Cowpea (Vigna unguiculata (L.) Walp) is an important food staple in sub-Saharan Africa. The legume pod borer Maruca vitrata Fabricius is one of the key pests of cowpea as the larvae feed on the tender parts of the stem, peduncles, flower buds, flowers and on pods of the plant, causing significant yield losses. Understanding the seasonal and geographical patterns of M. vitrata is essential for the establishment of effective pest management strategies. Sites in three ecological zones in Burkina Faso were sampled for the presence of M. vitrata adults and larvae both during and outside of the cowpea-growing season. Our data suggest that M. vitrata do not maintain a permanent population in the Sahelian or Sudano-Sahelian zones, but emigrate from the Sudanian zone where M. vitrata populations evidently may occur throughout the year.