Honey and sugar, as carbohydrates, only give a colony energy; they are one side of the nutritional coin. The other side is pollen, the bees’ only source of important protein, the building blocks that produce a colony’s replacement individuals each year.
During brood rearing, bees use immense quantities of pollen. Estimating the amount needed by a colony over a period of time is difficult. That’s because fresh pollen is often available in the field when most needed and is continually being brought in. We know that the physical location of stored pollen in a colony determines its brood rearing potential. This stored pollen is processed by fermentation into a product that the bees actually are able consume called “bee bread.” That stored within one to two inches of the brood is the most likely to be used.
The quality of the pollen collected by a colony is extremely important; some plants produce more nutritious pollen than others. Like any other organism, bees need a mixture of foods to make a balanced diet. But in their search for adequate nutrition, even they themselves have trouble discriminating protein sources. At times bees may be seen collecting everything from cattle feed to sawdust when natural pollen is not available.
Australian beekeeping practice has developed different protein feeding techniques. One method for determining the pollen requirements of colonies during nectar flows looks at the protein level of the bees chemically, especially while colonies are collecting nectar from eucalyptus, notorious for its poor pollen production. When the protein level drops to a certain threshold level, colonies are moved to areas where pollen is readily available. (G. Kleinschmidt and A. Kondos, “Colony Management on Low Quality Pollens,” Australasian Beekeeper, Vol. 81, No. 1, pp. 5-6, 1979). This technology is not practiced in the United States where natural pollen appears to be more widely available and a parallel phenomenon to eucalyptus in Australia is not thought to occur. A paper in Bee Biz, no longer in print provides a description of the value of feeding pollen in Queensland, Australia.
Many commercial beekeepers around the world use what one wag has called “diesel fumes” to feed bees. They truck colonies from pasture to pasture instead of feeding them. In order to ensure a supply of pollen to stationary colonies, the best alternative is to consider feeding pollen supplement/substitute, along with carbohydrates as part of standard management practice. Only in this way are both sides of the nutritional coin fully considered by the beekeeper.
In the absence of natural pollen, beekeepers often have turned to pollen substitutes/supplements. There is a fine line between the two groups. Substitutes are just that, designed to completely replace pollen as a protein source. Supplements, on the other hand, rely at least on some source of natural pollen. In reality, since at least some pollen is coming in most of the time so all substitutes are probably a “supplement” to a degree.
POLLEN FLOW: AS IMPORTANT AS HONEY FLOW
All beekeepers know about nectar flows; they look forward to them with eager anticipation. Most nectar-producing plants have been cataloged and written about extensively. There is, however, another side to the nutritional coin in beekeeping. There will be no honey if protein is not available to developing bees. Thus, flow of pollen is just as important, if not more so, than that from nectar. R. Nabors recently published an analysis of pollen flows in Portageville at the University of Missouri Delta Center Experiment Station (American Bee Journal, Vol. 137. pp. 215-216, March, 1997).
His analysis from three colonies showed a pollen flow in April (maple and dandelion), July (various agricultural crops) and September (goldenrod and ragweed). Although the dates correlated with the traditional plants present at the time, the study did not give information about specific plants and how much they might have contributed to the protein supply.
Given this set of data, the author suggests that the time pollen supplement/substitute would most benefit a colony would be early March, mid-May and August in the region. The time to trap pollen corresponds to April through early May and September. It pays to know these flows, which can vary greatly depending on region, the author concludes, to determine when supplemental feeding might be needed.
Besides timing and quantity, the quality of the pollen flow these days needs much more examination. It appears to be the most vulnerable part of the flower to environmental contamination and serves as a magnet for things like heavy metals, as shown by Dr. Jerry Bromenshenk retired from the University of Montana. Adverse conditions can also quickly erode its viability; studies in preservation of collected pollen provide abundant evidence of its ephemeral nutritional value. Pollen is plant sperm. Recent investigations on non-viability of sperm in animals from alligators to humans, thought to be the consequences of chemical contamination in both air and water, may also apply to that of plants. Though not as vulnerable as other kinds of sperm, being housed in a tough outer shell, pollen is nevertheless still a far more fragile commodity than honey.
Lack of pollen and consequent inadequate nutrition has been implicated in many conditions that have defied description. Although not proven to everyone’s satisfaction, “disappearing disease”, “autumn collapse”, “May disease” and others may be directly related to protein and thus, pollen deficiency. Some pollen is even toxic to colonies. A feeding study done in the Florida’s Panhandle was inconclusive concerning whether or not pollen deficiency had some impact on bee colony loss originally attributed to tracheal mites, but the symptoms were certainly similar to those conditions mentioned above. (M. Sanford and W. Johnson, Bee Science, Vol. 1, pp. 72-77, January 1991).
Pollen has recently taken on new importance in the wake of colony collapse disorder, caused in part by less-than-adequate nutrition. This has caused researchers and beekeepers to more closely look at this area as part of an overall consideration of “honey bee health.” Contributor Rusty Burlew concurs with this shift to greater consideration of pollen in the honey bee diet.