Cinnamon shoot borer
Grubs that tunnel into cinnamon shoots and kill them before harvest.
- Pest
- Wood-boring grubs inside the shoot
- Attacks
- Shoots and stems carrying the bark crop
- Sign
- Bore hole with fresh frass; shoot wilts above it
- Control
- Cut out bored shoots; monthly carbaryl smear (TNAU)
Overview
TNAU lists shoot borer among the main pests of cinnamon, and the Karnataka State Spices Development Board also records a pink shoot borer on the crop. The grubs feed inside the shoot, so the damage is hidden until a hole with frass or a wilting tip gives it away.
Cinnamon makes this worse than it is on most trees. The plant is coppiced and the crop is the bark of shoots 18 to 24 months old, so a bored shoot is not a branch lost — it is a quill lost. TNAU also lists the coffee red borer on cinnamon, which is treated by trunk injection with a 20-day gap before any bark is harvested.
How to identify it
- A small hole in a shoot or stem with sawdust-like frass pushed out of it.
- The shoot wilts, yellows or dries above the hole while the rest of the bush looks fine.
- Check the stump clump and the base of each shoot at every weeding round.
What causes it and when
- Grubs of wood-boring insects that live and feed inside the shoot.
- Stressed bushes, dead wood left in the garden and wounds from careless cutting make it easier for them.
Prevention and organic control
- Cut out and burn bored shoots at the next weeding round — do not leave them lying in the garden.
- Keep the stump clump clean of dead and broken wood.
- Cut shoots cleanly at harvest so wounds heal, and keep the bush fed and mulched.
Chemical control
- TNAU advises smearing the stem and branches with carbaryl 50 WP at 2 g per litre of water, once a month.
- For the coffee red borer, TNAU advises trunk injection, with a waiting period of 20 days between treatment and bark harvest.
- Confirm the currently registered product and dose with your state horticulture department or KVK, and never peel bark inside the waiting period.
Crops most at risk
Where this problem is called out in our crop guides — open a crop for the full package of practices.
Varieties to consider
Named seed varieties whose resistance or susceptibility to this problem is documented on their own variety page.
Frequently asked questions
A cinnamon shoot has wilted and there is wood dust at a hole. What do I do?
Cut that shoot out below the bored point and burn it, then look over the rest of the clump for more holes. TNAU advises a monthly smear of carbaryl 50 WP at 2 g per litre on the stem and branches, and trunk injection for the coffee red borer with 20 days between treatment and bark harvest. Confirm the current product with your KVK.
Is this the same stem borer that attacks maize and sugarcane?
No. Those are caterpillars of moths that bore into cereal stems. This is a wood-boring grub of a tree shoot, and TNAU does not name the species in its cinnamon guidance. The practical difference is that you treat the bark and the hole, not the foliage.
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.