Posts Tagged: pollen
Ever watched an in-flight honey bee packing her load of pollen?
A foraging bee carries her ball-like load of pollen on her hind legs and continually moistens it with a little nectar. The size and shape changes as she works. Sometimes you'll see BB-sized loads and at other times the pellets seem as large as beach balls. The color varies, depending on the color of the pollen she collects.
In the UC Agricultural and Natural Resources (UC ANR) publication, Beekeeping in California, (now out of print, but expected to be revised soon) the authors define pollen as "Male sex cells produced in anthers of flowers. Powderlike and composed of many grains, they are gathered and used by honey bees for food as a source of protein. A good mix of many different pollens is essential for adequate nutrition."
Humans use pollen as a supplement or as a way to desensitize the effects of hay fever. If you pick up a jar of pollen granules at your local health food store, the label is likely to read "All naturally occurring: vitamins, minerals, amino acids, carotenoids, bioflavonoids, phytosterols, fatty acids, and enzymes" and the like. Then there's the caution: "Bee pollen may cause allergic reactions in some sensitive people."
And the bees? The brood likes it just fine, except when it's toxic (California buckeye pollen is toxic to the larvae and can result in malformed, nonfunctional adults). Pollen contaminated with pesticides can also be life-threatening. Pesticides used on such crops as alfalfa, oranges, cotton, corn and beans can be hazardous to bees.
Meanwhile, a pollen-packing honey bee in flight is a sight to bee-hold.
Pollen-packing honey bee heading toward plum blossoms. (Photo by Kathy Keatley Garvey)
Honey bee adjusts her load. (Photo by Kathy Keatley Garvey)
Honey bee loaded with pollen heading home. (Photo by Kathy Keatley Garvey)
If you haven't made it over to the Häagen-Dazs Honey Bee Haven on Bee Biology Road, UC Davis, yet this year, you should.
The trees that form "Orchard Alley" are blooming. You'll see almonds and plums flowering, and soon, apples.
Really spectacular are the delicate plum blossoms. Look closely and you'll see the honey bees with heavy pollen loads weaving in and out of the branches.
The haven is a half-acre bee friendly garden located next to the Harry H. Laidlaw Jr. Honey Bee Research Facility. The Sacramento Bee just named it one of the Top 10 gardens to visit in Sacramento/Yolo County.
Wrote garden editor Debbie Arrington: "Local gardeners don't have to go far to find inspiration. Our region is dotted with memorable public gardens that offer beauty and food for thought along with relaxation. A stroll through any of these destinations may turn up a new favorite shrub or eye-catching flower. In these gardens, you can see firsthand how thousands of plants have adapted to our climate and often low-water conditions. Best of all: Admission is free."
No. 1 on the list? The UC Davis Arboretum. In fact, of the 10 gardens listed, two are located at UC Davis!
Honey bee foraging on plum blossoms. (Photo by Kathy Keatley Garvey)
Pollen-packing honey bee heading home. (Photo by Kathy Keatley Garvey)
Makes sense that the sunflower bee (Svastra spp.) forages on the genus Cosmos.
Cosmos (also the common name) is a member of the sunflower family, Asteraceae.
Sunflower bee: sunflower family. A specialist bee.
On a recent trip to the Luther Burbank Home and Gardens in Santa Rosa, we spotted scores of sunflower bees on cosmos, each bee packing a heavy load of golden pollen.
There was a pollen party going on, pure and simple.
Although the sunflower bee, as a floral visitor, is often mistaken for a honey bee, there's no mistaking that this is a pollinator, too.
Sunflower bee (Svastra spp.) foraging on cosmos. (Photo by Kathy Keatley Garvey)
Close-up of pollen on a sunflower bee. (Photo by Kathy Keatley Garvey)
You've heard of "Got milk?"
With honey bees, it's "Got pollen?"
We spotted a lone honey bee on an African daisy last weekend. It was clear she'd been foraging for pollen. Pollen covered her legs and antennae and rimmed her head. And it was clear where it came from. The pollen on the daisy and the pollen on her matched perfectly.
"The importance of pollen for the health and vigor of the honey bee colony cannot be overstated," writes Norman Gary, emeritus professor of entomology at UC Davis, in his newly published book, Honey Bee Hobbyist: The Care and Keeping of Bees. "Bees need a balanced diet. Honey satisfies the bees' carbohydrate requirements, while all of the other nutrients--minerals, proteins, vitamins and fatty acids--are derived from pollen."
"Nurse bees consume large amounts of pollen, converting it into nutritious secretions that are fed to developing larvae," Gary writes. "During an entire year, a typical bee colony gathers and consumes about 77 pounds of pollen."
Gary further points out: "When she contacts the flower, pollen grains are attracted to her body, similar to the attraction of iron fillings to a magnet."
So, when you see a honey bee covered with pollen grains and think--"What a load!"-- that's just part of the 77 pounds gathered and consumed in a colony per year.
Honey bee collecting pollen on an African daisy. (Photo by Kathy Keatley Garvey)
Close-up of bee covered with pollen. (Photo by Kathy Keatley Garvey
If you've ever watched honey bees work the blossoms, you'll probably see them packing pollen in their pollen baskets and cleaning their tongue as they buzz from flower to flower.
Pollen is protein, and nectar, carbohydrates. Worker bees collect both, plus water and propolis (plant resin) for their colony.
"Pollen in the plant world is the equivalent of sperm in the animal world," writes UC Davis emeritus professor Norm Gary in his book, Honey Bee Hobbyist: The Care and Keeping of Bees. "Fertilization and growth of seeds depend upon the transfer of pollen from the male flower parts (anthers) to the receptive female parts (stigmas). For many species, such as grains and nuts, pollination occurs by airborne pollen that is produced in great quantity and characterized by very small, lightweight pollen grains. Airborne pollen causes most human allergies."
That's what he calls "Pollen 101."
"Inexperienced foragers quickly learn the most efficient movements to dislodge pollen grains from the anthers," writes Gary, who spent 32 years in the academic world of teaching, research and public service and continues to be a professional bee wrangler. "This frequently involves the use of their tongues and mandibles in licking and scraping the anthers, which slightly moistens the pollen."
"After becoming coated in pollen grains, the bees meticulously brush pollen from the body hairs with the comblike hairs on their legs. This process gradually transfers the pollen to the hind legs, where it accumulates as two 'pellets,' adhering to the outer surface of the pollen baskets on their hind legs."
A pollen-collector can collect a full load in about 10 minutes, Gary says. Number of pollen-collecting trips a bee can make in a day? Ten is typical.
Gary, who has amassed more than six decades of beekeeping experience, marvels at how the bee transfers pollen from its body to its pollen basket. It's "choreography that almost defies description," he writes.
Honey bee packing pollen while foraging on a nectarine blossom. (Photo by Kathy Keatley Garvey
Honey bee pauses to clean her tongue. (Photo by Kathy Keatley Garvey)
Honey bee packing more pollen. (Photo by Kathy Keatley Garvey)