Pest identification
What's eating my sweetpotato?
Sweet potato weevil (Cylas formicarius)
Signs: Adults notch leaf edges; larvae tunnel into tubers causing dark, bitter, inedible flesh
Control: Use certified pest-free slips; hill soil over developing tubers; destroy all crop debris; no home-use insecticides are effective inside tubers
Wireworms (Agriotes spp. larvae)
Signs: Narrow tunnels bored into tubers; entry wounds invite secondary rot
Control: Avoid planting on recently broken-up grass; use wireworm traps (carrot or potato pieces as bait); rotate away from root crops
Hawk moth caterpillars (Agrius spp. and related)
Signs: Large caterpillars strip foliage rapidly; defoliation reduces tuber yield significantly
Control: Hand-pick large caterpillars; apply Bt (Bacillus thuringiensis) spray to foliage while larvae are small
Whitefly (Bemisia tabaci — sweet potato whitefly)
Signs: Yellowing leaves; sticky honeydew; sooty mold; virus transmission can stunt the whole plant
Control: Apply insecticidal soap or neem oil; use yellow sticky traps; introduce Encarsia parasitic wasps in greenhouse settings
Keep sweetpotato pest-free
Healthy plants resist pests best. Get the basics right:
Sweetpotato pests — FAQ
What is eating my sweetpotato?
Sweet potato is most seriously damaged by sweet potato weevil and wireworms in the soil, and above ground by caterpillars of the hawk moth. Whitefly and aphids attack foliage in warm climates. Deer and rabbits graze vines heavily. In the UK, slugs and vine weevil grubs are the main soil-level threats.
How do I get rid of sweet potato weevil (cylas formicarius) on sweetpotato?
Adults notch leaf edges; larvae tunnel into tubers causing dark, bitter, inedible flesh Use certified pest-free slips; hill soil over developing tubers; destroy all crop debris; no home-use insecticides are effective inside tubers
How do I get rid of wireworms (agriotes spp. larvae) on sweetpotato?
Narrow tunnels bored into tubers; entry wounds invite secondary rot Avoid planting on recently broken-up grass; use wireworm traps (carrot or potato pieces as bait); rotate away from root crops
How do I get rid of hawk moth caterpillars (agrius spp. and related) on sweetpotato?
Large caterpillars strip foliage rapidly; defoliation reduces tuber yield significantly Hand-pick large caterpillars; apply Bt (Bacillus thuringiensis) spray to foliage while larvae are small
How do I get rid of whitefly (bemisia tabaci — sweet potato whitefly) on sweetpotato?
Yellowing leaves; sticky honeydew; sooty mold; virus transmission can stunt the whole plant Apply insecticidal soap or neem oil; use yellow sticky traps; introduce Encarsia parasitic wasps in greenhouse settings