Pest identification
What's eating my red romaine lettuce?
Slugs and snails
Signs: Large ragged holes in outer leaves and bases of heads, worst after rain or overhead watering
Control: Iron phosphate pellets; copper tape around raised beds; evening hand-picking; water in the morning
Lettuce aphid (Nasonovia ribisnigri) and lettuce root aphid (Pemphigus bursarius)
Signs: Foliar aphids distort inner leaves and deposit honeydew; root aphids cause sudden wilting and death
Control: Check hearts regularly; jet off foliar colonies with water; for root aphid, remove plants and rotate; choose resistant varieties where possible
Caterpillars (Mamestra brassicae, Autographa gamma)
Signs: Irregular holes through leaves and into hearts; dark frass pellets visible among leaves
Control: Hand-pick caterpillars and egg clusters; apply Bacillus thuringiensis (Bt) spray; fine-mesh netting
Keep red romaine lettuce pest-free
Healthy plants resist pests best. Get the basics right:
Red Romaine Lettuce pests — FAQ
What is eating my red romaine lettuce?
Red Romaine lettuce is heavily targeted by slugs and snails, which shred outer leaves overnight, and by aphids that colonise the inner heart. Caterpillars of the cabbage white and angle-shades moth cause ragged holes in leaves. Lettuce root aphid is a hidden but serious threat, causing sudden wilting in mid-summer.
How do I get rid of slugs and snails on red romaine lettuce?
Large ragged holes in outer leaves and bases of heads, worst after rain or overhead watering Iron phosphate pellets; copper tape around raised beds; evening hand-picking; water in the morning
How do I get rid of lettuce aphid (nasonovia ribisnigri) and lettuce root aphid (pemphigus bursarius) on red romaine lettuce?
Foliar aphids distort inner leaves and deposit honeydew; root aphids cause sudden wilting and death Check hearts regularly; jet off foliar colonies with water; for root aphid, remove plants and rotate; choose resistant varieties where possible
How do I get rid of caterpillars (mamestra brassicae, autographa gamma) on red romaine lettuce?
Irregular holes through leaves and into hearts; dark frass pellets visible among leaves Hand-pick caterpillars and egg clusters; apply Bacillus thuringiensis (Bt) spray; fine-mesh netting