DISPOSITION OF MIROSAMICIN IN HONEYBEE HIVES

Disposition of mirosamicin, a macrolide antibiotic, to honeybee adults , larvae, honey and royal jelly in the beehive after in-feed administr ation to adult bees was studied. Treatment was initiated at the end of July when the availability of natural pollen and nectar was poor. The drug was mixed with pollen-substitute paste and administered to honey bee colonies continuously for a week at a dossage of 200 mg/hive/week. High distributions in adult bees, jelly, larvae and a relatively low distribution in honey, of mirosamicin were observed. One day dosing of microsamin in sucrose syrup, a nectar substitute, resulted in a very high and long lasting residue in honey. Both royal and worker jelly, s ecreted from the jelly glands of adult bees, are acidic, so that a hig h distribution of a basic drug, such as mirosamicin, in jelly can be e xpected. This mechanism was considered to be responsible for a high co ncentration of mirosamicin in honeybee larvae, the host of Paenibacill us-larvae infection (American foulbrood), as primary larval food is je lly.