If fantasy stories, or even our own history, are to be believed, being a royal was sometimes a dangerous endeavor. While ruling a kingdom certainly had its perks, the game of thrones could also be deadly, and might result in a swift end before you ever got a chance to rule.
This is also the case for a species of bees known as Melipona beecheii, according to a new paper published in the journal Biology Letters. Ricardo Caliari Oliveira from the Laboratory of Socioecology and Social Evolution at KU Leuven, and colleagues, investigated the species to uncover the mysteries behind their mass scale regicide.
“In most species, if the queen happens to die because she’s too old or not fertile anymore, they produce one queen to replace her. In the case of this species, at any given moment about 20% of the group that emerge are queens,” Oliveira told SYFY WIRE.
In the case of honeybees, which are perhaps the most well-known bee species, queens are created intentionally by the hive through a distinct set of processes. When a new queen is needed, the hive sets out to make one by crafting a special cell for the larva. That cell is larger than typical and is filled with specialized food called royal jelly.
The new queen is essentially selected before they even develop, and the combination of special treatments trigger their development. In M. beecheii, something wholly different is going on. For every new wave of bees, there’s a one in five chance they will develop into a queen. That means that each hive has thousands of potential queens vying for a throne which isn’t available.
“All these excess queens get killed and they don’t take over unless the existing queen happens to die,” Oliveira said. “This happens by chance, if a new queen happens to be in the right place at the right moment.”
Scientists want to understand why the species uses this sort of selection, as opposed to the intentional method utilized by other species. As it stands, it’s a massive waste of resources. One fifth of their total population is executed moments after their birth and tossed out of the hive. All of the food and energy used to rear them goes to waste.
Upon emerging from their cells, these virgin queens immediately go on the run as they’re chased down by other members of the hive. According to Oliveira, these queens are incredibly fast and sometimes they seek out hiding places in dark corners of the hive. Despite their speed and subterfuge, they are eventually captured, killed, and removed.
“Eventually they get beaten to death,” Oliveira said. “Or they get kicked out of the nest. Sometimes we see them on the ground outside, where they are eaten by predators.”
Initially researchers thought this overproduction of queens might have been an evolutionary strategy for spreading the hive’s genes through parasitism. In other species, bees will produce an excess of queens who then infiltrate competing hives and take over. Because queens produce all of the eggs for a given colony, this serves as a way for a particular lineage to spread their empire, essentially establishing new kingdoms, but that isn’t observed in M. beecheii.
“We looked for this behavior and what we saw was contrary to our expectations. We didn’t see any evidence of parasitizing in this case,” Oliveira said.
Instead, it’s believed that the overproduction of queens in this species is an example of the “tragedy of the commons,” in which there is competition between what is best for the individual and what’s best for the collective.
If any one individual bee manages to become the new bee, that’s a huge benefit for their particular genetic heritage. They then become the progenitor of the next generation of bees, but if every single bee attempted to become the new queen, the colony would collapse.
Consequently, natural selection settles into an equilibrium wherein the selfish ambitions of the individual are balanced with the needs of the colony. Apparently 20% is right about where those two forces meet. Still, it seems a rather inefficient process for maintaining a population.
We’re not saying the human royalty strategy is any better, but at least it doesn’t result in the consistent death of 20% of every generation.
