Hydroxymethylfurfural is the main reason that high-fructose corn syrup is not good for bees. Also known as HMF, hydroxymethylfurfural is a chemical that forms when high-fructose corn syrup is heated. It is known to damage honey bees by causing ulceration of the gut.
Lately it has become one of the suspects in the deaths of millions of honey bees across the globe. Beekeepers often supplement a colony’s diet with high-fructose corn syrup, especially in the early spring when they want colonies to build up quickly for the pollination season.
Heat makes it worse
Researchers have found that the more high-fructose corn syrup is heated, the more HMF is formed, and the production takes a big jump at around 120°F. Now 120°F isn’t very hot. It’s a bit warmer than the hot water in your tap, or sort of like a summer day in Death Valley. HMF formation also increases over time, so old high-fructose corn syrup contains more than new syrup.
The temperature inside a hive can easily be warm enough to produce HMF, so it is very possible that it has an effect on honey bee health. High-fructose corn syrup is most often used by commercial beekeepers. Tariffs on sugar imports keep sugar prices high, whereas domestic corn is subsidized, so high-fructose corn syrup becomes a cheap and easy-to-use alternative to sugar. Many commercial beekeepers buy it in tanker loads and fill their hive-top feeders with hoses that pump the stuff in. The bees are not hesitant to eat it and a colony will consume gallons.
Is is really a problem?
High-fructose corn syrup continues to be popular with commercial beekeepers, many of whom say they’ve been using it for years and it hasn’t hurt their bees. On the other hand, we know that bee hives have become hard to maintain, colony numbers are dropping, and something is causing bee declines. If scientific experimentation shows that high-fructose corn syrup is part of the problem, we probably should be listening.
If you are debating about what to feed your bees, and you don’t have honey from your own apiary, use sugar syrup. Some types of high-fructose corn syrup have less HMF than others, but until all the evidence is in, plain old sugar made into syrup is probably the safest bet. I will update this site as more information about HMF becomes available.
Honey Bee Suite
LeBlanc et al. Formation of Hydroxymethylfurfural in Domestic High-Fructose Corn Syrup and Its Toxicity to the Honey Bee (Apis mellifera). Journal of Agricultural and Food Chemistry, 2009; 57 (16): 7369 DOI: 10.1021/jf9014526