Greater yam beetle (Heteroligus meles)
Heteroligus meles is widespread in tropical Africa. It attacks the tubers. Adult beetles eat the planting setts and plants may wilt and die. The holes in tubers reduce market value.
Adult beetles are 23-33 mm long, dark brown to black, with 2 prominent knobs on the head. The beetles lay eggs in the soil close to river banks and these hatch to produce creamy-white to grey larvae, which feed on grass roots and other organic matter. From egg to adult takes 22-24 weeks and emergence coincides with the beginning of the rains and the planting of yams. Further attack occurs just before harvest when the beetles again feed voraciously and then migrate to the breeding sites.
- Yam beetles can be controlled by planting as late as possible in the season.