Posts Tagged: Eric Mussen
What's causing colony collapse disorder (CCD)?
Are we any closer to determining the cause?
CCD, the mysterious malady characterized by bees abandoning the hive, leaving behind the brood and food storage, continues to be of great concern--and rightfully so.
The headlines today read:
- Scientists discover virus that could explain drop in bee population--Science News, Timesonline
- DNA clue to honey bee deaths--BBC
A noted expert on honey bees, Mussen is frequently asked "The CCD Question."
What does he think is causing CCD?
"As the pieces are coming together, I think that a still undetermined virus is causing the problem," Mussen says. "The malady appears to be 'contagious' and 'drying' the combs seems to reduce or eliminate it."
"Our bees need to be in top physiological condition. I believe that malnutrition puts a physiological stress on the bees, especially the immune and chemical detoxification systems. Then diseases and exposures to chemicals become very significant."
Beekeepers who do a lot of supplementary feeding, he says, see fewer problems.
So, if you're a beekeeper, place your hives in locations with an abundance of high quality pollens and nectar.
And don't ignore those combs.
"If a beekeeper has them on hand, the bees most likely would be better off on newer, less contaminated (with mite-killing compounds) combs," Mussen says.
How can we help? We can plant trees, ornamentals, and flowers that provide food for the bees. "It's especially important to provide nectar and pollens at the end of the season--late summer and fall," he says. "That's when resources tend to become scarce."
What else can we do? Stop using pesticides on plants that bees visit. "The most suspect group of pesticides at this time are the neonicotinoid insecticides that move systemically in the plants," Mussen says. "They get into the nectar and pollen. However, the fungicides, thought by many to be benign to honey bees, are pretty common contaminants and may be causing more problems than we think."
Meanwhile, the search for the cause(s) of CCD continues.
Entomologists, geneticists and virologists are still searching for the cause of colony collapse disorder (CCD).
Yes, they're still searching, and no, there' s no known cause yet.
CCD is a mysterious phenomonen characterized by adult bees abandoning the hive. They leave behind the brood and stored food.
When we attended the 55th annual meeting of the Entomological Society of America in December 2007, one of the highly attended seminars dealt with the plight of the honey bees. Pennsylvania State University entomologist Dennis vanEngelsdorp and USDA entomologist Jeff Pettis were among those addressing the crowd.
In research just published in PLOS One, a peer-reviewed science publication, they and their colleagues found that a higher total load of pathogens--viruses, bacteria and fungi--appears to show the strongest link yet with CCD.
The researchers examined 91 colonies from 13 apiaries in Florida and California. They screened for bacteria, mites, Nosema (protozoan parasites) numerous viruses, nutrition status and 171 pesticides. They also sampled adult bees, wax comb bee bread (stored and processed pollen) and brood.
"Of 61 quantified variables (including adult bee physiology, pathogen loads, and pesticide levels), no single measure emerged as a most-likely cause of CCDm" they wrote. "Bees in CCD colonies had higher pathogen loads and were co-infected with a greater number of pathogens than control populations, suggesting either an increased exposure to pathogens or a reduced resistance of bees toward pathogens. Levels of the synthetic acaricide coumaphos (used by beekeepers to control the parasitic mite Varroa destructor) were higher in control colonies than CCD-affected colonies."
Their research, the first comprehensive survey of CCD-affected bee populations, suggests that CCD "involves an interaction between pathogens and other stress factors," they wrote. They presented evidence that CCD is "is contagious or the result of exposure to a common risk factor."
Bottom line: High pathogen loads are linked to CCD symptoms, but scientists still don't know what causes bees to become infected with SO MANY pathogens.
What this research does is narrow the direction of future CCD research. It's a big step in the right direction.
"Help the bees" continues to be a resounding cry. Helping to fund the research is Häagen-Dazs (about 50 percent of their ice cream flavors depend on bee pollination). Those visiting their educational Web site can donate funds to Penn State and UC Davis.
Plight of the Honey Bee
Beekeepers consider stings just a part of their job.
However, say the word "bee" and John Q. and Jane Q. Public may not think about the pollination of fruits, vegetables and nuts. Or the end product: honey.
The bee conjures up the "S" word: sting.
Of the scores of questions that Extension Apiculturist Eric Mussen has fielded since 1976 (when he joined the UC Davis Department of Entomology faculty), many relate to bee stings.
Here are his answers to some of the most commonly asked questions:
1. Can a honey bee sting kill you?
If a person is highly sensitized to honey bee venom, one sting could be fatal, causing anaphylactic shock. Otherwise, it is just painful and likely to cause some swelling and local tenderness that will last for two or three days.
2. How do you treat a honey bee sting?
Try to remove honey bee stings as quickly as possible, since venom is pumped from a sting into the victim for 45-60 seconds. Stings are easily scraped off with a fingernail. If many honey bees are stinging, leave the area quickly and deal with the stings when you are out of range of the defensive area (about 100 feet with European honey bees, but up to ¼ mile – 1,320 feet – with Africanized honey bees). The pain can be reduced a bit by putting ice on the sting site, but the stabbing pain backs off fairly quickly without any treatment.
3. Can a honey bee hear you?
Honey bees do not have sensory organs that can pick up sounds that we can hear. They are very sensitive to vibrations. They feel us walking toward the nesting site before we get there.
4. Why do beekeepers use smokers when they visit their beehives?
The smoke from the smoker has three effects on the bees. First, it prevents the guard bees from liberating much “alarm pheromone” (smells like bananas) in the hive. Second, it prevents “soldier” bees in the hive from smelling the pheromone that has been secreted. Third, it causes many bees to fill up on honey. Despite the wives’ tales to the contrary, there is no reason to believe that the bees “think” there is a fire or that bees full of honey cannot sting.
5. Can honey bees see color?
Yes, honey bees can see nearly all the colors we see. They cannot see red, which looks black to them. They can see into the UV wavelengths a ways, which is beyond our limit at purple. UV looks black to us.
6. Do honey bees need to eat meat?
No. Unlike wasps, honey bees derive nearly all the important ingredients in their diet from pollens. Pollens contain protein, fats, vitamins, minerals, carbohydrates, sterols, and many plant-derived antioxidants. No single pollen contains all the essential ingredients, so colonies do best where a good mix of attractive flowers are available. Nectar, the dilute sugar syrup honey bees collect from flowers, contains mostly sugar, an energy food. The flavor and color of honey depend upon the source of the nectar from which it is condensed.
There you have it: The A, Bee and C of the most commonly asked questions.
Bottom line: Sure, bees can and do sting, but our survival depends on them. Bees pollinate one-third of the food we eat (fruits, vegetables and nuts). They pollinate some 100 crops in California, including about 700,000 acres of almonds.
“The value of California crops pollinated by bees is $6.1 billion,” Mussen says.
Site of the Sting
Honey bees--what do you know about them?
Do you know what the queen bee, worker bees and drones do? Do you know why bees swarm? Do you want to learn to be a beekeeper? Or, if you already are a beekeeper, how do you keep your hives healthy? If you're a researcher, what are your colleagues doing? Are we closer to finding the cause/causes of colony collapse disorder (CCD)?
You'll find the answers to those questions--and more--on a newly launched Bee Health Web site, the work of Cooperative Extension or "eXtension."
Coordinated by John Skinner, a professor and Extension apiculturist at the University of Tennessee, Knoxville, this Community of Practices project is the work of scores of experts across the country, including our own Extension apiculturist Eric Mussen of the UC Davis Department of Entomology faculty. In fact, he and UC Davis native pollinator specialist Robbin Thorp, emeritus professor of entomology, are among those featured in videos on the site. In addition, yours truly has some bee photos on the site.
Our hat (okay, our bee veil) is off to Skinner; vice chairs Keith Delaplane, professor at the University of Georgia; Jeffery Pettis, research leader at the USDA's Agricultural Research Service (ARS) Bee Research Laboratory, Beltsville, Md., and IT technologist Michael Wilson, University of Tennessee.
Skinner hopes this will be the "go to" site for beekeeping information and bee science.
Indeed! This is like having the best and brightest minds in the research laboratories and bee industry at your workplace or in your living room.
If you have a question about bees, all you need do is ask. The cadre of experts will "bee" there for you.
Honey bee on Almond
The honey bee hive is not all sweetness.
The first virgin queen bee to emerge from her cell (each queen cell resembles a peanut shell) will rid the colony of her competition.
After emerging, the queen makes a mark on the other queen cells. That's an indication--or really, an order--for the worker bees to destroy the developing queen inside, says Cooperative Extension Apiculturist Eric Mussen of the UC Davis Department of Entomology faculty..
There can, after all, be only one queen bee in the hive.`
"The queen bee develops from a fertilized egg that hatches three days after being laid," wrote authors Eric Mussen, Len Foote, Norman Gary, Harry Laidlaw, Robbin Thorp and Lee Watkins in the UC Agriculture and Natural Resources booklet, Beekeeping in California, published in 1987. "Nurse bees, a class of worker bee, feed developing queen larvae a special diet consisting mostly of the royal jelly that they secrete from their glands. This special diet shortens the time spent to reach maturity to 16 days, compared with 21 days for the worker bee and 24 for the drone (male). The result is a bee larger than any others, with fully developed ovaries and a very large abdomen."
"The queen," they explain, "is reared in a large cell resembling a peanut shell that hangs vertically from the comb and about 10 days after emerging, she becomes sexually mature."
Then she takes one or more mating flights, mates with 10 to 20 drones, and returns to the hive to spend the rest of her life laying eggs. In her two-to-three-year life span, she'll lay about 1000 eggs a day. In peak season, she'll lay about 2000 eggs a day.
She's queen for the day, and every day.