Fumagillin-B (Fumadil-B)

Administer Fumagillin-B (trade name Fumadil-B) in sugar syrup during spring and fall to treat or prevent Nosema disease caused by Nosema apis. Mix the antibiotic into 1:1 sugar syrup following label dosage instructions precisely, and feed it to colonies before peak infection periods. Note that Fumagillin-B is significantly less effective against Nosema ceranae and has been discontinued or restricted in many regions due to concerns about antibiotic residues and resistance.

Why It Works

Fumagillin inhibits an enzyme (methionine aminopeptidase-2) critical to Nosema spore replication inside the bee's midgut cells. By disrupting spore development, it reduces the parasite load and allows the colony to recover. Its efficacy is well-documented specifically against N. apis.

Tips

• Check local regulations before use; Fumagillin-B is banned or unavailable in the EU, Canada, and other jurisdictions
• Use a syringe or graduated measuring device for accurate dosing
• Do not apply during honey flow to avoid residues in marketable honey
• Combine with hygienic management practices for best results
• Monitor spore counts before and after treatment to assess effectiveness