Systematics of the African cassava whitefly: identifying the enemy to increase food security

There has been an unprecedented increase in cassava-whitefly, Bemisia tabaci, abundance in the cassava growing regions of East and Central Africa.  The cassava whitefly is responsible for vectoring the plant viruses that have caused two on-going and devastating pandemics, Cassava Mosaic Disease (CMD) and Cassava Brown Streak Disease (CBSD).  Estimates for resulting production losses in nine East and Central African countries have been put as high as 47% and the areas affected are continuing to expand, resulting in hunger, recurrent famines and annual losses of more than US$1.25 billion.

Whiteflies, Bemisia tabaci (sensu Russell), are now recognized to be a group of more than 34 morphologically indistinguishable species. Although Africa is the evolutionary origin of B. tabaci, its diversity there remains poorly studied and so the number of species in this group will continue to increase. Several African B. tabaci species feed on cassava and the rapid spread of cassava virus-diseases has been associated unequivocally with high whitefly populations of the species.

 In this project, we will carry out the research required to understand the genetic variability of B. tabaci species currently present in East Africa. To achieve this, we shall generate the first multi-gene (including nuclear genes) phylogeny for the Bemisia tabaci species complex, which will clarify B. tabaci species boundaries generally and provide an improved and robust systematics framework.

Collaborator/s

  • Tanzania
  • Uganda, Malawi
  • Kenya
  • United Kingdom
  • USA
  • Spain
  • Israel
  • Colombia and China