Infestations of tubers and sometimes foliage cause poor growth. Stored tubers are particularly susceptible to attack and large numbers cause shrivelling.
Adult female scales are pinkish-brown, roughly oyster-shaped, conical, with a white patch at the tip of the cone. Younger scales are relatively more white. Crawlers are yellow.
- Inspect yams in storage regularly, and remove those that become infested with the scale.
- Select tubers that are free of scale insects for planting.
Yam scale (Aspidiella hartii)