Varroa Mites and Mite Treatments in Vermont

As we head into fall, both our beekeepers and beehives are preparing for winter. One of our checklist items is a final treatment for varroa mites! All summer long our beehives have been growing bigger and bigger, but unfortunately, that also means our mite levels are typically highest at this time of year.

We wanted to review what are varroa mites? What does our treatment process look like at CVA? Read on to learn about our mite treatments here in Vermont! 🐝

What Are Varroa Mites, and Why Are They So Dangerous?

Varroa mites are external parasites that attach to both adult bees and developing brood. They feed on the bee’s fat bodies and hemolymph (bee “blood”), weakening them and transmitting deadly viruses like Deformed Wing Virus (DWV). A single untreated infestation can lead to colony collapse within a matter of months.

Even worse? Mites can spread easily between colonies via drifting workers or robbing, meaning one beekeeper’s inaction can jeopardize others in the area. That’s why community-wide mite management is so critical—especially here at CVA, where we take our bee health very seriously.

Monitoring: Our First Line of Defense

The foundation of effective Varroa control is regular mite monitoring—not guessing or assuming. We check our hives once per month, especially during peak brood-rearing seasons (spring through early fall).

🧪 Best Monitoring Methods:

• Alcohol Wash – Fast and accurate. Kills the sampled bees but gives reliable mite counts.

• Powdered Sugar Roll – Gentler alternative; dislodges mites without killing bees.

• Sticky Boards – Passive method placed under screened bottom boards.

📉 Treatment thresholds:

• Spring: Treat if more than 1 mite per 100 bees.

• Summer–Fall: Treat if more than 2 mites per 100 bees.

Treatment Options: An Integrated Approach (IPM)

Beekeepers are encouraged to follow Integrated Pest Management (IPM) principles—using multiple, complementary strategies to reduce mite loads with minimal harm to bees. Here at Champlain Valley Apiaries, with our consistent monitoring, we're able to reduce the amount of treatments we have to administer to the hives. We always use cultural and mechanical controls first before resorting to softer, organic treatments on our bees.

🛠️ Cultural & Mechanical Controls

• Drone Brood Removal: Mites prefer drone cells. Trap and remove them.

• Brood Breaks: Caging the queen or splitting colonies interrupts mite reproduction.

• Screened Bottom Boards: Allow mites to fall out of the hive and prevent reinfestation.

• Hygienic Bee Stock: Some bee strains are bred to detect and remove infested brood.

🌿 Organic (Soft) Treatments

• Formic Acid (e.g. Formic Pro) – Penetrates capped brood; good in cooler temps.

• Oxalic Acid – Great for broodless periods (late fall or early spring). Administered by vapor or dribble.

• Thymol (Apiguard, ApiLife VAR) – Effective during warm months; remove honey supers first.

Final Buzz

Varroa mites may be relentless, but with vigilance, science, and smart management, at CVA we are up to the challenge. By staying informed and proactive, we can protect not just our own bees, but Vermont’s wild pollinators, ecosystems, and food systems as a whole.

Let’s keep Vermont buzzing! 🐝❤️