The Classroom April 2014
by Jerry Hayes
Q Honey Bee Nutrition... an Evolving Conversation
Jerry, I am studying honey bee nutrition. Frankly I am a bit of a skeptic at this point with what I have found about honey bee nutrition and how it may help honey bee health.
I can find a lot of references that show the negative impact of poor nutrition on bees. What I cannot find is information that characterizes the general nutritional state of bees currently in the US. For example, is there any evidence that the current landscape and beekeeping practices are reducing the quality of nutrition received by many colonies? As a continuation of that, is nutrition a significant factor in the increase of colony losses seen since 2006?
I sometimes think about a human example. Serving healthy meals at a hospital in a well-nourished, developed country will have little impact on the recovery of the patients. However, serving those same meals in a hospital in a malnourished, undeveloped country will likely have a huge impact on the patients’ recoveries.
So for me to be able to say that good nutrition will likely have a significant impact on the colony loss rates, I need to know if the bees are malnourished. I know this is a difficult question to answer experimentally and I’m making a generalization that the state of all colonies across the US is the same. What do we really know?
JM in Missouri
I think nutrition has been one of those elements that we as beekeepers intuitively know is important because it is important to us, our pets, the livestock and wildlife in our backyards, but we really don’t know how to control it for honey bees if needed. Honey bees forage in a 2-3 mile radius of their colony efficiently and access a variety of flowering plants that provide nutrition for the colony. But, sometimes this is not good enough and colonies don’t grow and expand as they should in a perfect world. We then experiment with supplemental food patties that we make or buy from the distributors, not knowing that they are nutritionally incomplete and many times the colony, even if starving, looks on it as trash since honey bees do not find and use ‘food’ in a patty on the top bars. It is not normal. They help (but not much) until real natural pollen is available. Sometimes I get tired of hearing myself talk, so I have asked Dr. Rosalind James to comment on your question(s). I think her answer is great.
ANSWER FROM DR. JAMES
A great deal of excellent research has been conducted to identify “the” cause for CCD and general honey bee health declines. We have had some of the best minds in the world working on it, but a single cause has not been found. That is because the cause is from multiple factors and complex interactions. The honey bee industry has been battling severe colony losses for years, and it is due to some new phenomenon, in addition to a great number of old insults (e.g. accidentally imported pests and diseases, pesticide kills, habitat loss). In addition, declines in native bumble bee populations have been well documented by more than one analysis. It is like the situation with the declining amphibians, first noticed by several independently for specific species and locations, before it was recognized as a more general phenomenon. What is the cause? In the case of amphibians, pathogen spread was found, but the picture is more complicated and cannot be ascribed all to one pathogen. And it begs the question, why did the pathogen spread to begin with? So it is with the bees, one reason cannot be found.
However, we know nutrition affects the health of organisms. And we know bees need a nearly constant supply of pollen and sugar. The nutritional details for bees have not been as deeply researched as they have for say, dairy cows (or humans). The value of the agricultural commodity has not provided the kind of funding that has been committed to dairy research. In addition, honey bees live in a colony, and the dynamics are much more complicated than for non-colony organisms. What you see happen to a single worker bee does not directly translate to the colony. The bees feed each other, they move from one caste to another, they have a queen who does all the egg-laying, and colony function is affected by the queen laying eggs fast enough and being healthy enough to assert sufficient chemical control over the workers. Then there are drones--the other side of the reproductive equation. All these dynamics are affected by the quality and rate of nutrients coming into the hive.
No completely satisfactory substitute for pollen has been developed. We get close, but it is never as good as actual pollen. On top of all of that, there are microbial and external enzymatic components to honey bee foodstuffs. Larvae are not fed pollen; they are fed bee bread (a fermented product of the colony). And the reproductive queen does not eat pollen; she eats food excreted by nurse bees. We know a lot about the complexities, but we cannot exactly answer your question. Not the way you or any of those of us who are ‘scientists’ want or would like.
But there is another dimension to your questions. The approach you are suggesting for analyzing the problems are kind of pin-point approaches. It is not an uncommon scientific approach--break things down into researchable elements. Do the bees need weeds in the field? Then, let’s offer them some flowering plants on the margins. Are certain fungicides toxic to bees? Let’s use other fungicides. Over and over throughout American history, we have had to learn that this approach to farming overlooks the complexity of the whole farm and the region around it. It typically does not provide sustainable systems. We do not/should not throw away chemicals, but we do need to reduce our focus on inputs. We are harming ourselves and the environment, and we too easily can get caught in a cycle that leads to an increasing dependence on input agriculture. Agriculture does not have to be a resource sink. As has been said many times in history about agriculture, we need to step back and take a look at the big picture and take a systems approach. Others might call it a holistic approach.
Below is a link to a paper describing to some extent what I mean. It has nothing to do with bees, but it demonstrates a systems approach that might work to reduce weed pressure. In addition, such an approach would lead to a more diverse landscape and reduced tillage. Adding landscape-complexity to a system can stabilize it. Stabilize the soil, reduce nutrient loss due to run off, and improved habitat for bees and other beneficial insects (like natural enemies of pests). Reducing tillage also stabilizes the soil and protects important soil microbial systems. Plus, it reduces labor and fuel costs. And, as far as wild bees are concerned, tillage is bad because most native bees are ground nesters.
George Washington developed a 7-year rotation system for his farm. The idea is not new. I realize problems are associated with it. For example, not all crops have the same value, and the value changes from one year to the next as demand changes, and planting and harvesting equipment are different for different crops (so the farmer might need more equipment of the expensive kind)—these issues have to be weighed in, though, with a big-picture look at things.
Is this all about nutrition? No, but bee nutrition is an important component. As I said earlier, anyone who has ever fed pollen to their honey bees in the spring knows that it improves the size of the colony. Pollen is generally considered a limited resource for bees. Give them more pollen, and their populations will increase. For honey bees, the colony is the honey bee, and bigger is healthier. It is a good measure for colony health, reproductive potential, winter survival, and pollination potential. http://naldc.nal.usda.gov/download/45095/PDF
Q Hopguard In the Cold
I read somewhere that the Europeans were getting good results from a Hopguard treatment for varroa mites in the winter. I was excited to hear that. It seemed to make sense. The bees have stopped or cut back on brood production, and so the varroa mites that are present would be out in the hive and on the bees where Hopguard would be more effective. But the problem is how do you get Hopguard into the hive in the winter? I live west of the Cascades, in the foothills, in Washington State, and day-time temperatures are often in the thirties or low 40s. It is my understanding that it is not a good idea to inspect a hive under about 55 to 60 degrees. Would it be okay to just take the brood boxes apart long enough to insert Hopguard strips?
For a variety of reasons Hopguard does work the best when varroa are exposed (phoretic) and riding around on adult honey bees and less so for the majority of varroa inside capped cells reproducing. I have thought exactly the same thing as you...how to get Hopguard gooey liquid into or on a cluster and spread around without using the strips that are a challenge at this time of the year. I am unaware of any data to show that if the liquid Hopguard material were available that it would work in this manner. Disruption or disturbance of the cluster by trying to insert Hopguard strips into it might not be the best answer.
I will ask one of the developers of Hopguard this question.
ANSWER FROM DR. GORDON WARDELL
I agree with you - I don’t think I would recommend drizzling liquid Hopguard on the cluster. Even using the strips in winter will potentially cause problems. You will likely kill a lot of bees, disrupt your cluster, lose heat and crash the colony. I sure wouldn’t do it that way in my colonies. Coating the bees in Hopguard will likely kill the bees that get coated.
The newly formulated Hopguard strips will be coming out soon - twice as much product in the strip and it will last longer in the colony.
All the best,
Q Feeding Invert Sugar Syrup
I have 25 gallons of inverted syrup, also called baker’s syrup. I work for a bakery and this was an experimental product from Domino’s that we did not use. It is basically fructose and glucose. I looked it up online and found out that it is basically a manufactured honey. They gave it to me to feed to my bees and I want to make sure it’s safe. Any advice would be welcomed.
As long as it hasn’t been heated and darkened or opened and has started growing things in it, you will be fine and it will work well. Commercial beekeepers use invert syrup all the time if the price is right as it takes the bees less internal energy to utilize it.
Lucky find. Take Care.
Q HONEY BEE NUTRITION
When I compared the results of the study you published with Dr. Amanda Ellis in 2009 titled An Evaluation of Fresh versus Fermented Diets for Honey Bees, you had shown that there was no increase in brood area with the fermented diets. In contrast, in the attached graph published by Diana Sammataro she shows graphically that the bees fed a fermented diet had significantly more brood than the control. Perhaps I am missing a fine point in the research, but it still has me wondering. I sincerely want to understand this topic, but I feel like I am missing something. Can you explain this discrepancy for me? Thank you again for all your advice.
No discrepancy Morris. In our 2009 paper we just looked at acceptance of the various diets and which ones might not be considered as trash and not dragged out, but really consumed. We did not measure brood area or production – we simply measured if it would be tolerated — and that is why we had a ”debris” score which no one else has done. And, as you saw, much of the patty-style supplemental diets are dragged out as trash.