Cannibalism in Bee Species

Until recently, I was under the impression that Queen bees were the only organisms in a bee colony that were able to reproduce and have offspring. Apparently, I was mistaken. It turns out that in many different species, worker bees have functional ovaries and are able to lay eggs. The only con being that they can't mate, which is why they end up producing unfertilized eggs. However, I found it really interesting that if the worker bees produced an unfertilized egg, the egg would eventually become a male if it was raised! In fact, this was exactly how male bumblebees were born!

However in certain bee species, such as the honeybee, some of the other worker bees would keep each other in check by killing and eating eggs that were laid by other workers or "confronting" them.

In 1964, William Hamilton an English biologist proposed his "relatedness hypothesis". It basically said that worker bees did not reproduce because most of the worker bees were half sisters. Instead the workers favored the queen's sons because she had mated with multiple males, ensuring variation in the species. Therefore, Hamilton's hypothesis predicted that in a bee species where the queen bee had multiple male partners, there would be a higher rate of cannibalism (consumption of the unfertilized eggs) within the worker bee population of that bee species' colony.

To prove this hypothesis, two scientists from the University of Sheffield: Tom Wenseleers and Francis Ratnieks, studied and compared 90 different bee species and found that worker bee's sons are reared 100 times less in a species where the queen bee has had several mating partners AND that in all of those species, the Queen Bee also took part in consuming the unfertilized eggs of the worker bees.

Posted by Luzviminda Maurillo (10)