A recent article in BEE BIZ (Number 9, February, 1999, pp. 12-14, no longer pubished) titled “Your Bees Are What You Feed Them, ” confirms that if you feed your bees well, they will feed you well. The author, Mr. Charlie Stevens, outlines the evolution of supplementary feeding in Condamine Apiaries, Queensland, Australia. Mr. Stevens says bees have benefited from the policy of when in doubt FEED. He says among other things that protein cakes have been very important to his operation. They are approximately 100 mm x 50 mm x 15 mm and two cakes are fed at 21-day intervals. They may increase the number of cakes fed per hive if conditions deteriorate. The only restriction they place on feeding is cost, preferring to feed all hives two cakes at 14-day intervals, prior to and during nectar flows. The cost of the cakes is AU$6.50 per kg (2.2 pounds = one kg) up to 99 kg and AU$6 per kg for 100 kgs and over. There are 20 kgs of protein cakes per carton and one carton will feed 100 hives. Although touting the advantages of these cakes, no information is provided in the article on what they are composed of. Only the name of the manufacturer, C.B. Palmer & Co., is given, along with the fact that the cakes are pollen enriched.
Mr. Stevens concludes that “hive population is critical, we endeavor to operate hives with at least five well-filled out frames of brood and maintain hive population levels in the area of 35,000 bees per hive. To sustain these levels we must provide supplementary protein, this is where the protein cakes come into their own. We have no faith in supplementary foods for bees that do not contain pollen or honey. From our observations we believe that caring for the nutritional well being of our hives assists hives in dealing with bee diseases often related to stress. For the future we plan to continue to fine tune our supplementary feeding program and have developed an interest in the value of supplying water by means to top feeders to hives. Comments by researchers and our own experience of supplying water for hives indicates that a ready supply of water may add another dimension to our understanding of the complete nutritional needs of our bee hives. Research into honeybee nutrition should be ongoing, we have already benefited as an industry from research in this field.”
Although many would agree that more study is needed in bee nutrition, the demands of the moment (e.g. tracheal mite, Varroa, small hive beetle) have often meant that funds for studying the basics are often not available. Fortunately, a recent contribution in the area comes from Brazil. Drs. Cremonez, De Jong and Bitondi, at USP Ribeirão Preto, have recently published a study in the Journal of Economic Entomology (Vol. 91, No. 6, December 1998, pp. 1284-1289) in this arena. Its title is “Quantification of Hemolymph Proteins as a Fast Method for Testing Protein Diets for Honey Bees.” The authors fed several diets to young worker bees. One hundred twenty newly emerged bees were confined for six days, fed various diets and their blood (hemolymph) collected. The protein concentration of the hemolymph was then calculated using a spectrophotometer. The diets consisted of:
Half freshly collected bee bread; half candy
40 percent soy bran flour; ten percent sugar cane yeast; fifty percent sucrose
Half pollen trapped from colonies; half candy
Half fine ground corn meal; half sucrose
50 percent sucrose solution in water (protein free)
The results showed that there was no difference in diets being accepted and consumed. The protein level increased over the six days for the bee bread, soybean/yeast and pollen diets, but decreased for both the corn meal and protein-free diet. Highest protein levels were seen in bees feeding on bee bread, followed by soybean/yeast and pollen.
A pollen substitute should be inexpensive, nutritionally adequate and readily consumed, the authors state. A rational approach would be to investigate animal and human foods already on the market and test their value in beekeeping. Ingredients available in one country may not be in others or may be too expensive. Likely candidates are different soybean flours (solvent or expeller processed), yeasts (torula, brewers) and perhaps others that become available in the future. A specific plant in Brazil, jatoba (Hymenaea courbaril), for example, is another possibility. The authors say that measurement of protein in the haemolymph of adult worker bees is a useful, rapid, practical and precise method for determining diet suitability. They conclude that because diets were most different in six-day-old bees, and those fed on bee bread had the highest protein levels, the logical strategy would be to use these conditions as standards when comparing various formulations.