Field Validation of Practical Mite Resistance Tests Across Apiaries To Strengthen Small-Scale Breeder Selection

Commodities

Practices

The core problem this project
aims to solve is that beekeepers still lack practical, reliable,
field-ready tools to identify true Varroa-resistant colonies.
Although decades of research show that resistance traits like
suppressed mite reproduction and hygienic behavior exist, most
small-scale and sideline beekeepers do not have accessible methods
to measure them. As a result, breeding decisions are often based on
survivorship, gut instinct, or single metrics like low mite washes
none of which reliably indicate heritable resistance. The
simplified Harbo assay, PKB test, and mite washes each capture part
of the picture, but my own multi-year data has shown inconsistent
results when these tools are used without standardization across
yards, equipment, colony age, and sampling timing.

This inconsistency means beekeepers often
misidentify breeder colonies, accidentally propagate weak genetics,
or treat more than necessary, masking the very traits we need. At
the same time, commercial operations report that resistant stock is
hard to find, and current supply cannot meet demand. Without a
validated, repeatable screening process that small producers can
actually perform, the pipeline of trustworthy resistant queens will
never develop. This project addresses that gap by testing,
comparing, and stabilizing these field tools so beekeepers can
finally select with confidence.

My innovative solution is to
create a simple, field-ready system that allows beekeepers to
identify truly Varroa-resistant colonies using tools they can
perform in their own apiaries. Instead of relying on survivorship
guesses or single metrics, this project tests three practical
resistance indicators the Simplified Harbo Assay (SHA), the
Pin-Killed Brood assay (PKB), and standardized mite washes under
real working conditions to determine which combination of methods
reliably identifies colonies that maintain low mite levels over
time. The goal is not to invent new lab techniques, but to validate
and refine accessible field tools until they form a consistent,
repeatable screening protocol for small-scale breeders.

The study uses two beekeepers,
each managing 20 standardized colonies for a total of 40 research
colonies. Every colony is started on identical equipment, equalized
as needed, and managed through the same treatment thresholds to
keep environmental variables as controlled as possible. Each year,
every colony receives:

• Two SHA tests to measure
  suppressed mite reproduction (NR:R ratios),

• Two PKB assays to assess
  hygienic response, and

• Four mite washes to track
  Varroa population growth through the season.

This creates a multi-layered
dataset that shows how each test behaves not just once, but
repeatedly, across differing colony strengths, nectar flows, and
environmental stress. The innovative piece is the integration:
instead of evaluating SHA, PKB, and mite washes in isolation, we
directly test how well they agree, which signals are most stable
over time, and which early-season measurements predict late-season
mite control. That allows us to build a practical "selection
filter" that breeders can use without expensive equipment,
specialized training, or complicated statistics.

To deepen the biological
context, a subset of colonies each year undergo viral testing
(DWV-A, DWV-B, ABPV, CBPV). This shows whether colonies flagged as
resistant by SHA/PKB/mite-wash profiles also maintain lower viral
loads. This adds rigor and helps ensure that the scoring system we
produce isn't only measuring low mites, but genuine tolerance or
resistance traits.

The regenerative agriculture
component lies in reducing chemical dependency. If beekeepers can
reliably identify resistant colonies, they can select and propagate
queens that require fewer treatments or none at all. This reduces
pesticide residues in comb, prevents chemical resistance in mites,
improves colony longevity, and strengthens local adaptation.
Instead of relying on continual chemical inputs, the system shifts
toward biological resilience and locally selected genetics, which
aligns directly with regenerative agriculture principles.

The project also includes a
strong educational component. Each year, the participating
beekeepers refine the testing protocol based on field experience.
Results are shared through the Sustainable Beekeepers Guild of
Michigan (SBGMI) and Northern Queen Initiative (NQI) via webinars,
field days, and plain-language summaries. The teaching emphasizes
hands-on demonstration, showing beekeepers exactly how to perform
each assay, how to interpret results, and how to apply the protocol
to their own stock.

The innovation is not a new test, it is
creating the first practical, validated, field-ready
resistance-screening system that small producers can trust,
replicate, and use to build healthier, chemical-independent
bees.

Objectives Include:

• Standardize and manage 40
  research colonies across two apiaries to create a controlled
  testing environment.

• Perform repeat, multi-season
  SHA, PKB, and mite-wash assays to evaluate how consistently each
  test identifies resistant colonies.

• Compare agreement between the
  tests and determine which early-season measures best predict
  late-season mite control.

• Conduct targeted viral testing
  to connect resistance indicators with actual colony health.

• Produce a simple, field-ready
  screening protocol that small-scale beekeepers can use to
  confidently select breeder colonies.

• Share
  results through SBGMI and NQI workshops, webinars, and written
  summaries.