Natural mating of instrumentally inseminated queen bees

Abstract - Virgin queens homozygous for the recessive cordovan body color gene were inseminated with semen of cordovan drones. The queens were divided into 4 groups and were treated as follows: 1), inseminated with 8 mm³ of semen; 2), treated with CO₂ before insemination with 8 mm³ of semen; 3), inseminated twice with 4 mm³ of semen; and 4), treated twice with CO₂, ie before and after insemination with 8 mm³ of semen. Queen excluders were removed from the entrances after the last treatment. Mating nuclei were placed in the apiary with dominant black drones. The number of emerging cordovan and black workers was determined. Of the queens which were only inseminated once, 50% mated naturally; however, out of those additionally treated once with CO₂, only 25% mated. No queen from the 2 other groups mated naturally. The ratio of wild black progeny originating from queens which also mated naturally was on average 33.4% for group 1, and 6.2% for group 2. Queens from group 1 additionally mated naturally on average with 3 drones per queen, and those from group 2 with only 1 drone per queen. Double insemination with the same total amount of semen or 2 additional CO₂ treatments prevented additional natural mating of instrumentally inseminated queens.