John, I'm from the west coast and the book I'm using is particular to my province and quarantine area. It says "to ensure against a nosema outbreak and queen problems, fumagillin should be fed in syrup to newly-hived packages...to control the disease, the colonies should be given fumagillin in the fall feed...control of nosema disease in the overwintering operation will take a minimum of two years of feeding medicated syrup in the fall to repress spring outbreaks." The book also says "Nosema has been described as more economically damaging than all the other bee diseases common in North America put together". I just fed my two hived packages 4.3 grams of fumagillin B in each frame feeder when I hived them out April 18th in British Columbia. Our spring flowers are definitely budding out, dandilions, apple trees, cherries. But in this area the spring flow doesn't start for a few weeks, and even then i will be leaving the honey for the girls to keep. I think its worth using fumagillin B in spring and sacrificing getting any honey from a spring flow for the long term benefit of your hives. I don't know what diseases are in your area, but unless you live on a quarantined island its a possibility for infection.