Arthropod pests
Broad and Russet Mites
Extremely small mites that can produce severe distortion, bronzing, shortened internodes, and abnormal new growth. Symptoms are not specific enough for a visual-only diagnosis.
What to look for
- Distorted, hardened, twisted, or unusually small new growth
- Bronzing or russeting of affected tissues
- Abnormal flower or shoot development
- Damage concentrated in rapidly growing tissues
Important look-alikes
- Herbicide or chemical injury
- Micronutrient-related disorders
- Heat or light stress
- Viral or viroid-associated growth abnormalities
How to confirm
- Use sufficient magnification to locate the mites or their eggs
- Collect multiple samples from symptomatic growing points
- Do not diagnose from leaf shape alone
Management principles
- Isolate suspect plants while confirming
- Use an integrated plan suited to the identified mite and production system
- Re-scout new growth because damaged tissue will not return to normal shape
Prevention
- Quarantine clones
- Inspect mother stock
- Control movement of tools and personnel between plant groups
- Maintain routine magnified scouting
Visual study guide
- High-magnification mite plate
- New-growth distortion progression
- Look-alike differential panel
- Sampling-location guide