How man and nature are killing the honeybee
By Art Van Kraft 05/08/2014
“Honeybees are flying dust-mops. They fly through a number of environments, and many agricultural environments are laced with pesticides. — Anonymous beekeeper.”
As April flowers bloom throughout Ventura County, a worker honeybee (which is an incomplete female) begins the most productive period of her short life. Her hive will be trucked to a farm field for the spring season. If it’s a raspberry field, she and her sisters will dodge in and out of the curved weather hoods over the crops. The white hoods are hard on bees and many will be trapped and die. The demands of gathering pollen and nectar will also take a toll and her wing muscles will wear out in about six weeks. In that time she will pollinate hundreds of plants and make about a tenth of a teaspoon of honey. Scientists recently found one of her ancient ancestors in a block of amber, and realized that bees have been around more than 100 million years, since plants first appeared on earth. In all that time, they survived and even thrived, until now.
“The current U.S. environment seems to be very stressful to honeybees. People have changed the equation too quickly for bees to adapt. We’ve altered their environment in a way that is detrimental,” said U.C. Davis bee expert Eric Mussen. “I am not a doom-and-gloom scientist, but I realize that things we have done are contributing to a death in bees. If we take a closer look at our worker bee today, we will see many changes.”
On the Oxnard plain, when you see a honeybee zoom by, you are probably looking at some farmers tiny livestock. As she goes about the business of being a bee, she’s almost certainly carrying parasites. There are many, but the Varroa destructor mite is the most dangerous; they carry viruses. She will also have been exposed to numerous toxins throughout her life and her immune system will be weakened. In the end, if she is in the unlucky 30 percent of bee hives, she will become a victim of colony collapse.
Photo by: Scott Alan Mount
New virus turns bees into zombies
“Honeybees can become the unwitting hosts of a fly parasite that causes them to abandon their hives and die after a bout of disoriented, ‘zombielike’ behavior, San Francisco State University researchers have found.” That’s according to the American Bee Journal news. The phenomenon was first observed on the SF State campus. The bizarre discovery may help scientists learn more about colony collapse disorder (CCD). This mysterious ailment has drastically increased honeybee colony losses since it began in 2006.
According to the study, the parasite fly deposits its eggs into a bee’s abdomen. “Usually about seven days after the bee dies, fly larvae push their way into the world from between the bee’s head and thorax. But it’s the middle part of this macabre story that may be the most scientifically interesting to those studying the dramatic and mysterious disappearance of honeybees. After being parasitized by the fly, the bees abandon their hives in what is literally a flight of the living dead to congregate near lights. When we observed the bees for some time — the ones that were alive — we found that they walked around in circles, often with no sense of direction,” researchers said.
Bees usually stay in one place, curling up before they die, but the parasitized bees were still alive, unable to stand up on their legs. “They kept stretching them out and then falling over. It really painted a picture of something like a zombie.” (Jan. 3, 2012, issue of PLOS ONE.)
Colony collapse disorder (CCD) was first noticed in 2006. It is a mysterious condition that causes worker bees to die or abandon the hive or apiary, as it is called. U.C. Davis expert Mussen said there are combinations of factors that suppress the immune system, including stress. Bees are often shipped thousands of miles on flatbed trucks. It takes billions of honeybees from around the U.S. just to pollinate the spring’s crop in California. The pesticides used in those fields can also have a negative impact.
“Exposure to pesticides during the early life stage of a honeybee’s life looks like it contributes to poor nutrition or poisoning with an impact on the survival of the entire bee brood. The bee insecticide problem may never be resolved to everyone’s satisfaction, but it appears that there’s probably not much of anything out there pesticidewise that is benign to honeybees,” Mussen said.
He explains that honeybees have been exposed to bee-toxic plants probably since the beginning of their existence. “From the earliest times, those toxins were happening naturally, plant-protective compounds secreted in nectars, pollens and resins. Over time, the bees worked out their differences with nature and have survived until today. Once humans truly began to impact the environment, honeybees have had to deal with human-applied compounds, many of which are quite toxic to honeybees.”
“It’s a complex issue,” he said, “but one thing is certain: It seems unlikely that we will find a specific, new and different reason for why bees are dying.”
Although the cause of CCD is unknown, scientists have discovered a high number of viruses, pesticides and parasites present in collapsed colonies. The high levels add to weakened immune systems, making the bees more vulnerable to pests and pathogens.
Four pesticides commonly used on crops to kill insects and fungi also kill honeybee larvae within their hives, according to Penn State and University of Florida researchers. Some chemicals used as pesticide additives are highly toxic to honeybee larvae. These pesticides may actually poison honeybee larvae or may kill them indirectly by disrupting the beneficial fungi that are essential for nurse bees to process pollen into beebread.
Larry Pender operates the Jubilee Honey Bee Company in Camarillo. He has given up on farming honey for a living and has switched to pollination.
“My main business is pollination now. Farmers actually pay us to bring our beehives on their property to pollinate the crops. Almond trees in the San Joaquin Valley pay about $180 a beehive per season. Avocados, blackberries, blueberries pay a little less. Years ago, honey was the main product; we’ve switched over where pollination is the main business. The honey is just not there because of the lack of rain, and that’s it. In California we don’t even make enough honey for the bees to survive year-round,” Pender said.
Berries are a big business for Pender in Ventura County. “Raspberries need bees year-round and supply good pollen some of that time, but the weather hoods that cover the crops make it tough on the bees to survive. I lose anywhere from 40 to 80 percent of my bee hives. Bees are like livestock, there are management techniques and production. Just leaving the honey with the hives doesn’t solve anything; it doesn’t make sense. They make a lot of it in a short period of time, and we manage that.”
“Our biggest problem is rain. Quite honestly, government organizations always run up and down and say they will solve problems, but I don’t believe that; they never have. In California we have plenty of plants good for bees, but we need rain,” Pender said.
He explains that prior to 250 years ago there were no European honeybees in this area. In California there are about 4,000 species of native bees. “The drought has caused a major decline in the Africanized honeybee. They are not surviving well. There has been a fundamental change in the way pesticides have been used in the last seven years. Instead of spraying a pesticide directly on the insect and killing it, we have been using systemic pesticides.”
Systemic pesticides are fairly new. The chemical is not sprayed on the plants, but put into the water, where it goes directly to the flowers. Unfortunately, the bees drink nectar from the flowers. So far, the chemicals are supposed to be used at nonlethal levels, but violations occur. Rudy Martel, chief deputy agricultural commissioner of Ventura County, says that while they try to monitor pesticide applications, they can’t be everywhere at once.
Bennett’s Honey Farm in Fillmore is under the supervision of Chip Vannoy. He’s been a commercial beekeeper for decades and continues to harvest honey despite the drought.
“We operate about 6,000 colonies. We winter them down in the Fillmore-Ventura area. They go to Sacramento for blueberry and almond pollination in March, then back to Ventura County for oranges and avocado. Because of the drought here, we are taking the bees over to Georgia and Florida.”
Honey still pays, Vannoy said, but in tough times the bees can suffer. “We are primarily a honey operation and the mono culture is really poor for the bees; they break out with European foul brood. My take on the problems with the honeybees is the varroa mite is the biggest key to the problems. We keep the bees on a natural diet of pollen and nectar. In the Midwest they don’t do that. When you have varroa mites living off bees or a mono-culture diet, the colonies are collapsing. We survive because we have natural sources of pollen and nectar.”
Vannoy said he feeds his bees a healthy diet of supplements, and past experience has shown that the bees would thrive. But something has changed in the last decade and drawing conclusions is difficult to impossible. One issue is that honey may be more important now than it was thought to be. Science is finding that many of the historical claims that honey can be used in medicine may indeed be true. There is mounting evidence that honey itself has healing properties. According to scientists from the Academic Medical Center at the University of Amsterdam, manuka and other honeys have antibacterial properties that heal wounds. They are searching for exactly how the honey inhibits the bacterial infections. Manuka honey is produced in New Zealand by bees that pollinate the native manuka bush. While the study is not designed to replace current antibacterial medicine, there is strong evidence that honey has always had healing properties that are beneficial to bees.
Commercialized beekeeping survives by altering the bees’ behavior. Beekeepers normally scrape off the honey for sale and use high-fructose corn syrup to keep the bees fed. It’s much cheaper and was considered harmless for the bees. Research in the 1970s suggested that there were no health consequences associated with feeding bees on corn syrup. But that was before beekeepers began putting mite-killing chemicals in hives, and before an entire class of agricultural pesticides was introduced.
Honeybees that live off the same sweetener found in soft drinks could be more vulnerable to the microbial enemies and pesticides believed to be linked to catastrophic collapse of honeybee colonies worldwide, according to the study published in the Proceedings of the National Academies of Science.
Researchers identified a compound found in the wall of plant pollen that appears to activate the genes that help metabolize toxins, including pesticides. Although pollen winds up in the honey produced by the bees, the bees that pollinate crops spend more time sipping on the same sugar substitute — high-fructose corn syrup. The honey substitute is an important way for the industry, which contributes about $14 billion to the U.S. economy, to make ends meet.
Honeybees are able to see ultraviolet light, which means that they see more colors in flowers than we do. They also zero in on the nectar-rich blossoms with an expert sense of smell. But new research suggests pollution from diesel exhaust may fool the honeybee’s “nose,” making its search for flowers more difficult. In a paper published recently in Scientific Reports, English scientists concluded that two components of diesel exhaust — nitrogen dioxide and nitric oxide — could alter the odor that combine to give a flower its unique smell.
This phenomenon could prevent honeybees from reaching their target flowers. Honeybees have a good sense of smell and an exceptional ability to learn and memorize new odors. If handicapped in the ability to locate the flowers by specific aromas, the honeybees would be lucky to survive, researchers concluded.
In a national effort to improve honeybees’ health, the U.S. Department of Agriculture recently announced it will spend millions of dollars to help farmers improve pastures in five Midwestern states. The goal is to provide food for the struggling hives. Many of the bee hives that come to California in the spring arrive in trucks from the Midwest. Bee deaths are significant and the USDA hopes to stem those losses by providing more areas for bees to build up food stores and strength for winter.
There are approximately 150 species of nectar and pollen plants in California, but only six are principal sources for commercial honey production. It appears that only large-scale changes will make a difference.