1. Institut de l'Environnement et de Recherches Agricoles (INERA), 04 BP 8645, Ouagadougou 04, Burkina Faso
2. International Crops Research Institute for the Semi-Arid Tropics, Niamey (ICRISAT), BP 10193, Niamey-Niger
3. Université Ouaga I Pr Joseph KI-ZERBO, BP 7021, Ouagadougou, Burkina Faso
4. Department of Entomology, Michigan State University, East Lansing, MI, U.S.A