Instrumental insemination is a fundamental technique in the moment when we select and improve the honeybee, not only in order to preserve our local ecotypes, but also due to the necessity to improve them, looking for hives with characteristics that increase the production and offer resistance to diseases (bees resistant to Varroa, Ascosphaeriosis, etc.). This study was carried out with the aim of comparing the activity of the colonies of Apis mellifera L. submitted to instrumental insemination with the activity of the colonies naturally mated. Following Schley’s insemination technique or natural mating, we compared treatments with regards to the percentage of losses, the effectiveness of the kind of treatment, the acceptance of the queens in the hives and the production of fertile queens that survived their introduction in the hives. The statistical analysis of the information was done using the ?2 Test. In the laboratory of Physiology and Reproduction of Superior Agrarian School of Bragança, we carried out the insemination of 30 queens and in the mating hive 26 queens were allowed to mate naturally. All the queens were selected according to their hygienic behaviour and their productiveness. With the instrumental insemination we obtained 80% of fertilized queens and, with the natural mating we obtained 85%. There were different frequencies (P<0.01) in the acceptance of the queens after their introduction in the colonies according to the kind of fertilization. Through the instrumental insemination the acceptance in the hives was 58.4%, and with natural fecundation was 72.7%. Likewise, the total number of fertile and living queens varied significantly (P<0.01) according to the kind of technique that was used. With the instrumental insemination, we obtained a production of 47.6% of fertile and living queens while the natural mated queens showed better results (61.5%).