Colony Collapse Disorder - Possible Causes - Malnutrition

Malnutrition

One of the patterns reported by the group at Pennsylvania State was that all producers in a preliminary survey noted a period of "extraordinary stress" affecting the colonies in question prior to their die-off, most commonly involving poor nutrition and/or drought. This is the only factor that all of the cases of CCD had in common in this report; accordingly, there is at least some significant possibility that the phenomenon is correlated to nutritional stress and may not manifest in healthy, well-nourished colonies. This is similar to the findings of a later independent survey in which small-scale beekeeping operations (up to 500 colonies) in several states reported their belief that malnutrition and/or weak colonies was the factor responsible for their bees dying in over 50% of the cases, whether the losses were believed to be due to CCD or not.

Some researchers have attributed the syndrome to the practice of feeding high-fructose corn syrup (HFCS) to supplement winter stores. The variability of HFCS may be relevant to the apparent inconsistencies of results. One European writer has suggested a possible connection with HFCS produced from genetically modified corn. If this were the sole factor involved, however, this should also lead to the exclusive appearance of CCD in wintering colonies being fed HFCS, but many reports of CCD occur in other contexts with beekeepers who do not use HFCS.

Other researchers state that colony collapse disorder is mainly a problem of feeding the bees a monoculture diet when they should receive food from a variety of sources/plants. In winter the bees are given a single food source such as corn syrup (high-fructose or other), sugar and pollen substitute. In summer they may only pollinate a single crop (e.g., almonds, cherries, or apples).

A study published in 2010 found that bees that were fed pollen from a variety of different plant species showed signs of having a healthier immune system than those eating pollen from a single species. Bees fed pollen from five species had higher levels of glucose oxidase than bees fed pollen from one species, even if the pollen had a higher protein content. The authors hypothesised that CCD may be linked to a loss of plant diversity.

A 2013 study found that p-coumaric acid, which is normally present in honey, assists bees in detoxifying certain pesticides. Its absence in artificial nutrients fed to bees may therefore contribute to CCD.