Hybridization between European and African-derived honeybee populations (Apis mellifera) at different altitudes in Perú J. Javier G. Quezada-Euán, Eleazar E. Pérez-Castro and William de J. May-Itzá Apidologie, 34 3 (2003) 217-225 DOI: 10.1051/apido:2003010