Evaluation the effectiveness of fumagillin for the control of Nosema ceranae

Nosema ceranae is a highly adapted parasitic fungus that infects Apis mellifera and has been associated with the depopulation and death of colonies in Europe and North America. A large-scale field experiment was undertaken to evaluate the effectiveness of fumagillin against N. ceranae during the spring, and to examine residual deposition of fumagillin in honey. Package bee colonies were inoculated by drenching with 200 mL of sucrose solution containing 1 × 10⁸ spores of N. ceranae. One week later, colonies were treated with 0.5, 1 and 2× label dose rates (190 mg ai/colony) of Fumagilin-B^®, at two weekly intervals, in either sucrose syrup, icing sugar or pollen patties. Foragers were sampled to determine Nosema spore infection levels compared with inoculated, untreated colonies. Honey samples (15 g) were also drawn from the brood nest and honey supers to determine fumagillin reside levels by LC-MS/MS. Results will be discussed.