Borers in Japanese Plum Trees: Identification and Control

Confirming Borer Activity

Sap oozing from trunk wounds with small white larvae inside indicates borers (likely peachtree borer or lesser peachtree borer). They target stressed trees—drought, poor drainage, or mechanical injury.

Integrated Treatment

1. Trunk spray: Merit (imidacloprid) applied to bark kills larvae entering/exiting.
2. Boost vigor: Fertilize with 10-10-10 at 1 lb per inch trunk diameter, broadcast and watered in.
3. Sanitation: Remove dead wood; avoid mulch volcanoes.

Prevention

Healthy, well-watered plums resist borers. Monitor annually for gumming/sawdust at base.