Pest identification
What's eating my japanese sweet potato?
Sweet potato weevil (Cylas formicarius)
Signs: Larvae create dark, foul-smelling tunnels through vines and flesh; entire crop can be lost in warm climates
Control: Source certified weevil-free slips; 3-year rotation; destroy all crop residue immediately; quarantine rules apply in some US states
Sweet potato hornworm (Eumorpha fasciatus)
Signs: Large green caterpillars strip foliage rapidly; complete defoliation possible on young vines
Control: Hand-pick and destroy; Bt kurstaki spray targeting young caterpillars; encourage parasitic wasps with companion flowers
Deer (Odocoileus virginianus)
Signs: Browsed vines and stripped leaves overnight; repeated grazing prevents plants from storing energy in tubers
Control: 8 ft (2.4 m) deer fencing or motion-activated sprinklers; apply commercial deer repellent to vine tips
Wireworms (Agriotes spp.)
Signs: Tunnels in the dense, starchy tuber flesh; worse in poorly drained or recently turfed soils
Control: Carrot bait traps pre-season; Steinernema feltiae nematodes applied in summer; harvest promptly after die-back
Keep japanese sweet potato pest-free
Healthy plants resist pests best. Get the basics right:
Japanese Sweet Potato pests — FAQ
What is eating my japanese sweet potato?
Murasaki Japanese sweet potato shares the same pest vulnerabilities as other Ipomoea batatas varieties. Sweet potato weevil is the most destructive pest in warmer US zones, tunnelling tubers to inedibility. Above ground, hornworms and tortoise beetles defoliate vines. Deer readily browse the sprawling foliage. Use certified disease-free slips and maintain strict rotation.
How do I get rid of sweet potato weevil (cylas formicarius) on japanese sweet potato?
Larvae create dark, foul-smelling tunnels through vines and flesh; entire crop can be lost in warm climates Source certified weevil-free slips; 3-year rotation; destroy all crop residue immediately; quarantine rules apply in some US states
How do I get rid of sweet potato hornworm (eumorpha fasciatus) on japanese sweet potato?
Large green caterpillars strip foliage rapidly; complete defoliation possible on young vines Hand-pick and destroy; Bt kurstaki spray targeting young caterpillars; encourage parasitic wasps with companion flowers
How do I get rid of deer (odocoileus virginianus) on japanese sweet potato?
Browsed vines and stripped leaves overnight; repeated grazing prevents plants from storing energy in tubers 8 ft (2.4 m) deer fencing or motion-activated sprinklers; apply commercial deer repellent to vine tips
How do I get rid of wireworms (agriotes spp.) on japanese sweet potato?
Tunnels in the dense, starchy tuber flesh; worse in poorly drained or recently turfed soils Carrot bait traps pre-season; Steinernema feltiae nematodes applied in summer; harvest promptly after die-back