- Author: Kathy Keatley Garvey
Varroa mites, those pesky little parasites that suck the blood out of honey bees and spread multiple viruses, are now found throughout the world, except in Australia.
Scientists blame these parasites as one of the causes of colony collapse disorder (CCD), characterized by adult bees abandoning the hive and leaving behind the queen, brood and food stores. They attribute CCD to a multitude of factors, including pests, pesticides, parasites, diseases, viruses, malnutrition and stress. Thus, varroa mites are a key factor in the declining honey bee population.
Today's honey bees are ill-equipped to rid their hives of a varroa mite infestation. Indeed, beekeepers consider the varroa mite (scientific name Varroa destructor) as Public Enemy No. 1.
And that's one of the reasons why we like bee breeder-geneticist Susan Cobey's efforts to increase the genetic diversity in our domestic honey bee gene pool.
Cobey, who has a dual appointment at the University of California, Davis and Washington State University, is directing a stock improvement program which aims to do just that.
"Increasing the overall genetic diversity of honey bees will lead to healthier and hardier bees that can better fight off parasites, pathogens and pests," she says.
"We have collected and imported honey bee semen (germplasm) from their original European homeland to inseminate select domestic queens produced by the California bee breeders," Cobey told us. These California breeders supply queen bees and package bees nationwide. Honey bees, as Cobey points out, "provide the essential pollination for our crops, especially in California, "the breadbasket" of our country and our world.
Cobey and her team have also re-introduced the subspecies, Apis mellifera caucasica, a dark race of bee known for its collection and use of propolis, self-medicating plant resins.
What does a mite look like? Check out the mite-infested drone below. A boy bee's only duty is to gather in the drone congregation area and mate with the queen during her maiden flight, but that won't happen with this one. No thanks to the parasitic mites, he has a weakened immune system, crippling his ability to fly.
What will happen to him? His sisters will kick him out of the hive and he will die.
- Author: Kathy Keatley Garvey
Drones--remotely piloted aircraft used in reconnaissance and target attacks--are in the news, but so are the other drones--male bees.
This time of year drones are as scarce as the proverbial hen's teeth. They're not needed in the hive now--just extra mouths to feed--so their sisters are booting them up. They're basically evicted, cold and shivering, from the hive.
Drones are easy to identify: big eyes, bulky body, and lumbering movements.
It's best to be a drone in the spring. When a virgin queen goes for her maiden flight, a group of drones will mate with her in the drone congregation area. The drones die shortly after mating. If they don't mate, then they'll die before winter sets in.
As Extension Apiculturist Eric Mussen of the UC Davis Department of Entomology faculty says: First the sisters stop feeding their brothers so they're easier to push out.
Then, out they go.
The sisters have no pity.
- Author: Kathy Keatley Garvey
It's not a pretty sight--the Varroa mite attacking a honey bee.
Beekeepers are accustomed to seeing the reddish-brown, eight-legged parasite (aka "blood sucker") in their hives.
UC Davis bee breeder-geneticist Susan Cobey, manager of the Harry H. Laidlaw Jr. Honey Bee Research Facility on Bee Biology Road, is among those who've declared war on the mites.
She's carrying out an intensive and comprehensive breeding and selection program aimed at developing honey bees that are resistant to pests and diseases.
The Varroa mite is a serious pest of honey bees worldwide, spreads diseases, and can weaken and destroy the colony. It is no doubt one of the culprits involved in colony collapse disorder, a mysterious phenomenon characterized by honey bees abandoning the hive.
Here's what the Varroa mite looks like attacking an immature bee.
- Author: Kathy Keatley Garvey
It's tough being a drone honey bee this time of year.
The drones, or male bees, don't survive the winter.
Bee breeder-geneticist Susan Cobey of the Harry H. Laidlaw Jr. Honey Bee Research Facility at UC Davis admits to having a soft spot for drones. Once the honey-gathering season is over, the worker bees (sterile females) evict the drones from the hive, as the only function of the males is to mate.
“They're cold and hungry, sitting there on the doorstep and wanting to go back in. They're attacked and they die. Well, it's a matriarchal society.”
Throughout the spring, summer and early fall, drones routinely leave the hive in mid-afternoon on a mating expedition. Last Friday at the Laidlaw facility, the drones exited the hives around 3 p.m. They wobbled out of the hive and then took off. The plan? Head for "the drone congregration area," said UC Davis apiculturist Eric Mussen. Drones congregate not far from the hive and wait for a virgin queen bee to arrive.
The virgin queen mates with mulitple drones, often as many as 12 to 25, and then returns to her hive to lay eggs for the rest of her life. She never leaves the hive after her maiden flight. "She's an egg-laying machine," as Cobey says.
For the drones, it's a different story. They mate and then they die. And if they can't find a mate? With the onset of cold weather and winter, if they try to return to the hive, their sisters won't let them back in. They don't want the drones taxing their food supply.
Oh, brother, where art thou?