Gel-coated tubes extend above-freezing storage of honey bee (Apis mellifera) semen to 439 days with production of fertilised offspring

Abstract

Honey bees are an important agricultural species; however, relatively little work has been done to improve artificial reproductive technologies for this animal. The collection and distribution of germplasm for breeding and conservation is critical for improving managed honey bee populations and conserving threatened subspecies. The most efficient method of controlling breeding in honey bees is by artificial insemination. The collection of semen for insemination requires the use of antibiotics, which is especially critical if semen is to be stored for any length of time. The introduction of antibiotics is normally done through a balanced salt solution. In this study we compare, at two temperatures, the storage of undiluted semen in antibiotic–gel-coated capillary tubes with storage of semen diluted in a balanced salt solution containing antibiotics. Live–dead cell staining and artificial insemination of honey bee queens were performed at 45, 99 and 439 days after collection of the semen. In every case the antibiotic–gel-coated tube storage method at 14°C produced a higher percentage of fertilised offspring. This study demonstrates the longest period of time spermatozoa have been stored above freezing while maintaining fertilisation capacity.