This is one of a series of articles about the 20 research projects for which CONNECTED provided pump-prime funding. A full set of articles about all 20 projects can be found here.

Identification of mealybug vectors involved in the transmission of Dioscorea bacilliform viruses infecting yam in northern Nigeria

A project seeking to understand the dynamics of a disease that devastates Nigerian yam crops

Nigeria produces more than 60% of the world’s yam. It is a crop that is a preferred staple food for at least 100 million West African people, and around a third of the gross income of Nigeria’s farmers is earned from yam. However, yields are significantly reduced by yam viruses and their insect vectors.

As well as being direct plant pests, mealybugs also act as vectors of badnaviruses, and at present little is known about how this happens. So this project is working to:

  • identify mealybug species infesting yam fields in northern Nigeria which are thought to be vectors of Dioscorea bacilliform viruses (DBVs)
  • detect and characterize DBV species in individual mealybugs, and
  • evaluate any correlations between certain mealybug- and DBV-species, which could inform insect vector specificity.

The project is helping our understanding of the dynamics of yam disease in the region, which is essential if effective disease control measures are to be developed. It will also assist yam breeding programmes. The project outputs have the potential to inform future insect vector control efforts in yam growing countries across sub-Saharan Africa.

Future project development

This project represents a first step in improving understanding of mealybug vector populations, the potential contribution of different mealybugs species in the transmission of different DBV species, and it could therefore inform future projects to investigate:

  • insect vector abundance and vector biology
  • transmission efficiencies of badnaviruses by individual mealybug species, and
  • DBV specificities of retention and potential virus transmission bottlenecks within mealybug species

At present DBV are difficult to diagnose, this project could enable more accurate diagnostic tests to be developed. This helps both determine the cleanliness of yam planting material supplied to farmers through multiplication and propagation projects, and how rapidly the material is likely to become infected.


  • Nigeria
  • UK

International research collaboration

  • Kebbi State University of Science and Technology, Nigeria
  • Natural Resources Institute, University of Greenwich, UK


  • Gonçalo Silva (PI)
  • Aliyu Abdullahi Turaki
  • Colin Andrew Michael Campbell
  • Susan Seal

Network members can find further details about those involved in the project by logging in to this site as a member, and using the Member Directory.

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