Varroa mites and assorted other infestations: 24 percent. Nosema cerinae is a new variety of the nosema fungus, introduced in the U.S. in the mid-1990s. It was associated with worker die-off in the field.

Multiple causes acting together: 16 percent

Bt toxin in GMO pollen: 15 percent, and Bt toxin in GMO beet sugar: 15 percent. Since the advent of GMO crops, the insecticidal toxin Bt has been bred into many common crops, including almost all sugar beets. High fructose corn syrup, HFCS, is processed from the juice of corn stalks, and contains Bt. Feeding honeybees sugar water containing sugar from sugar beets or HFCS can be expected to be hazardous to honey bees.

RNA viruses: 13 percent. Several RNA viruses have been found to occur almost exclusively in hives that have collapsed. These same hives typically have nosema cerinae present. The RNA viruses may be a downstream consequent of genetic manipulation to introduce Bt or Roundup resistance in crops.

Starvation: 11 percent when workers fail to return, the hive does starve, but one would expect dead bees, not missing bees, in the hives.

Navigational interference from cell-phone signals: 10 percent. The video on radio frequency (RF) health effects on honeybees and humans is at tinyurl.com/RF-documentary.

My best guess: multiple causes, especially indiscriminate use of neonicotinoid pesticides, the spread of nocema cerenae fungus in association with GMO-related RNA viruses, together with ever-greater RF interference from cell-phone towers, with widespread Bt-laden pollen and a declining robustness of the queen lines. In other words, no clear single cause.

The next meeting of the Carolina Foothills Beekeepers will be on Thursday, June 13 at Pine Crest Inn in Tryon at 7 p.m. Officers will be selected.

– Brian Crissey, Mill Spring