Scale Insects

Also known as: Armored scale, soft scale

Identification

Immobile bumps on stems and leaves. Armored: flat, hard shell, no honeydew. Soft: raised dome, produces honeydew/sooty mold. Crawlers (mobile phase) are tiny and barely visible.

Damage

Sucking — feed on phloem under protective shell; soft scale produces honeydew, armored scale does not

Best Organic Solutions (Ranked)

Solutions ranked by reliability tier — start with Tier A options.

Horticultural Oil Tier A

Best option — smothers through shell. Dormant and summer applications.

Insecticidal Soap Tier A

Effective on crawler stage only

Neem Oil Tier A

IGR disrupts crawler development

Biological Controls

Parasitic wasps (Aphytis, Encarsia), ladybeetles (Chilocorus, Rhyzobius)

Prevention

Dormant oil spray on fruit trees. Inspect nursery stock before planting. Prune heavily infested branches.

Common Mistake

Spraying adult scale under their shell — insecticidal soap only works on mobile crawlers. Time treatments to crawler emergence (spring).