What's eating my arugula?

Arugula is a prime target for flea beetles — tiny black beetles that riddle leaves with small round holes — and cabbage white caterpillars. Aphids cluster on young growth, and slugs attack seedlings at soil level. Row covers placed at planting time are the single most effective defense for the whole season.

Numerous tiny round shot-holes across leaves, giving foliage a peppered or riddled appearance; seedlings can be killed outright. Cover plants immediately at sowing with fine insect-proof mesh or row cover; delay planting until peak adult populations decline in late spring; diatomaceous earth around stems as a deterrent.

Irregular ragged holes in leaves, green frass visible; older caterpillars can strip plants to stems. Hand-pick eggs and caterpillars; apply Bacillus thuringiensis (Bt) spray when small caterpillars are first seen; row covers prevent butterfly egg-laying.

Colonies of small insects on the undersides of leaves and growing tips; leaves curl and turn yellow; sticky honeydew attracts sooty mold. Blast off with a strong jet of water; introduce or encourage ladybugs and parasitic wasps; insecticidal soap spray for heavy infestations.

Irregular holes eaten through leaves overnight, often with slime trails; seedlings and young transplants can be entirely consumed. Set out beer traps or copper tape barriers; hand-pick after dark; apply iron phosphate pellets (pet-safe) around the growing area.