Nashi Pear Core Rot: Insect Damage, Not Disease

The Issue

A 3‑year‑old Nashi pear bears abundant perfect‑looking fruit, but the core is rotten at harvest.

Likely Cause

Internal feeder insects—codling moth, oriental fruit moth, or pear midge larvae tunnel to the core. Look for tiny entry holes at the calyx or sides.

What to Do

1. Cut open several fruit; check for larvae or frass.
2. If insects found, apply a timed insecticide spray (e.g., spinosad) at petal fall and 2 weeks later.
3. Bag fruit early (paper bags) to exclude pests organically.

Not a Disease

No common pear disease rots only the core without external symptoms.