- Author: Kathy Keatley Garvey
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.
Still many unknowns about the toxicity of CA Buckeye to pollinators, especially native insects.
One blog that tells the story pretty well is: http://curbstonevalley.com/blog/?p=6474
We do not know if the toxic chemicals (mostly alkaloids) in CA buckeye pollen and/or nectar have any detrimental effects on native bees (including some bumble bees and long-horn bees) or other native insects (including many butterflies) that visit CA buckeye flowers. Mainly because they are not as easy to monitor for such effects as are managed colonies of honey bees. Our native insects have evolved with CA buckeye and probably have evolved mechanisms of dealing with the toxins.
The effects on managed honey bee colonies is quite dramatic, often referred to as the “buckeyed” condition, and reversible simply by moving colonies out of the areas where buckeye bloom is the dominant floral resource. But consider that European honey bees have only been in contact with CA buckeye for about 160 years in contrast to our native insects.