Worldwide distribution. On sweetpotato and wild Ipomoea (morning glory). An important pest.
Adults lay eggs in base of the stem ('crown') and in storage roots, and larvae tunnel through them. Adults eat the leaves and surface of the vines.
Damage is the same as done by West Indian weevil. Worse in dry times, and in light sandy soils.
Spread by adults on the wing, and in cuttings and storage roots.
Cultural control: early, deep rooting varieties; plant only tip cuttings; remove wild morning glory; hill-up, covering cracks during dry times; ideally, make one-time harvest; 3-4-year crop rotation; after harvest, collect and destroy vines and infested storage roots.
Chemical control: treat vines (bifenthrin); treat plants in field every 3-4 weeks (bifenthrin or fipronil).