Friday, September 9, 2011

Drones have a grandfather but no father...or Let the girls do ALL the work!

The lowly honeybee, feared by many, ignored by most is probably the most important insect that has ever lived on the Earth.  The Latin name, Apis mellifera, was coined in 1758 by Carolus Linnaeus.  The name literally means "honey-bearing bee."  Linnaeus soon realized his mistake--that is that bees carry nectar and make honey so he tried to change the name to Apis mellifica which means "honey-making bee."  Alas, the rules got Linnaeus too and the official naming committee said the earlier name had precedence.

Regardless of its name the honeybee is most important not for carrying or making honey but for its role in pollination.  Corn, wheat, oats, and other cereal crops are wind pollinated, meaning that wind blows the pollen from one plant to another, but all our field crops and fruit and nut crops depend on pollinators to move the pollen from one flower to another.  Most of the field, fruit, and nuts will not develop empty fruit--that is fruit without seeds.  (Yes, in another blog we will address seedless fruits like bananas, grapes, watermelon, and some oranges.)
Those pellets of pollen go back to the hive as feed.  The pollen grains on her body do the pollinating of the crops.

Without pollination, no seed formation, and no fruit formation, and no food on the shelf at the grocery store, farmer's market, or in your own pantry.

Almost all the work in the hive is done by sterile females called "workers."  There is one queen in the hive and it is her job to lay eggs where the workers tell her to.  When a new queen is needed, the workers know this and begin the process of producing a new queen and at the same time they produce some drones.

Drones have one function and that is to mate with the queen and then they die.  They do not eat on their own while in the hive, they are fed  by workers.  They have no sting to provide defense to the hive.  When the new, virgin queen leaves the hive, they accompany her.  It is best for the hive if drones from another hive also accompany her to provide diversity in genetic makeup; however, it is not absolutely necessary.

The new queen flies further and higher until all the drones have fallen away but one.  That one, the strongest of the "suitors" is the one with whom she mates.  He then dies and she saves his semen to be used throughout the rest of her life to fertilize her eggs.

The workers build the cells in the hive.  Most are the same, six-sided and small cells that fit together so well in the hive.  The workers keep track of the eggs laid by the queen, how many hatch, how healthy they are, etc.  When the queen shows signs of declining in her effectiveness as a worker bee producing machine, they build several larger cells called, not surprisingly, queen cells.  

The queen lays eggs in these cells as directed by the workers and in effect ensures her own demise.  The queen has an un-barbed sting so she can sting over and over, while the workers can only sting once.  If the queen figures out what is going on, she will sting the new queens to death right in their cells.

If she doesn't realize until the new queens are hatched, then she will be challenged by one of the new queens and will take her loyal followers and swarm.  That is where a swarm comes from.  One of the biggest facades of all is the beekeeper who comes and bravely captures the swarm and saves the lives of everyone around.  That is because, without a hive to protect, the bees are quite docile and go willingly into whatever he provides for them to build a new hive in.  Often this hive is not long-lived for obvious reasons.

The new queen who exhibits dominance is chosen by the hive as their new queen and the others that hatched near the same time are stung to death.

We need to get back to the three kinds of bees and where they come from or how they are formed from one queen having mated once.  It is a pretty cool method.  The workers who are the queens attendants form a shield around her.  There are three on each side, facing her, and one at each end, facing her.  They effectively push her around where they want her to go.  When she backs down into a cell to lay an egg, the posterior part of her body curves toward her head which allows a tiny amount of semen to be discharged from the seminal vesicle and fertilize the egg.  The workers then feed the larva that comes from this egg royal jelly and pollen for a few days and then just pollen until it forms a cocoon and pupates.  This egg eventually develops into a worker bee.  This bee has genes from the queen and her mate but cannot reproduce itself.

When it is time for a new queen, the old queen deposits the egg exactly as above but into a larger cell.  This time the workers feed the larva royal jelly and pollen for its entire life as a larva until it pupates.  This one comes out a queen.  She is fully developed and able to reproduce.

When it is time for drones, the workers make a larger cell but it is oriented slightly differently.  This time, to back down into this cell she must flex her posterior slightly away from her body, which pinches off the seminal vesicle so no semen is allowed to fertilize the egg.  This individual becomes a male with only half as many genes as the workers or queen.  Since he develops from an un-fertilized egg, he has NO father, but the queen's father is his grandfather...cool riddle, huh?

All the honeybees you see are sterile female workers with quite a busy schedule.  Since they have to gather pollen and nectar and get back to the hive, and since they die if they sting you, they really do not WANT to sting you.  If you leave them alone, they will leave you alone.

Their jobs include cleaning out the cells, carrying dead bees out of the hive, fanning their wings to keep the hive cool and fanning their wings to keep it warm in the winter, feeding larvae, gathering nectar and pollen and no doubt other things too.