Caterpillars (General)
Also known as: Larvae of butterflies and moths
Identification
Soft-bodied larvae with distinct head capsule and prolegs. Range from tiny inchworms to large hornworms. Look for frass (droppings), holes in leaves, and missing leaf edges.
Damage
Chewing — consume leaves, bore into fruit, defoliate plants
Best Organic Solutions (Ranked)
Solutions ranked by reliability tier — start with Tier A options.
Btk — the caterpillar standard. Must be ingested.
Contact + ingestion. Apply in evening to protect bees.
Species-specific viral control
Prevents egg-laying on treated surfaces
Biological Controls
Trichogramma wasps (parasitize eggs), Braconid wasps (parasitize larvae), birds, ground beetles
Prevention
Row covers during moth flight season. Bt preventive sprays before damage appears. Hand-pick large caterpillars.
Common Mistake
Applying Bt after caterpillars are large — Bt works best on small, actively feeding caterpillars. Large caterpillars have ingested their lethal dose by the time you notice damage.