Numbers of spermatozoa in queens and drones indicate multiple mating of queens in Apis andreniformis and Apis dorsata G. Koeniger, N. Koeniger, M. Mardan, R.W.K. Punchihewa and G.W. Otis Apidologie, 21 4 (1990) 281-286 DOI: 10.1051/apido:19900402