Selection's Double-Edged Sword: A New Perspective on Honey Bee Decline
- Frank Jeanplong
- Jan 14, 2025
- 2 min read
Beekeepers worldwide face the ongoing challenges of honeybee health, particularly in the fight against Varroa mites and related diseases. But did you know that selective breeding practices might be undermining honeybee resilience? A recently published article sheds light on how well-intentioned selection efforts could inadvertently contribute to honeybee decline by reducing genetic diversity critical for disease resistance.
Key Insights from the Article:
The Genetic Cost of Selection
Selective breeding for desirable traits (e.g., higher honey yields, calm behaviour, reduced swarming) often sacrifices rare genetic alleles. These rare alleles are crucial for natural disease resistance and pathogen adaptation.
The Role of Genetic Diversity
Honeybees rely on their high recombination rates and polyandry (queens mating with multiple drones) to maintain genetic diversity. This diversity enables colonies to combat emerging pathogens effectively. Selection, however, creates homozygous regions in the genome, reducing the efficacy of recombination.
Varroa Resistance: A Case Study
In South America and Africa, large, unmanaged populations of wild or feral bees developed resistance to Varroa mites through natural selection. By contrast, the heavily managed bees in Europe and North America lack this advantage, leading to higher colony losses.
Why Rare Alleles Matter
Rare alleles, often overlooked in small, selectively bred populations, may hold the key to combating new pathogens. Without large, panmictic populations, these alleles are lost forever.
Solutions for Sustainable Beekeeping
Prioritize the conservation of native subspecies to restore genetic diversity.
Reduce over-reliance on breed bees, allowing natural selection to enhance disease resistance.
Protect wild honeybee populations to serve as reservoirs of genetic variation.
Takeaway for Beekeepers:
Understanding the genetic implications of selective breeding can help beekeepers make informed decisions. Supporting practices that preserve genetic diversity—like allowing natural mating and maintaining local bee populations—can strengthen colonies against future challenges. By revisiting traditional breeding methods and encouraging a balance between selection and natural adaptation, we can give our bees the tools they need to thrive.
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