Managing Varroa During a Honey Flow

The honey flow creates the most difficult varroa management conflict a beekeeper faces. Mite populations are growing, colonies are building, and the treatment options that work best all require honey supers to be off the hive. The desire to capture a honey harvest collides with the need to protect colony health. Here is how to navigate that conflict with your colonies and your harvest intact.

Why Honey Flows Complicate Treatment

The core problem is contamination. Amitraz (Apivar) and thymol (Apiguard) can leave residues in honey that make it unsuitable for sale. The registered instructions for these products require honey supers to be absent during treatment. Applying them with supers in place is a label violation, a food safety risk, and in the US, a potential legal liability.

Oxalic acid is the most nuanced case. Oxalic acid occurs naturally in honey at low levels. The current EPA registration for some OAV formulations allows use with honey supers present, but the label language should be confirmed for your specific product. Read the label.

This leaves beekeepers during a flow with limited options: treat with MAQS (formic acid, approved for use with supers on), treat with Hopguard II (beta acids, approved for use with supers on), pull supers and treat with a more effective product, or accept elevated mite risk during the flow and treat immediately after.

MAQS During Honey Flow

MAQS (Mite Away Quick Strips) is the most widely used flow-compatible treatment. Formic acid penetrates capped brood, which means it works even during full brood production. Applied within the labeled temperature window of 50 to 85 degrees Fahrenheit, MAQS achieves approximately 90% efficacy in seven days.

The practical concerns with MAQS during flow:

• Temperature. In warm summer months, daytime temperatures may exceed 85 degrees. Do not apply MAQS when temperatures are forecast to exceed 85 degrees during the treatment period. Apply in the cooler parts of the season, or during a cooler week within the flow.
• Queen loss. MAQS causes queen loss at a higher rate than other registered treatments, particularly when applied at warm temperatures. Verify queen survival and laying pattern within two weeks of treatment.
• Reduced acceptability of honey. Some beekeepers report a faint formic acid taste in honey extracted from supers that were on during MAQS treatment. This is anecdotal, but pulling supers for the 7-day treatment period and replacing them afterward eliminates any concern.

Hopguard II During Honey Flow

Hopguard II (potassium salts of hop beta acids) is registered for use with honey supers on and has no significant residue concern in honey. Efficacy against phoretic mites is good but it does not penetrate capped brood cells. It works best when used as a preventive or during periods of reduced brood.

For mite counts that are borderline during a flow (1.5 to 2%), Hopguard II can help hold mite levels while you wait for a better treatment window. For counts clearly above 2%, it is unlikely to provide sufficient knockdown on its own.

Pulling Supers to Treat

If mite counts cross 2.5% or higher during a flow, the calculus changes. At that level, mite populations are growing fast, colony health is being actively compromised, and waiting until the flow ends may mean waiting too long. A colony with a 4% mite count heading into late summer has serious problems that will compound through the fall.

Pulling supers and treating with Apivar or another effective product is the right decision above about 2.5 to 3% during a flow. Yes, you sacrifice some honey production. The colony you save will produce honey next year. The colony you lose to varroa does not.

Monitoring More Frequently During Flows

During a honey flow, colonies build rapidly, brood nests are at maximum production, and varroa reproduction is at its fastest rate. This is exactly when monitoring matters most and when beekeepers are most likely to skip it because they are focused on honey production logistics.

Count every 3 to 4 weeks during the primary honey flow. If counts are rising toward threshold, you have time to act before they cross it. If you count at the start of the flow and again at the end, you may discover a problem that has had 8 weeks to develop.

Log all flow-period counts in VarroaVault with a note that supers were on. This gives you context when reviewing the historical record. A count of 1.8% logged with a note "supers on, MAQS not applied, within acceptable range" explains a management decision that might otherwise look like an untreated high count.

Pre-Harvest Planning

Before the flow ends and supers come off, have your treatment plan ready. Know which product you are using for the fall treatment, confirm you have supplies on hand, and schedule the application for within a week of the last super removal. The transition from harvest to treatment should be seamless, not a two-week delay while you order supplies. See the treatment calendar builder for how to integrate flow timing and treatment timing into a single annual planning view.