The declining bee population: Does chlorine in a swimming pool have anything to do with it?
Ever since PBS NewsHour correspondent Spencer Michels interviewed Extension apiculturist Eric Mussen of the UC Davis Department of Entomology and several other UC scientists and bee folks on the declining honey bee population, it's been busy on the bee front.
Everyone seems to have a theory on the cause of colony collapse disorder (CCD) and why the bee population is declining.
One person, known as "DK," posted a comment on the PBS NewsHour site that maybe chlorine has something to do with it.
"Every morning, when I sweep (skim) the family pool here in Sherman Oaks (Los Angeles), Calif., at least 3-4 bees from a hive in a nearby hedge are dead in the water, and I don't think it's from drowning," DK wrote. "It's like the La Brea Tar Pits were eons ago: The sparkling pool looks like potable water, but it just lures them to their deaths...When I "googled" this subject, it turned out a farmer in the San Joaquin valley who was experiencing colony collapse discovered that a neighboring farmer was using a chlorine based pesticide in his irrigation water on the adjacent watermelon patch; when I read further into it, the article said chlorine was a suspected 'neuro-toxin" for the bees, and that corresponds with my empirical observations. The chemical component also might explain why only 25% of bee colonies are experiencing this problem."
"So, scientists in northern California and elsewhere, that's your clue: CHLORINE (and its derivatives). It's worth a look."
Mussen, a noted expert on honey bees, responded:
"I read with interest your concern about a possible connection between chlorine and our honey bee problems. I believe that you are correct that honey bees actually prefer a bit salty water to pure water, so they might be attracted to your swimming pool water. However, honey bees do not like to get their feet wet when collecting water, if they can help it. They stand on the dry and drink from the film of water caused by capillarity. If you find one drinking water near your pool, on the poll apron, pool wall or a floating toy, check their behavior.
"The bees you find in the pool probably were not there for drinking purposes. You noted that you have a colony living nearby. Each day that colony raises about 1,000 newly emerging adult workers and around six weeks later those 1,000 bees will die of old age. They do not die in the hive. They tend to keep foraging until they flutter to the ground (lawn, driveway, sidewalk, pool, etc.) wherever they may be. Those bees are not yet dead, so for a little while they still can sting if bumped against or stepped on. That is most likely why they keep ending up in your pool.
"In reference to your statement about chlorine in pesticides harming a beekeeper's bees, there have been a succession of pesticides with chlorine incorporated into their structures that are toxic to bees. The group named organochlorides are pretty much obsolete, but a new group of chemicals, called neonicotinoids, have a chlorine in them. Beekeepers fear those compounds because they become systemic in the plants and are found in the nectar and pollen when the plants bloom. Recently, the systemics have been delivered in irrigation water, since they can be picked up from the soil by the plant roots. In 'chemigation' with underground emitters, you would think that the chemicals would stay away from the bees. But, the systems leak and the bees will forage at the junctions in the pipes and from puddles on the ground. So, the bees get the chemical at field delivery concentrations, not at the much reduced concentrations that end up in the blossoms."
Speaking of water, as any beekeeper will tell you, bees don't like to get their feet wet. Honey bees don't dive into a pool on a hot summer day. They don't head for the sprinklers for a quick shower. They don't stand in water. When they collect water to cool their hives, they stand on the very edge of a water-filled container, such as a birdbath or the lip of a flower pot.
Which reminds us: a recently published children's book (for ages 4 to 10) about honey bees seemed to have it all: colorful illustrations, catchy lines, and educational information about bees.
One look at an illustration, though, and it's apparent that neither the author nor the illustrator know that much about water and honey bees. The illustration clearly shows honey bees walking in water. Three of them. Three of them happily walking in a water-filled birdbath.
"What's wrong with this illustration?" I quizzed a veteran beekeeper. He looked at me as if I'd just asked him the second letter of the alphabet.
"Bees," he said, "don't like to get their feet wet. Those bees in that illustration are walking in water. They don't do that."
No, they don't.
Gotta love those dragonflies in the family Libellulidae.
The Thunderbirds of the insect world, they perform amazing aerial maneuvers as they skim over water, catching mosquitoes, knats, flies and other undesirables on the wing.
But oh--occasionally they nail a pollinator.
A red flame skimmer (Libellula saturata) skimmed over our fish pond and pool last Saturday and picked on the pollinators. Well, at least one pollinator.
It grabbed a female sweat bee, of the genus Halictus, probably H. tripartitus (as identified by native pollinator specialist Robbin Thorp, emeritus professor of entomology at the University of California, Davis, and Lynn Kimsey, director of the Bohart Museum of Entomology and professor of entomology at UC Davis).
Yes, they can even identify a mangled sweat bee in the mouth of a dragonfly.
And no sweat bee.
That very word summons a smile.
A public celebration--appropriately titled “Honey!”--will take place Friday, Oct. 21 in the UC Davis Conference Center.
Save the date!
The event, sponsored by the Robert Mondavi Institute for Wine and Food Science, will include tastings and a honey-focused lunch.
“Bees play a crucial role on our planet from pollinating to honey creation,” said Clare Hasler-Lewis, executive director of the institute, which is affiliated with the UC Davis College of Agricultural and Environmental Sciences.
The public is invited to “come celebrate with us and enjoy lectures, tastings and displays on honey,” she said.
The event is scheduled to include the history of honey and its use across the ages; honey as a food incorporating honey in your diet; and honey for health, from balancing blood sugar to wound healing.
Among the UC Davis speakers:
--Liz Applegate of the UC Davis Department of Nutrition faculty. A national expert on nutrition and fitness, she will discuss the health benefits of honey.
--Brian Johnson of the UC Davis Department of Entomology faculty. Johnson, who specializes in the behavior, genetics and evolution of honey bees, as well as apiculture, will explore the history of honey use across the ages.
--Extension apiculturist Eric Mussen of the UC Davis Department of Entomology. A nationally known expert on honey bees and honey, he will lead a honey tasting.
As plans progress, additional information will be posted on the Robert Mondavi Institute for Wine and Food Science website, Facebook and on Twitter.
Ah, sweet October!
Honey bees are still in trouble.
University of California scientists hammered home that point tonight during the PBS NewsHour program on the colony collapse disorder (CCD) and the declining bee population.
Extension apiculturist Eric Mussen of the UC Davis Department of Entomology told Spencer Michels of the PBS NewsHOur that "We really don't seem to have accomplished a whole lot (since CCD surfaced five years ago), because we're still losing, on an average, approximately 30 percent or more of our colonies each year. And that's higher than -- than it used to be. Only 25 percent of the beekeepers seem to have this CCD problem over and over and over. The other 75 percent have their fingers crossed and say, 'I don't know what this is, but it's not happening to me.'"
CCD is indeed frustrating, agreed Mussen, beekeeper-researcher Randy Oliver of Grass Valley, and UC San Francisco researchers Joseph DeRisi, Michelle Flenniken and Charles Runkel.
Flenniken, a postdoctoral fellow in the Raul Andino lab at UCSF and the recipient of the Häagen-Dazs Postdoctoral Fellowship in Honey Bee Biology at UC Davis, was among the team of scientists who recently discovered four new bee viruses, a discovery that may help unlock the secrets of why the bee population is declining.
The team found the new viruses while examining viruses and microbes in healthy commercially managed honey bee colonies over a 10-month period.
"Honey bee colonies, kind of like human populations, are exposed to a number of viruses and pathogens throughout the whole -- the entire course of the year," Flenniken told Michels. "So what this study provides us is a normal, healthy colony baseline of the ebb and flow of the microbes associated with that colony throughout the course of the year."
Oliver, who maintains 1000 hives and who has dealt with CCD, pointed out that CCD is resulting in "new science, new interest and new researchers" studying the mysterious malady.
As scientists delve in the mysteries of what's ailing the bees, they're bound to learn what's causing it. Meanwhile, it's good to see a national news program exploring this topic.
(Read PBS NewsHour transcript. Read more about the declining bee population on Spencer Michels' blog.)
Be careful when you're harvesting an artichoke.
You might find a European paper wasp (Polistes dominula) hunting for a little protein, such as ants, flies and tiny bees to carry back to its nest.
Entomologist Whitney Cranshaw of Colorado State University writes in one of his fact sheets that "European paper wasps rear their young on live insects. They do not produce nuisance problems around outdoor dining that characterize scavenging species, such as the western yellowjacket. European paper wasps will sometimes feed on sweet materials, including honeydew produced by aphids. On rare occasions, they also may feed and damage ripe fruit."
Don't consider the European paper wasp a pest. "European paper wasps have become one of the most important natural controls of many kinds of yard and garden insects," Cranshaw writes. "Most commonly they feed on caterpillars, including the larvae of hornworms, cabbageworms, and tent caterpillars. Sawfly larvae are also commonly taken prey."
As its name implies, it's a native of Europe. Says Cranshaw: 'The European paper wasp is the common paper wasp of Europe. It was first found in North America in the 1970s in the Boston area. Since then it has spread rapidly to much of the northern half of the United States and British Columbia."
Volunteers at the Häagen-Dazs Honey Bee Haven at the Harry H. Laidlaw Jr. Honey Bee Research Facility, University of California, Davis, recently spotted a paper wasp nest on a lush growth of grey musk sage.
As the paper wasps tended and guarded their nest, honey bees, bumble bees and carpenter bees gathered nectar.
The bees: vegetarians. The wasps: carnivores.