Field Study Reveals Optimal Practices for Introducing Virgin Queens

For much of my beekeeping life, I have been fascinated by the trickier aspects of our noble craft. One of these is queen introduction, although my focus has generally been on mated queens. However, there are queen producers selling virgin queens, and even queen cells, so this research paper (details below) caught my eye. The field study reveals optimal practices for introducing virgin queens. Their conditions were much hotter than in my area, and their introduction methods were slightly different, but it’s still worth a look, methinks.

Introduction

The acceptance of virgin queens can be challenging, with various factors influencing the success rates. These factors include the duration the colony has been queenless, the age of the virgin queens, the method of introduction, and environmental conditions such as weather and nectar flow. Previous studies have shown that queen acceptance rates can vary widely, and beekeepers often face difficulties in ensuring successful re-queening.

This study aimed to provide comprehensive, data-driven recommendations for beekeepers to increase the frequency of successful virgin queen introductions. Conducted in central Latvia during the summer of 2023, the research involved introducing 754 virgin queens of different ages and 194 queen cells into mating nuclei using three different methods. The study explored the effects of the queenless period, queen age, introduction method, seasonal timing, and the presence of laying worker bees on the acceptance rates of virgin queens.

Reference: Smilga-Spalvina, A., Spalvins, K., & Veidenbergs, I. (2024). Field study: Factors influencing virgin queen bee acceptance rate in Apis mellifera colonies. Czech Journal of Animal Science, 69(4), 155–164. https://doi.org/10.17221/22/2024-CJAS

Key Findings:

1. Queen Acceptance Rates:

• The acceptance rate of virgin queens in bee colonies is significantly influenced by the period the colony has been queenless. Queens introduced after a queenless period of 5–8 days had the highest acceptance rates (68-69%), compared to those introduced after just one day (41%) or 2–4 days (48%).

• The age of the virgin queens also plays a crucial role. Newly emerged queens (0-4 hours old) had the highest acceptance rate in 1-day queenless colonies (75%). For queens aged 1–4 days, the acceptance rate was significantly lower (9-18%), but it improved for queens aged 5 days or more (44%).

2. Introduction Methods:

• Three methods were tested: direct release with honey-ethanol spray and smoke, caging for one day with honey-ethanol spray and smoke, and direct release without smoke. The acceptance rates ranged from 43% to 60% but did not show statistically significant differences.

3. Seasonal and Weather Influences:

• The acceptance rates varied significantly across different weeks within the season, influenced by weather conditions. For instance, acceptance rates were lowest during rainy periods and higher during weeks with better weather conditions.

4. Presence of Laying Workers:

• In colonies with laying worker bees, the acceptance rate of virgin queens was 55%, compared to 65% in colonies without laying workers. There were no statistically significant differences between these two scenarios.

Implications for Beekeepers:

1. Preparation of Colonies:

• Beekeepers should prepare colonies by ensuring they are queenless for at least five days before introducing a new virgin queen to achieve higher acceptance rates. This preparation helps eliminate emergency queen cells and increases the likelihood of the colony accepting the new queen.

2. Timing and Age of Queens:

• Introducing newly emerged queens (0-4 hours old) is optimal for colonies that have been queenless for only one day. However, if this is not feasible, using queens aged at least five days old is recommended, especially when the colony has been queenless for longer periods.

3. Introduction Methods:

• While the study found no statistically significant differences between the three introduction methods tested, beekeepers can choose based on convenience and preference, knowing that each method has a relatively similar success rate.

4. Seasonal Considerations:

• Beekeepers should consider weather conditions and nectar flow when planning queen introductions. Introducing queens during favourable weather conditions can significantly enhance acceptance rates.

5. Managing Laying Worker Colonies:

• Even in colonies with laying worker bees, introducing virgin queens without the labor-intensive shaking-off method can be successful, saving time and effort.