs on the flush and buds.
- The young larva bores into the bud soon after hatching, after which it is protected from sprays.
- Builds through the flowering flush, worst at the peak when the most buds are forming.
Cultural & organic control
- Set pheromone traps to monitor the moths and time the spray, and to mass-trap where numbers are high.
- Spray Bacillus thuringiensis (Bt) or an NPV against the young caterpillars before they bore into the buds.
- Pick and destroy bored buds promptly to cut the carry-over, and keep the planting open and clean.
- Conserve natural enemies (parasitoids and predators) by avoiding broad-spectrum sprays where possible.
Chemical control
- Spray a recommended insecticide timed against the young larvae on the new flush, before they enter the buds тАФ once inside they are hard to reach.
- Rotate insecticide groups to avoid resistance, and observe the pre-harvest interval strictly on a crop picked daily.
- Time sprays by the pheromone-trap catch and the flush, not by calendar alone.
- Confirm the current product, dose and interval for your area with your KVK.
Prevent it coming back
- Run pheromone traps through every flush and spray on the trap/flush timing, not after the buds are bored.
- Remove and destroy bored buds at every picking to cut the population.
- Keep the planting open, clean and well-pruned so the crop is easy to monitor and treat.
Crops most at risk
Where this problem is called out in our crop guides тАФ open a crop for the full package of practices.
Frequently asked questions
My jasmine buds have holes and will not open. What is it?
That is the jasmine budworm, the crop's most damaging pest тАФ a caterpillar that bores into the buds and hollows them out, leaving a hole and frass, so the bud fails to open and cannot be sold. Pick and destroy the bored buds, set pheromone traps to monitor, and spray Bt or a recommended insecticide against the young caterpillars on the new flush, before they bore in. Once the caterpillar is inside the bud, sprays cannot reach it, so timing is everything.
How do I control jasmine budworm without too much spraying?
Monitor with pheromone traps so you spray only when the moths are active and on the new flush, use Bacillus thuringiensis (Bt) against the young caterpillars before they bore into the buds, pick and destroy bored buds at every harvest, and conserve natural enemies. This keeps spraying targeted and protects a crop that is picked daily.
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.