What's Eating My Potatoes?

Potato pests work two shifts: beetles defoliating above ground, and unseen tenants tunneling the tubers below. If the leaves look fine but the harvest is ruined, read to the end.

Colorado potato beetle

The signs: Leaves eaten to ragged stems, fast — a full defoliation takes days once larvae hatch.

What it looks like: Adults are yellow-domed with ten black pinstripes; larvae are soft brick-red humpbacked grubs with black spot rows. Orange egg clusters shine beneath leaves.

What to do: Handpick daily in season, crush egg clusters, mulch deeply with straw, and rotate beds — they overwinter in last year's potato soil. Spinosad works when picking can't keep up.

Flea beetles

The signs: Dense pinhole shotgun patterns on leaves, heaviest early.

What it looks like: Tiny hopping black beetles.

What to do: Healthy plants outgrow it; cover young plantings where pressure runs high.

Potato leafhopper

The signs: Leaf tips and edges yellow, curl, then scorch brown ('hopperburn') in early summer.

What it looks like: Pale wedge-shaped green insects that fly up in small clouds when you brush the row.

What to do: Row cover young plantings; insecticidal soap on nymphs under leaves. Damage mimics drought — check for the hoppers before blaming the weather.

Wireworms

The signs: Clean, narrow tunnels drilled straight into tubers, discovered at harvest.

What it looks like: Tough, golden-brown, wire-stiff larvae up to an inch long, worst in beds recently converted from sod.

What to do: Avoid planting right after turning lawn; trap with buried potato chunks on skewers pulled and trashed weekly; harvest promptly at maturity.

Voles

The signs: Gnawed hollows and tooth-marked craters in tubers near the surface, plus shallow runway paths in mulch.

What it looks like: Paired incisor marks, damage concentrated where mulch is thickest.

What to do: Pull mulch back from hills in late season, trap runways, harvest as soon as vines die back.

When it's not a pest at all

Dark target-ringed spots on lower leaves are early blight; a fast gray-black collapse in cool wet weather is late blight — act on that one immediately. Scabby corked patches on tuber skins are common scab, a soil condition, not an animal.

Or just point your phone at it

Snap a photo of the leaf, the bug, or the droppings, and Harold — the advisor built into Homestead Paradise — names what he sees, tells you friend or foe, and what he'd do next. Honest when he's unsure, and careful where it counts.

Put Harold's Eyes on it — free 14-day trial