Posts Tagged: pollen
That is, honey bees heading home to their colony.
Many beekeepers, especially beginning beekeepers, like to watch their worker bees--they call them "my girls"--come home. They're loaded with pollen this time of year. Depending on the floral source, it may be yellow, red, white, blue, red or colors in between.
Below, the girls are heading home to a bee observation hive located inside the conference room of the Harry H. Laidlaw Jr. Honey Bee Research Facility on Bee Biology Road, University of California, Davis.
They're bringing in food for the colony: pollen and nectar. They also collect water and propolis (plant resin). This is a matriarchal society where females do all the work in the hive. The worker bees--aptly named--serve as nurse maids, nannies, royal attendants, builders, architects, foragers, dancers, honey tenders, pollen packers, propolis or "glue specialists," air conditioning and/or heating technicians, guards and undertakers.
The glassed-in bee observation hive is indeed a popular and educational attraction to watch the queen lay eggs (she'll lay about 2000 eggs a day during peak season), the comb construction, honey production, pollen storage and all the other activities. The sisters feed the colony, including the queen and their brothers (drones). A drone's responsibility is solely reproduction, and that takes place in mid-air when a virgin queen takes her maiden flight. After mating, he dies. Done. That's it.
Meanwhile, life continues inside the hive.
Honey bees making a "bee line" for their home. (Photo by Kathy Keatley Garvey)
Note the load of yellow pollen. (Photo by Kathy Keatley Garvey)
Queen bee and her retinue. (Photo by Kathy Keatley Garvey)
They're there for the pollen.
"California poppies provide only pollen--no nectar," native pollinator specialist Robbin Thorp, emeritus professor of entomology at UC Davis, told the Pollinator Gardening Workshop last Saturday on the UC Davis campus. Thorp was one of the featured speakers at the event, sponsored by the California Center for Urban Horticulture.
Thorp, who identifies thousands of bees a year for researchers, enthralled the audience with facts about bees. Although he retired in 1994, he maintains an office at the Harry H. Laidlaw Jr. Honey Bee Research Facility at UC Davis, and is one of the instructors of The Bee Course.
Some of the information he presented:
- Unlike wasps, which are carnivorous, "bees are vegans." They gather pollen and nectar from plants. (They also collect water and propolis, or plant resin, for their colonies.)
- "Flowers don't have wings; so we need the pollinators to come to them."
- The global population of bees includes some 19,500 named species. Of that number, about 4000 different species of bees occur in North America; 1600 in California, and more than 300 species of bees in Yolo County. (Over the last four years, Thorp has found more than 80 species of bees in the Häagen-Dazs Honey Bee Haven a half-acre bee friendly garden on Bee Biology Road maintained by the UC Davis Department of Entomology and Nematology.)
- Seventy percent of bees are solitary, and most nest in the soil.
- Fifteen percent of bees are cuckoo bees; the females lay their eggs in other bees' nest and their offspring eat the provisions
- Only 10 percent of bees are social (honey bees are among them)
Thorp recommends that if you want to attract native bees, provide food (bee plants), water and shelter. "Leave some bare soil, avoid mulch madness, and provide bee condos (drilled blocks of wood that blue orchard bees and leafcutting bees use for their nesting sites.)
"Plant it and they will come," Thorp said. "Provide habitat and they will stay and reproduce."
Thorp is the co-author of a newly published book, "Bumble Bees of North America" (Princeton University Press) and a co-author (with Gordon Frankie of UC Berkeley and colleagues) of a pending book with the working title, "California Bees and Blooms."
One of the websites Thorp recommends is the UC Berkeley Urban Bee Lab website, http://www.helpabee.org/, which provides information on native bees, gardening for bees, and current projects and partnerships.
Two honey bees foraging on a California poppy. (Photo by Kathy Keatley Garvey)
Honey bee with a pollen load. (Photo by Kathy Keatley Garvey)
Why is that in a honey bee colony, workers can carry pollen but not the queen?
Well, scientists from Michigan State University and Wayne State University have discovered the answer.
They've isolated the gene that's responsible for leg and wing development, according to a news brief in Entomology Today, published by the Entomological Society of America (ESA). The 7000-member ESA, by the way, is headed by president Frank Zalom, integrated pest management specialist and professor of entomology at UC Davis.
The scientists' bee research is published in the current edition of Biology Letters.
“This gene is critical in making the hind legs of workers distinct so they have the physical features necessary to carry pollen,” said MSU entomologist Zachary Huang. “Other studies have shed some light on this gene's role in this realm, but our team examined in great detail how the modifications take place.”
"The gene in question is Ultrabithorax, or Ubx. Specifically, the gene allows workers to develop a smooth spot on their hind legs that hosts their pollen baskets. On another part of their legs, the gene promotes the formation of 11 neatly spaced bristles, a section known as the 'pollen comb.' The gene also promotes the development of a pollen press, a protrusion also found on hind legs, that helps pack and transport pollen back to the hive."
What the research team did was to isolate and silence Ubx, the target gene. "This made the pollen baskets, specialized leg features used to collect and transport pollen, completely disappear," Entomology Today reported. "It also inhibited the growth of pollen combs and reduced the size of pollen presses."
The scientists acknowledge that this won't provide a solution to Colony Collapse Disorder (CCD). They think, however, that their research could lead to bees becoming better pollinators; they could carry larger pollen loads.
Speaking of loads, have you ever seen a bee so heavy with pollen that you wonder if she can lift off? It seems somewhat like a human being weighted down with a bowling ball.
The next time you observe a bee foraging, check out the pollen load. If you're lucky, you'll see the bee packing the pollen, adjusting the load before she buzzes off back to her colony.
Honey bee packing pollen on an almond tree at UC Davis--on the grounds of the Harry H. Laidlaw Jr. Honey Bee Research Facility-- several years ago. (Photo by Kathy Keatley Garvey)
Now that's a load of pollen! Honey bee inside a pomegranate blossom. (Photo by Kathy Keatley Garvey)
The California Gold Rush (1848-1855) has nothing on honey bees.
Sometimes foraging honey bees are covered with their own kind of gold--pollen--or protein for their colonies.
We saw this honey bee dusted with gold from head to thorax to abdomen as she gathered pollen from blanket flowers (Gaillardia). Her flight plan seemed uncertain, as her load was heavy and her visibility, poor. She struggled to take off, but take off she did.
Speaking of the Gold Rush and honey bees, entomologists always associate the arrival of honey bees in California with the California Gold Rush. That's because honey bees were introduced to California in 1853, right in the middle of the Gold Rush.
Back then, the hills were covered with wildflowers where bees gathered nectar (carbohydrates) and pollen (protein). Today, however, scientists are worried about bee malnutrition.
"Honey bee colonies need a mix of pollens every day to meet their nutritional needs," says Extension apiculturist Eric Mussen of the UC Davis Department of Entomology and Nematology. "In fact, they should have a one-acre equivalent of blossoms available to them daily to meet their demands. They can fly up to four miles from the hive--a 50-square mile area--to gather that food and water (and propolis, plant resin)."
A worried beekeeper recently asked him about the declining bee population and wondered why his own colonies were dwindling. In addition to malnutrition, Mussen listed a few other possibilities:
Varroa mites – "They suck the blood from developing pupae and adult bees, shortening their lifespans. They vector virus diseases, the easiest to see being deformed wing virus. If you have adult bees around the colony with curly, undeveloped wings, then you have too many mites. If you see mites on the bees when you look in the hive, that is too many mites."
Nosema ceranae and other diseases – "You need a microscope to see the spores of a Nosema infection. Go to Randy Oliver’s webpage, Scientificbeekeeping.com, and look at the information on Nosema ceranae and spore counting."
Contact with toxic chemicals – "Since your bees can fly up to four miles away to forage, that also is the distance within which they can get into trouble with bee-toxic chemicals. It is not likely that the organic farm is a source. However, if there are other farms around, or if your neighbors (golf courses, shopping centers, parks, playgrounds, etc.) are having problems with sucking or chewing insects, they may have used one of the neonicotinoids on their shrubs or trees. Turf and ornamental dosages are considerably higher than those used in commercial agriculture. So, the amounts of toxins in nectar and pollens can be toxic to honey bees and other pollinators."
Mussen also acknowledged that California buckeye blossoms are toxic to bees. "This was a fairly dry spring," he said. "Not too many weeds and wildflowers were around when the California buckeye came into bloom. Buckeye pollen is toxic to developing bee brood and to adult bees, if it gets to be their primary food source in the colony."
The problem could also be due to other issues as well, Mussen said. "Maybe the queens did not mate with enough drones, or the queens got too hot or too cold during their journeys to your hives, etc."
"As beekeepers, it is up to you to stick your nose in the hive, look at everything and try to determine what may be going wrong. If you are feeling way too new at this to have any idea of what is going on, then contact your local bee club--there is one in practically half of the California counties--and find someone to help access your problems."
And the pollen, that precious protein? "When beekeepers examine their hives, they should see a good supply of pollen with many colors," Mussen says.
Honey bee is covered with pollen from a blanket flower, Gaillardia. (Photo by Kathy Keatley Garvey)
Honey bee is dusted with pollen from the blanket flower. (Photo by Kathy Keatley Garvey)
Lift off? The bee struggles to take off. (Photo by Kathy Keatley Garvey)
It's the Fourth of July--a time to celebrate our nation's Independence Day.
Hurrah for the red, white and blue!
That also covers red, white and blue pollen collected by our honey bees.
If you look closely, you'll see their "patriotic" colors.
"The importance of pollen to the health and vigor of the honey bee colony cannot be overstated," writes emeritus entomology professor Norman Gary of the University of California, Davis, in his best-selling book, "Honey Bee Hobbyist, The Care and Keeping of Bees."
"Honey satisfies the bees' carbohydrate requirements, while all of the other nutrients---minerals, proteins, vitamins and fatty substances--are derived from pollen. Nurse bees consume large amounts of pollen, converting it into nutritious secretions that are fed to developing larvae. During an entire year, a typical bee colony gathers and consumes about 77 pounds of pollen."
Gary adds: "Pollen in the plant world is the equivalent of sperm in the animal world. Fertilization and growth of seeds depends upon the transfer of pollen from the male flower parts (anthers) to the receptive female parts (stigmas)."
Our honey bees are not native to America, but they've been here so long that many people think they are. European colonists brought them here to Jamestown Colony, Virginia, in 1622. Honey bees were established here before our forefathers signed the Declaration of Independence on July 4, 1776.
So, today, a time to celebrate the Fourth and a time to celebrate our honey bees, Apis mellifera.
Honey bee packing red pollen from a rock purslane. (Photo by Kathy Keatley Garvey)
Close-up of white pollen. (Photo by Kathy Keatley Garvey)
Blue pollen from a bird's eye blossom. (Photo by Kathy Keatley Garvey)