- Reduced amount of stored sperm
- Queen runs out of sperm faster, resulting in supersedure or drone laying
- Reduced genetic diversity in colony
- Genetic diversity is critical for disease resistance and productivity
- Suboptimal pheromone production
- Queens inseminated with low volumes of semen produce less attractive pheromone blend and are more likely to be superseded
- Poor quality queens or drones
- Poor rearing conditions and/or nutrition, environmental toxins, parasites, diseases
- Poor mating conditions
- Bad weather
- Lack of healthy drones
- Queen production is not linked to drone production