Foliar Pests

• Sweet potato foliar pests include agromyzid leafminers, sweetpotato whitefly, morningglory leafminer and armyworms. These pests climb on vines to get to foliage where they feed. Agromyzid leafminers and morningglory leafminers feed within leaves, causing tunnel-looking patterns. Sweetpotato whiteflies suck up the sap from leaves, while leaving behind a sticky residue called honeydew. Armyworms look like caterpillars and feed on sweet potato foliage at night. When sweet potato foliar pests rise in numbers during the growing season, the overall health of the plant declines.
  
  

Foliar Pest Treatment

• Treat sweet potato foliar pests with pesticides that are chemically formulated to kill that particular insect. For instance, pesticides containing the active ingredient imidacloprid kills leafhoppers and whiteflies, but not armyworms. Spray the sweet potato crop once in a season with a pesticide containing imidacloprid. Treat armyworms with a pesticide that contains rynaxypyr up to four times in a season. Space the pesticide applications every 30 days to avoid causing further harm to the sweet potato crop.
  
  

Root Pests

• Sweet potato root pests include wireworms, sweetpotato weevils, banded cucumber beetles and sweetpotato flea beetles. Wireworms feed on stems, foliage and roots. Gardeners who have wireworm problems may notice scars in the sweet potatoes. Adult sweetpotato weevils look like small ants. These pests eat vines and produce larvae that eat root systems. Adult banded cucumber beetles cause little damage to vines and foliage. However, their larvae eat away at roots and sweet potatoes. Sweetpotato flea beetles are generally jumping around from vine to vine eating foliage. Their larvae eat the sweet potato root system. While most of the damage is inflicted by sweet potato root pests' larvae, gardeners see them on vines and foliage.
  
  

Root Pest Treatment

• Apply a pesticide that contains the active ingredient beta-cyfluthrin to treat sweet potato weevils and flea beetles. Avoid using more than 16.8 ounces per acre during the growing season. Treat the sweet potato crop using a pesticide that contains bifenthrin to kill wireworms and cucumber beetles. Spray the the crop twice in one season with the pesticide, but allow 21 days in between applications. Refrain from using more than half a pound per acre.