What's eating my lettuce?

Lettuce is a magnet for slugs, aphids, and rabbits. Slugs shred outer leaves overnight; aphids hide deep inside hearts and spread viruses. Rabbits and birds can graze an entire row. Caterpillars of the cabbage looper also cut through lettuce. Netting and slug barriers are the most effective defenses.

Ragged holes in outer and inner leaves; irregular shiny slime trails; worst in wet, mild weather Apply iron phosphate slug pellets around beds; set beer traps; use copper tape on raised beds; hand-pick after dark

Dense colonies inside the heart or on roots; yellowing, wilting; lettuce root aphid causes sudden collapse Wash leaves under water; apply insecticidal soap; for root aphid, soak soil with insecticidal soap drench; practice crop rotation

Ragged holes through leaves; dark green frass on the foliage surface Hand-pick caterpillars; apply Bt spray; cover with fine mesh netting to exclude egg-laying moths

Clean-cut stems at soil level or entire heads removed; damage appears overnight Erect rabbit-proof wire netting (at least 60 cm high, 15 cm buried); use raised beds with base mesh; repellent sprays give limited results