By sugar shakes in ten yards, we obtained 45 mites from two to four hives, using about a cup of bees per hive.  All the sugar was dumped into a single bag per yard for later analysis (by dissolving the sugar in water).

At the time of the first test, we immediately placed two Apistan(r) strips into each of the same tested hives and inserted sticky boards with screens. The strips and boards were left in the hives a minimum of 24 hours and a maximum of about a week (see data).

The sugar gave us 49 mites and the boards returned 2384 mites for a ratio of about 49 mites dropped by Apistan for each mite found by sugar in the same hives, however one must consider that some individual hives and some yards returned zeros for both tests and therefore a simple ratio like 50:1 cannot be used. A quick glance reveals that the ratio varies from around 15:1 to infinity:1. Several hive groups that gave zero results from sugar shake subsequently yielded mites in the hundreds.

Here is the raw data:

The work was done by our competent commercial beekeeping staff while going about their normal activities, following standard procedures. Our location is east and north of 51.1 N, 114.02 W or around halfway between Lethbridge and Edmonton, Alberta CANADA.

I would be interested in comments from scientists and extension people as well as beekeepers on what to think of this.

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