Pest on crop
San Jose Scale on japanese plum
Quadraspidiotus perniciosus
Tiny armored scale insect that encrusts bark, branches, and fruit. Heavy infestations weaken trees and produce red haloed spots on fruit at harvest. Persistent year-over-year if not controlled.
- Pest
- San Jose Scale
- Scientific name
- Quadraspidiotus perniciosus
- Crop
- Japanese Plum
- Total hosts
- 10
San Jose Scale on japanese plum
Detailed guidance for this section is being prepared. Check back soon.
Signs on japanese plum
- ▸ Tiny gray-black bumps on bark, often forming crusty patches
- ▸ Red 'halo' rings on fruit where scales fed during development
- ▸ Branch dieback in heavy infestations
- ▸ Yellowing leaves above affected branches
IPM controls
- ✓ Dormant oil spray during late winter (the foundation control; smothers overwintering scales)
- ✓ Targeted insecticide at crawler emergence (track with degree days, typically late May to early June)
- ✓ Prune out and destroy heavily infested branches
- ✓ Encourage twice-stabbed lady beetle and parasitoid wasps
Other crops affected by san jose scale
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