Pest identification
What's eating my merlot lettuce?
Slugs and snails
Signs: Ragged holes, especially near the base; entire young transplants eaten overnight in wet weather
Control: Iron phosphate pellets; hand-pick after dusk; use gritty barriers; avoid evening watering
Lettuce aphid (Nasonovia ribisnigri)
Signs: Pale-green aphids clustered inside the head, invisible until harvest; leave honeydew residue
Control: Inspect hearts weekly; blast with water; apply neem oil spray before heads tighten up
Caterpillars (angle-shades moth, silver-Y moth)
Signs: Irregular leaf holes with frass; occasional heart damage if caterpillars burrow in
Control: Bt spray; hand-pick and destroy; fine-mesh insect netting over beds
Keep merlot lettuce pest-free
Healthy plants resist pests best. Get the basics right:
Merlot Lettuce pests — FAQ
What is eating my merlot lettuce?
Merlot is a deeply pigmented, slow-bolt loose-leaf lettuce. Its pest profile is typical of Lactuca sativa: slugs are the dominant threat, aphids infiltrate hearts, and caterpillars rasp through leaves. The dark anthocyanin pigmentation may offer marginal deterrence to some aphid species but provides no meaningful pest resistance in practice.
How do I get rid of slugs and snails on merlot lettuce?
Ragged holes, especially near the base; entire young transplants eaten overnight in wet weather Iron phosphate pellets; hand-pick after dusk; use gritty barriers; avoid evening watering
How do I get rid of lettuce aphid (nasonovia ribisnigri) on merlot lettuce?
Pale-green aphids clustered inside the head, invisible until harvest; leave honeydew residue Inspect hearts weekly; blast with water; apply neem oil spray before heads tighten up
How do I get rid of caterpillars (angle-shades moth, silver-y moth) on merlot lettuce?
Irregular leaf holes with frass; occasional heart damage if caterpillars burrow in Bt spray; hand-pick and destroy; fine-mesh insect netting over beds