Nationwide Tracking for Winter and Early Spring Beekeeping Insights

The status of capped brood in honey bee colonies during winter is critical information beekeepers must consider when choosing an appropriate control product for the mite Varroa destructor. As colonies emerge from winter, insight into colony brood rearing also helps beekeepers plan for early spring management, such as feeding and swarm control.

Although colonies located in many parts of the United States experience predictable extended periods without brood, this may not be the case for those in coastal and southern regions with mild winters.

About the program

To help beekeepers make appropriate management decisions during winter and early spring, 17 land-grant universities, 1 statewide cooperative extension system, 5 USDA ARS labs (Baton Rouge, Beltsville, Poplarville, Stoneville, Tucson), and 3 beekeepers are jointly monitoring amount of capped brood in their colonies throughout the country from mid-October 2025 to the end of February 2026.

This page will be updated approximately every 2 weeks so that amount of capped brood in the monitored colonies can be communicated to the beekeeping community.

Logos of participants for the brood monitoring program

Biweekly Static Maps

Each blue point on a map below represents the average amount of capped brood among all monitored colonies at a particular location, as expressed as deep frame equivalents. One deep frame equivalent represents 100% coverage of capped brood on both sides of the frame.

Week of December 3, 2025

Winter brood monitoring map for the week of December 3, 2025

Week of November 19, 2025

Map of winter brood monitoring for the week of November 19, 2025

Week of November 5, 2025

Winter Brood Monitoring map for the week of November 5, 2025

Week of October 22, 2025

Winter brood monitoring map for the week of 10/23/25

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Citizen Science Winter Capped Brood Monitoring Program

Composite image with participant logos on the left and hands holding a hive frame with brood on the right

The US Winter Capped Brood Monitoring Project is underway for its fourth season. Every two weeks from October to February, Auburn University, along with other universities and USDA labs from across the country, inspects colonies for capped brood. This effort helps us understand the best times for winter oxalic acid mite treatments and which areas will be most at risk for another parasitic mite, Tropilaelaps, if it is introduced to the US.

Beekeepers: we need your help tracking capped brood across the US. This involves inspecting three hives (or fewer if necessary) for capped brood.

Inspection Windows

Inspections should happen during three windows in December and January, detailed below:

  1. Friday, December 19, 2025 to Sunday, December 21, 2025
  2. Friday, January 2, 2026 to Sunday, Janurary 4, 2026
  3. Friday, January 16, 2026 to Sunday, January 18, 2026

We ask that you please inspect your colonies during as many of these 3 event windows as possible. If you can only inspect colonies within one or two of these windows, we still want your observations!

Participate and submit observations Access live results map

Each colony inspection should take 2-3 minutes.

  1. Smoke the colony.
  2. Remove supers or hive bodies until you can locate the cluster. If it is very cold, you may cover bees in removed boxes with an extra inner or outer cover.
  3. Make note of colony strength. We consider clusters about the size of a basketball to be “normal” strength. Weak colonies have smaller clusters (softball-sized or smaller), while strong colonies are much larger than a basketball.
  4. Carefully remove 1-3 frames from the center of the cluster. If there is capped brood on any of the frames, report “Yes” on the survey. If you find uncapped brood (eggs or larvae without wax cappings) and no capped brood, report “No” on the survey. Fewer than a dozen total capped brood cells that are chilled, dead, or not guarded by the bee cluster count as no brood.

For more information, refer to our video below:

What does capped brood look like?

Close up of brood and bees Cells containing capped brood, or brood in the pupal stage, will have a slightly domed or convex wax capping. They have a rough, porous texture. This picture shows several dozen capped brood cells. If the inspected frame(s) looked like this, we would say yes, this colony has capped brood.


Close up of bees and larvae A colony may have eggs or larvae without wax cappings, but no capped brood. This picture shows both younger and older larvae. If the brood on all inspected frames looked like this, we’d say no, this colony does not have capped brood.


Close up of brood, bees, and honey Capped honey is sometimes mistaken for capped brood. Compared to brood, the wax cappings on honey cells are smoother. The comb surface may have a rippled texture. This photo does not show any brood.


Close up of bee cluster Often, bees in winter will form a tight cluster as they consume stored honey. Small patches of brood may still be present beneath the bees. In this case, we may need to move some bees aside to view the brood.

Collaborators

Contact

broodcontact

Geoffrey Williams
Associate Professor
301 Funchess Hall
Auburn, AL 36849
334-844-5068

Ben DeMoras
Ph.D. Student
952 Bee Lab Road
Auburn, AL 36849