Arthropod pests
Caterpillars & Chewing Insects
Chewing insects remove tissue rather than extracting sap. Holes, missing leaf margins, frass, webbing, and direct sightings are stronger evidence than general discoloration.
What to look for
- Irregular holes or missing leaf tissue
- Frass on leaves or inside flower clusters
- Larvae, webbing, or feeding shelters
- Localized flower injury that can create secondary disease opportunities
Important look-alikes
- Mechanical tears
- Slug or snail feeding outdoors
- Leafminer injury
- Damaged tissue removed during handling
How to confirm
- Inspect the plant at multiple times of day
- Open folded leaves or webbed areas carefully
- Look for frass and larvae together
- Identify larvae before choosing management
Management principles
- Remove or isolate heavily infested material where practical
- Use stage-specific biological or other IPM tactics
- Inspect flower interiors because hidden feeding can be missed
- Re-scout for eggs and small larvae after larger larvae are removed
Prevention
- Screen protected structures appropriately
- Inspect outdoor plants after moth activity or new feeding
- Remove nearby plant debris that shelters pests where relevant
- Maintain regular whole-plant scouting
Visual study guide
- Chewing-damage comparison
- Larva and frass inspection plate
- Flower-cluster inspection cutaway
- Mechanical tear versus feeding damage