Sweet Potato Weevil identification

Organic Control Profile

Sweet Potato Weevil

Cylas formicarius

9
Plants Affected
3
Natural Enemies
5
Control Strategies

A serious sweet potato pest whose larvae tunnel storage roots and vines, leaving frass, rot, and bitter flavor; adults are ant-like snout beetles. Infested roots fail market and home-kitchen tests alike.

Reddish-brown adults about 6 mm long with a narrow snout; legless grubs curve inside roots. Breeds year-round in frost-free zones on roots and vines.

More identification photos — verified field observations

Organic Control Methods

Organic Sprays

Entomopathogenic nematodes (Steinernema carpocapsae) to soil targeting pupae near harvest where permitted; neem soil drenches show partial suppression in research—combine with sanitation.

Biological Controls

Ant predation on larvae/pupae at soil line; fungal pathogens in moist soils—avoid waterlogging that favors rot instead.

Cultural Practices

Use certified slips; deep bury culls; rotate fields; hill soil to cover exposed cracks; harvest on time and cure quickly.

Mechanical & Physical

Pheromone trapping reduces males in small plots when combined with removal of wild Ipomoea hosts.

Prevention

Eliminate wild morning glories near beds; inspect slips; do not compost infested roots in warm climates.

Natural Enemies

Plants Affected — 9 in Database