Honeybee Reproduction, Part II: Nutrition and Pheromones
Note: If you haven’t already done so, you can read Part I here.
Hold on to your hats, ‘cause this story contains awesome parenting, sexual suppression, and murderous rampages!
A honeybee egg hatches after three days, and then emerges a tiny white larva that is completely helpless. It is meticulously cared for by its older sisters, who feed it a protein rich substance called royal jelly, from a special gland in their head. All bee babies get the same food for the first three days, and then an interesting phenomenon happens as the bees use nutrition to manipulate the development of workers vs. new queens.
Here our story must split into three: drones, workers, and queens. After three days, all of the males and most of the females begin receiving a different mixture of food that still includes some royal jelly, but also includes bee bread (pollen packed and fermented with bee spit) and honey. Drones have the longest gestational period. They are sealed into horizontal cells on day ten, emerging fourteen days later on day twenty-four, and reach sexual maturity two weeks later.
The workers are capped in horizontal cells on day nine, and emerge on day twenty-one to begin their life of toil for the good of the colony. Worker bees have ovaries but they are underdeveloped. The queen bee produces a pheromone that permeates the hive and suppresses the reproductive organs of her working daughters and sisters. When a hive loses its queen and is unsuccessful at raising a replacement, occasionally a few of the workers from the doomed colony will begin to lay unfertilized eggs. These laying workers have abdomens that are too short to reach the bottom of the cells and they are unpracticed, which results in eggs attached to the walls of the cells and multiple eggs laid in one cell. This is their last ditch effort to carry on the colony’s genetics in the form of drones that will hopefully mate with virgins from other hives.
Laying workers are unskilled and lay multiple eggs in one cell
Now let’s return to nutrition and how it relates to the production of queens. If the colony needs a new queen, either to supercede (replace) a failing older queen, or to send out a swarm (more on that later), they will select a few larvae and forever change their destiny by feeding them differently from their sisters. These few royal selects are provided with large quantities of protein rich royal jelly throughout their larvaehood. This concentration of nutrition causes developmental changes that include larger size, the development of ovaries, and a spermatheca. Eight days after the egg was laid, the cell is capped and the developing pupa is left in the dark to mature.
The queen cell looks much like a peanut hanging in the hive, with the queen situated vertically inside the cell with her head down. On day sixteen, the virgin queen chews her way out of the cell. She emerges with a blood lust that would rival any zombie; after a quick honey snack, she goes on a murderous rampage! She tracks down any queen cells that contain potential rivals, chews a hole in the side, inserts her stinger and stings to death the pupa inside. If two virgins have emerged simultaneously, they will “pipe” loud threats at each other before fighting to the death. The workers themselves will do one of two things while this is going on: if they raised the new queen due to the failure of the old, they will allow the virgin to kill the old queen. If the workers raised the new queen in order to swarm, they must keep both queens alive in order to separate and form a new colony. The workers will protect the old queen from the younger, stronger, and more agile newcomer until the colony is ready to split. Next we’ll explore the impressive springtime phenomenon of swarming!
Stay tuned for Part III!