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After we have presented in a previous article information that will help us understand the honey bee’s carbohydrate nutrition, we will continue with an in-depth analysis of the most common substances used for supplemental feeding: sugar (sucrose), corn syrup, inverted sugar syrup and honey.
Apart from the advantage of greater longevity in the case of sucrose as we saw in the above mentioned article, by using sugar for supplemental feedings we are also eliminating a host of other risks. Let us further explain this.
Regular sugar is pure sucrose, a disaccharide that is the main component of nectar that bees naturally collect. The honey bee’s digestive system is perfectly adapted to process sucrose, which is then transformed into two monosaccharides: glucose and fructose. Furthermore, it was proven that regular sugar is twice as attractive for the forager bee when compared to glucose or fructose (Fat bees, skinny bess – Doug Somerville).
Another benefit of using sugar is that depending on the concentration of the syrup, it can be used to achieve different goals, like stimulation or supplementation. We will talk more about this topic in our next article.
A possible drawback of using sugar is its tendency to ferment. In order to avoid this from happening, the syrup must be consumed within 3 or 4 days during hot weather, especially when lower concentrations are being used (50%, 1:1 sugar:water ratio). This drawback can be easily overcome by sterilization or by adding various additives; we will go into more details in the next article.
HFCS (High Fructose Corn Syrup) is widely used for supplemental feedings, especially in the USA. The main reason for this is its price, corn syrup being 30-40% cheaper than sugar. There are two major risk when using HFCS:
1.Not all types of corn syrup can be used for supplemental feeding of the honey bees, the main problem being the large quantities of starch, acids and enzymes in the final product. These substances are toxic to the bees and must be closely monitored.
Basically, corn syrup production starts by separating starch from the rest of the product. The starch (solid) is then liquefied using acids and/or enzymes and turned into a solution that also contains a small amount of glucose. By adding more enzymes, the process of transforming starch into sugar continues. In any moment this process can be stopped by the manufacturer, meaning that some corn syrup variants can contain large quantities of starch, which is toxic to the bees. For this particular reason, corn syrup used for feeding honey bees must not contain starch.
The best corn syrup that can be used for supplemental feeding is considered to be HFCS 55, 77% solid mass with 55% fructose. Lower grade HFCS, like HFCS 42 (71% solid mass, 42% fructose), are less stable and will form crystals once inside the comb three times faster than HFCS 55. Except for glucose and fructose, which are both monosaccharides, corn syrup contains other sugars as well. None of these additional sugars represent any caloric gains for the bees, so they do not help with ensuring energy. Moreover, some of these polysaccharides can be harmful to the honey bee.
2. The second major issue with high fructose corn syrup is HMF (Hydroxymethylfurfural). HMF, a toxical compound for both humans and bees, forms after exposing fructose to high temperatures in an acidic environment (according to Randy Oliver, HFCS can reach vinegar’s level of acidity depending on how it is obtained).
Considering these risks and also the fact that in most countries the price advantage is non-existent, using HFCS for supplemental feeding of the honey bees is completely unjustified.
Regarding the risk of forming HMF, we must say that it present in the case of using honey or inverted sugar syrup. These substances contain fructose and when exposed to higher temperatures (during storage, transportation or even during feeding), the amount of HMF can easily exceed safe limits. It’s needless to say that in the case of inverting sugar using thermal procedures, which involve high heat, the risks are even greater. Fructose that was exposed to high heat is toxic for the honey bees. The effect is similar in the case of exposing honey to high temperatures. In this article from beetime.eu, there is an in-depth review of all the risks associated with exposing to high heat honey and other substances used for supplemental feeding: HMF – Silent enemy in honey and bee food.
We see that even though there aren’t any scientific or practical reasons to use honey or HFCS for supplemental feeding, on the contrary, there are strong reasons not to, these myths still continue to have massive popularity. In the case of honey, this is because honey is considered to be the natural carbohydrate source of the bee (even though some types of honey, like grapes and sun-flower can be detrimental for the bee during winter); in the case of inverted sugar syrup, it is because it is thought that they do not wear the bee by emulating honey’s formula.
Even without all these arguments, we can easily observe that bees use honey only as a reserve when there isn’t any nectar flow or during winter and they prefer nectar over any other source of carbohydrate in all other scenarios. We all know that when there is nectar available, the bees prefer it over honey; a comb filled with honey doesn’t present any interest to the bee when there is nectar available. We can safely say that all these facts show that the best option for supplemental feeding with carbohydrates is sugar (sucrose).
Finally, we would like to make a few important motes. We are aware of the fact that this article will come as a surprise for many and will change the way you think about supplemental feedings. Therefore, to avoid any misinterpretation:
- the information only refers to supplemental feeding and not to replacing the honey in the combs;
- supplemental feedings should be carried out when there is a clearly defined goal and not during nectar flow when there are plenty of food resources available for the bees. Also, caution is required when deciding when to feed to avoid mixing the honey with any types of syrup;
- the sole purpose of this article is to present a personal opinion based on available data regarding supplemental feeding with carbohydrates; every beekeeper should be able to decide what is the best option.
In our next article we will try to answer based on arguments and experience to some of the most important questions regarding supplemental feedings: why, when and how to feed.