Common crops affected
- Corn
- Rice
- Sugarcane
- Sorghum
What is it?
Stem borers are the larvae of several moth species. After hatching on leaves or whorls, young larvae feed briefly in the open, then bore into stems and tunnel — which is why early timing is essential for control.
How to identify it
- “Deadheart” — the central whorl/shoot dies while outer leaves stay green.
- Shot-hole feeding and frass in whorls and leaf sheaths.
- Entry/exit holes with frass on stems and stalks; tunnels visible when split.
- Broken, lodged stems and weakened nodes in cereals and cane.
Life cycle & spread
Moths lay egg masses on leaves; young larvae feed in whorls/sheaths before boring into stems where they complete development; multiple generations per season in warm climates.
Conditions that favour it
Warm conditions, continuous cereal/cane cropping, and carry-over in stubble and volunteer plants sustain pressure.
Damage and how it spreads
Deadheart kills tillers; stem tunnelling weakens stalks, causing lodging and yield/quality loss; entry wounds invite secondary rots.
Monitoring & scouting
Scout whorls and leaf sheaths for egg masses and young larvae; use pheromone traps for moth flights; target the pre-boring window.
How to control it
- Time applications to egg-hatch/early instars before larvae bore in;
- manage stubble to reduce carry-over;
- conserve natural enemies.
Recommended Vegalab solution: Larva Control
Larva Control — natural broad-spectrum larvicide (oxymatrine) applied to whorls and foliage at egg-hatch/early-instar stage, before larvae bore into stems.
| Role | Product | Use |
|---|---|---|
| Primary control | Larva Control |
Preventing it next season
Stubble/volunteer management, pheromone monitoring, and timely first sprays before larvae enter the stem.
Claims and product availability vary by jurisdiction. Always read and follow the product label.