🧪 Sugar Roll vs Alcohol Wash Sampling Lab

About this simulation

Both the sugar roll and the alcohol wash sample roughly a half-cup (~300) of adult bees shaken from a brood frame, then agitate that sample so Varroa destructor mites lose their grip and fall through an 8-mesh screen into a tray for counting. The two jars in this lab run the same protocol side by side: sugar (or icing sugar) coats the bees and their feet, temporarily impairing the mites' claws without killing the bees, while 70% alcohol (or windshield-washer fluid) kills the sample outright but dislodges mites more completely.

Why the counts differ

• Sugar roll — typically recovers roughly 80–90% of the mites actually present, because a few stay clamped on despite the sugar coating. Its big advantage: the bees survive and can be returned to the hive.
• Alcohol wash — recovers close to 95–100% of mites, the closest thing to a "true count" available in the field, but it is destructive — every bee in the sample is sacrificed.
• Both are far more accurate than a natural mite-drop sticky board, which only catches mites that happen to fall off on their own.

Controls

• Protocol step — walks through collect → add medium → shake 60s → strain/count → compare, for both jars at once.
• Sample size — how many bees go into each jar (standard target is ~300, roughly a level half-cup).
• True mite load — the actual (usually unknowable) mite infestation being sampled, so you can see how each method's recovery rate compares to reality.
• Auto-advance steps — loops the protocol automatically so you can watch the whole sequence play out.

Did you know?

Research trials (e.g. Dietemann et al., 2013) that compared methods head-to-head found alcohol wash consistently detects more mites than sugar roll at the same true infestation — which is why alcohol wash is often recommended when treatment decisions are close to the action threshold, while sugar roll is preferred for breeding stock or small numbers of valuable colonies you want to keep alive.