Sweet potato weevil

The genus Cylas, most notably the species Cylas formicarius, belongs to the order Coleoptera and the family Brentidae. It is widely recognized as the most devastating pest affecting sweet potato crops globally, causing severe damage in tropical and subtropical agriculture.

The primary host for this pest is the sweet potato (Ipomoea batatas). The weevil attacks all parts of the plant, but the most severe economic impact occurs when larvae bore into the tubers, rendering them unmarketable and inedible due to internal damage.

The biology of the weevil involves four developmental stages: egg, larva, pupa, and adult. The female lays eggs in small cavities made in the stems or roots. Larval development takes place entirely inside the host tissue, which provides protection from many external environmental factors and complicates manual control.

The damage caused by the larvae is characterized by tunnels that honeycomb the root system. Infested tubers develop a bitter taste and an unpleasant odor as a chemical defense reaction by the plant. This makes the crop unfit for human consumption or livestock feed, leading to total yield loss in severe cases.

Effective management strategies include cultural practices such as crop rotation, deep plowing to destroy infested residues, and the use of healthy, weevil-free planting material.

• Using pheromone traps for monitoring populations
• Applying integrated pest management (IPM) practices
• Selecting resistant sweet potato varieties