Pest identification
What's eating my iceberg lettuce?
Lettuce aphid (Nasonovia ribisnigri) and green peach aphid
Signs: Dense colonies hidden in heart leaves; honeydew and mould; contaminated heads at harvest
Control: Choose aphid-resistant varieties where available; apply insecticidal soap or neem as heads begin to form; discard outer wrapper leaves
Slugs and snails
Signs: Holes in outer wrapper leaves; slime trails; damage worsens in wet weather
Control: Scatter iron phosphate pellets at transplanting; use beer traps; keep pathways dry
Cabbage looper caterpillar
Signs: Larvae bore into forming heads, leaving frass and entry holes
Control: Apply Bt (Bacillus thuringiensis var. kurstaki) weekly from transplant; cover young plants with row cover
Birds
Signs: Pecking damage to outer leaves and young transplants, especially in early spring
Control: Drape bird-proof netting or fleece over the bed until heads are established
Keep iceberg lettuce pest-free
Healthy plants resist pests best. Get the basics right:
- What eats lettuce — the species this cultivar belongs to
- What eats iceberg lettuce — our other guide for the same plant
- What's wrong with my plant? — the diagnosis apps compared
- Common iceberg lettuce problems & fixes
- Iceberg Lettuce watering schedule
- Iceberg Lettuce light requirements
- Full iceberg lettuce care guide
Iceberg Lettuce pests — FAQ
What is eating my iceberg lettuce?
Iceberg lettuce's dense, tightly packed head traps moisture and debris, making it especially prone to aphids hiding deep in the head and to slugs on outer wrapper leaves. Caterpillars bore into forming heads. In the US, lettuce aphid (Nasonovia ribisnigri) is a serious commercial pest that can render whole heads unsellable.
How do I get rid of lettuce aphid (nasonovia ribisnigri) and green peach aphid on iceberg lettuce?
Dense colonies hidden in heart leaves; honeydew and mould; contaminated heads at harvest Choose aphid-resistant varieties where available; apply insecticidal soap or neem as heads begin to form; discard outer wrapper leaves
How do I get rid of slugs and snails on iceberg lettuce?
Holes in outer wrapper leaves; slime trails; damage worsens in wet weather Scatter iron phosphate pellets at transplanting; use beer traps; keep pathways dry
How do I get rid of cabbage looper caterpillar on iceberg lettuce?
Larvae bore into forming heads, leaving frass and entry holes Apply Bt (Bacillus thuringiensis var. kurstaki) weekly from transplant; cover young plants with row cover
How do I get rid of birds on iceberg lettuce?
Pecking damage to outer leaves and young transplants, especially in early spring Drape bird-proof netting or fleece over the bed until heads are established