To celebrate fathers day this year we thought we'd share a fun fact about male honey bees.
Male honey bees - or Drones to give them the their correct title - have a grandfather, but no father... They also don't have sons...
Wait, what?!?.. How is that possible?
The answer is parthenogenesis. In short, its a form of reproduction in which an egg can develop into an embryo without being fertilized by a sperm.
How do this work with honeybees?
A queen bee goes on a mating flight when she is 2 weeks old where she will mate, mid air, with about 15 male drone bees. She stores all the sperm from these bees in her spermatheca - which is a small round ball inside her ovaries.
After the mating flight she will return to the hive and after a short while will start to lay eggs in the bottom of the hexagonal cells in the comb.
She will measure the size of the cell with her antennae. When the cell is <5mm she will know to lay a female egg, and therefore fertilises the egg with sperm on its way out of her oviduct (at the end of her abdomen near where her sting is). When the cell is >6mm she knows she is to lay a male bee, as male bees are larger and require a larger cell in which to pupate. She does not add any sperm to the egg therefore the resulting male bee had no father, but did have a grandfather as the Queen came from a fertilised egg.
The Queen's role in drone laying
The queen will only go on one mating flight at the beginning of her life. When she starts to run out of stored sperm the hive will raise a new queen to replace her. If they fail to do this the queen will eventually run out of sperm and become a 'drone-layer' and only lay male bees resulting in the colony collapsing.
Inside the hive
The ratio of female worker bees to male drone bees inside the hive is decided by the colony as a whole, not by the queen, and is determined by outside factors such as temperature, food resources and time of year. During the summer drones make up about 5% of the number of bees in the hive.
Some of the worker bees are wax builders and they will build or adjust the size of the cells as needed to determine how many drones the colony has. The workers may also kill adult drones or forfeit pupating larvae if circumstances change.
Some more quick facts about drones.
They have no sting.
They take 24 days to pupate from egg to bee instead of 21 like female worker bees do.
Drones will be 'kicked out' the hive as winter approaches. No mating flights take place during the winter months and so the drones are just a drain on resources. New young fit drones are reared the following spring.